WorldWideScience

Sample records for somatostatin receptors sstrs

  1. Somatostatin receptors

    DEFF Research Database (Denmark)

    Møller, Lars Neisig; Stidsen, Carsten Enggaard; Hartmann, Bolette

    2003-01-01

    functional units, receptors co-operate. The total receptor apparatus of individual cell types is composed of different-ligand receptors (e.g. SRIF and non-SRIF receptors) and co-expressed receptor subtypes (e.g. sst(2) and sst(5) receptors) in characteristic proportions. In other words, levels of individual......-peptides, receptor agonists and antagonists. Relatively long half lives, as compared to those of the endogenous ligands, have been paramount from the outset. Motivated by theoretical puzzles or the shortcomings of present-day diagnostics and therapy, investigators have also aimed to produce subtype...

  2. Quantitative Assessment of 99mTc-Depreotide Uptake in Oesophageal Cancer and Precursor Conditions and Its Reflection in Immunohistochemically Detected Somatostatin Receptors

    International Nuclear Information System (INIS)

    Herlin, G.; Aspelin, P.; Axelsson, R.; Herlin, G.; Aspelin, P.; Axelsson, R.; Lundell, L.; Ost, A.; Svensson, L.

    2012-01-01

    Background. Somatostatin receptors (SSTRs) are over-expressed in several tumors making it possible for imaging with labelled SSTR. A previous study showed feasibility to image oesophageal cancer with SSTR analogue 99m Tc-depreotide. Purpose. (1) To investigate expression of the SSTRs in different types of esophageal carcinoma and (2) to correlate such an expression with 99m Tc-depreotide uptake in these lesions. Material and Methods. Total 28 patients (17 with esophageal cancer and 11 with Barrett’s esophagus) were examined with 99m Tc-depreotide scintigraphy. The SSTR2A, SSTR2B, SSTR3, and SSTR5 were analyzed immunohistochemically in the lesion samples. Results. Among the patients with adenocarcinoma 10/11 expressed different amounts of SSTRs, while SSTRs were absent in 5/6 patients with Squamous cell carcinoma (Sqcc). There was no correlation neither between the 99m Tc-depreotide uptake and the amount of SSTRs nor between the amount of SSTRs and differentiation grade of the tumor. Conclusions. (1) SSTRs are expressed in esophageal carcinoma and more abundantly so in adenocancer specimens; (2) in vivo 99m Tc-depreotide uptake does not obviously correlate with the immunohistochemically detection of SSTRs of different subtypes in esophageal carcinoma.

  3. Quantitative Assessment of 99mTc-Depreotide Uptake in Oesophageal Cancer and Precursor Conditions and Its Reflection in Immunohistochemically Detected Somatostatin Receptors

    International Nuclear Information System (INIS)

    Herlin, Gunnar; Lundell, Lars; Öst, Åke; Aspelin, Peter; Svensson, Leif; Axelsson, Rimma

    2012-01-01

    Background. Somatostatin receptors (SSTRs) are over-expressed in several tumors making it possible for imaging with labelled SSTR. A previous study showed feasibility to image oesophageal cancer with SSTR analogue 99m Tc-depreotide. Purpose. (1) To investigate expression of the SSTRs in different types of esophageal carcinoma and (2) to correlate such an expression with 99m Tc-depreotide uptake in these lesions. Material and Methods. Total 28 patients (17 with esophageal cancer and 11 with Barrett's esophagus) were examined with 99m Tc-depreotide scintigraphy. The SSTR2A, SSTR2B, SSTR3, and SSTR5 were analyzed immunohistochemically in the lesion samples. Results. Among the patients with adenocarcinoma 10/11 expressed different amounts of SSTRs, while SSTRs were absent in 5/6 patients with Squamous cell carcinoma (Sqcc). There was no correlation neither between the 99m Tc-depreotide uptake and the amount of SSTRs nor between the amount of SSTRs and differentiation grade of the tumor. Conclusions. (1) SSTRs are expressed in esophageal carcinoma and more abundantly so in adenocancer specimens; (2) in vivo 99m Tc-depreotide uptake does not obviously correlate with the immunohistochemically detection of SSTRs of different subtypes in esophageal carcinoma

  4. Evolutionary history of the somatostatin and somatostatin receptors

    Indian Academy of Sciences (India)

    Somatostatin and its receptors have a critical role in mammalian growth through their control pattern of secretion of growth hormone, but the evolutionary history of somatostatin and somatostatin receptors are ill defined. We used comparative whole genome analysis of Danio rerio, Carassius auratus, Xenopus tropicalis, ...

  5. Somatostatin and opioid receptors do not regulate proliferation or apoptosis of the human multiple myeloma U266 cells

    Directory of Open Access Journals (Sweden)

    Allouche Stéphane

    2009-06-01

    Full Text Available Abstract Background opioid and somatostatin receptors (SSTRs that can assemble as heterodimer were individually reported to modulate malignant cell proliferation and to favour apoptosis. Materials and methods: SSTRs and opioid receptors expression were examined by RT-PCR, western-blot and binding assays, cell proliferation was studied by XTT assay and propidium iodide (PI staining and apoptosis by annexin V-PI labelling. Results almost all human malignant haematological cell lines studied here expressed the five SSTRs. Further experiments were conducted on the human U266 multiple myeloma cells, which express also μ-opioid receptors (MOP-R. XTT assays and cell cycle studies provide no evidence for a significant effect upon opioid or somatostatin receptors stimulation. Furthermore, neither direct effect nor potentiation of the Fas-receptor pathway was detected on apoptosis after these treatments. Conclusion these data suggest that SSTRs or opioid receptors expression is not a guaranty for an anti-tumoral action in U266 cell line.

  6. Characterization of somatostatin receptors and associated signaling pathways in pancreas of R6/2 transgenic mice.

    Science.gov (United States)

    Somvanshi, Rishi K; Jhajj, Amrit; Heer, Michael; Kumar, Ujendra

    2018-02-01

    The present study describes the status of somatostatin receptors (SSTRs) and their colocalization with insulin (β), glucagon (α) and somatostatin (δ) producing cells in the pancreatic islets of 11weeks old R6/2 Huntington's Disease transgenic (HD tg) and age-matched wild type (wt) mice. We also determined expression of tyrosine hydroxylase (TH), glutamic acid decarboxylase (GAD) and presynaptic marker synaptophysin (SYP) in addition to signal transduction pathways associated with diabetes. In R6/2 mice, islets are relatively smaller in size, exhibit enhanced expression and nuclear inclusion of mHtt along with the loss of insulin, glucagon and somatostatin expression. In comparison to wt, R6/2 mice display enhanced mRNA for all SSTRs except SSTR2. In the pancreatic lysate, SSTR1, 4 and 5 immunoreactivity decreases whereas SSTR3 immunoreactivity increases with no discernible changes in SSTR2 immunoreactivity. Furthermore, at the cellular level, R6/2 mice exhibit a receptor specific distributional pattern of SSTRs like immunoreactivity and colocalization with β, α and δ cells. While GAD expression is increased, TH and SYP immunoreactivity was decreased in R6/2 mice, anticipating a cross-talk between the CNS and pancreas in diabetes pathophysiology. We also dissected out the changes in signaling pathway and found decreased activation and expression of PKA, AKT, ERK1/2 and STAT3 in R6/2 mice pancreas. These findings suggest that the impaired organization of SSTRs within islets may lead to perturbed hormonal regulation and signaling. These interconnected complex events might shed new light on the pathogenesis of diabetes in neurodegenerative diseases and the role of SSTRs in potential therapeutic intervention. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Does somatostatin have a role in the regulation of cortisol secretion in primary pigmented nodular adrenocortical disease (PPNAD)? A clinical and in vitro investigation

    NARCIS (Netherlands)

    Z. Bram (Zakariae); P. Xekouki (Paraskevi); E. Louiset (Estelle); M. Keil (Mark); D. Avgeropoulos (Dimitrios); C. Giatzakis (Christoforos); M. Nesterova (Maria); N. Sinaii (Ninet); L.J. Hofland (Leo); R. Cherqaoui (Rabia); H. Lefebvre (Hervé); C.A. Stratakis (Constantine)

    2014-01-01

    textabstractContext: Somatostatin (SST) receptors (SSTRs) are expressed in a number of tissues, including the adrenal cortex, but their role in cortisol secretion has not been well characterized. Objectives: The objective of the study was to investigate the expression of SSTRs in the adrenal cortex

  8. Kidney protection during peptide receptor radionuclide therapy with somatostatin analogues.

    NARCIS (Netherlands)

    Rolleman, E.J.; Melis, M.; Valkema, R.; Boerman, O.C.; Krenning, E.P.; Jong, M. de

    2010-01-01

    This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides

  9. Pattern of somatostatin receptors expression in normal and bladder cancer tissue samples.

    Science.gov (United States)

    Karavitakis, Markos; Msaouel, Pavlos; Michalopoulos, Vassilis; Koutsilieris, Michael

    2014-06-01

    Known risks factors for bladder cancer progression and recurrence are limited regarding their prognostic ability. Therefore identification of molecular determinants of disease progression could provide with more specific prognostic information and could be translated into new approaches for biomarker development. In the present study we evaluated, the expression patterns of somatostatin receptors 1-5 (SSTRs) in normal and tumor bladder tissues. The expression of SSTR1-5 was characterized in 45 normal and bladder cancer tissue samples using reverse transcriptase-polymerase chain reaction (RT-PCR). SSTR1 was expressed in 24 samples, SSTR2 in 15, SSTR3 in 23, SSTR4 in 16 and SSTR5 in all but one sample. Bladder cancer tissue samples expressed lower levels of SSTR3. Co-expression of SSTRs was associated with superficial disease. Our results demonstrate, for the first time, that there is expression of SSTR in normal and bladder cancer urothelium. Further studies are required to evaluate the prognostic and therapeutic significance of these findings. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  10. Functional somatostatin receptors on a rat pancreatic acinar cell line

    International Nuclear Information System (INIS)

    Viguerie, N.; Tahiri-Jouti, N.; Esteve, J.P.; Clerc, P.; Logsdon, C.; Svoboda, M.; Susini, C.; Vaysse, N.; Ribet, A.

    1988-01-01

    Somatostatin receptors from a rat pancreatic acinar cell line, AR4-2J, were characterized biochemically, structurally, and functionally. Binding of 125 I-[Tyr 11 ]Somatostatin to AR4-2J cells was saturable, exhibiting a single class of high-affinity binding sites with a maximal binding capacity of 258 ± 20 fmol/10 6 cells. Somatostatin receptor structure was analyzed by covalently cross-linking 125 I-[Tyr 11 ]somatostatin to its plasma membrane receptors. Gel electrophoresis and autoradiography of cross-linked proteins revealed a peptide containing the somatostatin receptor. Somatostatin inhibited vasoactive intestinal peptide (VIP)-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) formation in a dose-dependent manner. The concentration of somatostatin that caused half-maximal inhibition of cAMP formation was close to the receptor affinity for somatostatin. Pertussis toxin pretreatment of AR4-2J cells prevented somatostatin inhibition of VIP-stimulated cAMP formation as well as somatostatin binding. The authors conclude that AR4-2J cells exhibit functional somatostatin receptors that retain both specificity and affinity of the pancreatic acinar cell somatostatin receptors and act via the pertussis toxin-sensitive guanine nucleotide-binding protein N i to inhibit adenylate cyclase

  11. Purification of a putative brain somatostatin receptor

    International Nuclear Information System (INIS)

    He, Haitao; Johnson, K.; Thermos, K.; Reisine, T.

    1989-01-01

    The brain somatostatin receptor was purified by affinity chromatographic techniques. A protein of 60 kDa could be purified from rat brain. The protein was eluted from a [D-Trp 8 ]SRIF affinity column with either sodium acetate (pH 5.5) or free [D-Trp 8 ]SRIF. The binding of the protein to the affinity column was prevented by free [D-Trp 8 ]SRIF or the stable SRIF analogue SMS 201-996 but not by the inactive somatostatin 28-(1-14). The purified receptor could be covalently labeled by the 125 I-labeled SRIF analogue CGP 23996. Excess [D-Trp 8 ]SRIF blocked the binding of 125 I-labeled CGP 23996 to the purified receptor, but somatostatin 28-(1-14) did not affect the binding. A 60-kDa protein was also purified from the anterior pituitary cell line AtT-20, which has a high expression of SRIF receptors. In contrast, no 60-kDa protein could be purified from CHO cells, which have no detectable SRIF receptors. These findings present evidence for the purification of the SRIF receptor

  12. Somatostatin receptors in gastroentero-pancreatic neuroendocrine tumours

    NARCIS (Netherlands)

    W.W. de Herder (Wouter); L.J. Hofland (Leo); A-J. van der Lely (Aart-Jan); S.W.J. Lamberts (Steven)

    2003-01-01

    textabstractFive somatostatin receptor (sst) subtype genes, sst(1), sst(2), sst(3), sst(4) and sst(5), have been cloned and characterised. The five sst subtypes all bind natural somatostatin-14 and somatostatin-28 with high affinity. Endocrine pancreatic and endocrine digestive

  13. Somatostatin receptor 1 and 5 double knockout mice mimic neurochemical changes of Huntington's disease transgenic mice.

    Directory of Open Access Journals (Sweden)

    Padmesh S Rajput

    Full Text Available Selective degeneration of medium spiny neurons and preservation of medium sized aspiny interneurons in striatum has been implicated in excitotoxicity and pathophysiology of Huntington's disease (HD. However, the molecular mechanism for the selective sparing of medium sized aspiny neurons and vulnerability of projection neurons is still elusive. The pathological characteristic of HD is an extensive reduction of the striatal mass, affecting caudate putamen. Somatostatin (SST positive neurons are selectively spared in HD and Quinolinic acid/N-methyl-D-aspartic acid induced excitotoxicity, mimic the model of HD. SST plays neuroprotective role in excitotoxicity and the biological effects of SST are mediated by five somatostatin receptor subtypes (SSTR1-5.To delineate subtype selective biological responses we have here investigated changes in SSTR1 and 5 double knockout mice brain and compared with HD transgenic mouse model (R6/2. Our study revealed significant loss of dopamine and cAMP regulated phosphoprotein of 32 kDa (DARPP-32 and comparable changes in SST, N-methyl-D-aspartic acid receptors subtypes, calbindin and brain nitric oxide synthase expression as well as in key signaling proteins including calpain, phospho-extracellular-signal-regulated kinases1/2, synapsin-IIa, protein kinase C-α and calcineurin in SSTR1/5(-/- and R6/2 mice. Conversely, the expression of somatostatin receptor subtypes, enkephalin and phosphatidylinositol 3-kinases were strain specific. SSTR1/5 appears to be important in regulating NMDARs, DARPP-32 and signaling molecules in similar fashion as seen in HD transgenic mice.This is the first comprehensive description of disease related changes upon ablation of G- protein coupled receptor gene. Our results indicate that SST and SSTRs might play an important role in regulation of neurodegeneration and targeting this pathway can provide a novel insight in understanding the pathophysiology of Huntington's disease.

  14. Pathophysiology of GPCR Homo- and Heterodimerization: Special Emphasis on Somatostatin Receptors

    Directory of Open Access Journals (Sweden)

    Rishi K. Somvanshi

    2012-04-01

    Full Text Available G-protein coupled receptors (GPCRs are cell surface proteins responsible for translating >80% of extracellular reception to intracellular signals. The extracellular information in the form of neurotransmitters, peptides, ions, odorants etc is converted to intracellular signals via a wide variety of effector molecules activating distinct downstream signaling pathways. All GPCRs share common structural features including an extracellular N-terminal, seven-transmembrane domains (TMs linked by extracellular/intracellular loops and the C-terminal tail. Recent studies have shown that most GPCRs function as dimers (homo- and/or heterodimers or even higher order of oligomers. Protein-protein interaction among GPCRs and other receptor proteins play a critical role in the modulation of receptor pharmacology and functions. Although ~50% of the current drugs available in the market target GPCRs, still many GPCRs remain unexplored as potential therapeutic targets, opening immense possibility to discover the role of GPCRs in pathophysiological conditions. This review explores the existing information and future possibilities of GPCRs as tools in clinical pharmacology and is specifically focused for the role of somatostatin receptors (SSTRs in pathophysiology of diseases and as the potential candidate for drug discovery.

  15. Evolutionary history of the somatostatin and somatostatin receptors

    Indian Academy of Sciences (India)

    Table 1. The identified somatostations. Somatostatin (SST1). Name. Scientific name. Length. High ID (to). Low ID (to) Chromosome. GS. Drs. Danio rerio. 324. 48.1 mms ...... ancestral source. References. Baranowska B., Chmielowska M., Wolinska-Witort E., Bik W.,. Baranowska-Bik A. and Martynska L. 2006 Direct effect of.

  16. Somatostatin receptor imaging in intracranial tumours

    International Nuclear Information System (INIS)

    Schmidt, M.; Scheidhauer, K.; Voth, E.; Schicha, H.; Luyken, C.; Hildebrandt, G.; Klug, N.

    1998-01-01

    The somatostatin analogue [ 111 In-DTPA-d-Phe 1 ]-octreotide ( 111 In-octreotide) allows scintigraphic visualization of somatostatin receptor-expressing tissue. While it is well known that a large variety of tissues express somatostatin receptors and 111 In-octreotide scintigraphy has a clearly defined role in various neuroendocrine diseases, the clinical value of 111 In-octreotide scintigraphy in brain tumours is still under clinical investigation. In 124 patients with 141 brain lesions (63 meningiomas, 24 pituitary adenomas, 10 gliomas WHO class I and II, 12 gliomas WHO class III and IV, 11 neurinomas and 2 neurofibromas, 7 metastases and 12 other varieties: three non-Hodgkin B-cell lymphomas, two epidermoids, one abscess, one angioleiomyoma, one chordoma, one haemangiopericytoma, one osteosarcoma, one plasmacytoma and one pseudocyst), 111 In-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 110-220 MBq 111 In-octreotide. Planar images of the head in four views with a 128 x 128 matrix and single-photon emission tomographic images (64 x 64 matrix) were acquired, and lesions were graded according to qualitative tracer uptake. Fifty-nine of the 63 meningiomas showed moderate to intense tracer uptake. Nine of 24 pituitary adenomas were visible; the remaining 15 did not show any tracer uptake. None of the class I and II gliomas with an intact blood-brain barrier were detected whereas 11/12 class III and IV gliomas showed 111 In-octreotide uptake. None of the neurinomas or neurofibromas were positive. Five of seven metastases were classified as positive, as were the osteosarcoma, two of three non-Hodgkin B-cell lymphomas, one abscess, one angioleiomyoma, one chordoma and one haemangiopericytoma. The other varieties (one non-Hodgkin B-cell lymphoma, two epidermoids, one plasmacytoma and one pseudocyst) did not show 111 In-octreotide uptake. The results demonstrate that a large variety of intracranial lesions express somatostatin receptors and

  17. Somatostatin receptor imaging in intracranial tumours

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, M.; Scheidhauer, K.; Voth, E.; Schicha, H. [Department of Nuclear Medicine, University of Koeln (Germany); Luyken, C.; Hildebrandt, G.; Klug, N. [Department of Neurosurgery, University of Kolen (Germany)

    1998-07-01

    The somatostatin analogue [{sup 111}In-DTPA-d-Phe{sup 1}]-octreotide ({sup 111}In-octreotide) allows scintigraphic visualization of somatostatin receptor-expressing tissue. While it is well known that a large variety of tissues express somatostatin receptors and {sup 111}In-octreotide scintigraphy has a clearly defined role in various neuroendocrine diseases, the clinical value of {sup 111}In-octreotide scintigraphy in brain tumours is still under clinical investigation. In 124 patients with 141 brain lesions (63 meningiomas, 24 pituitary adenomas, 10 gliomas WHO class I and II, 12 gliomas WHO class III and IV, 11 neurinomas and 2 neurofibromas, 7 metastases and 12 other varieties: three non-Hodgkin B-cell lymphomas, two epidermoids, one abscess, one angioleiomyoma, one chordoma, one haemangiopericytoma, one osteosarcoma, one plasmacytoma and one pseudocyst), {sup 111}In-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 110-220 MBq {sup 111}In-octreotide. Planar images of the head in four views with a 128 x 128 matrix and single-photon emission tomographic images (64 x 64 matrix) were acquired, and lesions were graded according to qualitative tracer uptake. Fifty-nine of the 63 meningiomas showed moderate to intense tracer uptake. Nine of 24 pituitary adenomas were visible; the remaining 15 did not show any tracer uptake. None of the class I and II gliomas with an intact blood-brain barrier were detected whereas 11/12 class III and IV gliomas showed {sup 111}In-octreotide uptake. None of the neurinomas or neurofibromas were positive. Five of seven metastases were classified as positive, as were the osteosarcoma, two of three non-Hodgkin B-cell lymphomas, one abscess, one angioleiomyoma, one chordoma and one haemangiopericytoma. The other varieties (one non-Hodgkin B-cell lymphoma, two epidermoids, one plasmacytoma and one pseudocyst) did not show {sup 111}In-octreotide uptake. The results demonstrate that a large variety of intracranial

  18. Somatostatin receptor scintigraphy on thyroid carcinoma

    International Nuclear Information System (INIS)

    Pan Weimin; Tan Tianzhi

    2004-01-01

    Purpose: To study the diagnostic value and clinical method of somatostatin receptor scintigraphy on thyroid carcinoma using 99 Tc m -RC-160 labeled with direct method as scintigraphy reagent; Methods: Somatostatin receptor scintigraphy (SRS) were performed on 25 patients with thyroid carcinoma, using 99 Tc m -RC-160 labeled with direct method as scintigraphy reagent, controlling with 131 I- whole- body- imaging(1312 -WBI). Results: Of 4 patients with MTC (medullary thyroid carcinoma), positive metastasis and primary tumour were detected on 3 patients by SRS, negative results were obtained by 131 I-WBI, the positive detective rate by SRS is 3/4; of 12 patients with PTC (papillary thyroid carcinoma), positive metastasis and primary tumour were detected on 2 patients by SRS or 131 I-WBI,1 of which only by SRS, while negative results were obtained by 131 I- WBI, the positive detective rate by SRS is 3/12; of 8 patients with FTC(follicular thyroid carcinoma), positive metastasis and primary tumour were detected on 1 patients by SRS or 131 I-WBI, and 2 positive results were obtained only by SRS, while negative by 131 I-WBI, the positive detective rate by SRS is 3/8; of 1 patients with HCC (hurthle cell carcinoma ), positive metastasis and primary tumour were detected by SRS, while negative by 131 I-WBI; Conclusions: SRS using 99 Tc m -RC-160 labeled with direct method as scintigraphy reagent has high diagnostic value on thyroid carcinoma, especially on MTC and HCC. (authors)

  19. Novel Somatostatin Receptor Ligands Therapies for Acromegaly

    Directory of Open Access Journals (Sweden)

    Rosa Maria Paragliola

    2018-03-01

    Full Text Available Surgery is considered the treatment of choice in acromegaly, but patients with persistent disease after surgery or in whom surgery cannot be considered require medical therapy. Somatostatin receptor ligands (SRLs octreotide (OCT, lanreotide, and the more recently approved pasireotide, characterized by a broader receptor ligand binding profile, are considered the mainstay in the medical management of acromegaly. However, in the attempt to offer a more efficacious and better tolerated medical approach, recent research has been aimed to override some limitations related to the use of currently approved drugs and novel SRLs therapies, with potential attractive features, have been proposed. These include both new formulation of older molecules and new molecules. Novel OCT formulations are aimed in particular to improve patients’ compliance and to reduce injection discomfort. They include an investigational ready-to-use subcutaneous depot OCT formulation (CAM2029, delivered via prefilled syringes and oral OCT that uses a “transient permeability enhancer” technology, which allows for OCT oral absorption. Another new delivery system is a long-lasting OCT implant (VP-003, which provide stable doses of OCT throughout a period of several months. Finally, a new SRL DG3173 (somatoprim seems to be more selective for GH secretion, suggesting possible advantages in the presence of hyperglycemia or diabetes. How much these innovations will actually be beneficial to acromegaly patients in real clinical practice remains to be seen.

  20. Design, Synthesis, and Biological Evaluation of 68Ga-DOTA-PA1 for Lung Cancer: A Novel PET Tracer for Multiple Somatostatin Receptor Imaging.

    Science.gov (United States)

    Liu, Fei; Liu, Teli; Xu, Xiaoxia; Guo, Xiaoyi; Li, Nan; Xiong, Chiyi; Li, Chun; Zhu, Hua; Yang, Zhi

    2018-02-05

    Most of the radiolabeled somatostatin analogues (SSAs) are specific for subtype somatostatin receptor 2 (SSTR 2 ). Lack of ligands targeting other subtypes of SSTRs, especially SSTR 1, SSTR 3 , and SSTR 5 , limited their applications in tumors of low SSTR 2 expression, including lung tumor. In this study, we aimed to design and synthesize a positron emission tomography (PET) radiotracer targeting multi-subtypes of SSTRs for PET imaging. PA1 peptide and its conjugate with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelator or fluorescein isothiocyanate (FITC) at the N-terminal of the lysine position were synthesized. 68 Ga was chelated to DOTA-PA1 to obtain 68 Ga-DOTA-PA1 radiotracer. The stability, lipophilicity, binding affinity, and binding specificity of 68 Ga-DOTA-PA1 and FITC-PA1 were evaluated by various in vitro experiments. Micro-PET imaging of 68 Ga-DOTA-PA1 was performed in nude mice bearing A549 lung adenocarcinoma, as compared with 68 Ga-DOTA-(Tyr3)-octreotate ( 68 Ga-DOTA-TATE). Histological analysis of SSTR expression in A549 tumor tissues and human tumor tissues was conducted using immunofluorescence staining and immunohistochemical assay. 68 Ga-DOTA-PA1 had high radiochemical yield and radiochemical purity of over 95% and 99%, respectively. The radiotracer was stable in vitro in different buffers over a 2 h incubation period. Cell uptake of 68 Ga-DOTA-PA1 was 1.31-, 1.33-, and 1.90-fold that of 68 Ga-DOTA-TATE, which has high binding affinity only for SSTR 2 , after 2 h incubation in H520, PG, and A549 lung cancer cell lines, respectively. Micro-PET images of 68 Ga-DOTA-PA1 showed that the PET imaging signal correlated with the total expression of SSTRs, instead of SSTR 2 only, which was measured by Western blotting and immunofluorescence analysis in mice bearing A549 tumors. In summary, a novel PET radiotracer, 68 Ga-DOTA-PA1, targeting multi-subtypes of SSTRs, was successfully synthesized and was confirmed to be useful for PET

  1. Immunohistochemical detection of somatostatin receptor subtypes sst1 and sst2A in human somatostatin receptor positive tumors

    NARCIS (Netherlands)

    L.J. Hofland (Leo); Q. Liu; P.M. van Koetsveld (Peter); J. Zuijderwijk; F. van der Ham (Frieda); R.R. de Krijger (Ronald); A. Schonbrunn; S.W.J. Lamberts (Steven)

    1999-01-01

    textabstractAlthough in situ hybridization has been used to examine the distribution of messenger RNA for somatostatin receptor subtypes (sst) in human tumors, the cellular localization of sst1 and sst2A receptors has not been reported. In this study, we describe the

  2. Development of 99mTc labelled somatostatin analogues with high affinity for somatostatin receptors

    International Nuclear Information System (INIS)

    Maina, T.; Nock, B.; Nicolopoulou, A.; Tsipra, C.; Poppe, M.; Chiotellis, E.

    2001-01-01

    A recent development in oncology involves the use of metabolically stabilized peptide hormone analogues labelled with metallic radionuclides for the diagnosis or therapy of malignant disease. This approach was successfully applied for the first time in the visualization of somatostatin positive tumours and their metastases with 111 In DTPA-octreotide. In an effort to obtain a 99m Tc somatostatin receptor affine radioligand we describe herein the synthesis, radiochemistry and preliminary biological evaluation of two novel 99m Tc labelled somatostatin analogues, N 4 -TOC and N 4 -RC-160. In these compounds a tetraamine bifunctional unit was covalently attached to the N-terminal (D)Phe 1 of the peptide chain using Boc-protection strategies. The peptide conjugates were purified by high performance liquid chromatography (HPLC) and characterized by UV/Vis and ES-MS spectroscopies. As revealed by HPLC, 99m Tc labelling was quantitative under mild conditions, leading to a single 99m Tc species in high specific activities. Affinity of 99m Tc N 4 -TOC for the somatostatin receptor, as determined by in vitro binding assays in rat brain cortex membranes, was found unaffected by the presence of the bulky metal chelate. The binding properties of 99m Tc N 4 -RC-160 could not be determined by this assay due to an extremely high non-specific binding of this radioligand, and will be shortly investigated by other methods. Tissue distribution in healthy mice revealed that 99m Tc N 4 -TOC is clearing mainly through the kidneys and the urinary tract whereas 99m Tc N 4 -RC-160 shows a high accumulation in the liver as a result of its lipophilicity. Analysis of urine samples by HPLC showed that 99m Tc N 4 -TOC is excreted integer from the body of mice, while 99m Tc N 4 -RC-160 is totally transformed to an unidentified hydrophilic metabolite in vivo. The location of this metabolism is currently investigated. In vivo blocking experiments using animals pre-treated with 50 μg octreotide

  3. Somatostatin receptor scintigraphy in patients with cat-scratch disease

    International Nuclear Information System (INIS)

    Krause, R.; Schnedl, W.J.; Hoier, S.; Piswanger-Soelkner, C.; Lipp, R.W.; Daxboeck, F.; Reisinger, E.C.

    2006-01-01

    Aim: somatostatin receptor scintigraphy images various neoplastic, granulomatous, and auto-immun diseases. Cat-scratch disease in an infectious granulomatous disease usually affecting the lymphnodes. It is not known whether cat-scratch disease provides positive somatostatin receptor scintigrams. Patients, methods: twelve patients with lymphadenitis and suspected cat-scratch disease were investigated by immunofluorescence antibody testing and somatostatin receptor scintigraphy. Suppurated lymphnodes were extracted or drained and Bartonella henselae specific PCR was then performed. Results: eleven of 12 patients showed IgG antibodies against B. henselea. SRS showed positive scintigraphic results in 6 of 11 patients with CSD. B. henselae DNA was detected in tissue of lymphnodes from 4 of 5 patients with lymphnode extraction or lymphnode drainage. SRS demonstrated positive scintigrams in all patients with a positive PCR. In one patient with suspected CSD SRS was negative as well as antibody testing. Conclusion: somatostatin receptor scintigraphy correlated with positive Bartonella henselae specific PCR tests and positive Bartonella henselae specific antibody tests in patients with CSD. (orig.)

  4. Somatostatin receptor scintigraphy in patients with cat-scratch disease

    Energy Technology Data Exchange (ETDEWEB)

    Krause, R.; Schnedl, W.J.; Hoier, S. [Div. of Infectious Diseases, Dept. of Internal Medicine, Univ. Graz (Austria); Piswanger-Soelkner, C.; Lipp, R.W. [Div. of Nuclear Medicine, Dept. of Internal Medicine, Univ. Graz (Austria); Daxboeck, F. [Clinical Inst. for Hygiene and Medical Microbiology, Div. of Hospital Hygiene, Univ. of Vienna (Austria); Reisinger, E.C. [Div. of Infectious Diseases and Tropical Medicine, Dept. of Internal Medicine, Univ. Rostock (Germany)

    2006-07-01

    Aim: somatostatin receptor scintigraphy images various neoplastic, granulomatous, and auto-immun diseases. Cat-scratch disease in an infectious granulomatous disease usually affecting the lymphnodes. It is not known whether cat-scratch disease provides positive somatostatin receptor scintigrams. Patients, methods: twelve patients with lymphadenitis and suspected cat-scratch disease were investigated by immunofluorescence antibody testing and somatostatin receptor scintigraphy. Suppurated lymphnodes were extracted or drained and Bartonella henselae specific PCR was then performed. Results: eleven of 12 patients showed IgG antibodies against B. henselea. SRS showed positive scintigraphic results in 6 of 11 patients with CSD. B. henselae DNA was detected in tissue of lymphnodes from 4 of 5 patients with lymphnode extraction or lymphnode drainage. SRS demonstrated positive scintigrams in all patients with a positive PCR. In one patient with suspected CSD SRS was negative as well as antibody testing. Conclusion: somatostatin receptor scintigraphy correlated with positive Bartonella henselae specific PCR tests and positive Bartonella henselae specific antibody tests in patients with CSD. (orig.)

  5. Somatostatin receptor-mediated imaging and therapy: basic science, current knowledge, limitations and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Breeman, W.A.P.; Jong, M. de; Kwekkeboom, D.J.; Valkema, R.; Bakker, W.H.; Kooij, P.P.M. [Dept. of Nuclear Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Visser, T.J. [Dept. of Internal Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Krenning, E.P. [Dept. of Nuclear Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Dept. of Internal Medicine, Erasmus Medical Centre Rotterdam (Netherlands)

    2001-09-01

    In vivo somatostatin receptor-mediated scintigraphy has proven to be a valuable method for the visualisation of neuroendocrine tumours and their metastases. A new application is the use of radiolabelled analogues for somatostatin receptor-mediated therapy. This paper presents a review on the basic science, historical background and current knowledge of somatostatin receptor subtypes and their expression in neuroendocrine tumours. New somatostatin analogues, new chelators, ''new'' radionuclides and combinations thereof are also discussed. Due attention is given to limitations and future perspectives of somatostatin receptor-mediated imaging and therapy. (orig.)

  6. Somatostatin receptor-mediated imaging and therapy: basic science, current knowledge, limitations and future perspectives

    International Nuclear Information System (INIS)

    Breeman, W.A.P.; Jong, M. de; Kwekkeboom, D.J.; Valkema, R.; Bakker, W.H.; Kooij, P.P.M.; Visser, T.J.; Krenning, E.P.

    2001-01-01

    In vivo somatostatin receptor-mediated scintigraphy has proven to be a valuable method for the visualisation of neuroendocrine tumours and their metastases. A new application is the use of radiolabelled analogues for somatostatin receptor-mediated therapy. This paper presents a review on the basic science, historical background and current knowledge of somatostatin receptor subtypes and their expression in neuroendocrine tumours. New somatostatin analogues, new chelators, ''new'' radionuclides and combinations thereof are also discussed. Due attention is given to limitations and future perspectives of somatostatin receptor-mediated imaging and therapy. (orig.)

  7. Kidney protection during peptide receptor radionuclide therapy with somatostatin analogues

    Energy Technology Data Exchange (ETDEWEB)

    Rolleman, Edgar J.; Melis, Marleen; Valkema, Roelf; Krenning, Eric P.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, V 220, Rotterdam (Netherlands); Boerman, Otto C. [Radboud University Hospital, Department of Nuclear Medicine, Nijmegen (Netherlands)

    2010-05-15

    This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides resulting in dose-limiting high kidney radiation doses. Radiation nephropathy has been described in several patients. Studies on the mechanism and localization demonstrate that renal uptake of radiolabelled somatostatin analogues largely depends on the megalin/cubulin system in the proximal tubule cells. Thus methods are needed that interfere with this reabsorption pathway to achieve kidney protection. Such methods include coadministration of basic amino acids, the bovine gelatin-containing solution Gelofusine or albumin fragments. Amino acids are already commonly used in the clinical setting during PRRT. Other compounds that interfere with renal reabsorption capacity (maleic acid and colchicine) are not suitable for clinical use because of potential toxicity. The safe limit for the renal radiation dose during PRRT is not exactly known. Dosimetry studies applying the principle of the biological equivalent dose (correcting for the effect of dose fractionation) suggest that a dose of about 37 Gy is the threshold for development of kidney toxicity. This threshold is lower when risk factors for development of renal damage exist: age over 60 years, hypertension, diabetes mellitus and previous chemotherapy. A still experimental pathway for kidney protection is mitigation of radiation effects, possibly achievable by cotreatment with amifostine (Ethylol), a radiation protector, or with blockers of the renin-angiotensin-aldosterone system. Future perspectives on improving kidney protection during PRRT include combinations of agents to reduce renal retention of radiolabelled peptides, eventually together with mitigating medicines. Moreover, new somatostatin analogues with lower

  8. Kidney protection during peptide receptor radionuclide therapy with somatostatin analogues

    International Nuclear Information System (INIS)

    Rolleman, Edgar J.; Melis, Marleen; Valkema, Roelf; Krenning, Eric P.; Jong, Marion de; Boerman, Otto C.

    2010-01-01

    This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides resulting in dose-limiting high kidney radiation doses. Radiation nephropathy has been described in several patients. Studies on the mechanism and localization demonstrate that renal uptake of radiolabelled somatostatin analogues largely depends on the megalin/cubulin system in the proximal tubule cells. Thus methods are needed that interfere with this reabsorption pathway to achieve kidney protection. Such methods include coadministration of basic amino acids, the bovine gelatin-containing solution Gelofusine or albumin fragments. Amino acids are already commonly used in the clinical setting during PRRT. Other compounds that interfere with renal reabsorption capacity (maleic acid and colchicine) are not suitable for clinical use because of potential toxicity. The safe limit for the renal radiation dose during PRRT is not exactly known. Dosimetry studies applying the principle of the biological equivalent dose (correcting for the effect of dose fractionation) suggest that a dose of about 37 Gy is the threshold for development of kidney toxicity. This threshold is lower when risk factors for development of renal damage exist: age over 60 years, hypertension, diabetes mellitus and previous chemotherapy. A still experimental pathway for kidney protection is mitigation of radiation effects, possibly achievable by cotreatment with amifostine (Ethylol), a radiation protector, or with blockers of the renin-angiotensin-aldosterone system. Future perspectives on improving kidney protection during PRRT include combinations of agents to reduce renal retention of radiolabelled peptides, eventually together with mitigating medicines. Moreover, new somatostatin analogues with lower

  9. Reduced Numbers of Somatostatin Receptors in the Cerebral Cortex in Alzheimer's Disease

    Science.gov (United States)

    Flint Beal, M.; Mazurek, Michael F.; Tran, Vinh T.; Chattha, Geetinder; Bird, Edward D.; Martin, Joseph B.

    1985-07-01

    Somatostatin receptor concentrations were measured in patients with Alzheimer's disease and controls. In the frontal cortex (Brodmann areas 6, 9, and 10) and temporal cortex (Brodmann area 21), the concentrations of somatostatin in receptors in the patients were reduced to approximately 50 percent of control values. A 40 percent reduction was seen in the hippocampus, while no significant changes were found in the cingulate cortex, postcentral gyrus, temporal pole, and superior temporal gyrus. Scatchard analysis showed a reduction in receptor number rather than a change in affinity. Somatostatin-like immunoreactivity was significantly reduced in both the frontal and temporal cortex. Somatostatin-like immunoreactivity was linearly related to somatostatin-receptor binding in the cortices of Alzheimer's patients. These findings may reflect degeneration of postsynaptic neurons or cortical afferents in the patients' cerebral cortices. Alternatively, decreased somatostatinlike immunoreactivity in Alzheimer's disease might indicate increased release of somatostatin and down regulation of postsynaptic receptors.

  10. Somatostatin-receptor imaging in the localization of endocrine tumors

    International Nuclear Information System (INIS)

    Lamberts, S.W.; Bakker, W.H.; Reubi, J.C.; Krenning, E.P.

    1990-01-01

    A number of different tumors have receptors for somatostatin. We evaluated the efficacy of scanning with 123 I-labeled Tyr3-octreotide, a somatostatin analogue, for tumor localization in 42 patients with carcinoid tumors, pancreatic endocrine tumors, or paragangliomas. We then evaluated the response to octreotide therapy in some of these patients. Primary tumors or metastases, often previously unrecognized, were visualized in 12 of 13 patients with carcinoid tumors and in 7 of 9 patients with pancreatic endocrine tumors. The endocrine symptoms of these patients responded well to therapy with octreotide. Among 20 patients with paragangliomas, 8 of whom had more than one tumor, 10 temporal (tympanic or jugular), 9 carotid, and 10 vagal tumors could be visualized. One small tympanic tumor and one small carotid tumor were not seen on the scan. The 123 I-labeled Tyr3-octreotide scanning technique is a rapid and safe procedure for the visualization of some tumors with somatostatin receptors. A positive scan may predict the ability of octreotide therapy to control symptoms of hormonal hypersecretion

  11. Somatostatin receptor subtype expression in human thyroid tumours.

    Science.gov (United States)

    Klagge, A; Krause, K; Schierle, K; Steinert, F; Dralle, H; Fuhrer, D

    2010-04-01

    Somatostatin receptors (SSTR) are expressed in various endocrine tumours. The expression of SSTR at the tumour cell surface confers the possibility for diagnostic imaging and therapy of tumours using radiolabeled somatostatin analogues. The majority of currently available somatostatin analogues show a higher binding affinity for the SSTR2 subtype. To date, the precise expression pattern of the SSTR subtypes 1-5 in thyroid epithelial tumours remains to be determined. We investigated the mRNA expression of SSTR1-5 in benign and malignant epithelial thyroid tumours [20 cold thyroid nodules (CTNs), 20 toxic thyroid nodules (TTNs), 20 papillary, 20 follicular, and 5 anaplastic carcinomas (PTCs, FTCs, ATCs, respectively)] and compared them to normal surrounding thyroid tissues. Four out of five SSTR subtypes were detected in malignant thyroid tumours, benign neoplasia, and normal surrounding tissue with a predominant expression of SSTR2 and SSTR5, and a weak expression of SSTR1 and SSTR3. Weak SSTR4 mRNA expression was detected in some PTCs. Compared to normal thyroid tissue, SSTR2 was significantly upregulated in PTC and ATC. In addition significant upregulation of SSTR3 was found in PTC. SSTR5 mRNA expression was increased in PTC and FTC and significantly decreased in CTN and TTN compared to normal thyroid tissue. SSTR2 is the predominant subtype in thyroid epithelial tumours with a high expression pattern, in particular, in PTC . Perspectively, the expression of distinct SSTR in thyroid epithelial tumours might represent a promising avenue for diagnostics and therapy of advanced thyroid cancer with somatostatin analogues. Georg Thieme Verlag KG Stuttgart New York.

  12. Somatostatin receptor scintigraphy in endocrine ophthalmopathy; Somatostatin-Rezeptor-Szintigraphie bei endokriner Orbitopathie

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, M. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Mainz (Germany); Kahaly, G. [3. Medizinische Klinik und Poliklinik, Innere Medizin - Endokrinologie, Univ. Mainz (Germany); Muehlbach, A. [3. Medizinische Klinik und Poliklinik, Innere Medizin - Endokrinologie, Univ. Mainz (Germany); Bockisch, A. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Mainz (Germany); Beyer, J. [3. Medizinische Klinik und Poliklinik, Innere Medizin - Endokrinologie, Univ. Mainz (Germany); Hahn, K. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Mainz (Germany)

    1994-12-01

    Somatostatin receptor scintigraphy with {sup 111}In-labeled octreotide proves to be a very sensitive diagnostic tool for evaluation of inflammative activity in endocrine ophthalmopathy (EO). The results of somatostatin receptor scintigraphy (SRS) in 40 patients with EO show a high orbital accumulation of {sup 111}In-octreotide in clinically active EO (4h-median/orbit-brain-ratio: 12.6; controls 4h-median: 5.8) Patients with clinically inactive EO (4h-median: 7.1) show a similar orbital accumulation of radioactivity compared to controls. 5 patients with active orbital myositis also revealed an even higher orbital accumulation of radioactivity (4h-median: 42.3). The diagnostic value of SRS lies in its ability to act as a measure of inflammation and an be useful as an activity parameter when planning therapeutic procedure as well as for EO follow-up. The results in patients with orbital myositis nevertheless do not permit a differential diagnosis with this method. The therapeutic value of {sup 111}In-octreotide in Graves` disease has yet to be established. (orig.) [Deutsch] Die Somatostatin-Rezeptor-Szintigraphie (SRS) mit dem {sup 111}Indium-markierten Somatostatinanalogon Octreotid stellt ein sensitives Verfahren zur Einschaetzung der entzuendlichen Aktivitaet bei endokriner Orbitopathie (EO) dar. Die Untersuchungen an 40 Patienten mit EO ergaben eine im Vergleich zur Kontrollgruppe signifikant hoehere orbitale Octreotidanreicherung bei klinisch aktiver Erkrankung (4h-Median/Orbita-Hirn-Quotient: 12,6; Kontrollgruppe 4h-Median: 5,8; p=0,0032). Patienten mit klinisch nicht aktiver Erkrankung (4h-Median: 7,1) unterschieden sich bezueglich der orbitalen Octreotidanreicherung nicht wesentlich von der Kontrollgruppe. Auch 5 Patienten mit florider orbitaler Myositis zeigten eine deutlich gesteigerte orbitale Aktivitaetsanreicherung (4h-Median: 42,3). Der diagnostische Nutzen der SRS liegt somit in ihrer Eigenschaft als Aktivitaets- und Entzuendungsparameter und kann mit

  13. Development of antibodies against the rat brain somatostatin receptor.

    Science.gov (United States)

    Theveniau, M; Rens-Domiano, S; Law, S F; Rougon, G; Reisine, T

    1992-05-15

    Somatostatin (SRIF) is a neurotransmitter in the brain involved in the regulation of motor activity and cognition. It induces its physiological actions by interacting with receptors. We have developed antibodies against the receptor to investigate its structural properties. Rabbit polyclonal antibodies were generated against the rat brain SRIF receptor. These antibodies (F4) were able to immunoprecipitate solubilized SRIF receptors from rat brain and the cell line AtT-20. The specificity of the interaction of these antibodies with SRIF receptors was further demonstrated by immunoblotting. F4 detected SRIF receptors of 60 kDa from rat brain and adrenal cortex and the cell lines AtT-20, GH3, and NG-108, which express high densities of SRIF receptors. They did not detect immunoreactive material from rat liver or COS-1, HEPG, or CRL cells, which do not express functional SRIF receptors. In rat brain, 60-kDa immunoreactivity was detected by F4 in the hippocampus, cerebral cortex, and striatum, which have high densities of SRIF receptors. However, F4 did not interact with proteins from cerebellum and brain stem, which express few SRIF receptors. Immunoreactive material cannot be detected in rat pancreas or pituitary, which have been reported to express a 90-kDa SRIF receptor subtype. The selective detection of 60-kDa SRIF receptors by F4 indicates that the 60- and 90-kDa SRIF receptor subtypes are immunologically distinct. The availability of antibodies that selectively detect native and denatured brain SRIF receptors provides us with a feasible approach to clone the brain SRIF receptor gene(s).

  14. Physiologic basics and clinical experience with somatostatin-receptor-scintigraphy

    International Nuclear Information System (INIS)

    Henze, E.; Eberhardt, J.U.; Bohuslavizki, K.H.

    1994-01-01

    The introduction of radiolabelled octreotide, an analogon to the receptor binding hormone Somatostatin, has markedly increased the ability to detect structures and tumours carrying somatostatin receptors by nuclear medicine imaging with high sensitivity and specificity. It has been shown that in vitro receptor density and in vivo scintigraphic results correlate well in particular in tumours of neuroendocrine origin of the GI tract such as insulinomas, gastrinomas, glucagonomas, carcionoids, but also in paragangliomas, small cell lung cancer and meningiomas. As receptors were also shown to be present on so called activated leucocytes granulomas, lymphomas and autoimmune disease have been imaged with octreotide successfully. The specific tracer (In-111-DTPA-D-PHE-Octreotide, Octreoscan R ) is rapidly cleared from the blood pool by the kidneys and, partially, via the liver providing a high target to background ratio. Physiologic uptake is usually observed in the pituitary and thyroid glands, in spleen and liver. Optimum tracer accumulation for tumour scintigraphy is seen on the 24-h-images with the best target to background ratios. Additional SPECT-imaging is recommended in particular in the abdominal regions. The sensitivity in imaging the above named tumours ranges from 70 up to 100%. In-111 octreotide imaging is of diagnostic impact both for the primary diagnostic evaluation as well as for detecting or excluding secondary manifestations in known tumour sites. Of specific value is the information on relative receptor density in the tumour to be treated as may be obtained by quantitative In-111 octreotide imaging for decision making whether or not to use cold octreotide (Sandostatin R ) as a receptor blocking drug for therapy as well as for treatment follow-up studies. (author)

  15. Somatostatin receptors in rat hippocampus: localization to intrinsic neurons

    International Nuclear Information System (INIS)

    Palacios, J.M.; Reubi, J.C.; Maurer, R.

    1986-01-01

    The effect of neurotoxic chemical and electrolytical lesions on somatostatin (SS) receptor binding in the septo-hippocampal afferents, pyramidal and granule cells of the rat hippocampus was examined by autoradiography using the stable SS analogue 125 I-204-090 as radioligand. Electrolytical lesions of the septum did not result in modification of SS binding in the hippocampus. In contrast, both granule cell lesion with colchicine and pyramidal or pyramidal and granule cell lesions with increasing kainic acid doses did result in a specific decrease of binding in the dentate gyrus and hippocampus (CA 1 and CA 3 ). These results suggest that SS receptors in the hippocampus are probably associated with elements from intrinsic neurons. (Author)

  16. Validation of somatostatin receptor scintigraphy in the localization of neuroendocrine tumors

    International Nuclear Information System (INIS)

    Lamberts, S.W.J.; Reubi, J.C.; Krenning, E.P.

    1993-01-01

    Somatostatin analogs are used in the control of hormonal hypersecretion and tumor growth of patients with acromegaly, islet cell carcinomas and carcinoids. Recently we showed that somatostatin receptor positive tumors can be visualized in vivo after the administration of radionuclide-labeled somatostatin analogs. Receptor imaging was positive in 18/21 islet cell tumors, 32/37 carcinoids, 26/28 paragangliomas, 9/14 medullary thyroid carcinomas, and 5/7 small cell lung cancers. Somatostatin receptor imaging is an easy, harmless and painless diagnostic method. It localizes multiple and/or metastatic tumors, predicts the successful control of hormonal hypersecretion by octreotide and seems to be of prognostic value in certain types of cancer. This scintigraphic method might help in patient selection for clinical trials with somatostatin analogs in the treatment of neuroendocrine cancers. (orig.)

  17. Validation of somatostatin receptor scintigraphy in the localization of neuroendocrine tumors

    Energy Technology Data Exchange (ETDEWEB)

    Lamberts, S.W.J. (Depts. of Medicine and Nuclear Medicine, Erasmus Univ., Rotterdam (Netherlands) Div. of Cell Biology and Experimental Cancer Research, Institution of Pathology, Bern Univ. (Switzerland)); Reubi, J.C. (Depts. of Medicine and Nuclear Medicine, Erasmus Univ., Rotterdam (Netherlands) Div. of Cell Biology and Experimental Cancer Research, Institution of Pathology, Bern Univ. (Switzerland)); Krenning, E.P. (Depts. of Medicine and Nuclear Medicine, Erasmus Univ., Rotterdam (Netherlands) Div. of Cell Biology and Experimental Cancer Research, Institution of Pathology, Bern Univ. (Switzerland))

    1993-01-01

    Somatostatin analogs are used in the control of hormonal hypersecretion and tumor growth of patients with acromegaly, islet cell carcinomas and carcinoids. Recently we showed that somatostatin receptor positive tumors can be visualized in vivo after the administration of radionuclide-labeled somatostatin analogs. Receptor imaging was positive in 18/21 islet cell tumors, 32/37 carcinoids, 26/28 paragangliomas, 9/14 medullary thyroid carcinomas, and 5/7 small cell lung cancers. Somatostatin receptor imaging is an easy, harmless and painless diagnostic method. It localizes multiple and/or metastatic tumors, predicts the successful control of hormonal hypersecretion by octreotide and seems to be of prognostic value in certain types of cancer. This scintigraphic method might help in patient selection for clinical trials with somatostatin analogs in the treatment of neuroendocrine cancers. (orig.).

  18. Identification of the receptors for somatostatin (SST) and cortistatin (CST) in chickens and investigation of the roles of cSST28, cSST14, and cCST14 in inhibiting cGHRH1-27NH2-induced growth hormone secretion in cultured chicken pituitary cells.

    Science.gov (United States)

    Meng, Fengyan; Huang, Guian; Gao, Shunyu; Li, Juan; Yan, Zhenxin; Wang, Yajun

    2014-03-25

    Somatostatin receptors (SSTRs) are proposed to mediate the actions of somatostatin (SST) and its related peptide, cortistatin (CST), in vertebrates. However, the identity, functionality, and tissue expression of these receptors remain largely unknown in most non-mammalian vertebrates including birds. In this study, five SSTRs (named cSSTR1, cSSTR2, cSSTR3, cSSTR4, cSSTR5) were cloned from chicken brain by RT-PCR. Using a pGL3-CRE-luciferase reporter system, we demonstrated that activation of each cSSTR expressed in CHO cells by cSST28, cSST14 and cCST14 treatment could inhibit forskolin-induced luciferase activity of CHO cells, indicating the functional coupling of all cSSTRs to Gi protein(s). Interestingly, cSSTR1-4 expressed in CHO cells could be activated by cSST28, cSST14 and cCST14 with high potencies, suggesting that they may function as the receptors common for these peptides. In contrast, cSSTR5 could be potently activated by cSST28 only, indicating that it is a cSST28-specific receptor. Using RT-PCR, wide expression of cSSTRs was detected in chicken tissues including pituitary. In accordance with their expression in pituitary, cSST28, cSST14, and cCST14 were demonstrated to inhibit basal and novel cGHRH1-27NH2-induced GH secretion in cultured chicken pituitary cells dose-dependently (0-10nM) by Western blot analysis, suggesting the involvement of cSSTR(s) common for these peptides in mediating their inhibitory actions. Collectively, our study establishes a molecular basis to elucidate the roles of SST/CST in birds and provide insights into the roles of SST/CST in vertebrates, such as their conserved actions on pituitary. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Truncated somatostatin receptor 5 may modulate therapy response to somatostatin analogues--Observations in two patients with acromegaly and severe headache

    DEFF Research Database (Denmark)

    Marina, Djordje; Burman, Pia; Klose, Marianne

    2015-01-01

    BACKGROUND: Somatotropinomas have unique "fingerprints" of somatostatin receptor (sst) expression, which are targets in treatment of acromegaly with somatostatin analogues (SSAs). However, a significant expression of sst is not always related to the biochemical response to SSAs. Headache is a com...

  20. Coupling of guanine nucleotide inhibitory protein to somatostatin receptors on pancreatic acinar membranes

    International Nuclear Information System (INIS)

    Sakamoto, C.; Matozaki, T.; Nagao, M.; Baba, S.

    1987-01-01

    Guanine nucleotides and pertussis toxin were used to investigate whether somatostatin receptors interact with the guanine nucleotide inhibitory protein (NI) on pancreatic acinar membranes in the rat. Guanine nucleotides reduced 125 I-[Tyr 1 ]somatostatin binding to acinar membranes up to 80%, with rank order of potency being 5'-guanylyl imidodiphosphate [Gpp(NH)p]>GTP>TDP>GMP. Scatchard analysis revealed that the decrease in somatostatin binding caused by Gpp(NH)p was due to the decrease in the maximum binding capacity without a significant change in the binding affinity. The inhibitory effect of Gpp(NH)p was partially abolished in the absence of Mg 2+ . When pancreatic acini were treated with 1 μg/ml pertussis toxin for 4 h, subsequent 125 I-[Tyr 1 ]somatostatin binding to acinar membranes was reduced. Pertussis toxin treatment also abolished the inhibitory effect of somatostatin on vasoactive intestinal peptide-stimulated increase in cellular content of adenosine 3',5'-cyclic monophosphate (cAMP) in the acini. The present results suggest that 1) somatostatin probably functions in the pancreas to regulate adenylate cyclase enzyme system via Ni, 2) the extent of modification of Ni is correlated with the ability of somatostatin to inhibit cAMP accumulation in acini, and 3) guanine nucleotides also inhibit somatostatin binding to its receptor

  1. Somatostatin receptor scintigraphy using (99m)Tc-EDDA/HYNIC-TOC in patients with medullary thyroid carcinoma

    NARCIS (Netherlands)

    Czepczynski, Rafal; Parisella, Maria Gemma; Kosowicz, Jerzy; Mikolajczak, Renata; Ziemnicka, Katarzyna; Gryczynska, Maria; Sowinski, Jerzy; Signore, Alberto

    2007-01-01

    Purpose Several new somatostatin analogues have been developed for the diagnosis and therapy of different tumours. Since somatostatin receptors are often over-expressed in medullary thyroid carcinoma (MTC), the aim of our study was to evaluate the utility of scintigraphy with the somatostatin

  2. Activation of Brain Somatostatin Signaling Suppresses CRF Receptor-Mediated Stress Response

    Directory of Open Access Journals (Sweden)

    Andreas Stengel

    2017-04-01

    Full Text Available Corticotropin-releasing factor (CRF is the hallmark brain peptide triggering the response to stress and mediates—in addition to the stimulation of the hypothalamus-pituitary-adrenal (HPA axis—other hormonal, behavioral, autonomic and visceral components. Earlier reports indicate that somatostatin-28 injected intracerebroventricularly counteracts the acute stress-induced ACTH and catecholamine release. Mounting evidence now supports that activation of brain somatostatin signaling exerts a broader anti-stress effect by blunting the endocrine, autonomic, behavioral (with a focus on food intake and visceral gastrointestinal motor responses through the involvement of distinct somatostatin receptor subtypes.

  3. Activation of Brain Somatostatin Signaling Suppresses CRF Receptor-Mediated Stress Response.

    Science.gov (United States)

    Stengel, Andreas; Taché, Yvette F

    2017-01-01

    Corticotropin-releasing factor (CRF) is the hallmark brain peptide triggering the response to stress and mediates-in addition to the stimulation of the hypothalamus-pituitary-adrenal (HPA) axis-other hormonal, behavioral, autonomic and visceral components. Earlier reports indicate that somatostatin-28 injected intracerebroventricularly counteracts the acute stress-induced ACTH and catecholamine release. Mounting evidence now supports that activation of brain somatostatin signaling exerts a broader anti-stress effect by blunting the endocrine, autonomic, behavioral (with a focus on food intake) and visceral gastrointestinal motor responses through the involvement of distinct somatostatin receptor subtypes.

  4. Somatostatin Receptor Scintigraphy Findings in a Patient with Metastatic Gastrinoma and MEN 1 Syndrome

    Directory of Open Access Journals (Sweden)

    Gözde Mütevelizade

    2011-12-01

    Full Text Available Liver metastases from neuroendocrine tumours frequently occur and significantly worsen their prognosis. Somatostatin receptor scintigraphy (SRS is a valuable method for the detection of somatostatin receptor-positive lesions like gastrinoma. In this case report, the importance of SRS to localize the primary tumor and the spread of disease is emphasized in a patient with neuroendocrine liver metastases. A 45-year-old man was admitted to hospital with multiple liver metastasis of neuroendocrine carcinoma. Somatostatin receptor scintigraphy showed multiple intense radiotracer uptakes in the liver and a focal tracer uptake at the right side of the upper abdominal region corresponding to duodenum or pancreas. Elevated serum gastrin levels confirmed the gastrinoma diagnosis. (MRT 2011;20:117-120

  5. Clinical value of somatostatin receptor imaging in patients with suspected head and neck paragangliomas

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Matthias; Dietlein, Markus; Weber, Kerstin; Moka, Detlef; Schicha, Harald [Klinik und Poliklinik fuer Nuklearmedizin, Universitaet zu Koeln, Joseph-Stelzmann-Strasse 9, 50924 Koeln (Germany); Fischer, Eva; Michel, Olaf; Stennert, Eberhard [Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenheilkunde, Universitaet zu Koeln, Koeln (Germany)

    2002-12-01

    Paragangliomas or glomus tumours of the head and neck region are rare somatostatin receptor-expressing neuroendocrine tumours. Precise preoperative diagnosis is of special importance in order to adequately weigh the potential benefit of the operation against the inherent risks of the procedure. In this study, the clinical value of somatostatin receptor imaging was assessed in 19 patients who underwent somatostatin receptor scintigraphy because of known or suspected paraganglioma of the head and neck region. The results were compared with the results of computed tomography and/or magnetic resonance imaging, histology and clinical follow-up. [{sup 111}In-DTPA-D-Phe{sup 1}]-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 140-220 MBq {sup 111}In-octreotide. Whole-body and planar images as well as single-photon emission tomography images were acquired and lesions were graded according to qualitative tracer uptake. Somatostatin receptor imaging was positive in nine patients, identifying paragangliomas for the first time in three patients and recurrent disease in six patients. In one patient, a second, previously unknown paraganglioma site was identified. Negative results were obtained in ten patients. These patients included one suffering from chronic hyperplastic otitis externa, one with granuloma tissue and an organised haematoma, one with an acoustic neuroma, one with an asymmetric internal carotid artery, two with ectasia of the bulbus venae jugularis and one with a jugular vein thrombosis. In two patients with a strong family history of paraganglioma, individual involvement could be excluded. In only one patient did somatostatin receptor imaging and magnetic resonance imaging yield false negative results in respect of recurrent paraganglioma tissue. It is concluded that somatostatin receptor scintigraphy provides important information in patients with suspected paragangliomas of the head and neck region and has a strong impact on further

  6. Experimental peptide receptor radionuclide therapy in radioiodine negative somatostatin receptor positive thyroid cancer

    International Nuclear Information System (INIS)

    Nilica, B.; Kroiss, A.; Putzer, D.; Uprimmy, C.; Warwitz, B.; Kendler, D.; Waitz, D.; Virgolini, I.

    2015-01-01

    Full text of publication follows. Purpose: This retrospective analysis evaluated the time to progression (TTP), progression free survival (PFS) and overall survival (OS) in patients with radioiodine negative thyroid cancer who had undergone peptide receptor radionuclide therapy (PRRT) with 177 Lu-DOTA-TATE, 177 Lu-DOTA-LAN, 90 Y-DOTA-TOC or 90 Y-DOTA-LAN after tumor progression. Methods: Data derived from twenty patients with either differentiated (n=15), anaplastic (n=1) or medullary (n=4) somatostatin receptor positive thyroid cancer who had received treatment with PRRT after tumor progression. TTP, PFS and OS were defined according to the clinical trial endpoints suggested by the FDA (Food and Drug Administration). Progressive disease was defined by sonography, FDG-PET, Ga-DOTA-TOC-PET, or CT (RECIST Criteria). Results: In 17 patients the median overall survival time after the first PRRT was 17.3 (range: 0.1 - 109.7) months. Three patients still alive are actually showing stable disease. The median of PFS in 20 Patients (6 with more than one PRRT-cycle or PRRT-substance) has been 10.9 (range: 0.1 - 44.0) months. The median TTP was 15.6 (range 4.4 to 29.2) months. Conclusion: PRRT appears to be useful in patients with somatostatin receptor positive but radioiodine negative thyroid cancer as a complementary palliative cytotoxic therapy. (authors)

  7. Carboxyl-terminal multi-site phosphorylation regulates internalization and desensitization of the human sst2 somatostatin receptor.

    Science.gov (United States)

    Lehmann, Andreas; Kliewer, Andrea; Schütz, Dagmar; Nagel, Falko; Stumm, Ralf; Schulz, Stefan

    2014-04-25

    The somatostatin receptor 2 (sst2) is the pharmacological target of somatostatin analogs that are widely used in the diagnosis and treatment of human neuroendocrine tumors. We have recently shown that the stable somatostatin analogs octreotide and pasireotide (SOM230) stimulate distinct patterns of sst2 receptor phosphorylation and internalization. Like somatostatin, octreotide promotes the phosphorylation of at least six carboxyl-terminal serine and threonine residues namely S341, S343, T353, T354, T356 and T359, which in turn leads to a robust receptor endocytosis. Unlike somatostatin, pasireotide stimulates a selective phosphorylation of S341 and S343 of the human sst2 receptor followed by a partial receptor internalization. Here, we show that exchange of S341 and S343 by alanine is sufficient to block pasireotide-driven internalization, whereas mutation of T353, T354, T356 and T359 to alanine is required to strongly inhibited both octreotide- and somatostatin-induced internalization. Yet, combined mutation of T353, T354, T356 and T359 is not sufficient to prevent somatostatin-driven β-arrestin mobilization and receptor desensitization. Replacement of all fourteen carboxyl-terminal serine and threonine residues by alanine completely abrogates sst2 receptor internalization and β-arrestin mobilization in HEK293 cells. Together, our findings demonstrate for the first time that agonist-selective sst2 receptor internalization is regulated by multi-site phosphorylation of its carboxyl-terminal tail. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. 99m Tc- la bed somatostatin analogs for imaging somatostatin-receptor-positive tumors

    International Nuclear Information System (INIS)

    Gandomkar, M.; Najafi, R.; Shafiei, A.; Sadat Ebrahimi, E.; Babaie, M.H.; Rabani, M.

    2002-01-01

    Over the least few years, 111 In-DTPA- Octreotide has found widespread clinical applicability, especially in oncology. However limitation, especially concerning availability, imaging properties, and costs, remain and have stimulated research on radiolabeling with many alternative radionuclides. The purpose of this investigation was to labeling somatostatin analogs with 99 m Tc and evaluate their suitability as an agents for in vivo use. Octreotide and Tyr-3-Octreotide were labeled by 99 mTc with direct and indirect methods. Sodium ascorbate and sodium dithionite were used for reduction of cystine bridge and HYNIC was used as bifunctional agents and different co ligands used for labeling by 99 mTc. Yield of labeling, purity, stability, internalisation, binding affinity and biodistribution of peptide conjugates were studied. Direct labeling of octreotide was simple, rapid, efficient and yield was good (%60). K d for binding affinity as high (10 -9 ) but stability was low. Labeling for HYNIC-Tyr-Octreotide had a high yield (>%90), good stability, internalisation and biodistribution. with more experimental work and some improve this peptide-based radiopharmaceuticals can be employed in all nuclear medicine centers as a useful agent for imaging of tumors

  9. Receptor binding of somatostatin-14 and somatostatin-28 in rat brain: differential modulation by nucleotides and ions.

    Science.gov (United States)

    Srikant, C B; Dahan, A; Craig, C

    1990-02-04

    The tissue-selective binding of the two principal bioactive forms of somatostatin, somatostatin-14 (SS-14) and somatostatin-28 (SS-28), their ability to modulate cAMP-dependent and -independent regulation of post-receptor events to different degrees and the documentation of specific labelling of SS receptor subtypes with SS-28 but not SS-14 in discrete regions of rat brain suggest the existence of distinct SS-14 and SS-28 binding sites. Receptor binding of SS-14 ligands has been shown to be modulated by nucleotides and ions, but the effect of these agents on SS-28 binding has not been studied. In the present study we investigated the effects of adenine and guanine nucleotides as well as monovalent and divalent cations on rat brain SS receptors quantitated with radioiodinated analogs of SS-14 ([125I-Tyr11]SS14, referred to in this paper as SS-14) and SS-28 ([Leu8, D-Trp22, 125I-Tyr25] SS-28, referred to as LTT* SS-28) in order to determine if distinct receptor sites for SS-14 and SS-28 could be distinguished on the basis of their modulation by nucleotides and ions. GTP as well as ATP exerted a dose-dependent inhibition (over a concentration range of 10(-7)-10(-3) M) of the binding of the two radioligands. The nucleotide inhibition of binding resulted in a decrease the Bmax of the SS receptors, the binding affinity remaining unaltered. GTP (10(-4) M) decreased the Bmax of LTT* SS-28 binding sites to a greater extent than ATP (145 +/- 10 and 228 +/- 16 respectively, compared to control value of 320 +/- 20 pmol mg-1). Under identical conditions GTP was less effective than ATP in reducing the number of T* SS-14 binding sites (Bmax = 227 +/- 8 and 182 +/- 15, respectively, compared to 340 +/- 15 pmol mg-1 in the absence of nucleotides). Monovalent cations inhibited the binding of both radioligands, Li+ and Na+ inhibited the binding of T* SS-14 to a greater extent than K+. The effect of divalent cations on the other hand was varied. At low concentration (2 mM) Mg2+, Ba2

  10. Critical role of somatostatin receptor 2 in the vulnerability of the central noradrenergic system

    DEFF Research Database (Denmark)

    Ádori, Csaba; Glück, Laura; Barde, Swapnali

    2015-01-01

    Alzheimer’s disease and other age-related neurodegenerative disorders are associated with deterioration of the noradrenergic locus coeruleus (LC), a probable trigger for mood and memory dysfunction. LC noradrenergic neurons exhibit particularly high levels of somatostatin binding sites. This is n......Alzheimer’s disease and other age-related neurodegenerative disorders are associated with deterioration of the noradrenergic locus coeruleus (LC), a probable trigger for mood and memory dysfunction. LC noradrenergic neurons exhibit particularly high levels of somatostatin binding sites...... morphometry and mRNA profiling in a cohort of Alzheimer’s and age-matched control brains in combination with genetic models of somatostatin receptor deficiency to establish causality between defunct somatostatin signalling and noradrenergic neurodegeneration. In Alzheimer’s disease, we found significantly....../IV and onwards, i.e., a process preceding advanced Alzheimer’s pathology. The loss of SSTR2 transcripts in the LC neurons appeared selective, since tyrosine hydroxylase, dopamine β-hydroxylase, galanin or galanin receptor 3 mRNAs remained unchanged. We modeled these pathogenic changes in Sstr2 −/− mice and...

  11. High sensitivity of the in vivo detection of somatostatin receptors by 111Indium (DTPA-Octreotide)-scintigraphy in meningioma patients

    International Nuclear Information System (INIS)

    Hildebrandt, G.; Luyken, C.; Klug, N.; Scheidhauer, K.; Schicha, H.; Dahms, P.; Krisch, B.

    1994-01-01

    The recent availability of isotope-labelled somatostatin analogues has allowed one to detect somatostatin receptors in normal tissue as well as in endocrine or non-endocrine cranial tumours. The purpose of the present study was to establish the value of somatostatin receptor scintigraphy using an 111 indium-labelled somatostatin analogue, octreotide, in the diagnostic work-up of meningioma patients. Twenty-two patients (16 women, 6 men, aged from 19-70 years) with newly diagnosed, residual or recurrent cranial meningiomas were examined. 111 indium-labelled DTPA-octreotide was injected i.v.. Planar and tomographic images were obtained with a gamma camera 4-6, and 24 hours after injection. In all of the meningiomas studies a high density of somatostatin receptor was detected by scintigraphy. No false negative test result was found. Due to this, a 100% predictive value of a negative test was calculated. However, when the tumours were taken in culture differing staining intensity could be seen in the light- and electron microscopic level even on individual cells of a single culture when silver intensified somatostatin-gold was used as ligand. We conclude, that in vivo somatostatin receptor scintigraphy may aid in the pre-operative differential diagnosis of skull base tumours

  12. Diagnostic value of somatostatin receptor scintigraphy in patients with intracranial tumours

    International Nuclear Information System (INIS)

    Luyken, C.; Hildebrandt, G.; Scheidhauer, K.; Kirsch, B.

    1993-01-01

    The aim of the study was to detect the SR binding sites in intracranial tumours and to evaluate the benefit of SRS in pre- and postoperative diagnostics. 86 patients with 94 intracranial tumours (39 meningiomas, 18 pituitary adenomas, 11 gliomas grade 3 or 4, 8 gliomas grade 2, 5 neurinomas, 5 intracranial metastases, 4 tumours of the orbit, 2 neurofibromas, 1 brain abscess and 1 cystic lesion) were examined. 111 In-octreotide was injected i.v. as 10 μg or 20 μg bolus, corresponding to 110 or 220 MBq (3 or 6 mCi). Gamma-camera images and SPECT were obtained 3-6 h and 24 h post injection. The scintigraphic evaluation was performed without knowledge of CT and MRI results. The histological classification corresponded to the WHO grading system. Somatostatin binding sites were detected in vito using somatostatin-gold conjugates. All patients with meningiomas showed a high focal tracer uptake corresponding to SR binding sites in vitro, whereas only in 50% of the pituitary adenomas SRS was positive. Neurinomas did not show any tracer uptake. In patients with gliomas with disturbed blood-brain-barrier positive tracer uptake was detected, while none of the gliomas with intact blood-brain-barrier could be visualized by SRS but showed somatostatin binding sites in vitro. In intracranial metastases a local tracer uptake was detected in vivo. In vitro 3 of 4 cases showed somatostatin binding sites. In 2 cases extracranial tracer uptake showed the primary tumour and metastases of the lymphnodes. Somatostatin receptor scintigraphy can help to detect or to exclude meningiomas especially in the cerebellopontine angle or in the orbit. In intracranial metastases SRS may point to the primary tumour or other metastases. In all other intracranial tumours receptor scintigraphy provides no clinical relevant information. (orig./MG) [de

  13. Role of somatostatin receptor-2 in gentamicin-induced auditory hair cell loss in the Mammalian inner ear.

    Directory of Open Access Journals (Sweden)

    Yves Brand

    Full Text Available Hair cells and spiral ganglion neurons of the mammalian auditory system do not regenerate, and their loss leads to irreversible hearing loss. Aminoglycosides induce auditory hair cell death in vitro, and evidence suggests that phosphatidylinositol-3-kinase/Akt signaling opposes gentamicin toxicity via its downstream target, the protein kinase Akt. We previously demonstrated that somatostatin-a peptide with hormone/neurotransmitter properties-can protect hair cells from gentamicin-induced hair cell death in vitro, and that somatostatin receptors are expressed in the mammalian inner ear. However, it remains unknown how this protective effect is mediated. In the present study, we show a highly significant protective effect of octreotide (a drug that mimics and is more potent than somatostatin on gentamicin-induced hair cell death, and increased Akt phosphorylation in octreotide-treated organ of Corti explants in vitro. Moreover, we demonstrate that somatostatin receptor-1 knockout mice overexpress somatostatin receptor-2 in the organ of Corti, and are less susceptible to gentamicin-induced hair cell loss than wild-type or somatostatin-1/somatostatin-2 double-knockout mice. Finally, we show that octreotide affects auditory hair cells, enhances spiral ganglion neurite number, and decreases spiral ganglion neurite length.

  14. The potential value of somatostatin receptor scintigraphy in medullary thyroid carcinoma

    International Nuclear Information System (INIS)

    Doerr, U.; Bihl, H.; Frank-Raue, K.; Raue, F.; Sautter-Bihl, M.L.; Buhr, H.J.; Guzman, G.; Inst. de Neurocirugia, Investigationes Cerebrales 'Dr Asenjo' Santiago

    1993-01-01

    In a prospective study, ten patients with recurrent medullary thyroid carcinoma (markedly elevated calcitonin levels) were investigated by means of somatostatin receptor scintigraphy (SRS) with 111 In-pentetreotide. Scintigraphically, 30 sites of pathological uptake were found, mostly located in the neck and upper mediastinum. So far, 18 suspected tumour sites underwent histological examination and 14 of them could be verified as metastases of medullary thyroid carcinoma (MTC). The remaining four putative tumour lesions turned out to be false positive scintigraphic findings caused by chronic inflammation and somatostatin receptor positive tumours other than MTC. We conclude that SRS is a promising imaging modality for localization of MTC recurrence and may thus make a contribution to better management of this patient group. (Author)

  15. Ga-68 Somatostatin Receptor PET/CT in von Hippel-Lindau Disease

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jong-Ryool; Min, Jung-Joon [Chonnam National Univ. Hwasun Hospital, Hwasun (Korea, Republic of); Kulkarui, Harshad; Carreras, Cecilia; Schalch, Georg; Baum, Richard P. [Nuclear Medicine and Center for PET/CT, Zentralk Bad Berka, Bad Verka (Germany)

    2012-06-15

    Von Hippel-Lindau (VHL) disease is a dominantly inherited familial cancer syndrome with a variety of benign and malignant tumors such as retinal and central nervous system hemangioblastomas, endolymphatic sac tumors, renalcysts and tumors, pancreatic cysts and tumors, pheochromo-cytomas, and epididymal cystadenomas. Cross-sectional mo-dalities (computed tomography and magnetic resonance imaging) as well as ultrasound play a major role in the initial evaluation and follow-up of the various manifestations of VHL disease. Ga-68-labeled somatostatin receptor analogs already have a significant role in the diagnosis, staging, and therapy management of neuroendocrine neoplasms and neural crest tumors. Herein, we report a case presenting a variety of malignancies in VHL and showing the usefulness of Ga-68 somatostatin receptor PET/CT as a one-stop-shop imaging modality in the management of VHL disease.

  16. Ga-68 Somatostatin Receptor PET/CT in von Hippel-Lindau Disease

    International Nuclear Information System (INIS)

    Oh, Jong-Ryool; Min, Jung-Joon; Kulkarui, Harshad; Carreras, Cecilia; Schalch, Georg; Baum, Richard P.

    2012-01-01

    Von Hippel-Lindau (VHL) disease is a dominantly inherited familial cancer syndrome with a variety of benign and malignant tumors such as retinal and central nervous system hemangioblastomas, endolymphatic sac tumors, renalcysts and tumors, pancreatic cysts and tumors, pheochromo-cytomas, and epididymal cystadenomas. Cross-sectional mo-dalities (computed tomography and magnetic resonance imaging) as well as ultrasound play a major role in the initial evaluation and follow-up of the various manifestations of VHL disease. Ga-68-labeled somatostatin receptor analogs already have a significant role in the diagnosis, staging, and therapy management of neuroendocrine neoplasms and neural crest tumors. Herein, we report a case presenting a variety of malignancies in VHL and showing the usefulness of Ga-68 somatostatin receptor PET/CT as a one-stop-shop imaging modality in the management of VHL disease

  17. The potential value of somatostatin receptor scintigraphy in medullary thyroid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Doerr, U.; Bihl, H. (Katharinenhospital, Stuttgart (Germany). Dept. of Nuclear Medicine); Frank-Raue, K.; Raue, F. (Heidelberg Univ. (Germany). Dept. of Internal Medicine); Sautter-Bihl, M.L.; Buhr, H.J. (Staedt. Klinikum, Karlsruhe (Germany). Dept. of Radiooncology and Nuclear Medicine); Guzman, G. (Katherinenhospital, Stuttgart (Germany). Dept. of Nuclear Medicine Inst. de Neurocirugia, Investigationes Cerebrales ' Dr Asenjo' Santiago (Chile). Dept. de Medicina Nuclear)

    1993-06-01

    In a prospective study, ten patients with recurrent medullary thyroid carcinoma (markedly elevated calcitonin levels) were investigated by means of somatostatin receptor scintigraphy (SRS) with [sup 111]In-pentetreotide. Scintigraphically, 30 sites of pathological uptake were found, mostly located in the neck and upper mediastinum. So far, 18 suspected tumour sites underwent histological examination and 14 of them could be verified as metastases of medullary thyroid carcinoma (MTC). The remaining four putative tumour lesions turned out to be false positive scintigraphic findings caused by chronic inflammation and somatostatin receptor positive tumours other than MTC. We conclude that SRS is a promising imaging modality for localization of MTC recurrence and may thus make a contribution to better management of this patient group. (Author).

  18. Somatostatin receptor scintigraphy - a case report and review of the literature

    International Nuclear Information System (INIS)

    Yamaga, Lilian Yuri Itaya; Belfer, Aron J.; Segal, Amisa

    1997-01-01

    The authors report a case of carcinoid tumor, diagnosed in a 75-year-old male patient, confirmed by laparotomy and anatomo-pathological study. The patient was examined by somatostatin receptor scintigraphy with In-pentetreotide, and correlation was performed with I-MIBG and CT scan. A review of current literature about this new tracer for detection of carcinoid tumor is presented. (author)

  19. Molecular imaging of neuroendocrine tumors using 68Ga-labeled peptides (Somatostatin receptor PET/CT)

    International Nuclear Information System (INIS)

    Baum, R.P.; Prasad, V.; Hoersch, D.

    2009-01-01

    Receptor PET/CT using 68 Ga-labeled somatostatin analogues (DOTA-NOC, DOTA-TOC or DOTA-TATE) enables the highly sensitive molecular imaging of neuroendocrine tumors (NETs) based on the expression of somatostatin receptors and even the detection of receptor subtypes. Our experience after more than 3000 studies shows that receptor PET/CT has a significantly higher tumor detection rate than conventional scintigraphy (even in SPECT/CT technique), and that tumor lesions can be very accurately localized. By calculating standardized uptake values (SUV) - which are reproducible and investigator-independent - patients can be selected for peptide receptor radiotherapy and also the course after therapy can be controlled. Receptor-PET/CT is the most sensitive imaging modality for the detection of unknown primary tumors (CUP syndrome), which is especially true for the detection of neuroendocrine tumors of the pancreas and small bowel; whole-body staging (''one stop shop'') as well as restaging and selection of patients for peptide receptor radiotherapy can be performed using a patient-friendly procedure (examination finished within one hour) exposing the patient to less radiation than whole-body CT scanning. The 68 Ge/ 68 Ga generator has proved very reliable over the years - even in a hospital environment. The effective costs for 68 Ga labeled somatostatin analogues might be less than for scintigraphic agents, provided a certain number of studies per year are performed. The development of new tumor-specific peptides as well as of other DOTA- or NOTA-coupled radiopharmaceuticals opens a new avenue into the future: finally, the 68 Ga generator could play a similar important role for PET/CT as did the 99m Tc-Generator for conventional gamma camera imaging over the last decades. (orig.)

  20. Somatostatin Receptor Scintigraphy (SRS) with 99m-Tc HYNIC-TOC

    International Nuclear Information System (INIS)

    Zarlenga, A.C.; Parma, P.; Arashiro, J.; Castiglia, S.; Obenaus, E.

    2002-01-01

    Background: This compound is a synthetic analogue of somatostatin by conjugating the Hydrazinocotinamide (Hynic) to Tyr 3 -Octreotide (Toc) radiolabeling via quelation with 99m Tc. Purpose: We have analyzed the feasibility in detecting neuroendocrine tumors (NET) by somatostatin receptor with 99m Tc Hynic-Toc. Methods: After comparative studies between 99m Tc Hynic-Toc and 111 In (pentetreotide) with excellent correlation, we have performed 48 scintigrams with 99m Tc Hynic-Toc. 35 patients with suspicions of NET were included (19 women, 16 men. Age range 22-75 y). We have performed planar images at 1,2,24 hs and tomographic images at 150 min after intravenous injection of 740 MBq 99m Tc Hynic-Toc. We compare the results with other diagnosis modalities and /or the histopathological findings after biopsy or surgery. Results: True Positive:17; True Negative:11; False Positive: 4; False Negative:3. Specificity=73.3%; Sensitivity=85%; Accuracy=80%; Not adverse effects were observed. Conclusions: 99m Tc Hynic-Toc is not limited availability of the isotope. It is a suitable radiopharmaceutical for in vivo evaluation to define tumor receptor status, staging, and for identification of patients who may benefit from therapy with somatostatin. The tumor uptake at 24 hs allows a better visualization of abdominal tumor sites. Tc Hynic-Toc is an alternative to 111 In-pentetreotide for imaging somatostatin receptor positive tumors. The study was offered to patients whom the scintigraphy with 111 In-pentetreotide offers a diagnosis alternative with high specificity and accessible cost

  1. Diagnostic value of somatostatin receptor scintigraphy in patients with intracranial tumours. Diagnostische Wertigkeit der Somatostatin-Rezeptor-Szintigraphie bei Patienten mit intrakraniellen Raumforderungen

    Energy Technology Data Exchange (ETDEWEB)

    Luyken, C. (Klinik fuer Neurochirurgie, Koeln Univ. (Germany)); Hildebrandt, G. (Klinik fuer Neurochirurgie, Koeln Univ. (Germany)); Scheidhauer, K. (Klinik fuer Nuklearmedizin, Koeln Univ. (Germany)); Kirsch, B. (Anatomisches Inst., Kiel Univ. (Germany))

    1993-12-01

    The aim of the study was to detect the SR binding sites in intracranial tumours and to evaluate the benefit of SRS in pre- and postoperative diagnostics. 86 patients with 94 intracranial tumours (39 meningiomas, 18 pituitary adenomas, 11 gliomas grade 3 or 4, 8 gliomas grade 2, 5 neurinomas, 5 intracranial metastases, 4 tumours of the orbit, 2 neurofibromas, 1 brain abscess and 1 cystic lesion) were examined. [sup 111]In-octreotide was injected i.v. as 10 [mu]g or 20 [mu]g bolus, corresponding to 110 or 220 MBq (3 or 6 mCi). Gamma-camera images and SPECT were obtained 3-6 h and 24 h post injection. The scintigraphic evaluation was performed without knowledge of CT and MRI results. The histological classification corresponded to the WHO grading system. Somatostatin binding sites were detected in vito using somatostatin-gold conjugates. All patients with meningiomas showed a high focal tracer uptake corresponding to SR binding sites in vitro, whereas only in 50% of the pituitary adenomas SRS was positive. Neurinomas did not show any tracer uptake. In patients with gliomas with disturbed blood-brain-barrier positive tracer uptake was detected, while none of the gliomas with intact blood-brain-barrier could be visualized by SRS but showed somatostatin binding sites in vitro. In intracranial metastases a local tracer uptake was detected in vivo. In vitro 3 of 4 cases showed somatostatin binding sites. In 2 cases extracranial tracer uptake showed the primary tumour and metastases of the lymphnodes. Somatostatin receptor scintigraphy can help to detect or to exclude meningiomas especially in the cerebellopontine angle or in the orbit. In intracranial metastases SRS may point to the primary tumour or other metastases. In all other intracranial tumours receptor scintigraphy provides no clinical relevant information. (orig./MG)

  2. 99mTc-EDDA/HYNIC-TOC somatostatin receptor scintigraphy in daily clinical practice.

    Science.gov (United States)

    Chrapko, Beata Ewa; Nocuń, Anna; Gołebiewska, Renata; Stefaniak, Bogusław; Korobowicz, Elzbieta; Czekajska-Chehab, Elzbieta; Sawicki, Marek; Polkowski, Wojciech Piotr

    2010-04-01

    This study aimed to assess the impact of 99mTc-EDDA/HYNIC-TOC (99mTc-TOC) somatostatin receptor scintigraphy (SRS) in clinical practice. One hundred seventeen patients were divided into 6 groups: 1, initial detection and localization of suspected neuroendocrine tumor (NET); 2, tumor staging before therapy; 3, staging of NET of unknown origin, 4, restaging after surgery of primary tumor; 5, diagnosis of solitary pulmonary nodules (SPNs), and 6, follow-up after "cold" somatostatin analogues treatment. In group 1, clinical suspicions were not confirmed in any of the patients; in group 2, most of the primary lesions showed overexpression of somatostatin receptors (SSRT); in group 3, the primary tumor was not identified in any of the patients; in group 4, recurrences were depicted in 7 out of 47 patients; in group 5, only 1 malignant SPN was detected, and in group 6, regression of primary mass and metastases were seen on follow-up SRS in 1 patient. 99mTc-TOC SRS is useful in staging of SSRT-overexpressing tumors of known and unknown primary origin, as well as in restaging after primary tumor surgery. This method is less effective in detecting suspected NET and assessing SPNs. Further investigation is necessary to evaluate the usefulness of SRS in monitoring patients after biological treatment.

  3. Honey Bee Allatostatins Target Galanin/Somatostatin-Like Receptors and Modulate Learning: A Conserved Function?

    Directory of Open Access Journals (Sweden)

    Elodie Urlacher

    Full Text Available Sequencing of the honeybee genome revealed many neuropeptides and putative neuropeptide receptors, yet functional characterization of these peptidic systems is scarce. In this study, we focus on allatostatins, which were first identified as inhibitors of juvenile hormone synthesis, but whose role in the adult honey bee (Apis mellifera brain remains to be determined. We characterize the bee allatostatin system, represented by two families: allatostatin A (Apime-ASTA and its receptor (Apime-ASTA-R; and C-type allatostatins (Apime-ASTC and Apime-ASTCC and their common receptor (Apime-ASTC-R. Apime-ASTA-R and Apime-ASTC-R are the receptors in bees most closely related to vertebrate galanin and somatostatin receptors, respectively. We examine the functional properties of the two honeybee receptors and show that they are transcriptionally expressed in the adult brain, including in brain centers known to be important for learning and memory processes. Thus we investigated the effects of exogenously applied allatostatins on appetitive olfactory learning in the bee. Our results show that allatostatins modulate learning in this insect, and provide important insights into the evolution of somatostatin/allatostatin signaling.

  4. Activation of somatostatin 2 receptors in the brain and the periphery induces opposite changes in circulating ghrelin levels: functional implications

    Directory of Open Access Journals (Sweden)

    Andreas eStengel

    2013-01-01

    Full Text Available Somatostatin is an important modulator of neurotransmission in the central nervous system and acts as a potent inhibitor of hormone and exocrine secretion and regulator of cell proliferation in the periphery. These pleiotropic actions occur through interaction with five G-protein coupled somatostatin receptor subtypes (sst1-5 that are widely expressed in the brain and peripheral organs. The characterization of somatostatin’s effects can be investigated by pharmacological or genetic approaches using newly developed selective sst agonists and antagonists and mice lacking specific sst subtypes. Recent evidence points towards a divergent action of somatostatin in the brain and in the periphery to regulate circulating levels of ghrelin, an orexigenic hormone produced by the endocrine X/A-like cells in the gastric mucosa. Somatostatin interacts with the sst2 in the brain to induce an increase in basal ghrelin plasma levels and counteracts the visceral stress-related decrease in circulating ghrelin in rats. By contrast, stimulation of peripheral somatostatin-sst2 signaling results in the inhibition of basal ghrelin release and mediates the postoperative decrease in circulating ghrelin in rats. The peripheral sst2-mediated reduction of plasma ghrelin is likely to involve a paracrine action of D-cell derived somatostatin acting on sst2 bearing X/A-like ghrelin cells in the gastric mucosa. The other member of the somatostatin family, named cortistatin, in addition to binding to sst1-5 also directly interacts with the ghrelin receptor and therefore may simultaneously modulate ghrelin release and actions at target sites bearing ghrelin receptors representing a link between the ghrelin and somatostatin systems.

  5. Somatostatin receptor gene therapy combined with targeted therapy with radiolabeled octreotide: a new treatment for liver metastases.

    NARCIS (Netherlands)

    A. Mearadji (Amir); W.A.P. Breeman (Wouter); L.J. Hofland (Leo); R.L. Marquet (Richard); J. Jeekel (Hans); E.P. Krenning (Eric); C.H.J. van Eijck (Casper); P.M. van Koetsveld (Peter)

    2002-01-01

    textabstractOBJECTIVE: To evaluate the effect of peptide receptor radionuclide therapy (PRRT) on somatostatin receptor (SSR)-transfected colon carcinoma cells in a rat liver metastases model.SUMMARY BACKGROUND DATA: Previously the authors have shown highly effective therapy with

  6. DOTA-derivatives of octreotide dicarba-analogues with high affinity for somatostatin sst2,5 receptors

    Science.gov (United States)

    Pratesi, Alessandro; Ginanneschi, Mauro; Lumini, Marco; Papini, Anna M.; Novellino, Ettore; Brancaccio, Diego; Carotenuto, Alfonso

    2017-02-01

    In vivo somatostatin receptor scintigraphy is a valuable method for the visualization of human endocrine tumours and their metastases. In fact, peptide ligands of somatostatin receptors (sst’s) conjugated with chelating agents are in clinical use. We have recently developed octreotide dicarba-analogues, which show interesting binding profiles at sst’s. In this context, it was mandatory to explore the possibility that our analogues could maintain their activity also upon conjugation with DOTA. In this paper, we report and discuss the synthesis, binding affinity and conformational preferences of three DOTA-conjugated dicarba-analogues of octreotide. Interestingly, two conjugated analogues exhibited nanomolar affinities on sst2 and sst5 somatostatin receptor subtypes.

  7. Development and preclinical evaluation of radiolabelled somatostatin receptor agonists and αvβ3-integrin antagonists

    International Nuclear Information System (INIS)

    Stoecklin, G.; Wester, H.J.; Haubner, R.; Schottelius, M.

    2002-01-01

    Tumours express specific receptors for peptide ligands. This can be exploited for tumour targeting. New bioactive peptides are available, in particular new somatostatin analogs and RGD-Peptides for targeting the α V β 3 -integrin. The design and optimization of radiolabelled peptides with respect to their receptor affinity, tumour uptake, biodistribution, pharmacokinetics and stability may provide better tracers for tumour imaging and therapy. Based on two basic structures, new radioiodinated and carbohydrated somatostatin analogs and cyclic RGD-peptides were developed and evaluated. (author)

  8. Correlation of Somatostatin Receptor-2 Expression with Gallium-68-DOTA-TATE Uptake in Neuroblastoma Xenograft Models

    OpenAIRE

    Zhang, Libo; Vines, Douglass C.; Scollard, Deborah A.; McKee, Trevor; Komal, Teesha; Ganguly, Milan; Do, Trevor; Wu, Bing; Alexander, Natasha; Vali, Reza; Shammas, Amer; Besanger, Travis; Baruchel, Sylvain

    2017-01-01

    Peptide-receptor imaging and therapy with radiolabeled somatostatin analogs such as 68Ga-DOTA-TATE and 177Lu-DOTA-TATE have become an effective treatment option for SSTR-positive neuroendocrine tumors. The purpose of this study was to evaluate the correlation of somatostatin receptor-2 (SSTR2) expression with 68Ga-DOTA-TATE uptake and 177Lu-DOTA-TATE therapy in neuroblastoma (NB) xenograft models. We demonstrated variable SSTR2 expression profiles in eight NB cell lines. From micro-PET imagin...

  9. Somatostatin receptor scintigraphy in sarcoidosis: relation to selected clinical and laboratory markers.

    Science.gov (United States)

    Piotrowski, Wojciech J; Bieńkiewicz, Małgorzata; Frieske, Izabella; Marczak, Jerzy; Antczak, Adam; Górski, Paweł; Kuśmierek, Jacek; Płachcińska, Anna

    2012-01-01

    Discriminating between active and inactive sarcoidosis may be problematic in everyday clinical practice. There are numerous biochemical markers used in the diagnosis and monitoring of sarcoidosis. Somatostatin receptor (SR) scintigraphy with the use of 99mTc-octreotide may be used to estimate disease activity. The aim of the paper was to assess the value of traditional biomarkers (serum angiotensin-converting enzyme [SACE], C-reactive protein, markers of calcium metabolism, bronchoalveolar lavage fluid [BALF] lymphocytes) and a novel biomarker, 8-isoprostane (8-IP) in exhaled breath condensate (EBC), in the assessment of sarcoidosis activity in relation to somatostatin receptor scintigraphy. The study included 32 patients with sarcoidosis. Scintigraphy was performed using somatostatin analogue, 99mTc-HYNIC-TOC; planar and SPECT/CT images were recorded. The study group was divided into a subgroup with positive radiotracer uptake (n = 20) and without a visible uptake (n = 12). 8-IP levels were measured in EBC by an immunoenzymatic assay. RESULTS We observed a significantly higher EBC 8-IP levels in the subgroup with positive uptake compared with those with negative uptake (19.1 ± 19.8 vs. 5.4 ± 3.5 pg/ml, P = 0.02). The levels of SACE and the percentage of BALF lymphocytes were also nonsignificantly elevated. In the group of patients with positive scintigraphy results, a positive correlation was observed between the uptake ratio and SACE (r = 0.44, P = 0.041). The results indicate low value of biochemical markers in the assessment of disease activity. SR scintigraphy may have practical usefulness in the monitoring of sarcoidosis.

  10. Somatostatin receptor 2 knockout/lacZ knockin mice show impaired motor coordination and reveal sites of somatostatin action within the striatum.

    Science.gov (United States)

    Allen, Jeremy P; Hathway, Gareth J; Clarke, Neil J; Jowett, Mike I; Topps, Stephanie; Kendrick, Keith M; Humphrey, Patrick P A; Wilkinson, Lawrence S; Emson, Piers C

    2003-05-01

    The peptide somatostatin can modulate the functional output of the basal ganglia. The exact sites and mechanisms of this action, however, are poorly understood, and the physiological context in which somatostatin acts is unknown. Somatostatin acts as a neuromodulator via a family of five 7-transmembrane G protein-coupled receptors, SSTR1-5, one of which, SSTR2, is known to be functional in the striatum. We have investigated the role of SSTR2 in basal ganglia function using mice in which Sstr2 has been inactivated and replaced by the lacZ reporter gene. Analysis of Sstr2lacZ expression in the brain by beta-galactosidase histochemistry demonstrated a widespread pattern of expression. By comparison to previously published in situ hybridization and immunohistochemical data, Sstr2lacZ expression was shown to accurately recapitulate that of Sstr2 and thus provided a highly sensitive model to investigate cell-type-specific expression of Sstr2. In the striatum, Sstr2 expression was identified in medium spiny projection neurons restricted to the matrix compartment and in cholinergic interneurons. Sstr2 expression was not detected in any other nuclei of the basal ganglia except for a sparse number of nondopaminergic neurons in the substantia nigra. Microdialysis in the striatum showed Sstr2-null mice were selectively refractory to somatostatin-induced dopamine and glutamate release. In behavioural tests, Sstr2-null mice showed normal levels of locomotor activity and normal coordination in undemanding tasks. However, in beam-walking, a test of fine motor control, Sstr2-null mice were severely impaired. Together these data implicate an important neuromodulatory role for SSTR2 in the striatum.

  11. Synthesis of a Fluorescently Labeled 68Ga-DOTA-TOC Analog for Somatostatin Receptor Targeting.

    Science.gov (United States)

    Ghosh, Sukhen C; Hernandez Vargas, Servando; Rodriguez, Melissa; Kossatz, Susanne; Voss, Julie; Carmon, Kendra S; Reiner, Thomas; Schonbrunn, Agnes; Azhdarinia, Ali

    2017-07-13

    Fluorescently labeled imaging agents can identify surgical margins in real-time to help achieve complete resections and minimize the likelihood of local recurrence. However, photon attenuation limits fluorescence-based imaging to superficial lesions or lesions that are a few millimeters beneath the tissue surface. Contrast agents that are dual-labeled with a radionuclide and fluorescent dye can overcome this limitation and combine quantitative, whole-body nuclear imaging with intraoperative fluorescence imaging. Using a multimodality chelation (MMC) scaffold, IRDye 800CW was conjugated to the clinically used somatostatin analog, 68 Ga-DOTA-TOC, to produce the dual-labeled analog, 68 Ga-MMC(IRDye 800CW)-TOC, with high yield and specific activity. In vitro pharmacological assays demonstrated retention of receptor-targeting properties for the dual-labeled compound with robust internalization that was somatostatin receptor (SSTR) 2-mediated. Biodistribution studies in mice identified the kidneys as the primary excretion route for 68 Ga-MMC(IRDye 800CW)-TOC, along with clearance via the reticuloendothelial system. Higher uptake was observed in most tissues compared to 68 Ga-DOTA-TOC but decreased as a function of time. The combination of excellent specificity for SSTR2-expressing cells and suitable biodistribution indicate potential application of 68 Ga-MMC(IRDye 800CW)-TOC for intraoperative detection of SSTR2-expressing tumors.

  12. δ-opioid receptor and somatostatin receptor-4 heterodimerization: possible implications in modulation of pain associated signaling.

    Directory of Open Access Journals (Sweden)

    Rishi K Somvanshi

    Full Text Available Pain relief is the principal action of opioids. Somatostatin (SST, a growth hormone inhibitory peptide is also known to alleviate pain even in cases when opioids fail. Recent studies have shown that mice are prone to sustained pain and devoid of analgesic effect in the absence of somatostatin receptor 4 (SSTR4. In the present study, using brain slices, cultured neurons and HEK-293 cells, we showed that SSTR4 and δ-Opioid receptor (δOR exist in a heteromeric complex and function in synergistic manner. SSTR4 and δOR co-expressed in cortical/striatal brain regions and spinal cord. Using cultured neuronal cells, we describe the heterogeneous complex formation of SSTR4 and δOR at neuronal cell body and processes. Cotransfected cells display inhibition of cAMP/PKA and co-activation of SSTR4 and δOR oppose receptor trafficking induced by individual receptor activation. Furthermore, downstream signaling pathways either associated with withdrawal or pain relief are modulated synergistically with a predominant role of SSTR4. Inhibition of cAMP/PKA and activation of ERK1/2 are the possible cellular adaptations to prevent withdrawal induced by chronic morphine use. Our results reveal direct intra-membrane interaction between SSTR4 and δOR and provide insights for the molecular mechanism for the anti-nociceptive property of SST in combination with opioids as a potential therapeutic approach to avoid undesirable withdrawal symptoms.

  13. Synthesis and evaluation of ligand targeting the somatostatin receptor for drug delivery to tumor cell

    Energy Technology Data Exchange (ETDEWEB)

    Lee, So Young; Hong, Young Don; Jung, Sung Hee; Choi, Sun Ju [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    Most of targeted therapies block the action of certain enzymes, proteins, or other molecules involved in the growth and spread of cancer cells to produce its cytotoxic effect. Either small molecule drugs or monoclonal antibodies are mostly used in targeted therapies. Unfortunately, targeted therapy has a certain degree of unwanted side effect like other cytotoxicity inducing chemotherapies. To overcome and to reduce unwanted side effects during a cancer therapy, recently radiopeptide therapies has got the worlds' attraction for the tumor targeting modalities due to its beneficial effect on less side effect compared to cytotoxic chemotherapies. Among radiopeptide therapies, {sup 177}Lu-DOTATATE is a major modality as an effective one invented so far in treating neuroendocrine tumor (NET) and it has been in clinical trials at least one decade. Although it does have rather effective therapeutic effect on NET, it has less effective in rather large solid tumor. There are many ways to improve or increase therapeutic effect of radiopeptide are a finding the potent small molecules to target the tumor site selectively, or a labeling with radioisotope of emitting high energy, or an improving its biological half-life by introducing different moieties to increase lipophilicity. Present study was focus to increase a biological halflife of radio somatostatin which will target the somatostatin receptor by altering the bifunctional chelator (BFCA) by introducing lipophilic moiety to the somatostatin, which would make the labeled peptide stay longer in the tumor site and thus it can intensify the therapeutic effect on tumor cell itself and around tissues.

  14. Novel, potent, and radio-iodinatable somatostatin receptor 1 (sst1) selective analogues.

    Science.gov (United States)

    Erchegyi, Judit; Cescato, Renzo; Grace, Christy Rani R; Waser, Beatrice; Piccand, Véronique; Hoyer, Daniel; Riek, Roland; Rivier, Jean E; Reubi, Jean Claude

    2009-05-14

    The proposed sst(1) pharmacophore (J. Med. Chem. 2005, 48, 523-533) derived from the NMR structures of a family of mono- and dicyclic undecamers was used to design octa-, hepta-, and hexamers with high affinity and selectivity for the somatostatin sst(1) receptor. These compounds were tested for their in vitro binding properties to all five somatostatin (SRIF) receptors using receptor autoradiography; those with high SRIF receptor subtype 1 (sst(1)) affinity and selectivity were shown to be agonists when tested functionally in a luciferase reporter gene assay. Des-AA(1,4-6,10,12,13)-[DTyr(2),DAgl(NMe,2naphthoyl)(8),IAmp(9)]-SRIF-Thr-NH(2) (25) was radio-iodinated ((125)I-25) and specifically labeled sst(1)-expressing cells and tissues. 3D NMR structures were calculated for des-AA(1,4-6,10,12,13)-[DPhe(2),DTrp(8),IAmp(9)]-SRIF-Thr-NH(2) (16), des-AA(1,2,4-6,10,12,13)-[DAgl(NMe,2naphthoyl)(8),IAmp(9)]-SRIF-Thr-NH(2) (23), and des-AA(1,2,4-6,10,12,13)-[DAgl(NMe,2naphthoyl)(8),IAmp(9),Tyr(11)]-SRIF-NH(2) (27) in DMSO. Though the analogues have the sst(1) pharmacophore residues at the previously determined distances from each other, the positioning of the aromatic residues in 16, 23, and 27 is different from that described earlier, suggesting an induced fit mechanism for sst(1) binding of these novel, less constrained sst(1)-selective family members.

  15. Somatostatin receptor scintigraphy in advanced renal cell carcinoma. Results of a phase II-trial of somatostatine analogue therapy in patients with advanced RCC

    International Nuclear Information System (INIS)

    Freudenberg, L.S.; Goerges, R.; Stergar, H.; Bockisch, A.; Gauler, T.; Bauer, S.; Antoch, G.; Schuette, J.

    2008-01-01

    Aims: objective of this prospective study was to evaluate the role of somatostatin receptor scintigraphy (SRS) in advanced renal cell carcinoma (RCC) with respect to potential therapy with somatostatin analogue (SST-A) and to assess the response rate under therapy with SST-A. Patients, methods: 16 patients with documented progression of histologically confirmed advanced RCC were included. Planar whole-body SRS was performed 4, 24 and 48h post i.v. injection of 175-200 MBq 111 In-pentetreoide. 5 and 25 h p.i. SPECT of thorax and abdomen were performed. Documentation of somatostatin receptor expression via SRS in > 50% of known tumour lesions was the criteria for treatment start with SST-A (Sandostatin LAR registered -Depot 30mg i.m. every four weeks). Results: in 9/16 of the patients SRS showed at least one metastasis with moderate (n = 5) or intense (n = 4) tracer uptake. Lesion-based SRS evaluation showed only 12.1% (20/165) of all metastases. Most false-negative lesions were located in the lungs. In too patients, the majority of the known metastases was SRS positive and these patients received SST-A therapy. The first radiographic evaluation after a two-month interval showed progressive disease in both patients. Conclusions: we conclude that SRS is of limited value in staging of advanced RCC. In our patients SST-A did not result in a growth control of RCC. Consequently, the use of SST-A in advanced RCC seems to be no relevant therapeutic option. (orig.)

  16. Molecular imaging with 68Ga-SSTR PET/CT and correlation to immunohistochemistry of somatostatin receptors in neuroendocrine tumours

    International Nuclear Information System (INIS)

    Kaemmerer, Daniel; Haugvik, Sven-Petter; Hommann, Merten; Peter, Luisa; Lupp, Amelie; Schulz, Stefan; Saenger, Joerg; Prasad, Vikas; Kulkarni, Harshad; Baum, Richard Paul

    2011-01-01

    Somatostatin receptors (SSTR) are known for an overexpression in gastroenteropancreatic neuroendocrine tumours (GEP-NET). The aim of the present study was to find out if the receptor density predicted by the semi-quantitative parameters generated from the static positron emission tomography (PET/CT) correlated with the in vitro immunohistochemistry using a novel rabbit monoclonal anti-SSTR2A antibody (clone UMB-1) for specific SSTR2A immunohistochemistry and polyclonal antibodies for SSTR1 and 3-5. Overall 14 surgical specimens generated from 34 histologically documented GEP-NET patients were correlated with the preoperative 68 Ga-DOTA-NOC PET/CT. Quantitative assessment of the receptor density was done using the immunoreactive score (IRS) of Remmele and Stegner; the additional 4-point IRS classification for immunohistochemistry and standardized uptake values (SUV max and SUV mean ) were used for PET/CT. The IRS for SSTR2A and SSTR5 correlated highly significant with the SUV max on the PET/CT (p mean (p max on the 68 Ga-DOTA-NOC PET/CT scans is concordant with the affinity profile of 68 Ga-DOTA-NOC to the SSTR subtypes and demonstrates the excellent qualification of somatostatin analogues in the diagnostics of NET. This study correlating somatostatin receptor imaging using 68 Ga-DOTA-NOC PET/CT with immunohistochemically analysed SSTR also underlines the approval of therapy using somatostatin analogues, follow-up imaging as well as radionuclide therapy. (orig.)

  17. Studies on mRNA expression of the somatostatin receptor family in lung cancer

    International Nuclear Information System (INIS)

    Wang Jing; Deng Jinglan; Wu Shengxi; Qiao Hongqing

    2000-01-01

    Objective: To investigate the characteristics of expression and distribution of 5 subtypes of somatostatin receptors (SSTR1∼5) in lung cancer. Methods: With [α- 35 S]dATP labelled oligonucleotides of the 5 SSTR subtypes as probes, using in situ hybridization, patterns of mRNA expression were detected in lung cancer tissue sections of 21 cases which fell in varied pathologic types. Additionally, Leica Q-500 image analyzing device was employed to semi-quantitatively analyze density of the expression. Results: Patterns of SSTR1∼5 expression in lung cancer were as follows: SSTR2 expression was dominant in small cell lung cancer (SCLC) while in non-small cell lung cancer (NSCLC) such as adenous and squamous, SSTR1 expression was stronger than that of the other 4 subtypes, In density of SSTR1∼5 expression in lung cancer, NSCLC was higher than SCLC (P<0.01). Conclusions: even though patterns and density of expression of SSTR subtypes in the lung cancer showed heterogeneity in different histopathologic types, as in SCLC and in NSCLC. Therefore, it has positive prospects for somatostatin analog-oriented agents to be used in treatment of both types of the lung cancers

  18. Expression of the somatostatin receptor family mRNAs in lung cancer

    International Nuclear Information System (INIS)

    Wang Jing; Wang Liangang; Deng Jinglan; Wu Shengxi

    2000-01-01

    To investigate the characteristics of expression and distribution of 5 subtypes of somatostatin receptors (SSTR1-5) in lung cancer, in situ hybridization was used to examine the expression patterns of SSTR mRNAs in 21 cases of different pathologic types of lung cancer tissues with [α- 35 S]dATP labelled oligonucleotides of the 5 SSTR subtypes as probes. Additionally, Leica Q-500 image analysis processing system was employed for the semi-quantitatively analysis of the hybridization signals. Patterns of SSTR1-5 expression in lung cancer tissues were found as follows. SSTR2 was prominent in small cell lung cancer (SCLC), whereas in non-small cell lung cancer (NSCLC) including the adenous cancer (Ad) and the squamous cancer (Sq), the expression of SSTR1 mRNA was stronger than that of the other 4 types. the expression density of SSTR1-5 in the NSCLC was higher that the SCLC (p < 0.01). The expression patterns and densities of the SSTR subtypes showed heterogeneity in different pathologic types of lung cancer. The expressions of the SSTR mRNAs in both SCLC and NSCLC indicated the positive prospects for somatostatin analog (SSA)-oriented agents in the treatment of both types of the lung cancer

  19. Analysis of transmission of novel polymorphisms in the somatostatin receptor 5 (SSTR5) gene in patients with autism

    DEFF Research Database (Denmark)

    Lauritsen, Marlene B; Nyegaard, Mette; Betancur, Catalina

    2003-01-01

    growth hormone response has been reported in some individuals with autism. Moreover, the somatostatinergic system interacts with the dopaminergic system, which has been hypothesized to be involved in the etiology of autism; in particular, somatostatin secretion is regulated by dopamine, and the dopamine......Infantile autism is a pervasive developmental disorder with a strong genetic component. The mode of inheritance appears to be complex and no specific susceptibility genes have yet been identified. Chromosome 16p13.3 may contain a susceptibility gene based on findings from genome scans and reports...... of chromosome abnormalities in individuals with autism. The somatostatin receptor 5 (SSTR5) gene is located on chromosome 16p13.3 and is thus a positional candidate gene for autism. SSTR5 may also be a functional candidate gene for autism because somatostatin inhibits growth hormone secretion, and increased...

  20. Detecting somatostatin receptor in breast tumor tissue and its clinical significance

    International Nuclear Information System (INIS)

    Zhang Yongjian; Yu Xian; Lin Wei; Ding Xuan; Huang Shizhang; Lu Guangming

    2002-01-01

    The authors observe the difference of somatostatin receptor (SSR) between benign and malignant breast tumor and the relation between SSR and estrogen receptor (ER) or progesterone receptor (PR) in breast tumor tissue, and to predict the clinical value of detecting breast tumor by SSR receptor imaging. These tissues excised from operation in breast tumor were divided into 4 groups: breast malignant tumor group (BMTG) and its control group (C1G), breast benign tumor group (BBTG) and its control group (C2G). SSR was detected by radioligand binding assay (RBA) and ER, PR by LsAB method in these groups. Results is: (1) The SSR express quantity is 108.6 +- 67.3 fmol/mg pr, 37.2 +- 9.6 fmol/mg pr, 43.4 +- 12.6 fmol/mg pr 33.9 +- 10.2 fmol/mg pr respectively in BMTG, C1G, BBTG, C2G. The SSR of BMTG is the most among these groups, the difference is obvious, P 0.05); (2) The correlation coefficient of SSR and ER is 0.859, SSR and PR is 0.750. Most breast tumor tissues express high density SSR, the authors suppose that malignant tumor can been distinguished from benign tumor preliminarily by SSR receptor imaging. There is a good correlation between SSR and ER, PR, detecting SSR may predict the quality of tumor and the prognosis of the patient

  1. Pertussis toxin modifies the characteristics of both the inhibitory GTP binding proteins and the somatostatin receptor in anterior pituitary tumor cells

    International Nuclear Information System (INIS)

    Mahy, N.; Woolkalis, M.; Thermos, K.; Carlson, K.; Manning, D.; Reisine, T.

    1988-01-01

    The effects of pertussis toxin treatment on the characteristics of somatostatin receptors in the anterior pituitary tumor cell line AtT-20 were examined. Pertussis toxin selectively catalyzed the ADP ribosylation of the alpha subunits of the inhibitory GTP binding proteins in AtT-20 cells. Toxin treatment abolished somatostatin inhibition of forskolin-stimulated adenylyl cyclase activity and somatostatin stimulation of GTPase activity. To examine the effects of pertussis toxin treatment on the characteristics of the somatostatin receptor, the receptor was labeled by the somatostatin analog [125I]CGP 23996. [125I]CGP 23996 binding to AtT-20 cell membranes was saturable and within a limited concentration range was to a single high affinity site. Pertussis toxin treatment reduced the apparent density of the high affinity [125I]CGP 23996 binding sites in AtT-20 cell membranes. Inhibition of [125I]CGP 23996 binding by a wide concentration range of CGP 23996 revealed the presence of two binding sites. GTP predominantly reduced the level of high affinity sites in control membranes. Pertussis toxin treatment also diminished the amount of high affinity sites. GTP did not affect [125I]CGP 23996 binding in the pertussis toxin-treated membranes. The high affinity somatostatin receptors were covalently labeled with [125I] CGP 23996 and the photoactivated crosslinking agent n-hydroxysuccinimidyl-4-azidobenzoate. No high affinity somatostatin receptors, covalently bound to [125I]CGP 23996, were detected in the pertussis toxin-treated membranes. These results are most consistent with pertussis toxin uncoupling the inhibitory G proteins from the somatostatin receptor thereby converting the receptor from a mixed population of high and low affinity sites to only low affinity receptors

  2. Immunohistochemical Detection and Localization of Somatostatin Receptor Subtypes in Prostate Tissue from Patients with Bladder Outlet Obstruction

    Directory of Open Access Journals (Sweden)

    Rodolfo Montironi

    2008-01-01

    Full Text Available Background and Aim of the Study: Scant information on the cellular distribution of the five somatostatin receptor (SSTR subtypes in the normal prostate and in neoplasms of the prostate has been reported in very few studies in which techniques, such as in situ hybridization histochemistry, autoradiography, and more recently immunohistochemistry, have been applied. The aim of the study was to examine immunohistochemically the distribution and localization of these 5 subtypes in the various tissue components in normal prostate.

  3. Evaluation of somatostatin and nucleolin receptors for therapeutic delivery in non-small cell lung cancer stem cells applying the somatostatin-analog DOTATATE and the nucleolin-targeting aptamer AS1411.

    Directory of Open Access Journals (Sweden)

    Sif Holmboe

    Full Text Available Cancer stem cells represent the putative tumor-driving subpopulation thought to account for drug resistance, relapse, and metastatic spread of epithelial and other cancer types. Accordingly, cell surface markers for therapeutic delivery to cancer stem cells are subject of intense research. Somatostatin receptor 2 and nucleolin are known to be overexpressed by various cancer types, which have elicited comprehensive efforts to explore their therapeutic utilization. Here, we evaluated somatostatin receptor 2 targeting and nucleolin targeting for therapeutic delivery to cancer stem cells from lung cancer. Nucleolin is expressed highly but not selectively, while somatostatin receptor 2 is expressed selectively but not highly by cancer cells. The non-small cell lung cancer cell lines A549 and H1299, displayed average levels of both surface molecules as judged based on analysis of a larger cell line panel. H1299 compared to A549 cells showed significantly elevated sphere-forming capacity, indicating higher cancer stem cell content, thus qualifying as suitable test system. Nucleolin-targeting 57Co-DOTA-AS1411 aptamer showed efficient internalization by cancer cells and, remarkably, at even higher efficiency by cancer stem cells. In contrast, somatostatin receptor 2 expression levels were not sufficiently high in H1299 cells to confer efficient uptake by either non-cancer stem cells or cancer stem cells. The data provides indication that the nucleolin-targeting AS1411 aptamer might be used for therapeutic delivery to non-small cell lung cancer stem cells.

  4. Morphological Imaging in the Localization of Neuroendocrine Gastroenteropancreatic Tumors Found by Somatostatin Receptor Scintigraphy

    International Nuclear Information System (INIS)

    Saga, T.; Doi, R.; Endo, K.; Shimatsu, A.; Koizumi, K.; Ichikawa, T.; Yamamoto, K.; Noguchi, S.; Ishibashi, M.; Machinami, R.; Nakamura, K.; Sakahara, H.

    2005-01-01

    Purpose: To evaluate the necessity of morphological images (MI) in reading somatostatin receptor scintigraphy (SRS) in patients with suspected neuroendocrine gastroenteropancreatic (GEP) tumors. Material and Methods: A Japanese multicenter clinical trial of SRS was conducted in 40 patients with suspected GEP tumors. Three experienced radiologists interpreted the images in three separate sessions in a blinded manner (1: SRS images alone, 2: MI alone, 3: SRS and MI analyzed simultaneously), and the reading results of each session were compared. In addition, the diagnostic abilities of SRS, MI and SRS alone and simultaneous SRS and MI readings were compared for patients where final diagnosis was obtained. Results: SRS detected more suspected lesions (positive or inconclusive uptake) than morphological images did (51 vs 27 lesions), but included many physiological uptakes detected as positive or inconclusive uptakes. Combined reading of SRS and morphological images helped to correctly recognize these physiological uptakes, and also helped in determining the anatomical localization of the abnormal uptakes. Combined reading of SRS and morphological images gave the highest diagnostic impact. Conclusion: The sensitivity of SRS with regard to GEP is high. However the specificity is very low. Morphologic imaging is necessary for the exclusion of physiological uptake and correct anatomic location of an abnormal tracer uptake. The combined reading of SRS and morphologic imaging studies gives the highest diagnostic impact

  5. Somatostatin receptor scintigraphy to predict the clinical evolution and therapeutic response of thyroid-associated ophthalmopathy

    International Nuclear Information System (INIS)

    Nocaudie, M.; Bailliez, A.; Itti, E.; Marchandise, X.

    1999-01-01

    Management of thyroid-associated ophthalmopathy remains a topic of controversy. Immunosuppressive treatments have to be applied at peak disease activity and before criteria of severity develop. Expression of somatostatin receptors on activated lymphocytes allows scintigraphic imaging with indium-111 pentetreotide. We conducted a prospective study with 17 patients who presented severe ophthalmopathy (11 Graves' disease, four Hashimoto's thyroiditis, two isolated in appearance: Means' syndrome). Each patient underwent hormonal (free T 3 and TSH) and immunological (TBII) assessment, an orbital computed tomography scan or magnetic resonance imaging, a visual functional examination and 111 In-pentetreotide orbital scintigraphy before undergoing treatment by steroids and/or radiotherapy, independently of scintigraphic results. At 4 and 24 h after the intravenous injection of 111 MBq of 111 In-pentetreotide, planar imaging centred on the head and neck (anterior and both lateral views) was carried out. Retrobulbar uptake was assessed by visual semi-quantitative analysis (score given by two independent trained observers) and by quantitative analyses (regions of interest, orbit/brain uptake indices). Patients were ophthalmologically followed up for 6 months and then classified as improved or not. Visual semi-quantitative analysis of 4-h/24-h planar images was correlated with the ophthalmological evolution (χ 2 test, P 111 In-pentetreotide scintigraphy requires further developments, including quantitative single-photon emission tomographic acquisition, if its role as a guide to therapeutic strategy in thyroid-associated ophthalmopathy is to be confirmed. (orig.)

  6. Ectopic ACTH secretion due to a bronchopulmonary carcinoid localized by somatostatin receptor scintigraphy.

    Science.gov (United States)

    Iser, G; Pfohl, M; Dörr, U; Weiss, E M; Seif, F J

    1994-11-01

    We present the case of a 65-year-old woman with an adrenocorticotropic hormone (ACTH) secreting bronchopulmonary carcinoid. This patient showed the typical long history of Cushing's syndrome, including hypokaliemia, impaired glucose tolerance, high levels of ACTH and beta-endorphin, and coproduction of other peptides. At the onset of clinical symptoms in 1979 an adrenal adenoma was suspected, and left-sided adrenalectomy was performed. The symptoms soon recurred, and the diagnosis of ACTH-dependent Cushing's syndrome was made. As no ACTH-secreting tumor was found, the right adrenal was resected, and the patient was followed up regularly. Fourteen years later chest roentgenography and computed tomography revealed a para-aortic pulmonary lesion, which was suspicious for a bronchopulmonary carcinoid. ACTH and beta-endorphin were excessively, pancreatic polypeptide slightly elevated at that time. The final diagnosis was made using somatostatin receptor scintigraphy which confirmed the hormonal activity of the suspicious lesion; no additional focus was found. This method turned out to be not only a useful additional localization technique but also a promising tool for characterization and staging of a suspected ACTH-producing carcinoid. The tumor was resected curatively, and the diagnosis was confirmed histologically.

  7. Somatostatin receptor scintigraphy and magnetic resonance imaging in recurrent medullary thyroid carcinoma: A comparative study

    International Nuclear Information System (INIS)

    Doerr, U.; Wuerstlin, S.; Frank-Raue, K.; Raue, F.; Hehrmann, R.; Iser, G.; Scholz, M.; Guhl, L.; Buhr, H.J.; Bihl, H.

    1993-01-01

    In a prospective study, 18 patients with recurrent medullary thyroid carcinoma (MTC) underwent magnetic resonance imaging (MRI) of the neck and mediastinum and somatostatin receptor scintigraphy (SRS) with 111 In-labeled pentetreotide. In nine patients with macroscopic MTC, 17 corresponding lesions were found on MRI and SRS; in addition, 13 suspicious lesions were seen on SRS only. Histological confirmation was available for 19 metastatic lesions, showing MRI to be true positive in 13 metastases, SRS in 18. In minimal residual disease (n=10), MRI and SRS were compared with the histological findings in three patients and with selective venous catheterization (SVC) in seven patients. Corresponding findings on MRI and SVC were seen in one of seven, whereas SRS and SVC showed concordant localization of tumor recurrence in five of seven. Histological examination demonstrated MTC tissue in one of three cases; MRI and SRS were false positive in one of three cases, while in the others the interpretation remained uncertain. In conclusion, SRS is a promising imaging modality for localization of MTC recurrence. MRI provides better spatial resolution and thus facilitates the planning of surgery for macroscopic metastases. In minimal residual disease, SRS turned out to be superior in detecting occult MTC recurrence, confirming SVC findings. (orig.)

  8. Somatostatin receptor scintigraphy and intraoperative gamma probe detection in the localisation and treatment of pancreatic insulinoma

    International Nuclear Information System (INIS)

    Loh, Nelson K.; Macdonald, William B.; Dunne, Marina L.; Rao, Sudhakar

    2009-01-01

    Full text: Aims: We report a case of insulinoma that was successfully enucleated under radio-guidance after an initial unsuccessful laparotomy. This case highlights the utility of Somatostatin Receptor Scintigraphy (SRS) and gamma probe in the localisation and treatment of neuroendocrine tumours. Methods: The patient presented with recurrent hypoglycaemia. An abdominal CT scan identified a lesion in the uncinate process of the pancreas, however, laparotomy with use of intraoperative ultrasound failed to localise the lesion. SRS with SPECTICT was then requested by the surgical team with a view to radio-guided surgery. Results: SRS demonstrated an octreotide-avid tumour in the posterior uncinate process of the pancreas, and confirmed suitability for radio-guided surgery. At re-exploration, the surgeon was again unable to palpate the lesion or localise it with intraoperative ultrasound, however, the lesion was successfully detected and removed with the use of a gamma probe. A postoperative SRS confirmed complete excision and histopathology was diagnostic of insulinoma. Conclusion: This case highlights the utility of SRS in the intraoperative localisation and surgical excision of neuroendocrine tumours. The lesion was unable to be localised clinically or with intraoperative ultrasound but was successfully detected with scintigraphic techniques. The surgical team acknowledge that the use of a gamma probe enabled enucleation of the insulinoma, which obviated the need for an invasive Whipple's procedure.

  9. Somatostatin receptor expression in Merkel cell carcinoma as target for molecular imaging

    International Nuclear Information System (INIS)

    Buder, Kristina; Becker, Jürgen C; Lapa, Constantin; Kreissl, Michael C; Schirbel, Andreas; Herrmann, Ken; Schnack, Alexander; Bröcker, Eva-Bettina; Goebeler, Matthias; Buck, Andreas K

    2014-01-01

    Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment. To non-invasively assess SSTR expression in MCC using PET and the radiotracers [ 68 Ga]DOTA-D-Phe 1 -Tyr 3 -octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT). SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73% for nodal metastases, 100% for bone, and 67% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13%). SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management

  10. In vivo detection of somatostatin receptors in patients with functionless pituitary adenomas by means of a radioiodinated analog of somatostatin ((123I)SDZ 204-090)

    Energy Technology Data Exchange (ETDEWEB)

    Faglia, G.; Bazzoni, N.; Spada, A.; Arosio, M.; Ambrosi, B.; Spinelli, F.; Sara, R.; Bonino, C.; Lunghi, F. (Institute of Endocrine Sciences, University of Milan, Ospedale Maggiore IRCCS (Italy))

    1991-10-01

    The recent availability of a Tyr3-substituted octreotide (SDZ 204-090) for radioiodination has allowed somatostatin (SRIH) receptor binding to be studied in vivo, and receptor-positive tumors of different origins to be visualized with a gamma-camera. This prompted us to investigate whether this compound could be used for external imaging of functionless pituitary adenomas displaying SRIH receptors. Eight patients with functionless pituitary adenomas, three patients with acromegaly, and three with macroprolactinoma were injected iv with 123I-labeled Tyr3-octreotide and then scanned with a gamma-camera. Positive scans were obtained in the three acromegalics and in two of the eight patients with functionless pituitary tumors. The patients with macroprolactinoma had negative scans. The diagnosis of functionless pituitary adenomas was confirmed by light and electron microscopic examination as well as immunocytochemical studies. In vitro binding of (125I)Tyr11-SRIH to cell membranes was evaluated in four functionless and three GH-secreting adenomas removed from seven of the patients. All of the GH-secreting as well as one of the four functionless adenomas had high affinity SRIH-binding sites, without differences in number or affinity, whereas SRIH-binding sites were not detected in the others. Positive scans were observed only in patients bearing tumors with high affinity SRIH-binding sites. In conclusion, (123I)Tyr3-octreotide appears to be a promising tool for singling out, in vivo, patients with functionless pituitary tumors displaying SRIH receptors who might potentially benefit from octreotide treatment.

  11. Somatostatin receptor 2A expression in choroidal neovascularization secondary to age-related macular degeneration

    NARCIS (Netherlands)

    A.C. Lambooij (Antoinette); R.W.A.M. Kuijpers (Robert); E.G. van Lichtenauer-Kaligis; M. Kliffen (Mike); G.S. Baarsma (Seerp); P.M. van Hagen (Martin); C.M. Mooy (Cornelia)

    2000-01-01

    textabstractPURPOSE: The growth of ocular neovascularization is regulated by a balance between stimulating and inhibiting growth factors. Somatostatin affects angiogenesis by inhibiting the growth hormone-insulin-like growth factor axis and also has a direct

  12. Inverse expression of somatostatin and CXCR4 chemokine receptors in gastroenteropancreatic neuroendocrine neoplasms of different malignancy

    Science.gov (United States)

    Kaemmerer, Daniel; Träger, Tina; Hoffmeister, Maike; Sipos, Bence; Hommann, Merten; Sänger, Järg; Schulz, Stefan; Lupp, Amelie

    2015-01-01

    Introduction Somatostatin receptors (SSTR) are widely distributed in well-differentiated neuroendocrine neoplasms (NEN) and serve as primary targets for diagnostics and treatment. An overexpression of the chemokine receptor CXCR4, in contrast, is considered to be present mainly in highly proliferative and advanced tumors. Comparative data are still lacking, however, for neuroendocrine carcinomas (NEC). Methods SSTR subtype (1, 2A, 3, 5) and CXCR4 expression was evaluated in G1 (n = 31), G2 (n = 47), and low (G3a; Ki-67: 21–49%; n = 21) and highly proliferative (G3b; Ki-67: >50%, n = 22) G3 (total n = 43) gastroenteropancreatic NEN samples by performing immunohistochemistry with monoclonal rabbit anti-human anti-SSTR and anti-CXCR4 antibodies, respectively, and was correlated with clinical data. Results Both CXCR4 and SSTR were widely expressed in all tumors investigated. CXCR4 expression differed significantly between the G1 and G3 specimens and within the G3 group (G3a to G3b), and was positively correlated with Ki-67 expression. SSTR2A, in contrast, exhibited an inverse association with Ki-67. SSTR2A was highly expressed in G1 and G2 tumors, but was significantly less abundant in G3 carcinomas. Additionally, SSTR1 expression was higher in G3a than in G3b tumors. Conclusion We observed an elevation in CXCR4 and a decrease in SSTR2A expression with increasing malignancy. Interestingly, 23% of the G3 specimens had strong SSTR2A expression. Because CXCR4 was strongly expressed in highly proliferative G3 carcinomas, it is an interesting new target and needs to be validated in larger studies. PMID:26259237

  13. Iodine-131 labelled octreotide: not an option for somatostatin receptor therapy

    International Nuclear Information System (INIS)

    Bakker, W.H.; Breeman, W.A.P.; Pluijm, M.E. van der; Jong, M. de; Visser, T.J.; Krenning, E.P.

    1996-01-01

    This study deals with the radioiodination of very small amounts of peptide on a therapeutic scale, the required purification procedures after radioiodination, and the influence of high beta fluxes from 131 I on a peptide during radioiodination and purification. Based on the regularly used therapeutic doses of 131 I in cancer treatment and out previous experience with [ 111 In-DTPA-D-Phe 1 ]-octreotide, it was assumed that a minimal effective therapeutic dose of 3.7 GBq 131 I has to be coupled to a maximum of ∼100 μg peptide, representing only a slight excess of peptide over 131 I. This contrasts with non-peptide radiopharmaceuticals in which high compound to radionuclide ratios are usually used. Labelling at low peptide to radionuclide ratios (low labelling yields) results in the formation of di-iodinated compounds, whereas at high peptide to radionuclide ratios mono-iodinated products of low specific activity are formed. Thus, after radioiodination the desired mono-iodinated peptide has to be separated form unreacted iodide, and from di-iodinated and unreacted peptide, as both compounds compete for the receptors. Possible radiolysis of the peptide during labelling and separation steps were investigated by irradiating 30 μg unlabelled peptide with 370 MBq 131 I in a small volume. The peptide composition of the incubation mixtures was investigated by high-performance liquid chromatography after irradiation for 30 min to 24 h. The results showed that the peptide was degraded with a half-life of less than 1 h. During the preparation of a real therapeutic dose (at much higher β-flux) the peptide will be degraded even faster during the various steps required. In conclusion, intact mono-iodinated 131 I-labelled somatostatin analogues for peptide receptor therapy will be difficult to obtain. (orig./VHE)

  14. Activation of Brain Somatostatin Signaling Suppresses CRF Receptor-Mediated Stress Response

    OpenAIRE

    Andreas Stengel; Yvette F. Taché; Yvette F. Taché

    2017-01-01

    Corticotropin-releasing factor (CRF) is the hallmark brain peptide triggering the response to stress and mediates—in addition to the stimulation of the hypothalamus-pituitary-adrenal (HPA) axis—other hormonal, behavioral, autonomic and visceral components. Earlier reports indicate that somatostatin-28 injected intracerebroventricularly counteracts the acute stress-induced ACTH and catecholamine release. Mounting evidence now supports that activation of brain somatostatin signaling exerts a br...

  15. Preparation, formulation and quality control of one step kit 99m Tc - EDDA/HYNIC-Tyr3-Octreotide as a peptide radiopharmaceutical for imaging somatostatin receptor positive tumors

    International Nuclear Information System (INIS)

    Gandomkar, M.; Najafi, R.; Sadat-Ebrahimi, E.; Babaei, M.H.

    2004-01-01

    The high expression of somatostatin receptors in many tumours, have made receptor scintigraphy with 11I n-DTPA-Octreotide a widely used procedure in nuclear medicine. Despite its clinical success, some limitation and drawbacks of radiolabelling with 11I n remain, especially those concerned with the cost, availability and physical decay properties of this radionuclide. 99m Tc - EDDA/HYNIC-Tyr 3 -Octreotide was studied as a new agent with the potential to replace octreoscan in somatostatin receptor scintigraphy. This hydrazino nicotinic acid derivatized somatostatin complex contains ethylenediamine N, N diacetic acid as a co-ligand resulting in a high in vitro and in vivo stability. High labeling yields (>90%) were achieved at high specific activities. Characterization via HPLC, biodistribution and receptor binding of the resulting complex are described. The formulation developed enables rapid and simple labeling of 99m Tc - EDDA/HYNIC-TOC in a manner suitable for clinical setting

  16. Multiparametric PET imaging in thyroid malignancy characterizing tumour heterogeneity: somatostatin receptors and glucose metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Traub-Weidinger, Tatjana [Medical University of Vienna, Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Medical University of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Putzer, Daniel; Bale, Reto [Medical University of Innsbruck, Department of Radiology, Innsbruck (Austria); Guggenberg, Elisabeth von; Dobrozemsky, Georg; Nilica, Bernhard; Kendler, Dorota; Virgolini, Irene Johanna [Medical University of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria)

    2015-12-15

    Radiolabelled somatostatin (SST) analogues have proven useful in diagnosing tumours positive for SST receptor (SSTR). As different subtypes of SSTR are expressed on the tumour cell surface, the choice of appropriate therapeutic SST analogue is crucial. We evaluated the SSTR status of thyroid cancer patients who had signs of progressive disease comparing different SSTR ligands for PET imaging to evaluate possible further therapeutic options. PET with {sup 68}Ga-radiolabelled SSTR ligands DOTA lanreotide (DOTA-LAN), DOTA-Tyr{sup 3} octreotide (DOTA-TOC) and {sup 18}F-FDG was performed in 31 patients with thyroid cancer (TC). These 31 patients comprised 18 with radioiodine non-avid differentiated TC (DTC) including 6 papillary TC (PTC), 8 follicular TC (FTC) and 4 oxyphilic TC (oxyTC), 5 with anaplastic TC (ATC), and 8 with medullary TC (MTC). The PET results were compared in a region-based evaluation. All patients underwent a PET study with {sup 68}Ga-DOTA-LAN, 28 patients with {sup 68}Ga-DOTA-TOC and 28 patients with {sup 18}F-FDG. A lack of SSTR expression was found in 13 of the 31 patients (42 %) with negative results with both SSTR tracers in 12 patients. Ambiguous results with both SSTR tracers were observed in one patient. High tracer uptake in SSTR PET images was seen in seven DTC patients (39 %; two PTC, three FTC, two oxyTC), in four ATC patients (80 %) and in six MTC patients (75 %). Lesions showing aerobic glycolysis on {sup 18}F-FDG PET were found in 24 of 28 patients (86 %) with corresponding positive results with {sup 68}Ga-DOTA-LAN in 35 % and with {sup 68}Ga-DOTA-TOC in 29 %. The heterogeneous SSTR profile of TC tumour lesions needs to be evaluated using different SSTR PET tracers to characterize more closely the SSTR subtype affinities in patients with progressive TC in order to further stratify therapy with SSTR therapeutics. (orig.)

  17. Somatostatin receptor scintigraphy to predict the clinical evolution and therapeutic response of thyroid-associated ophthalmopathy

    Energy Technology Data Exchange (ETDEWEB)

    Nocaudie, M.; Bailliez, A.; Itti, E. [Centre Hospitalier Regional et Universitaire, Lille (France). Service Central de Medecine Nucleaire et Imagerie Fonctionnelle; Bauters, C.; Wemeau, J.L. [Clinique d`Endocrinologie, Centre Hospitalier Regional et Universitaire de Lille (France); Marchandise, X.

    1999-05-01

    Management of thyroid-associated ophthalmopathy remains a topic of controversy. Immunosuppressive treatments have to be applied at peak disease activity and before criteria of severity develop. Expression of somatostatin receptors on activated lymphocytes allows scintigraphic imaging with indium-111 pentetreotide. We conducted a prospective study with 17 patients who presented severe ophthalmopathy (11 Graves` disease, four Hashimoto`s thyroiditis, two isolated in appearance: Means` syndrome). Each patient underwent hormonal (free T{sub 3} and TSH) and immunological (TBII) assessment, an orbital computed tomography scan or magnetic resonance imaging, a visual functional examination and {sup 111}In-pentetreotide orbital scintigraphy before undergoing treatment by steroids and/or radiotherapy, independently of scintigraphic results. At 4 and 24 h after the intravenous injection of 111 MBq of {sup 111}In-pentetreotide, planar imaging centred on the head and neck (anterior and both lateral views) was carried out. Retrobulbar uptake was assessed by visual semi-quantitative analysis (score given by two independent trained observers) and by quantitative analyses (regions of interest, orbit/brain uptake indices). Patients were ophthalmologically followed up for 6 months and then classified as improved or not. Visual semi-quantitative analysis of 4-h/24-h planar images was correlated with the ophthalmological evolution ({chi}{sup 2} test, P<0.01). All ten patients in whom scintigraphy was considered positive were clinically improved at 6 months, and of the seven patients in whom scintigraphy was negative, six were not improved. Nevertheless, objective quantitative analysis did not succeed in confirming these results. We conclude that {sup 111}In-pentetreotide scintigraphy requires further developments, including quantitative single-photon emission tomographic acquisition, if its role as a guide to therapeutic strategy in thyroid-associated ophthalmopathy is to be confirmed

  18. Tumor-associated macrophages in glioblastoma multiforme-a suitable target for somatostatin receptor-based imaging and therapy?

    Directory of Open Access Journals (Sweden)

    Constantin Lapa

    Full Text Available Glioblastoma multiforme (GBM is the most common primary brain tumor in adults. Tumor-associated macrophages (TAM have been shown to promote malignant growth and to correlate with poor prognosis. [1,4,7,10-tetraazacyclododecane-NN',N″,N'″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE labeled with Gallium-68 selectively binds to somatostatin receptor 2A (SSTR2A which is specifically expressed and up-regulated in activated macrophages. On the other hand, the role of SSTR2A expression on the cell surface of glioma cells has not been fully elucidated yet. The aim of this study was to non-invasively assess SSTR2A expression of both glioma cells as well as macrophages in GBM.15 samples of patient-derived GBM were stained immunohistochemically for macrophage infiltration (CD68, proliferative activity (Ki67 as well as expression of SSTR2A. Anti-CD45 staining was performed to distinguish between resident microglia and tumor-infiltrating macrophages. In a subcohort, positron emission tomography (PET imaging using 68Ga-DOTATATE was performed and the semiquantitatively evaluated tracer uptake was compared to the results of immunohistochemistry.The amount of microglia/macrophages ranged from 50% in the tumor samples with the vast majority being resident microglial cells. A strong SSTR2A immunostaining was observed in endothelial cells of proliferating vessels, in neurons and neuropile. Only faint immunostaining was identified on isolated microglial and tumor cells. Somatostatin receptor imaging revealed areas of increased tracer accumulation in every patient. However, retention of the tracer did not correlate with immunohistochemical staining patterns.SSTR2A seems not to be overexpressed in GBM samples tested, neither on the cell surface of resident microglia or infiltrating macrophages, nor on the surface of tumor cells. These data suggest that somatostatin receptor directed imaging and treatment strategies are less promising in GBM.

  19. 99mTc-EDDA/HYNIC-TOC in management of patients with head and neck somatostatin receptor positive tumors.

    Science.gov (United States)

    Trogrlic, Mate; Tezak, Stanko

    2016-01-01

    Aim of this study was to determine the value of technetium-99m-hydrazinonicotinyl-Tyr3-octreotide (99mTc-ED-DA/HYNIC-TOC) in patients with somatostatin receptor (SSR) positive tumors of head and neck region. A total number of 16 patients were enrolled in this study. Planar whole body (WB) and single photon emission computed tomography (SPECT) images were acquired at 2 and 4 hours after the injection of approximately 670 MBq of 99mTc-EDDA/HYNIC-TOC. Additional single photon emission computed tomography/computed tomography (SPECT/CT) images of the head and neck region were acquired at 4h post tracer injection. Clinical and imaging follow up were taken as the reference standard. There were 10 female and 6 male patients of age 57.7 ± 12.9 years (58.5; 32-78) years. 99mTc-EDDA/HYNIC-TOC somatostatin receptor scintigraphy (SRS) was TP in 13 patients, TN in two and FP in one. Follow up period for SRS was 31.1 ± 19.4 (29; 2-63) months. 99mTc-EDDA/HYNIC-TOC scintigraphy provided additional information in 50% of patients, with impact on patient management in the same percentage of patients. Distant metastases were found in nine out of 16 patients (56%). 99mTc-EDDA/HYNIC-TOC SRS had sensitivity of 100% (75.3-100%), specificity of 66.7% (9.4-99.2%), accuracy of 93.7%, positive predictive value of 92.9% (66.1-99.8%), and negative predictive value of 100% (15.8-100%). Somatostatin receptor scintigraphy using 99mTc-EDDA/HYNIC-TOC is very useful imaging method in the evalu-ation of patients with SSR positive tumors of head and neck region.

  20. Somatostatin receptor positron emission tomography/computed tomography (PET/CT) in the evaluation of opsoclonus-myoclonus ataxia syndrome

    International Nuclear Information System (INIS)

    Joshi, Prathamesh; Lele, Vikram

    2013-01-01

    Opsoclonus-myoclonus ataxia (OMA) syndrome is the most common paraneoplastic neurological syndrome of childhood, associated with occult neuroblastoma in 20%-50% of all cases. OMA is the initial presentation of neuroblastoma in 1%-3% of children. Conventional radiological imaging approaches include chest radiography and abdominal computed tomography (CT). Nuclear medicine techniques, in form of 123 I/ 131 I-metaiodobenzylguanidine (MIBG) scintigraphy have been incorporated in various diagnostic algorithms for evaluation of OMA. We describe use of somatostatin receptor PET/CT with 68 Gallium- DOTA-DPhe 1 , Tyr 3 -octreotate (DOTATATE) in diagnosis of neuroblastoma in two cases of OMA

  1. Somatostatin receptor positron emission tomography/computed tomography (PET/CT) in the evaluation of opsoclonus-myoclonus ataxia syndrome.

    Science.gov (United States)

    Joshi, Prathamesh; Lele, Vikram

    2013-04-01

    Opsoclonus-myoclonus ataxia (OMA) syndrome is the most common paraneoplastic neurological syndrome of childhood, associated with occult neuroblastoma in 20%-50% of all cases. OMA is the initial presentation of neuroblastoma in 1%-3% of children. Conventional radiological imaging approaches include chest radiography and abdominal computed tomography (CT). Nuclear medicine techniques, in form of (123)I/(131)I-metaiodobenzylguanidine (MIBG) scintigraphy have been incorporated in various diagnostic algorithms for evaluation of OMA. We describe use of somatostatin receptor PET/CT with (68)Gallium- DOTA-DPhe(1), Tyr(3)-octreotate (DOTATATE) in diagnosis of neuroblastoma in two cases of OMA.

  2. NMDAR hypofunction and somatostatin-expressing GABAergic interneurons and receptors: A newly identified correlation and its effects in schizophrenia

    Directory of Open Access Journals (Sweden)

    Fatemah Alherz

    2017-06-01

    Full Text Available This review investigates the association between N-methyl-d-Aspartate receptor (NMDAR hypofunction and somatostatin-expressing GABAergic interneurons (SST+ and how it contributes to the cognitive deficits observed in schizophrenia (SZ. This is based on evidence that NMDAR antagonists caused symptoms resembling SZ in healthy individuals. NMDAR hypofunction in GABAergic interneurons results in the modulation of the cortical network oscillation, particularly in the gamma range (30–80 Hz. These gamma-band oscillation (GBO abnormalities were found to lead to the cognitive deficits observed in the disorder. Postmortem mRNA studies have shown that SST decreased more significantly than any other biomarker in schizophrenic subjects. The functional role of Somatostatin (SST in the aetiology of SZ can be studied through its receptors. Genetic knockout studies in animal models in Huntington's disease (HD have shown that a specific SST receptor, SSTR2, is increased along with the increased NMDAR activity, with opposing patterns observed in SZ. A direct correlation between SSTR and NMDAR is hence inferred in this review with the hope of finding a potential new therapeutic target for the treatment of SZ and related neurological conditions.

  3. SSTR-Mediated Imaging in Breast Cancer: Is There a Role for Radiolabeled Somatostatin Receptor Antagonists?

    Science.gov (United States)

    Dalm, Simone U; Haeck, Joost; Doeswijk, Gabriela N; de Blois, Erik; de Jong, Marion; van Deurzen, Carolien H M

    2017-10-01

    Recent studies have shown enhanced tumor targeting by novel somatostatin receptor (SSTR) antagonists compared with clinically widely used agonists. However, these results have been obtained mostly in neuroendocrine tumors, and only limited data are available for cancer types with lower SSTR expression, including breast cancer (BC). To date, two studies have reported higher binding of the antagonist than the agonist in BC, but in both studies only a limited number of cases were evaluated. In this preclinical study, we further investigated whether the application of an SSTR antagonist can improve SSTR-mediated BC imaging in a large panel of BC specimens. We also generated an in vivo BC mouse model and performed SPECT/MRI and biodistribution studies. Methods: Binding of 111 In-DOTA-Tyr 3 -octreotate (SSTR agonist) and 111 In-DOTA-JR11 (SSTR antagonist) to 40 human BC specimens was compared using in vitro autoradiography. SSTR2 immunostaining was performed to confirm SSTR2 expression of the tumor cells. Furthermore, binding of the radiolabeled SSTR agonist and antagonist was analyzed in tissue material from 6 patient-derived xenografts. One patient-derived xenograft, the estrogen receptor-positive model T126, was chosen to generate in vivo mouse models containing orthotopic breast tumors for in vivo SPECT/MRI and biodistribution studies after injection with 177 Lu-DOTA-Tyr 3 -octreotate or 177 Lu-DOTA-JR11. Results: 111 In-DOTA-JR11 binding to human BC tissue was significantly higher than 111 In-DOTA-Tyr 3 -octreotate binding ( P < 0.001). The median ratio of antagonist binding versus agonist binding was 3.39 (interquartile range, 2-5). SSTR2 immunostaining confirmed SSTR2 expression on the tumor cells. SPECT/MRI of the mouse model found better tumor visualization with the antagonist. This result was in line with the significantly higher tumor uptake of the radiolabeled antagonist than of the agonist as measured in biodistribution studies 285 min after radiotracer

  4. Somatostatin: a metabolic regulator

    International Nuclear Information System (INIS)

    Dileepan, K.N.; Wagle, S.R.

    1985-01-01

    Somatostatin, the hypothalamic release-inhibiting factor, has been found to stimulate gluconeogenesis in rat kidney cortical slices. Stimulation by somatostatin was linear and dose-dependent. Other bioactive peptides such as cholecystokinin, gastro-intestinal peptide, secretin, neurotensin, vasoactive intestinal peptide, pancreatic polypeptide, beta endorphin and substance P did not affect the renal gluconeogenic activity. Somatostatin-induced gluconeogenesis was blocked by phentolamine (alpha adrenergic antagonist) and prazosin (alpha 1 adrenergic antagonist) but not by propranolol (beta adrenergic antagonist) and yohimbine (alpha 2 adrenergic antagonist) suggesting that the effect is via alpha 1 adrenergic stimuli. Studies on the involvement of Ca 2+ revealed that tissue depletion and omission of Ca 2+ from the reaction mixture would abolish the stimulatory effect of somatostatin. Furthermore, somatostatin enhanced the uptake of 45 calcium in renal cortical slices which could be blocked by lanthanum, an inhibitor of Ca 2+ influx. It is proposed that the stimulatory effect of somatostatin on renal gluconeogenesis is mediated by alpha 1 adrenergic receptors, or those which functionally resemble the alpha 1 receptors and that the increased influx of Ca 2+ may be the causative factor for carrying out the stimulus. 88 references

  5. Somatostatin: a metabolic regulator

    Energy Technology Data Exchange (ETDEWEB)

    Dileepan, K.N.; Wagle, S.R.

    1985-12-23

    Somatostatin, the hypothalamic release-inhibiting factor, has been found to stimulate gluconeogenesis in rat kidney cortical slices. Stimulation by somatostatin was linear and dose-dependent. Other bioactive peptides such as cholecystokinin, gastro-intestinal peptide, secretin, neurotensin, vasoactive intestinal peptide, pancreatic polypeptide, beta endorphin and substance P did not affect the renal gluconeogenic activity. Somatostatin-induced gluconeogenesis was blocked by phentolamine (alpha adrenergic antagonist) and prazosin (alpha/sub 1/ adrenergic antagonist) but not by propranolol (beta adrenergic antagonist) and yohimbine (alpha/sub 2/ adrenergic antagonist) suggesting that the effect is via alpha/sub 1/ adrenergic stimuli. Studies on the involvement of Ca/sup 2 +/ revealed that tissue depletion and omission of Ca/sup 2 +/ from the reaction mixture would abolish the stimulatory effect of somatostatin. Furthermore, somatostatin enhanced the uptake of /sup 45/calcium in renal cortical slices which could be blocked by lanthanum, an inhibitor of Ca/sup 2 +/ influx. It is proposed that the stimulatory effect of somatostatin on renal gluconeogenesis is mediated by alpha/sub 1/ adrenergic receptors, or those which functionally resemble the alpha/sub 1/ receptors and that the increased influx of Ca/sup 2 +/ may be the causative factor for carrying out the stimulus. 88 references.

  6. Ga-66 labeled somatostatin analogue DOTA-DPhe1-Tyr3-octreotide as a potential agent for positron emission tomography imaging and receptor mediated internal radiotherapy of somatostatin receptor positive tumors

    International Nuclear Information System (INIS)

    Ugur, Oemer; Kothari, Paresh J.; Finn, Ronald D.; Zanzonico, Pat; Ruan, Shutian; Guenther, Ilonka; Maecke, Helmut R.; Larson, Steven M.

    2002-01-01

    Radionuclide labeled somatostatin analogues selectively target somatostatin receptor (SSTR)-expressing tumors as a basis for diagnosis and treatment of these tumors. Recently, a DOTA-functionalized somatostatin analogue, DOTATOC (DOTA-DPhe 1 -Tyr 3 -octreotide) has been developed. This compound has been shown to be superior to the other somatostatin analogues as indicated by its uniquely high tumor-to-non-target tissue ratio. DOTATOC can be labeled with a variety of radiometals including gallium radioisotopes. Gallium-66 is a positron emitting radionuclide (T 1/2 =9.5 hr; β + =56%), that can be produced in carrier free form by a low-beam energy cyclotron. In this study we investigated SSTR targeting characteristics of 66 Ga-DOTATOC in AR42J rat pancreas tumor implanted nude mice as a potential agent for diagnosis and receptor-mediated internal radiotherapy of SSTR-expressing tumors. We compared our results with 67 Ga- and 68 Ga- labeled DOTATOC. The radiolabeling procedure gave labeling yield ranged from 85-95% and radiochemical and chemical purity was >95%. In-vitro competitive binding curves and in-vivo competitive displacement studies with an excess of unlabeled peptide indicates that there is specific binding of the radioligand to SSTR. Animal biodistribution data and serial microPET TM images demonstrated rapid tumor uptake and rapid clearance from the blood and all tissues except kidney. Maximum % ID/g values for tumor were 10.0±0.7, 13.2±2.1 and 9.8±1.5 for 66 Ga-, 67 Ga-, and 68 Ga-DOTATOC, respectively. Calculated tumor, kidney and bone marrow doses for 66 Ga-DOTATOC based on biodistribution data were 178, 109 and 1.2 cGy/MBq, respectively. We conclude that 66 Ga labeled DOTATOC can be used for PET diagnosis and quantitative imaging-based dosimetry of SSTR positive tumors. 66 Ga-DOTATOC may also be used in higher doses for ablation of these tumors. However, kidney is the critical organ for toxicity (tumor/kidney ratio 1.64), and high kidney uptake must

  7. Ga-66 labeled somatostatin analogue DOTA-DPhe{sup 1}-Tyr{sup 3}-octreotide as a potential agent for positron emission tomography imaging and receptor mediated internal radiotherapy of somatostatin receptor positive tumors

    Energy Technology Data Exchange (ETDEWEB)

    Ugur, Oemer E-mail: ougur@hacettepe.edu.tr; Kothari, Paresh J.; Finn, Ronald D.; Zanzonico, Pat; Ruan, Shutian; Guenther, Ilonka; Maecke, Helmut R.; Larson, Steven M

    2002-02-01

    Radionuclide labeled somatostatin analogues selectively target somatostatin receptor (SSTR)-expressing tumors as a basis for diagnosis and treatment of these tumors. Recently, a DOTA-functionalized somatostatin analogue, DOTATOC (DOTA-DPhe{sup 1}-Tyr{sup 3}-octreotide) has been developed. This compound has been shown to be superior to the other somatostatin analogues as indicated by its uniquely high tumor-to-non-target tissue ratio. DOTATOC can be labeled with a variety of radiometals including gallium radioisotopes. Gallium-66 is a positron emitting radionuclide (T{sub 1/2} =9.5 hr; {beta}{sup +}=56%), that can be produced in carrier free form by a low-beam energy cyclotron. In this study we investigated SSTR targeting characteristics of {sup 66}Ga-DOTATOC in AR42J rat pancreas tumor implanted nude mice as a potential agent for diagnosis and receptor-mediated internal radiotherapy of SSTR-expressing tumors. We compared our results with {sup 67}Ga- and {sup 68}Ga- labeled DOTATOC. The radiolabeling procedure gave labeling yield ranged from 85-95% and radiochemical and chemical purity was >95%. In-vitro competitive binding curves and in-vivo competitive displacement studies with an excess of unlabeled peptide indicates that there is specific binding of the radioligand to SSTR. Animal biodistribution data and serial microPET{sup TM} images demonstrated rapid tumor uptake and rapid clearance from the blood and all tissues except kidney. Maximum % ID/g values for tumor were 10.0{+-}0.7, 13.2{+-}2.1 and 9.8{+-}1.5 for {sup 66}Ga-, {sup 67}Ga-, and {sup 68}Ga-DOTATOC, respectively. Calculated tumor, kidney and bone marrow doses for {sup 66}Ga-DOTATOC based on biodistribution data were 178, 109 and 1.2 cGy/MBq, respectively. We conclude that {sup 66}Ga labeled DOTATOC can be used for PET diagnosis and quantitative imaging-based dosimetry of SSTR positive tumors. {sup 66}Ga-DOTATOC may also be used in higher doses for ablation of these tumors. However, kidney is the

  8. Transcriptional and Functional Characterization of the G Protein-Coupled Receptor Repertoire of Gastric Somatostatin Cells

    DEFF Research Database (Denmark)

    Egerod, Kristoffer L; Engelstoft, Maja S; Lund, Mari L

    2015-01-01

    In the stomach, somatostatin (SST) acts as a general paracrine negative regulator of exocrine secretion of gastric acid and pepsinogen and endocrine secretion of gastrin, ghrelin, and histamine. Using reporter mice expressing red fluorescent protein (RFP) under control of the SST promotor, we hav...

  9. Impact of the scintigraphy of somatostatin receptors upon the therapeutic strategy in patients bearing digestive endocrine tumors

    International Nuclear Information System (INIS)

    Lebtahi, R.; Cadiot, G.; Genin, R.; Delahaye, N.; Faraggi, M.; Daou, D.; Peker, C.; Migon, M.; Le Guludec, D.

    1997-01-01

    The scintigraphy of somatostatin receptors (SSR) is a sensible method for detecting the gastroenteric-pancreatic endocrine tumors and their metastases. The aim of this study is to evaluate the clinical impact of the results of SSR in taking patients in therapeutic charge. A hundred and sixty patients bearing biologically and/or histologically proved digestive endocrine tumors were prospectively studied. The patients were classified in 3 groups: group I - 90 patients with no known metastases; group II - 59 patients with liver metastases and group III - 11 patients with known extra-hepatic metastases. The results of the scintigraphy were compared with those of conventional imaging. The following results were obtained: in group 1 (90 patients) the conventional imaging has allowed detecting 53 primitive tumors in 44 patients. The SSR visualized 68% of these sites and has detected 26 supplementary primitive sites in 20 patients and 29 metastatic sites in 25 patients. In group II the scintigraphy has detected 95% of hepatic metastases and revealed 23 new metastasis sites and 18/59 patients. In group III the scintigraphy has detected 11 new sites in 7 patients. The results of scintigraphy modified the patient's classification in 38 cases (24%). The therapeutic strategy was modified for 40 patients (25%). In conclusion, the scintigraphy of somatostatin receptors is able to detect a significant number of digestive endocrine tumors what has important implications for therapeutical planning of the treatment of patients. It must be carried out during pre-therapeutic extension examination of these tumors

  10. Normal uptake of 68Ga-DOTA-TOC by the pancreas uncinate process mimicking malignancy at somatostatin receptor PET.

    Science.gov (United States)

    Jacobsson, Hans; Larsson, Patricia; Jonsson, Cathrine; Jussing, Emma; Grybäck, Per

    2012-04-01

    To characterize a commonly occurring increased uptake by the uncinate process of the pancreas at PET/CT using 68Ga-DOTA-d-Phe1-Tyr3-octreotide (68Ga-DOTA-TOC). This tracer has replaced In pentetreotide (OctreoScan®) for somatostatin receptor scintigraphy at our laboratory. Fifty of our first 74 PET/CT examinations with 68Ga-DOTA-TOC could be evaluated in retrospect. None of these patients had surgery or showed any pathology in the pancreas head at the concomitant CT. Thirty-five of the 50 examinations (70%) showed an uptake by the uncinate process sufficiently intense to be interpreted as pathologic and simulating a tumor. Mean SUVmax was 9.2. Mean SUVmean using an isoactivity cut-off of >75% and >50% was 7.8 and 6.0, respectively. Volume calculations of the uncinate process activity using these definitions gave 0.9 mL and 4.2 mL, respectively. There is a frequent physiological uptake of 68Ga-DOTA-TOC by the pancreas uncinate process. This may be caused by an accumulation of pancreatic polypeptide-containing cells expressing somatostatin receptors. If there is a normal finding at concomitant diagnostic CT, this uptake should be regarded as physiological.

  11. The influence of somatostatin receptor scintigraphy during preoperative staging of non-functioning pancreatic neuroendocrine tumours

    International Nuclear Information System (INIS)

    Jilesen, A.P.J.; Hoefnagel, S.J.M.; Busch, O.R.C.; Bennink, R.J.; Gouma, D.J.; Nieveen van Dijkum, E.J.M.

    2016-01-01

    Aim: To determine whether somatostatin receptor scintigraphy (SRS) influences the preoperative staging and clinical management of non-functioning pancreatic neuroendocrine tumours (NF-pNETs). Materials and methods: All SRS examinations performed between 2002–2013 were selected. Patients with NF-pNET were included if both computed tomography (CT) and SRS was performed during preoperative staging. The diagnostic accuracy of CT and SRS for detecting NF-pNET metastases was analysed. Altered TNM classification and changed clinical management were calculated. Changed management was defined as a change from surgical resection into systemic treatment or vice versa. NF-pNETs were defined as tumours without clinical symptoms of hormonal hypersecretion. Results: Overall, 62 patients with NF-pNET were included with a mean age of 57 years (SD: 12.4) 2 . In 28 patients (45%), CT and SRS were correct and in agreement in the detection of primary tumour/metastases. In 34 patients (55%), one of the techniques was incorrect and therefore, there was no agreement. SRS altered the TNM classification in 14 patients (23%) and clinical management in nine patients (15%). In patients without metastases on CT, SRS detected lymph node metastases in one patient. The sensitivity to detect the primary tumour with CT was 95% and with SRS was 73%. In detecting metastases, the sensitivity and specificity were both 85% for CT versus 80% and 90% for SRS. Conclusion: Overall, CT and SRS were in agreement in the detection of NF-pNET. In NF-pNET without suspicious metastatic lesions on CT, SRS has limited value. SRS may be indicated to confirm lesions suspicious for neuroendocrine tumours metastases. - Highlights: • In 28 patients (45%), CT and SRS were correct and in agreement in the detection of primary tumor/metastases. • In 34 patients (55%) one of the modalities was incorrect and therefore, there was no agreement. • Sensitivity to detect the primary tumor with CT and SRS were 95% versus 73

  12. Somatostatin receptor scintigraphy using 99mTc-EDDA/HYNIC-TOC in patients with medullary thyroid carcinoma.

    Science.gov (United States)

    Czepczyński, Rafał; Parisella, Maria Gemma; Kosowicz, Jerzy; Mikołajczak, Renata; Ziemnicka, Katarzyna; Gryczyńska, Maria; Sowiński, Jerzy; Signore, Alberto

    2007-10-01

    Several new somatostatin analogues have been developed for the diagnosis and therapy of different tumours. Since somatostatin receptors are often over-expressed in medullary thyroid carcinoma (MTC), the aim of our study was to evaluate the utility of scintigraphy with the somatostatin analogue (99m)Tc-EDDA/HYNIC-TOC in MTC in comparison with other diagnostic techniques. Forty-five patients with MTC, aged 14-83 years, were investigated. Scintigraphy using (99m)Tc-EDDA/HYNIC-TOC (Tektrotyd) was performed 2 and 4 h post injection of 740 MBq (20 mCi) of the tracer. Other imaging techniques were also applied and analysed in individual cases (ultrasonography, computed tomography, (99m)Tc(V)-DMSA, (131)I-MIBG, (99m)Tc-MDP, (111)In-DTPA-octreotide and (18)F-FDG-PET) and compared with (99m)Tc-EDDA/HYNIC-TOC. In group 1 (eight patients before thyroidectomy), uptake of the tracer was found in the primary tumours. In group 2 (six patients with remission), a false positive result was found in one patient; in the remaining five patients, no pathological foci were visualised. In group 3 (31 patients with post-surgical hypercalcitoninaemia), scintigraphy was true positive in 23 patients (74.2%): uptake in the thyroid bed was found in five patients, in the lymph nodes in 18 and in bone metastases in four. Using (99m)Tc-EDDA/HYNIC-TOC scintigraphy, the overall sensitivity was 79.5%, specificity 83.3%, accuracy 80.0%, positive predictive value 96.9% and negative predictive value 38.5%. (99m)Tc-EDDA/HYNIC-TOC is clinically useful for scintigraphy in the follow-up of patients with MTC. It can be used in clinical practice for preoperative evaluation, for localisation of local recurrence or distant metastases and particularly for therapy decision making.

  13. Somatostatin receptor scintigraphy using 99mTc-EDDA/HYNIC-TOC in patients with medullary thyroid carcinoma

    International Nuclear Information System (INIS)

    Czepczynski, Rafal; Kosowicz, Jerzy; Ziemnicka, Katarzyna; Gryczynska, Maria; Sowinski, Jerzy; Parisella, Maria G.; Mikolajczak, Renata; Signore, Alberto

    2007-01-01

    Several new somatostatin analogues have been developed for the diagnosis and therapy of different tumours. Since somatostatin receptors are often over-expressed in medullary thyroid carcinoma (MTC), the aim of our study was to evaluate the utility of scintigraphy with the somatostatin analogue 99m Tc-EDDA/HYNIC-TOC in MTC in comparison with other diagnostic techniques. Forty-five patients with MTC, aged 14-83 years, were investigated. Scintigraphy using 99m Tc-EDDA/HYNIC-TOC (Tektrotyd) was performed 2 and 4 h post injection of 740 MBq (20 mCi) of the tracer. Other imaging techniques were also applied and analysed in individual cases (ultrasonography, computed tomography, 99m Tc(V)-DMSA, 131 I-MIBG, 99m Tc-MDP, 111 In-DTPA-octreotide and 18 F-FDG-PET) and compared with 99m Tc-EDDA/HYNIC-TOC. In group 1 (eight patients before thyroidectomy), uptake of the tracer was found in the primary tumours. In group 2 (six patients with remission), a false positive result was found in one patient; in the remaining five patients, no pathological foci were visualised. In group 3 (31 patients with post-surgical hypercalcitoninaemia), scintigraphy was true positive in 23 patients (74.2%): uptake in the thyroid bed was found in five patients, in the lymph nodes in 18 and in bone metastases in four. Using 99m Tc-EDDA/HYNIC-TOC scintigraphy, the overall sensitivity was 79.5%, specificity 83.3%, accuracy 80.0%, positive predictive value 96.9% and negative predictive value 38.5%. 99m Tc-EDDA/HYNIC-TOC is clinically useful for scintigraphy in the follow-up of patients with MTC. It can be used in clinical practice for preoperative evaluation, for localisation of local recurrence or distant metastases and particularly for therapy decision making. (orig.)

  14. Induction of Human Somatostatin Receptor Subtype 2 on Breast Tumors with an Adenoviral Vector for Their Treatment and Detection with a Radiolabeled Peptide

    National Research Council Canada - National Science Library

    Rogers, Buck

    2002-01-01

    .... An adenoviral vector encoding the human somatostatin receptor subtype 2 (AdSSTr2) has been produced. The MDA- MB-468 and BT-474 human breast cancer cells were infected with AdSSTr2 and harvested 48 h later for membrane preparations...

  15. The somatostatin receptor-targeted radiotherapeutic [90Y-DOTA-dPhe1,Tyr3]octreotide (90Y-SMT 487) eradicates experimental rat pancreatic CA 20948 tumours

    International Nuclear Information System (INIS)

    Stolz, B.; Weckbecker, G.; Smith-Jones, P.M.; Albert, R.; Raulf, F.; Bruns, C.

    1998-01-01

    Somatostatin receptor-expressing tumours are potential targets for therapy with radiolabelled somatostatin analogues. We have synthesized a number of such analogues in the past and identified [DOTA-dPhe 1 , Tyr 3 ]octreotide (SMT 487) as the most promising candidate molecule because of its advantageous properties in cellular and in vivo tumour models. In the current paper we describe the radiotherapeutic effect of yttrium-90 labelled SMT 487 in Lewis rats bearing the somatostatin receptor-positive rat pancreatic tumour CA 20948. SMT 487 binds with nanomolar affinity to both the human and the rat somatostatin receptor subtype 2 (sst 2 ) (human sst 2 IC 50 =0.9 nM, rat sst 2 IC 50 =0.5 nM). In vivo, 90 Y-SMT 487 distributed rapidly to the sst 2 expressing CA 20948 rat pancreatic tumour, with a tumour-to-blood ratio of 49.15 at 24 h post injection. A single intravenous administration of 10 mCi/kg 90 Y-SMT 487 resulted in a complete remission of the tumours in five out of seven CA 20948 tumour-bearing Lewis rats. No regrowth of the tumours occurred 8 months post injection. Control animals that were treated with 30 μg/kg of unlabelled SMT 487 had to be sacrificed 10 days post injection due to excessive growth or necrotic areas on the tumour surface. Upon re-inoculation of tumour cells into those rats that had shown complete remission, the tumours disappeared after 3-4 weeks of moderate growth without any further treatment. The present study shows for the first time the curative potential of 90 Y-SMT 487-based radiotherapy for somatostatin receptor-expressing tumours. Clinical phase I studies with yttrium-labelled SMT 487 have started in September 1997. (orig.)

  16. Expression of somatostatin receptors subtype 2 and 5 in extraocular muscle tissue of hypothyroidism animal induced by 131I

    International Nuclear Information System (INIS)

    Li Fangdu; Chu Qiaomei; Xu Peikang; Yao Xiaohong; Shen Jiangfan

    2012-01-01

    Objective: To observe the expression and distribution of somatostatin receptors 2 and 5 (SSTR2, 5) in extraocular muscle in hypothyroidism and thyroid associated ophthalmopathy (TAO) Wister rats induced by 131 I. Methods: 20 Wister rats were randomly divided into experimental group and normal group(group D). According to 131 I doses of intraperitoneal injection, the experimental groups were divided into low (group A), middle (group B) and high dose group (group C). After 8 weeks, all rats were sacrificed and orbital tissue sections were applied to HE staining and Immunohistochemistry for the analysis of rat orbital tissue changes and SSTR2 and 5 distribution in extraocular muscle. Results: The serum FT 4 levels in group A (16.98±2.92 pmol / L), group B (1.84±0.44 pmol / L) and group C (1.35 ±0.37 pmol /L) eight weeks after 131 I injection were decreased, and had significant difference compared with group D (P 4 levels in group B and C were significantly lower than that in group A (P 0.05). Orbital tissue in experimental group showed mucoid degeneration and edema, the extent was about 25% in group A, 50% in group B, 70% in group C. The rats in group B and group C appeared obvious proliferation of fibrous and adipose tissue, muscle fibers degeneration fracture, even extraocular muscles in group C have vacuole formation. Immunohistochemical analysis displayed highest SSTR5 distribution and strongest expression was in extraocular muscle of group C, second in A B combination group (A and B groups)and weakest in group D. There were significant differences between A B combination group,group C and group D (P 0.05). Conclusion: This study observed the distribution and expression of SSTR2 and SSTR5 in extraocular muscle on the established hypothyroidism animal model. It is some significance for understanding the mechanism of somatostatin receptors in occurrence and development of TAO, similar to provide a reference for the use of somatostatin analogue orbital imaging

  17. Evaluation of somatostatin receptors in large cell pulmonary neuroendocrine carcinoma with 99mTc-EDDA/HYNIC-TOC scintigraphy.

    Science.gov (United States)

    Nocuń, Anna; Chrapko, Beata; Gołębiewska, Renata; Stefaniak, Bogusław; Czekajska-Chehab, Elżbieta

    2011-06-01

    Large cell pulmonary neuroendocrine carcinoma (LCNEC) is a poorly differentiated and high-grade neoplasm. It is positioned between an atypical carcinoid and small cell neuroendocrine carcinoma of the lung in a distinct family of pulmonary neuroendocrine tumors. The aim of our study was to detect somatostatin receptors in this uncommon malignancy and to evaluate the sensitivity of somatostatin receptor scintigraphy (SRS) in LCNEC staging. We analyzed data of 26 patients (mean age: 61.5±7.9 years) with histologically confirmed diagnosis of LCNEC, including 18 cases not treated surgically and eight patients after the resection of the primary tumor. SRS was carried out with technetium-99m ethylene diamine-diacetic acid/hydrazinonicotinyl-Tyr3-octreotide (Tc-TOC). A visual analysis of scintigraphic images was done with reference to conventional imaging modalities (computed tomography and bone sicintigraphy). SRS sensitivity for the detection of primary lesions, supradiaphragmatic metastases, and infradiaphragmatic metastases was 100, 83.3%, and 0%, respectively. Five out of 13 metastases to the liver appeared on SRS as photopenic foci, visible on the background of physiological hepatic activity. Only one of the nine metastases to the skeletal system was found by SRS with sensitivity as low as 11.1%. The overall SRS sensitivity for the detection of secondary lesions and of all lesions was 54.8 and 62.2%, respectively. Within a rather large series of LCNEC, the primary tumor showed an uptake of Tc-TOC in all cases, whereas some metastases did show Tc-TOC uptake and some others did not.

  18. Correlation of Somatostatin Receptor-2 Expression with Gallium-68-DOTA-TATE Uptake in Neuroblastoma Xenograft Models.

    Science.gov (United States)

    Zhang, Libo; Vines, Douglass C; Scollard, Deborah A; McKee, Trevor; Komal, Teesha; Ganguly, Milan; Do, Trevor; Wu, Bing; Alexander, Natasha; Vali, Reza; Shammas, Amer; Besanger, Travis; Baruchel, Sylvain

    2017-01-01

    Peptide-receptor imaging and therapy with radiolabeled somatostatin analogs such as 68 Ga-DOTA-TATE and 177 Lu-DOTA-TATE have become an effective treatment option for SSTR-positive neuroendocrine tumors. The purpose of this study was to evaluate the correlation of somatostatin receptor-2 (SSTR2) expression with 68 Ga-DOTA-TATE uptake and 177 Lu-DOTA-TATE therapy in neuroblastoma (NB) xenograft models. We demonstrated variable SSTR2 expression profiles in eight NB cell lines. From micro-PET imaging and autoradiography, a higher uptake of 68 Ga-DOTA-TATE was observed in SSTR2 high-expressing NB xenografts (CHLA-15) compared to SSTR2 low-expressing NB xenografts (SK-N-BE(2)). Combined autoradiography-immunohistochemistry revealed histological colocalization of SSTR2 and 68 Ga-DOTA-TATE uptake in CHLA-15 tumors. With a low dose of 177 Lu-DOTA-TATE (20 MBq/animal), tumor growth inhibition was achieved in the CHLA-15 high SSTR2 expressing xenograft model. Although, in vitro , NB cells showed variable expression levels of norepinephrine transporter (NET), a molecular target for 131 I-MIBG therapy, low 123 I-MIBG uptake was observed in all selected NB xenografts. In conclusion, SSTR2 expression levels are associated with 68 Ga-DOTA-TATE uptake and antitumor efficacy of 177 Lu-DOTA-TATE. 68 Ga-DOTA-TATE PET is superior to 123 I-MIBG SPECT imaging in detecting NB tumors in our model. Radiolabeled DOTA-TATE can be used as an agent for NB tumor imaging to potentially discriminate tumors eligible for 177 Lu-DOTA-TATE therapy.

  19. Correlation of Somatostatin Receptor-2 Expression with Gallium-68-DOTA-TATE Uptake in Neuroblastoma Xenograft Models

    Directory of Open Access Journals (Sweden)

    Libo Zhang

    2017-01-01

    Full Text Available Peptide-receptor imaging and therapy with radiolabeled somatostatin analogs such as 68Ga-DOTA-TATE and 177Lu-DOTA-TATE have become an effective treatment option for SSTR-positive neuroendocrine tumors. The purpose of this study was to evaluate the correlation of somatostatin receptor-2 (SSTR2 expression with 68Ga-DOTA-TATE uptake and 177Lu-DOTA-TATE therapy in neuroblastoma (NB xenograft models. We demonstrated variable SSTR2 expression profiles in eight NB cell lines. From micro-PET imaging and autoradiography, a higher uptake of 68Ga-DOTA-TATE was observed in SSTR2 high-expressing NB xenografts (CHLA-15 compared to SSTR2 low-expressing NB xenografts (SK-N-BE(2. Combined autoradiography-immunohistochemistry revealed histological colocalization of SSTR2 and 68Ga-DOTA-TATE uptake in CHLA-15 tumors. With a low dose of 177Lu-DOTA-TATE (20 MBq/animal, tumor growth inhibition was achieved in the CHLA-15 high SSTR2 expressing xenograft model. Although, in vitro, NB cells showed variable expression levels of norepinephrine transporter (NET, a molecular target for 131I-MIBG therapy, low 123I-MIBG uptake was observed in all selected NB xenografts. In conclusion, SSTR2 expression levels are associated with 68Ga-DOTA-TATE uptake and antitumor efficacy of 177Lu-DOTA-TATE. 68Ga-DOTA-TATE PET is superior to 123I-MIBG SPECT imaging in detecting NB tumors in our model. Radiolabeled DOTA-TATE can be used as an agent for NB tumor imaging to potentially discriminate tumors eligible for 177Lu-DOTA-TATE therapy.

  20. Effect of Peptide Receptor Radionuclide Therapy on Somatostatin Receptor Status and Glucose Metabolism in Neuroendocrine Tumors: Intraindividual Comparison of Ga-68 DOTANOC PET/CT and F-18 FDG PET/CT

    Science.gov (United States)

    Oh, Sowon; Prasad, Vikas; Lee, Dong Soo; Baum, R. P.

    2011-01-01

    The heterogeneous nature of the neuroendocrine tumors (NET) makes it challenging to find one uniformly applicable management protocol which is especially true for diagnosis. The discovery of the overexpression of somatostatin receptors (SMS-R) on neuroendocrine tumor cells lead to the generalized and rapid acceptance of radiolabeled somatostatin receptor analogs for staging and restaging of NET as well as for Peptide Receptor Radionuclide Therapy (PRRNT) using Y-90 and Lu-177 DOTATATE/DOTATOC. In this present work we tried to look in to the effect of PRRNT on the glucose metabolism assessed by F-18 FDG PET/CT and SMS-R density assessed by Ga-68 DOTANOC PET/CT. We observed a complex relationship between the somatostatin receptor expression and glucose metabolism with only 56% (77/138) of the lesions showing match, while the others show mismatch between the receptor status and metabolism. The match between receptor expression and glucose metabolism increases with the grade of NET. In grade 3 NET, there is a concurrence between the changes in glucose metabolism and somatostatin receptor expression. PRRNT was found to be more effective in lesions with higher receptor expression. PMID:22121482

  1. The Inhibitory Effect of Somatostatin Receptor Activation on Bee Venom-Evoked Nociceptive Behavior and pCREB Expression in Rats

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-01-01

    Full Text Available The present study examined nociceptive behaviors and the expression of phosphorylated cAMP response element-binding protein (pCREB in the dorsal horn of the lumbar spinal cord and the dorsal root ganglion (DRG evoked by bee venom (BV. The effect of intraplantar preapplication of the somatostatin analog octreotide on nociceptive behaviors and pCREB expression was also examined. Subcutaneous injection of BV into the rat unilateral hindpaw pad induced significant spontaneous nociceptive behaviors, primary mechanical allodynia, primary thermal hyperalgesia, and mirror-thermal hyperalgesia, as well as an increase in pCREB expression in the lumbar spinal dorsal horn and DRG. Octreotide pretreatment significantly attenuated the BV-induced lifting/licking response and mechanical allodynia. Local injection of octreotide also significantly reduced pCREB expression in the lumbar spinal dorsal horn and DRG. Furthermore, pretreatment with cyclosomatostatin, a somatostatin receptor antagonist, reversed the octreotide-induced inhibition of the lifting/licking response, mechanical allodynia, and the expression of pCREB. These results suggest that BV can induce nociceptive responses and somatostatin receptors are involved in mediating the antinociception, which provides new evidence for peripheral analgesic action of somatostatin in an inflammatory pain state.

  2. In vitro comparison of renal handling and uptake of two somatostatin receptor-specific peptides labeled with indium-111

    International Nuclear Information System (INIS)

    Trejtnar, F.; Novy, Z.; Petrik, M.; Laznickova, A.; Melicharova, L.; Vankova, M.; Laznicek, M.

    2008-01-01

    Radiolabeled receptor-specific somatostatin analogs labeled with gamma- or beta-emitting radionuclides are useful for scintigraphic imaging and/or therapy of selected neuroendocrine tumors. However, significant renal uptake may result in radiotoxicological injury of the kidney and can limit clinical application of the agents. The aim of the study was to analyze renal handling, rate, and mechanism of renal accumulation of two somatostatin receptor-targeted peptides, [DOTA 0 , Tyr 3 , Thr 8 ]-octreotide (DOTA-TATE) and [DOTA 0 , 1-Nal 3 ]-octreotide (DOTA-NOC), labeled with indium-111 using in vitro methods. The perfused rat kidney and freshly isolated rat renal cells were used as experimental models. The perfusion was performed in a recirculation regimen at constant pressure with solution containing bovine albumin, erythrocytes, and a mixture of essential substrates. The renal cells were isolated from rat kidneys using two-phase collagenase perfusion. Accumulation studies were used to evaluate the renal uptake of the peptides and to compare their accumulation with that of passively or actively transported model drugs. The influence of selected inhibitors of receptor-mediated endocytosis and the inhibition of energy-dependent transport processes on the uptake were also investigated using isolated renal cells. The renal clearance of 111 In-DOTA-NOC in the perfused rat kidney was significantly lower than that of 111 In-DOTA-TATE. Reverse situation was found in the case of renal retention. Pretreatment of the perfused kidney with maleate markedly decreased the renal retention. 111 In-DOTA-NOC was accumulated in the isolated renal cells at a higher rate than 111 In-DOTA-TATE (ratio 3:1). The uptake of the radiopeptides in renal cells was higher than the uptake of not only the passively transported sucrose but also actively transported and accumulated methylglucose. The rank order of potency to inhibit the uptake by active endocytosis was approximately aprotinin

  3. Somatostatin Receptor SPECT/CT using 99mTc Labeled HYNIC-TOC Aids in Diagnosis of Primary Optic Nerve Sheath Meningioma.

    Science.gov (United States)

    Chandra, Piyush; Purandare, Nilendu; Shah, Sneha; Agrawal, Archi; Rangarajan, Venkatesh

    2017-01-01

    Primary optic nerve sheath meningiomas (ONSM) are rare, benign and slow growing tumor involving the intra-orbital/intra-canalicular segment of the optic nerve. Untreated, they can potentially lead to visual deterioration. Magnetic resonance (MR) is the gold standard imaging modality for diagnosing the entity. Often, a clinical dilemma exists to narrow the differential diagnosis of an enhancing intra-orbital mass on MR. Molecular imaging provides a high degree of precision in diagnosing meningioma in view of relatively high levels of somatostatin receptor expression by these tumors. The following case demonstrates the potential clinical utility of somatostatin receptor SPECT using 99m Tc- labeled HYNIC-TOC in clinical diagnosis of ONSM.

  4. PET/CT imaging of human somatostatin receptor 2 (hsstr2) as reporter gene for gene therapy

    International Nuclear Information System (INIS)

    Hofmann, M.; Gazdhar, A.; Weitzel, T.; Schmid, R.; Krause, T.

    2006-01-01

    Localized information on region-selective gene expression in small animals is widely obtained by use of reporter genes inducing light emission. Using these reporter genes for imaging deep inside the human body fluorescent probes are hindered by attenuation, scattering and possible fluorescence quenching. This can be overcome by use of radio-peptide receptors as reporter genes. Therefore, the feasibility of the somatostatin receptor 2 expression vector system for expression imaging was checked against a control vector containing luciferase gene. For in vivo transduction of vector DNA into the rat forelimb muscles the in vivo electroporation technique was chosen because of its high regio-selectivity. The gene expression was imaged by high-sensitive CCD camera (luciferase activity) and by PET/CT using a Ga-68-DOTATOC as radio peptide probe. The relative sstr2 expression was enhanced by gene transduction at maximum to a factor of 15. The PET/CT images could be fully quantified. The above demonstrated feasibility of radio-peptide PET/CT reporter gene imaging may serve in the future as a tool for full quantitative understanding of regional gene expression, especially in large animals and humans

  5. PET/CT imaging of human somatostatin receptor 2 (hsstr2) as reporter gene for gene therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, M. [Molecular Imaging and Therapy Group (MIT-Bern), Clinic of Nuclear Medicine, Inselspital, Medical School Bern (Switzerland)]. E-mail: Michael.Hofmann@insel.ch; Gazdhar, A. [Division of Pulmonary Medicine, University Hospital Bern (Switzerland); Weitzel, T. [Molecular Imaging and Therapy Group (MIT-Bern), Clinic of Nuclear Medicine, Inselspital, Medical School Bern (Switzerland); Schmid, R. [Division of Thoracic Surgery, University Hospital Bern (Switzerland); Krause, T. [Molecular Imaging and Therapy Group (MIT-Bern), Clinic of Nuclear Medicine, Inselspital, Medical School Bern (Switzerland)

    2006-12-20

    Localized information on region-selective gene expression in small animals is widely obtained by use of reporter genes inducing light emission. Using these reporter genes for imaging deep inside the human body fluorescent probes are hindered by attenuation, scattering and possible fluorescence quenching. This can be overcome by use of radio-peptide receptors as reporter genes. Therefore, the feasibility of the somatostatin receptor 2 expression vector system for expression imaging was checked against a control vector containing luciferase gene. For in vivo transduction of vector DNA into the rat forelimb muscles the in vivo electroporation technique was chosen because of its high regio-selectivity. The gene expression was imaged by high-sensitive CCD camera (luciferase activity) and by PET/CT using a Ga-68-DOTATOC as radio peptide probe. The relative sstr2 expression was enhanced by gene transduction at maximum to a factor of 15. The PET/CT images could be fully quantified. The above demonstrated feasibility of radio-peptide PET/CT reporter gene imaging may serve in the future as a tool for full quantitative understanding of regional gene expression, especially in large animals and human000.

  6. Molecular imaging with {sup 68}Ga-SSTR PET/CT and correlation to immunohistochemistry of somatostatin receptors in neuroendocrine tumours

    Energy Technology Data Exchange (ETDEWEB)

    Kaemmerer, Daniel; Haugvik, Sven-Petter; Hommann, Merten [Zentralklinik Bad Berka GmbH, Department of General and Visceral Surgery, Bad Berka (Germany); Peter, Luisa; Lupp, Amelie; Schulz, Stefan [University of Jena, Department of Pharmacology and Toxicology, Jena (Germany); Saenger, Joerg [Laboratory of Pathology and Cytology, Bad Berka (Germany); Prasad, Vikas; Kulkarni, Harshad; Baum, Richard Paul [Zentralklinik Bad Berka, Department of Nuclear Medicine and Center for PET, Bad Berka (Germany)

    2011-09-15

    Somatostatin receptors (SSTR) are known for an overexpression in gastroenteropancreatic neuroendocrine tumours (GEP-NET). The aim of the present study was to find out if the receptor density predicted by the semi-quantitative parameters generated from the static positron emission tomography (PET/CT) correlated with the in vitro immunohistochemistry using a novel rabbit monoclonal anti-SSTR2A antibody (clone UMB-1) for specific SSTR2A immunohistochemistry and polyclonal antibodies for SSTR1 and 3-5. Overall 14 surgical specimens generated from 34 histologically documented GEP-NET patients were correlated with the preoperative {sup 68}Ga-DOTA-NOC PET/CT. Quantitative assessment of the receptor density was done using the immunoreactive score (IRS) of Remmele and Stegner; the additional 4-point IRS classification for immunohistochemistry and standardized uptake values (SUV{sub max} and SUV{sub mean}) were used for PET/CT. The IRS for SSTR2A and SSTR5 correlated highly significant with the SUV{sub max} on the PET/CT (p < 0.001; p < 0.05) and the IRS for SSTR2A with the SUV{sub mean} (p < 0.013). The level of SSTR2A score correlated significantly with chromogranin A staining and indirectly to the tumour grading. The highly significant correlation between SSTR2A and SSTR5 and the SUV{sub max} on the {sup 68}Ga-DOTA-NOC PET/CT scans is concordant with the affinity profile of {sup 68}Ga-DOTA-NOC to the SSTR subtypes and demonstrates the excellent qualification of somatostatin analogues in the diagnostics of NET. This study correlating somatostatin receptor imaging using {sup 68}Ga-DOTA-NOC PET/CT with immunohistochemically analysed SSTR also underlines the approval of therapy using somatostatin analogues, follow-up imaging as well as radionuclide therapy. (orig.)

  7. Selective central activation of somatostatin receptor 2 increases food intake, grooming behavior and rectal temperature in rats.

    Science.gov (United States)

    Stengel, A; Goebel, M; Wang, L; Rivier, J; Kobelt, P; Monnikes, H; Tache, Y

    2010-08-01

    The consequences of selective activation of brain somatostatin receptor-2 (sst2) were assessed using the sst2 agonist, des-AA(1,4-6,11-13)-[DPhe(2),Aph7(Cbm),DTrp(8)]-Cbm-SST-Thr-NH2. Food intake (FI) was monitored in ad libitum fed rats chronically implanted with an intracerebroventricular (i.c.v.) cannula. The sst(2) agonist injected i.c.v. at 0.1 and 1 microg/rat dose-dependently increased light phase FI from 2 to 6 hours post injection (2.3+/-0.5 and 7.5+/-1.2 respectively vs. vehicle: 0.2+/-0.2 g/300 g bw, P<0.001). Peptide action was reversed by i.c.v. injection of the sst2 antagonist, des-AA(1,4-6,11-13)-[pNO(2)-Phe(2),DCys(3),Tyr(7),DAph(Cbm)8]-SST-2Nal-NH(2) and not reproduced by intraperitoneal injection (30 microg/rat). The sst(2) antagonist alone i.c.v. significantly decreased the cumulative 14-hours dark phase FI by 29.5%. Other behaviors, namely grooming, drinking and locomotor activity were also increased by the sst(2) agonist (1 microg/rat, i.c.v.) as monitored during the 2(nd) hour post injection while gastric emptying of solid food was unaltered. Rectal temperature rose 1 hour after the sst(2) agonist (1 microg/rat, i.c.v.) with a maximal response maintained from 1 to 4 hours post injection. These data show that selective activation of the brain sst(2) receptor induces a feeding response in the light phase not associated with changes in gastric emptying. The food intake reduction following sst(2) receptor blockade suggests a role of this receptor in the orexigenic drive during the dark phase.

  8. 99Tcm labelling and in vitro binding of dextran-somatostatin conjugate

    International Nuclear Information System (INIS)

    Cui Haiping; China Inst. of Atomic Energy, Beijing; Zhai Shizhen; Du Jin; Beijing Univ., Beijing

    2006-01-01

    Natural somatostatin and dextran-20 are used to synthesis somatostatin-dextran (SMS-Dx 20 ). The in vitro somatostatin receptor competition binding study of somatostatin-dextran is carried out by using rate brain cortex membranes (express somatostatin receptor type 2) and 125 I-Tyr 3 -Octreotide as a radioligand. The somatostatin-dextran conjugate is then labelled with 99 Tc m using SnCl 2 as reduce agent and tested for its in vitro binding properties. The somatostatin-dextran conjugate shows high somatostatin receptor binding affinity, i.e. in the same IC 50 value as the reference ligand Octreotide (IC 50 ∼5.95 nmol/L). The labelling efficiency is more than 85%. The specific binding of 99 Tc m labeled somatostatin-dextran conjugate is 25%-40%. The somatostatin-dextran conjugate is worthy of further investigation for 99 Tc m radiolabeling with diagnostic possibilities for somatostatin receptor positive tumors. (authors)

  9. Preparation and biological evaluation of [(99m)Tc/EDDA/Tricine/HYNIC(0), BzThi(3)]-octreotide for somatostatin receptor-positive tumor imaging.

    Science.gov (United States)

    Erfani, Mostafa; Shafiei, Mohammad; Mazidi, Mohammad; Goudarzi, Mostafa

    2013-04-01

    Somatostatin-derived analogues play an important role in the diagnosis and treatment of neuroendocrine tumors. The aim of this study was to evaluate a new somatostatin analogue designed for labeling with (99m)Tc: [6-hydrazinopyridine-3-carboxylic acid (HYNIC(0)), β-(3-benzothienyl)-Ala (BzThi(3))]-octreotide ([HYNIC]-BOC), using ethylenediamine-N,N'-diacetic acid (EDDA) and tricine as coligands. Synthesis was performed on a solid phase using a standard Fmoc strategy. The HYNIC-peptide conjugate was radiolabeled with (99m)Tc and characterized by ITLC and high-performance liquid chromatography (HPLC). In vitro studies were carried out in sstr2 expressing AR4-2J cell lines. In vivo distribution studies were performed in rats bearing the AR4-2J tumor. The radiolabeled complex could be prepared at high-specific activities and >95% radiochemical yield as determined by HPLC. The peptide conjugate showed high-affinity binding for sstr2. The radioligand showed high and specific internalization into AR4-2J cells (18.19%±0.21% at 4 hours). In vivo distribution studies in rats bearing tumor have shown a receptor-specific uptake of radioactivity in somatostatin receptor-positive organs. After 4 hours, uptake in the AR4-2J tumor was 1.71%±0.36% injected dose per gram tissue (%ID/g). These data show that [(99m)Tc/EDDA/Tricine/HYNIC(0), BzThi(3)]-octreotide is a specific radioligand for the somatostatin receptor-positive tumors and is a suitable candidate for clinical studies.

  10. Single photon emission computed tomography procedure improves accuracy of somatostatin receptor scintigraphy in endocrine gastro-entero-pancreatic tumours

    International Nuclear Information System (INIS)

    Lebtahi, R.; Genin, R.; Rouzet, F.; Bleicner-Perez, S.; Lievre, A.; Scigliano, S.; Vialle, C.; Le Guludec, D.; Cadiot, G.; Sobhani, I.; Mignon, M.

    2005-01-01

    Somatostatin receptors scintigraphy (SRS) is a sensitive method for the detection of endocrine gastro-entero-pancreatic tumors. The aim of this study was to evaluate the sensitivity of anterior and posterior planar associated to single photon emission computerized tomography (SPECT) compared to anterior and posterior planar associated to additional lateral and oblique views in the detection of abdominal endocrine tumors. One hundred and sixty four patients with endocrine gastro-entero-pancreatic tumors were included in this study. Scintigraphic images were performed after injection of 189 ± 23 MBq of 111 In-Pentetreotide. Abdominal planar images were performed 4 h and 24 hours after injection. Abdominal SPECT was performed at 24 hours. The combination of anterior and posterior abdominal planar images with SPECT using iterative reconstruction detected significantly more tumoral sites compared to multiple planar images (298 versus 280 for the liver, p = 0.01 and 90 versus 88 for coeliac area). In particular liver lesions were better delineated on tomographic slices. The combination of 111 In-Pentetreotide SPECT with anterior and posterior planar images is more sensitive than multiple planar images to detect abdominal endocrine tumors. (author)

  11. “In-house” preparation of 99mTc-EDDA/HYNIC-TOC, a specific targeting agent for somatostatin receptor scintigraphy

    Directory of Open Access Journals (Sweden)

    Sonja Kuzmanovska

    2012-01-01

    Full Text Available The use of radiolabeled peptide ligands as diagnostics and therapeutics in nuclear oncology has increased recently. One of the most frequently used radiopharmaceutical is 99mTc-EDDA/HYNIC-TOC, a somatostatin analog with affinity for certain types of somatostatin receptors, overexpressed in tumors of neuroendocrine origin. The radiopharmaceutical is not readily available; therefore we introduced its “in house” preparation within project activities supported by the International Atomic Energy Agency (IAEA. We optimized the radiolabeling protocol, prepared a small batch of frozen kits, performed ITLC quality control and animal biodistribution during the preclinical evaluation procedures. The co-ligand exchange labeling procedure was carried out at 100°C during 10 min, resulting in radiochemical purity >90%. The biodistribution scintigrams in normal Wistar rats showed rapid blood clearance after 15 min and predominant kidney accumulation after 4 h, in accordance with the data reported by other authors. Storage stability of the formulated small batch frozen kit (-20°C was evaluated within 6 months, with radiolabeling yield ranging between 94,3% and 96,9%. We conclude that frozen kit can be a safe alternative to the freeze-dried for small batch in house production, and after the satisfactory preclinical evaluation, the “in house” prepared 99mTc-EDDA/ HYNIC-TOC can be introduced in clinical practice as specific targeting agent for somatostatin receptor scintigraphy.

  12. Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with 68Ga-DOTA-octreotide: a potential PET tracer for beta cell mass measurement.

    Science.gov (United States)

    Sako, Takeo; Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky; Senda, Michio; Watanabe, Yasuyoshi

    2013-12-06

    Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with (68)Gallium ((68)Ga). After intravenous injection of (68)Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that (68)Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of (68)Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with (68)Ga-DOTA-octreotide could be a potential tool for evaluating BCM. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Preliminary clinical evaluation of Somatostatin Receptor Scintigraphy (SRS) with 99mTc-EDDA/HYNIC-TATE in comparison to 111In-Octreoscan and 131 I MIBG scans

    International Nuclear Information System (INIS)

    Hubalewska, A.; Fross, K.; Staszczak, A.; Huszno, B.; Mikolajczak, R.; Gorska, A.

    2004-01-01

    Full text: Over expression of somatostatin receptors in various neuroendocrine tumours prompted development of somatostatin analogues, which after radioactive labelling, could be used in oncological diagnostics. Somatostatin Receptor Positive Tumour (Spt) imaging with 111In-DTPA-DPhe1- octreotide (111In-Octreoscan) has become a widely used diagnostic procedure in clinical nuclear medicine. However 111In as a radiolabel has several drawbacks, including limited availability, sub optimal gamma energy and high radiation burden to the patient. Technetium (99mTc) labelling of somatostatin analogues is especially attractive due to the ready availability of 99mTc from generators and its well recognised favourable imaging characteristics. HYNIC conjugated Tyr 3 -Octreotate (HYNIC-TATE) prepared in our laboratory in a dry kit form was labelled with technetium-99mTc, with tricine and EDDA used as coligands. Tyr3-octreotate differs from octreotide (OC) by more hydrophilic tyrosine in the third position and the terminal threonine, which replaced threoninol present in OC. In vitro studies using cell lines transfected with somatostatin receptors (SSTR) revealed that octreotate shows 14- 17 times better binding affinity for SSTR type 2 than does OC. It is expected to clear more rapidly from non-target tissues as a result of the carboxylic group at the C-terminal of the peptide. HYNIC has been used as bifunctional chelator in 99mTc-HYNIC-Tyr3-octreotide (TOC) by Maecke and Behe, who reported on its favourable preclinical characteristics when EDDA was used as a co-ligand. These pre-clinical data were confirmed by Decristoforo and Mather and their early clinical studies appeared recently. The new radiopharmaceutical - 99mTc-DDA/HYNICTATE was evaluated in-vitro and in-vivo in an animal model and its potential for SSTR scintigraphy was documented. In the current patient study the diagnostic usefulness of the new radiopharmaceutical was tested for detection of tumours expressing SSTR

  14. Scintigraphy with labelled analogues of the somatostatin

    International Nuclear Information System (INIS)

    Duet, M.; Ajzenberg, C.; Warnet, A.; Mundler, O.

    1998-01-01

    The receptors of the somatostatin have been localized in a big number of tumors, whom a great number are neuro-endocrine tumors. However, some tumors that have not this differentiation (breast cancer, lymphomas, cerebral tumors) possess them as well. Analogues of somatostatin, labelled with isotopes having a gamma emission, allow from now their detection in vivo. (N.C.)

  15. Enhanced bilateral somatostatin receptor expression in mediastinal lymph nodes (''chimney sign'') in occult metastatic medullary thyroid cancer: a typical site of tumour manifestation?

    International Nuclear Information System (INIS)

    Behr, T.M.; Gratz, S.; Markus, P.M.; Dunn, R.M.; Huefner, M.; Becker, H.; Becker, W.

    1997-01-01

    In medullary thyroid cancer (MTC), post-surgically elevated plasma calcitonin and/or carcinoembryonic antigen levels frequently indicate persisting metastatic disease, although conventional diagnostic procedures fail to localize the responsible lesions (occult disease). Somatostatin analogues have been used successfully in disease localization, but recently concerns have been raised that increased thoracic uptake of indium-111 pentetreotide in patients with previous external beam irradiation may represent a false-positive finding, caused by post-irradiation pulmonary fibrosis. We recently examined seven patients with metastatic MTC by somatostatin receptor scintigraphy (six with occult and one with established disease). In four patients, all of whom had stable or slowly rising tumour marker levels over several years, a chimney-like bilateral mediastinal uptake of indium-111 pentetreotide was found. In two patients with persisting hypercalcitonaemia immediately after primary surgery, supraclavicular lymph node metastases were identified as the responsible lesions. None of these seven patients had prior external beam radiation therapy. In two cases, histological confirmation was obtained. In one patient, disease progression could be shown during follow-up. These data suggest that bilateral mediastinal lymph node involvement is a typical site of disease in slowly progressing occult metastatic MTC; the ''chimney sign'' may represent a typical finding with somatostatin analogues in such cases. Therefore, we believe that even in the case of prior external beam irradiation, mediastinal uptake of octreotide might represent metastatic MTC rather than radiation fibrosis. (orig.). With 2 figs., 1 tab

  16. The clinical impact of a combined gamma camera/CT imaging system on somatostatin receptor imaging of neuroendocrine tumours

    International Nuclear Information System (INIS)

    Hillel, P.G.; Beek, E.J.R. van; Taylor, C.; Lorenz, E.; Bax, N.D.S.; Prakash, V.; Tindale, W.B.

    2006-01-01

    AIM: With a combined gamma camera/CT imaging system, CT images are obtained which are inherently registered to the emission images and can be used for the attenuation correction of SPECT and for mapping the functional information from these nuclear medicine tomograms onto anatomy. The aim of this study was to evaluate the clinical impact of SPECT/CT using such a system for somatostatin receptor imaging (SRI) of neuroendocrine tumours. MATERIALS AND METHODS: SPECT/CT imaging with 111 In-Pentetreotide was performed on 29 consecutive patients, the majority of whom had carcinoid disease. All SPECT images were first reported in isolation and then re-reported with the addition of the CT images for functional anatomical mapping (FAM). RESULTS: Fifteen of the 29 SPECT images were reported as abnormal, and in 11 of these abnormal images (73%) FAM was found to either establish a previously unknown location (7/11) or change the location (4/11) of at least one lesion. The revised location could be independently confirmed in 64% of these cases. Confirmation of location was not possible in the other patients due to either a lack of other relevant investigations, or the fact that lesions seen in the SPECT images were not apparent in the other investigations. FAM affected patient management in 64% of the cases where the additional anatomical information caused a change in the reported location of lesions. CONCLUSION: These results imply that FAM can improve the reporting accuracy for SPECT SRI with significant impact on patient management

  17. Contribution of scintigraphy for somatostatin receptors in case of non-iodine-fixating metastases of thyroid epithelioma

    International Nuclear Information System (INIS)

    Couty, H.; Andrieu, J.M.; Baudet, L.; Faurous, P.; Artus, J.C.; Jaffiol, C.

    1997-01-01

    The objective of this work was to evaluate the sensitivity and importance of scintigraphy of somatostatin receptors (SSR) in the detection of non iodine-fixating metastases of thyroid epithelioma. We have studied retrospectively 7 patients with a detectable thyroglobulin under hormonal hindrance, amounting after cessation of treatment up to 72 - 1500 μ g/l and a normal post-irradiation therapy (3.7 GBq of 131 I) scintigraphy. These patients (4 F / 3 M), aged from 27 to 74 years (average age, 54 years), were treated by total and ganglionic curettage for papillary cancer of thyroid. Their evolutive surveillance extended from 1 to 24 years (on average, 8.4 years) and they received curative cumulated 131 I activities of 13 to 26 GBq. Each of them benefited by an osseous scintigraphy, of a cervico-thoraco-abdominal TDM and of a 111 In Pentetreotide SSR. The SSR was positive for 4/7 patients showing cervico-mediastinal fixations, the localizations being not detected by TDM. The osseous scintigraphy revealed once to be positive showing a costal lesion already detected by SSR. Cervical non-palpable adenopathies were detected by TDM for one patient. The anatomical-pathological analysis confirmed their thyroid origin. For other two patients the TDM showed suspect pulmonary nodules. These cervical and pulmonary localization were not detected by SSR. The SSR + TDM couple was positive for 6/7 patients. In conclusion, in this series the sensitivity of SSR was estimated to be 57%. Besides, the results obtained showed a net complementarity between the detection performances of SSR and TDM

  18. Receptor PET/CT for determining the somatostatin receptor status of neuroendocrine tumors before and after peptide receptor radionuclide therapy (PRRT): Clinical experience after 1,500 studies

    International Nuclear Information System (INIS)

    Baum, R.P.; Prasad, V.; Leonhardi, J.; Kroeger, R.; Wortmann, R.; Mueller, D.

    2007-01-01

    Full text: The octapeptide [DOTA]-1-Nal3-octreotide (DOTA-NOC) has 3 to 4 times higher binding affinity to sstr2 than DOTATOC (Wild 2003). We labeled this peptide with the Ga-68 (t1/2 68 min) and used it in pts with metastatic NET before/after PRRT for evaluating the sstr status by semiquantitative PET/CT imaging. Methods: Ga-68 was eluted from a Ge-68/Ga-68 generator using 0.1 M HCl. Following purifications, Ga-68 was eluted into a labeling vial containing 0.05 mg DOTA-NOC. Radiolabeling yields of >80% were achieved within 15 min at >95C. After purification (C18 cartridge) and a final elution, 370-700 MBq of Ga-68 DOTA-NOC were obtained with 100% radiochemical purity within 20 min (about 70% yield). Results: 1,500 PET/CT studies were performed in pts with histologically proven NET and progressive metastases before and after PRRT. Acquisition was started 20-270 min after injection of a mean of 100 MBq (46-260 MBq) Ga-68 DOTA-NOC using an LSO-based PET/CT (biograph DUO, Siemens). SUV were determined for all tumor lesions and normal tissues. SUV in metastases was as high as 152 whereas normal tissue was in the range of 0.4 (lung) to 33 (spleen). Outstanding PET/CT images of all known tumor lesions and in addition very small lymph node and bone metastases (<5 mm) were easily visualized as early as 20 min p.i. Clearly more lesions were detected as compared to Tc-99m EDDA-HYNIC-TOC or In-111 DOTA-NOC SPECT or as seen on CT or MRI images (especially regarding lymph node metastases, bone lesions and unknown primaries). Conclusions: Molecular receptor PET/CT imaging using the Ga-68-labeled somatostatin analogue DOTA-NOC detects neuroendocrine tumor metastases with very high diagnostic sensitivity and specificity. Semiquantitative uptake measurements (SUV) allow predicting the tumor uptake of Y-90 or Lu-177- labeled peptides before PRRT and are highly useful for therapy control to determine the 'molecular tumor response' which can precede the morphologic responses by months

  19. Unicentric Castleman's Disease Revealed by 18F-FDG PET/CT and Somatostatin Receptor Scintigraphy With 99mTc-HYNIC-TOC.

    Science.gov (United States)

    Luo, Yaping; Wang, Ling; Pan, Qingqing; Ma, Yanru; Li, Fang

    2018-07-01

    A 51-year-old woman with a history of hypertension and abdominal pain was found with a retroperitoneal mass. The mass had intense enhancement in contrast-enhanced CT, and it showed a moderate degree of increased FDG uptake in PET/CT. The mass was also positive in somatostatin receptor scintigraphy with Tc-HYNIC-TOC, but it was negative in I-MIBG scan. The histopathological result after surgical resection of the mass confirmed the diagnosis of Castleman's disease, the hyaline vascular variant.

  20. Current knowledge on the sensitivity of the 68Ga-somatostatin receptor positron emission tomography and the SUVmax reference range for management of pancreatic neuroendocrine tumours

    OpenAIRE

    Virgolini, Irene; Gabriel, Michael; Kroiss, Alexander; von Guggenberg, Elisabeth; Prommegger, Rupert; Warwitz, Boris; Nilica, Bernhard; Roig, llanos Geraldo; Rodrigues, Margarida; Uprimny, Christian

    2016-01-01

    Physiologically increased pancreatic uptake at the head/uncinate process is observed in more than one-third of patients after injection of one of the three 68Ga-labelled octreotide-based peptides used for somatostatin (sst) receptor (r) imaging. There are minor differences between these 68Ga-sstr-binding peptides in the imaging setting. On 68Ga-sstr-imaging the physiological uptake can be diffuse or focal and usually remains stable over time. Differences in the maximal standardised uptake val...

  1. Guideline for PET/CT imaging of neuroendocrine neoplasms withGa-DOTA-conjugated somatostatin receptor targeting peptides andF-DOPA

    DEFF Research Database (Denmark)

    Bozkurt, Murat Fani; Virgolini, Irene; Balogova, Sona

    2017-01-01

    PURPOSE & METHODS: Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing......, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using68Ga-DOTA-conjugated peptides, as well as18F-DOPA imaging for various neuroendocrine neoplasms. RESULTS & CONCLUSION: The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with68Ga...

  2. Peptide receptor radionuclide therapy of Merkel cell carcinoma using 177lutetium-labeled somatostatin analogs in combination with radiosensitizing chemotherapy. A potential novel treatment based on molecular pathology

    International Nuclear Information System (INIS)

    Salavati, A.; Prasad, V.; Baum, R.P.; Schneider, C.P.; Herbst, R.

    2012-01-01

    Few studies have been published on the safety and feasibility of synchronous use of peptide receptor radionuclide therapy (PRRNT), as source of internal radiation therapy, in combination with chemotherapy. In this study we reported a 53-year-old man with stage IV Merkel cell carcinoma (MCC), who underwent synchronous internal radiation therapy and chemotherapy. Based on presumable poor prognosis with chemotherapy only, functional similarities of MCC with other neuroendocrine tumors and available evidence of effectiveness and safety of synchronous use of external beam radiation therapy and chemotherapy in treatment of high-risk MCC patients, our interdisciplinary neuroendocrine tumor board recommended him to add PRRNT to his ongoing chemotherapy. He received 2 courses of 177 Lu-DOTATATE(1, 4, 7, 10-Tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid-1-D-Phe1-Tyr3-Thr8-octreotide) in combination with ongoing 8 cycles of liposomal doxorubicin based on standard protocols. Response to therapy was evaluated by 18 F-fluorodeoxyglucose ( 18 F-FDG) and 68 gallium-somatostatin-receptor PET/CT. There was an impressive improvement of the clinical symptoms. However, follow-up positron emission tomography (PET)/CT studies showed mixed pattern of response. Synchronous use of PRRNT and radiosensitizing chemotherapy seems safe and feasible in high risk MCC patients, however, further prospective studies and clinical trials are warranted to provide reliable evidence of possible pitfalls and effectiveness of PRRNT and 68 Ga-somatostatin-receptor PET/CT in the management of MCC. (author)

  3. Role of Transient Receptor Potential Ankyrin 1 Ion Channel and Somatostatin sst4 Receptor in the Antinociceptive and Anti-inflammatory Effects of Sodium Polysulfide and Dimethyl Trisulfide

    Directory of Open Access Journals (Sweden)

    István Z. Bátai

    2018-02-01

    Full Text Available Transient receptor potential ankyrin 1 (TRPA1 non-selective ligand-gated cation channels are mostly expressed in primary sensory neurons. Polysulfides (POLYs are Janus-faced substances interacting with numerous target proteins and associated with both protective and detrimental processes. Activation of TRPA1 in sensory neurons, consequent somatostatin (SOM liberation and action on sst4 receptors have recently emerged as mediators of the antinociceptive effect of organic trisulfide dimethyl trisulfide (DMTS. In the frame of the present study, we set out to compare the participation of this mechanism in antinociceptive and anti-inflammatory effects of inorganic sodium POLY and DMTS in carrageenan-evoked hind-paw inflammation. Inflammation of murine hind paws was induced by intraplantar injection of carrageenan (3% in 30 µL saline. Animals were treated intraperitoneally with POLY (17 µmol/kg or DMTS (250 µmol/kg or their respective vehicles 30 min prior paw challenge and six times afterward every 60 min. Mechanical pain threshold and swelling of the paws were measured by dynamic plantar aesthesiometry and plethysmometry at 2, 4, and 6 h after initiation of inflammation. Myeloperoxidase (MPO activity in the hind paws were detected 6 h after challenge by luminescent imaging. Mice genetically lacking TRPA1 ion channels, sst4 receptors and their wild-type counterparts were used to examine the participation of these proteins in POLY and DMTS effects. POLY counteracted carrageenan-evoked mechanical hyperalgesia in a TRPA1 and sst4 receptor-dependent manner. POLY did not influence paw swelling and MPO activity. DMTS ameliorated all examined inflammatory parameters. Mitigation of mechanical hyperalgesia and paw swelling by DMTS were mediated through sst4 receptors. These effects were present in TRPA1 knockout animals, too. DMTS inhibited MPO activity with no participation of the sensory neuron–SOM axis. While antinociceptive effects of

  4. Role of 68Ga somatostatin receptor PET/CT in the detection of endogenous hyperinsulinaemic focus: an explorative study

    International Nuclear Information System (INIS)

    Prasad, Vikas; Sainz-Esteban, Aurora; Arsenic, Ruza; Ploeckinger, Ursula; Denecke, Timm; Pape, Ulrich-Frank; Pavel, Marianne; Pascher, Andreas; Kuehnen, Peter; Blankenstein, Oliver

    2016-01-01

    To explore the role of 68 Ga-DOTATATE/DOTATOC PET/CT (SR PET/CT) in patients with suspicion of or histopathologically proven pancreatogenic hyperinsulinaemic hypoglycaemia. We included 13 patients with histopathologically proven or a high clinical suspicion of pancreatogenic hyperinsulinaemia. All the patients underwent a SR PET/CT scan. The results were correlated with histopathological findings. Normalization of blood glucose levels after resection of the pancreatic lesion, as well as a cytological and/or pathological diagnosis of insulinoma, was considered the diagnostic gold standard for insulinoma. The diagnosis of nesidioblastosis was based on exclusion of an insulinoma and conclusive pathological examination of a segment of the pancreas. Malignant insulinoma was defined as the presence of locoregional or distant metastases. Based on histopathology, 13 patients were found to have pancreatic hyperinsulinaemia: two patients had malignant insulinoma, eight had nonmetastasized insulinoma, and three had nesidioblastosis. SR PET was positive in 11 of the 13 patients (84.6 %) with a final diagnosis of endogenous pancreatic hypoglycaemia. Histopathological staining confirmed 16 foci of hyperinsulinism (insulin positivity). SR PET detected 14 of the 16 lesions, resulting in a sensitivity of 87 %. One intrapancreatic spleen was falsely diagnosed as insulinoma focus on SR PET, resulting in positive predictive value of 93.3 %. Immunohistochemical staining of somatostatin receptor (SSR) subtype 2a was available in ten specimens: two nesidioblastosis, and seven benign and one malignant insulinoma. Eight out of the ten specimens (80 %) stained strongly to moderately positive. Seven of the eight SSR2a-positive lesions were picked up on SR PET. Based on the results of SR PET/CT, nine patients achieved complete remission of the hypoglycaemic events during follow-up. This explorative study suggests that SR PET in combination with CT may play a significant role in the detection

  5. In vivo binding of [68Ga]-DOTATOC to somatostatin receptors in neuroendocrine tumours - impact of peptide mass

    International Nuclear Information System (INIS)

    Velikyan, Irina; Sundin, Anders; Eriksson, Barbro; Lundqvist, Hans; Soerensen, Jens; Bergstroem, Mats; Langstroem, Bengt

    2010-01-01

    Objectives: The aim of this pilot study was to explore the impact of peptide mass on binding of [ 68 Ga]-DOTATOC to neuroendocrine tumour somatostatin receptors in vivo using a tracer of variable specific radioactivity (SRA) and to show the logistic feasibility of sequential PET scans in the same patient. Material and Methods: Nine patients with gastroenteropancreatic neuroendocrine tumours were included. Six of them underwent three sequential PET-CT examinations with intravenous injections of [ 68 Ga]-DOTATOC proceeded by 0, 50 and 250 or 500 μg of octreotide, administered 10 min before the tracer. Three patients were examined by dynamic and static PET/CT for pharmacokinetic and dosimetric calculations. The [ 68 Ga]-DOTATOC synthesis included preconcentration and purification of the generator eluate and microwave heating in a semi-automated in-house procedure. Results: [ 68 Ga]-DOTATOC synthesis and quality control were accomplished within 30 min and radiochemical purity was >95%. The tracer accumulation in the tumours varied and depended on the total amount of the administered peptide. In five of six patients, the highest tumour-to-normal tissue ratio was found when 50 μg of octreotide was preadministered. One patient showed a continuously increasing tumour uptake. Dosimetrically, a large variation in organ doses was found (kidney: 0.086-0.168 mSv/MBq; liver: 0.026-0.096 mSv/MBq; spleen: 0.046-0.226 mSv/MBq). The effective dose (0.015, 0.0067 and 0.0042 mSv/MBq) was correlated to the total amount of decays. Discussion: Three sequential PET-CT examinations using 68 Ga-based tracer was carried out in 1 day. The use of high SRA [ 68 Ga]-DOTATOC and unlabelled octreotide indicates an optimal mass leading to better image contrast. [ 68 Ga]-DOTATOC-PET-CT employing variable SRA may be utilised for accurate quantification of tumour uptake with subsequent dosimetry for personalized therapy management.

  6. In vivo binding of [{sup 68}Ga]-DOTATOC to somatostatin receptors in neuroendocrine tumours - impact of peptide mass

    Energy Technology Data Exchange (ETDEWEB)

    Velikyan, Irina [Department of Biochemistry and Organic Chemistry, BMC, Uppsala University, Box 599, SE-751 24 Uppsala (Sweden); Uppsala Applied Science Lab, GEMS PET Systems, GE Healthcare, SE-752 28 Uppsala (Sweden); Sundin, Anders [Department of Radiology, Karolinska University Hospital, SE-171 76 Stockholm (Sweden); Eriksson, Barbro [Department of Endocrine Oncology, Uppsala University Hospital, SE-751 85 Uppsala (Sweden); Lundqvist, Hans [Department of Oncology, Radiology and Clinical Immunology, Uppsala University, SE-751 85 Uppsala (Sweden); Soerensen, Jens [Department of Medicinal Sciences, Clinical Physiology and Nuclear Medicine, Uppsala University Hospital, SE-751 85 Uppsala (Sweden); Bergstroem, Mats [Department of Pharmaceutical Biosciences, Uppsala Biomedical Centre, Uppsala University, Uppsala (Sweden); Langstroem, Bengt [Department of Biochemistry and Organic Chemistry, BMC, Uppsala University, Box 599, SE-751 24 Uppsala (Sweden)], E-mail: langstrom@biorg.uu.se

    2010-04-15

    Objectives: The aim of this pilot study was to explore the impact of peptide mass on binding of [{sup 68}Ga]-DOTATOC to neuroendocrine tumour somatostatin receptors in vivo using a tracer of variable specific radioactivity (SRA) and to show the logistic feasibility of sequential PET scans in the same patient. Material and Methods: Nine patients with gastroenteropancreatic neuroendocrine tumours were included. Six of them underwent three sequential PET-CT examinations with intravenous injections of [{sup 68}Ga]-DOTATOC proceeded by 0, 50 and 250 or 500 {mu}g of octreotide, administered 10 min before the tracer. Three patients were examined by dynamic and static PET/CT for pharmacokinetic and dosimetric calculations. The [{sup 68}Ga]-DOTATOC synthesis included preconcentration and purification of the generator eluate and microwave heating in a semi-automated in-house procedure. Results: [{sup 68}Ga]-DOTATOC synthesis and quality control were accomplished within 30 min and radiochemical purity was >95%. The tracer accumulation in the tumours varied and depended on the total amount of the administered peptide. In five of six patients, the highest tumour-to-normal tissue ratio was found when 50 {mu}g of octreotide was preadministered. One patient showed a continuously increasing tumour uptake. Dosimetrically, a large variation in organ doses was found (kidney: 0.086-0.168 mSv/MBq; liver: 0.026-0.096 mSv/MBq; spleen: 0.046-0.226 mSv/MBq). The effective dose (0.015, 0.0067 and 0.0042 mSv/MBq) was correlated to the total amount of decays. Discussion: Three sequential PET-CT examinations using {sup 68}Ga-based tracer was carried out in 1 day. The use of high SRA [{sup 68}Ga]-DOTATOC and unlabelled octreotide indicates an optimal mass leading to better image contrast. [{sup 68}Ga]-DOTATOC-PET-CT employing variable SRA may be utilised for accurate quantification of tumour uptake with subsequent dosimetry for personalized therapy management.

  7. Somatostatin receptor scintigraphy in patients with rheumatoid arthritis and secondary Sjögren's syndrome treated with Infliximab: a pilot study.

    Science.gov (United States)

    Anzola-Fuentes, L K; Chianelli, M; Galli, F; Glaudemans, A W J M; Martin Martin, L; Todino, V; Migliore, A; Signore, A

    2016-12-01

    Human T lymphocytes infiltrating tissues in autoimmune diseases are known to express somatostatin receptors amongst other activation markers. In this study, we evaluated whether somatostatin receptor scintigraphy (SRS) using a radiolabelled somatostatin analogue ((99m)Tc-EDDA/tricine-HYNIC-tyr(3)-octreotide ((99m)Tc-EDDA/HYNIC-TOC)) is able to detect the presence of immune-mediated processes in patients with rheumatoid arthritis and secondary Sjögren's syndrome. We also aimed to evaluate whether positivity to SRS was predictive of therapeutic response and if SRS could be used for monitoring the efficacy of immunomodulatory treatment. Eighteen patients with rheumatoid arthritis and secondary Sjögren's syndrome not responding to conventional treatment were recruited for treatment with infliximab, a monoclonal antibody against TNF-α. All patients had complete blood cell count, renal and liver function tests, measurements of ESR, CRP, ANA, ENA, and anti-dsDNA antibodies, functional salivary gland scintigraphy, labial biopsy, and ophthalmologic assessment with Schirmer's test and tear film break-up time (BUT). Diagnosis was made according to the revised criteria of the American-European Consensus Group. All patients underwent SRS at baseline and after 3-6 months of therapy with infliximab. Eleven out of 18 had repeat SRS images. Images of the salivary glands and major joints were acquired 3 h after injection of 370 MBq of (99m)Tc-EDDA/HYNIC-TOC. Image analysis was performed semi-quantitatively. All patients showed uptake of (99m)Tc-EDDA/HYNIC-TOC in the joints. Salivary glands also showed variable radiopharmaceutical uptake in 12 out of 18 patients, but all patients showed presence of lymphocytic infiltration at labial salivary gland biopsy. All patients, who repeated the study after treatment, showed significant reduction of somatostatin uptake in the joints but not in the salivary glands. SRS using (99m)Tc-EDDA/HYNIC-TOC may be a useful imaging tool to assess

  8. Examination of the somatostatin receptor status in non-medullary thyroid cancer; Untersuchungen zum Somatostatinrezeptor-Status bei nicht-medullaeren Schilddruesenkarzinomen

    Energy Technology Data Exchange (ETDEWEB)

    Goerges, R.; Brandt-Mainz, K.; Bockisch, A. [Essen Univ. (Gesamthochschule) (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Kahaly, G. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Medizin - Endokrinologie und Stoffwechselerkrankungen; Mueller-Brand, J.; Maecke, H. [Kantonsspital Basel (Switzerland). Inst. fuer Nuklearmedizin; Walgenbach, S. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Allgemein- und Abdominalchirurgie; Bruns, C. [Praeklinische Forschung Novartis, Basel (Switzerland); Andreas, J. [Universitaetsklinik Mainz (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    1999-06-01

    Aim: Recent in-vitro and in-vivo studies demonstrated a somatostatin receptor expression in some non-medullary thyroid carcinomas. In this study we investigated the somatostatin receptor status for this particular tumor entity in a larger patient group. Subject and methods: We compared 131-iodine with 111-In-pentetreotide scans in 24 patients with metastasizing, non-medullary thyroid cancer. The findings were correlated with other imaging modalities. Additionally, we performed receptor autoradiography in one patient, octreotide therapy in another patient and administration of 90-Y- and 111-In-DOTATOC in 2 consecutive patients. Results: In the 15 patients with papillary or follicular carcinoma, 111-In-pentetreotide was inferior to 131-I in 8/15, equal in 1/15, and superior in 6/15 patients. In 8/9 of the patients with Huerthle cell cacinoma, metastases showed a 111-In-pentetreotide accumulation of various intensity, while 131-iodine scans were negative except for one patient. 111-In-pentetreotide was equal or superior compared to 201-Tl or 99m-Tc-sestamibi, but for the most part inferior in comparison with 18-F-FDG-PET. The findings of 111-In-pentetreotide scintigraphy correlated well with the receptor autoradiography and the accumulation of DOTATOC, but not with the therapeutic effect of `cold` octreotide on the thyroid cancer metastases. Conclusions: Several metastases of papillary and follicular carcinoma, and the majority of Huerthle cell cancer metastases can express somatostatin receptors. 111-In-pentetreotide scintigraphy is a promising tool for localization of metastases especially in Huerthle cell cancer or if PET is not available, and may be useful for selection of possible candidates, if therapeutic effective {beta}-emitting somatostatin analogues will be available for routine application. (orig.) [Deutsch] Ziel: in aktuellen In-vitro und In-vivo-Untersuchungen wurde eine Somatostatinrezeptor-Expression bei einigen nicht

  9. DOTA-NOC, a high-affinity ligand of somatostatin receptor subtypes 2, 3 and 5 for labelling with various radiometals

    International Nuclear Information System (INIS)

    Wild, Damian; Schmitt, Joerg S.; Ginj, Mihaela; Maecke, Helmut R.; Bernard, Bert F.; Krenning, Eric; Jong, Marion de; Wenger, Sandra; Reubi, Jean-Claude

    2003-01-01

    Earlier studies have shown that modification of the octapeptide octreotide in positions 3 and 8 may result in compounds with increased somatostatin receptor affinity that, if radiolabelled, display improved uptake in somatostatin receptor-positive tumours. The aim of a recent research study in our laboratory was to employ the parallel peptide synthesis approach by further exchanging the amino acid in position 3 of octreotide and coupling the macrocyclic chelator DOTA(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) to these peptides for labelling with radiometals like gallium-67 or -68, indium-111, yttrium-90 and lutetium-177. The purpose was to find radiopeptides with an improved somatostatin receptor binding profile in order to extend the spectrum of targeted tumours. A first peptide, [ 111 In, 90 Y-DOTA]-1-Nal 3 -octreotide ( 111 In, 90 Y-DOTA-NOC), was isolated which showed an improved profile. In III -DOTA-NOC exhibited the following IC 50 values (nM) when studied in competition with [ 125 I][Leu 8 , d-Trp 22 , Tyr 25 ]somatostatin-28 (values for Y III -DOTA-NOC are shown in parentheses): sstr2, 2.9±0.1 (3.3±0.2); sstr3, 8±2 (26±1.9); sstr5, 11.2±3.5 (10.4±1.6). Affinity towards sstr1 and 4 was very low or absent. In III -DOTA-NOC is superior to all somatostatin-based radiopeptides having this particular type of binding profile, including DOTA-lanreotide, and has three to four times higher binding affinity to sstr2 than In III ,Y III -DOTA-Tyr 3 -octreotide (In III ,Y III -DOTA-TOC). In addition, [ 111 In]DOTA-NOC showed a specific and high rate of internalization into AR4-2J rat pancreatic tumour cells which, after 4 h, was about two times higher than that of [ 111 In]DOTA-TOC and three times higher than that of [ 111 In]DOTA-octreotide ([ 111 In]DOTA-OC). The internalized radiopeptides were externalized intact upon 2 h of internalization followed by an acid wash. After 2-3 h of externalization a plateau is reached, indicating a steady

  10. Influence of PET/CT 68Ga somatostatin receptor imaging on proceeding with patients, who were previously diagnosed with 99mTc-EDDA/HYNIC-TOC SPECT.

    Science.gov (United States)

    Madrzak, Dorota; Mikołajczak, Renata; Kamiński, Grzegorz

    2016-01-01

    The aim of this study was the assessment of utility of somatostatin receptor scintigraphy (SRS) by SPECT imaging using 99mTc-EDDA/HYNIC-Tyr3-octreotide (99mTc-EDDA/HYNIC-TOC) in patients with neuroendocrine neoplasm (NEN) or suspected NEN, referred to Nuclear Medicine Dept. of Voivodship Specialty Center in Rzeszow. The selected group of patients was referred also to 68Ga PET/CT. The posed question was the ratio of patients for whom PET/CT with 68Ga would change their management. The distribution of somatostatin receptors was imaged using 99mTc-EDDA/HYNIC-TOC in 61 planar and SPECT studies between 13/05/2010 and 04/02/2013 in Nuclear Medicine Dept. of Voivodship Specialty Center in Rzeszow. The patient age was within a range of 17-80, with the average age of 57.6. The average age of women (65% of patients over-all) was 55.6 and the average age of men (35% of patients overall) was 61.4. In 46 participants (75% of the study group), that underwent SRS, NEN was documented using pathology tests. Selected patients were referred to PET/CT with 68Ga labeled somatostatin analogs, DOTATATE or DOTANOC. This study group consisted of 14 female and 10 male participants with age range of 35-77 and average age of 55.5 years. Patients were classified into 3 groups, as follows: detection - referral due to clinical symptoms and/or biochemical markers (CgA-Chromogranin A, IAA-indoleacetic acid) with the aim of primary diagnosis, staging - referral with the aim of assessment of tumor spread, and follow-up - assessment of the therapy. Out of 61 patients, 24 underwent both 99mTc-EDDA/HYNIC-Tyr3-octreotide SPECT and 68Ga PET/CT. The result of PET/CT was used as a basis for further evaluation. Therefore, the patients were divided into groups; true positive TP (confirmed presence of tissue somatostatin receptors with 68Ga PET/CT) and TN (68Ga PET/CT did not detect any changes and the results were comparable and had the same influence on treatment protocol). In case of SPECT, the results

  11. New octreotide derivatives for in vivo targeting of somatostatin receptor-positive tumors for Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Maecke, H.R.; Smith-Jones, P.; Maina, T.; Stolz, B.; Albert, R.; Bruns, C.; Reist, H.

    1993-01-01

    Two new modifications of the somatostatin analog octreotide, designed to hold the gallium isotopes 67 Ga and 68 Ga (DFO-SMS) and 99m Tc (PnAO-SMS) have been synthesized and evaluated in vitro and in vivo in tumor bearing rats. DFO-SMS can be labeled with 67 Ga 3+ and 68 Ga 3+ with high specific activity within less than 30 minutes in a ''cold kit'' type formulation. The labeled conjugate is stable under physiologgical conditions. Moreover the binding affinity to somatostatin receptors on rat brain cortex membranes was shown to be retained. In vivo fast tumor localization was demonstrated and the pharmacokinetics proved to be favourable as the main excretion route was via the kidneys. First PET studies with [ 68 Ga]-DFO-SMS showed a rapid accumulation in the tumor and a residence half-life at the tumor site of about 6 hours. PnAO-SMS can be labeled with 99m Tc with high radiochemical purity. In vivo the radiotracer accumulates well in the tumor but due to its high lipohilicity, its main excretion route is via the hepatobiliary system. (orig.)

  12. Union of 99m Tc-HYNIC-TOC at the somatostatin receptors in cells of pancreas cancer

    International Nuclear Information System (INIS)

    Rodriguez C, J.; Ramirez I, M.T.; Ferro F, G.; Pedraza L, M.

    2005-01-01

    The radiation toxic effects have been used in therapy however much 50 years. The absorbed radiation dose can be determined at cellular level using cancerous cell cultures. If the deposited In vitro radiation dose coming from similar activities of several therapeutic radiopharmaceuticals it can compare it will be possible to choose the therapeutic radiopharmaceutical that it offers better dosimetric characteristics for the patient. The objective of this original investigation was to determine the union percentage of the octreotide 99m Tc-HYNlC-TOC to the somatostatin receivers in cells of cancer pancreas as well as the internalization, externalization and cellular viability. It was used the octapeptide, (octreotide, TOC) labelled with 99m Tc by means of the HYNIC chelating agent (6-hydrazine pyridine-3-carboxylic acid) and 3 cellular lines of murine pancreas cancer (AR42J), of cancer of human pancreas (CAPAN) and of one negative cellular line for somatostatin receivers (WRL-68). The 99m Tc-HYNIC-TOC was compared against two negative proofs for somatostatin receivers: the peptide 99m Tc-UBI and the 99m TcO 4 . The cellular lines were conserved in the synthetic media Dulbecco-Eagle. After 2, 4 and 24 h of exhibition to the radiation, the cells are picked up and its are determined the viability by count in a Neubauer camera using tripan blue. In the same times it was calculated the union percentage of the radiopharmaceutical to the cells and the internalization (union to the cytoplasm) and the externalization (union to membrane receivers). With those figures it was calculated the absorbed radiation dose at cellular level. Results: At 4 hours the union percentage of the 99m Tc-HYNlC-TOC to the AR42-J cells was 6.83 times greater than for the WRL-68 control cells of human papilloma, (without receivers of the somatostatin) and for the CAPAN them 4 times greater than for the same cells used as negative control, for the case of the 99m Tc-UBI and the 99m TcO 4 one doesn

  13. Evaluation of (64)Cu-labeled DOTA-D-Phe(1)-Tyr (3)-octreotide ((64)Cu-DOTA-TOC) for imaging somatostatin receptor-expressing tumors.

    Science.gov (United States)

    Hanaoka, Hirofumi; Tominaga, Hideyuki; Yamada, Keiich; Paudyal, Pramila; Iida, Yasuhiko; Watanabe, Shigeki; Paudyal, Bishnuhari; Higuchi, Tetsuya; Oriuchi, Noboru; Endo, Keigo

    2009-08-01

    In-111 ((111)In)-labeled octreotide has been clinically used for imaging somatostatin receptor-positive tumors, and radiolabeled octreotide analogs for positron emission tomography (PET) have been developed. Cu-64 ((64)Cu; half-life, 12.7 h) is an attractive radionuclide for PET imaging and is produced with high specific activity using a small biomedical cyclotron. The aim of this study is to produce and fundamentally examine a (64)Cu-labeled octreotide analog, (64)Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-D: -Phe(1)-Tyr(3)-octreotide ((64)Cu-DOTA-TOC). (64)Cu produced using a biomedical cyclotron was reacted with DOTA-TOC for 30 min at 45 degrees C. The stability of (64)Cu-DOTA-TOC was evaluated in vitro (incubated with serum) and in vivo (blood collected after administration) by HPLC analysis. Biodistribution studies were performed in normal mice by administration of mixed solution of (64)Cu-DOTA-TOC and (111)In-DOTA-TOC and somatostatin receptor-positive U87MG tumor-bearing mice by administration of (64)Cu-DOTA-TOC or (64)Cu-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid-octreotide ((64)Cu-TETA-OC). The tumor was imaged using (64)Cu-DOTA-TOC, (64)Cu-TETA-OC, and FDG with an animal PET scanner. (64)Cu-DOTA-TOC can be produced in amounts sufficient for clinical study with high radiochemical yield. (64)Cu-DOTA-TOC was stable in vitro, but time-dependent transchelation to protein was observed after injection into mice. In biodistribution studies, the radioactivity of (64)Cu was higher than that of (111)In in all organs except kidney. In tumor-bearing mice, (64)Cu-DOTA-TOC showed a high accumulation in the tumor, and the tumor-to-blood ratio reached as high as 8.81 +/- 1.17 at 6 h after administration. (64)Cu-DOTA-TOC showed significantly higher accumulation in the tumor than (64)Cu-TETA-OC. (64)Cu-DOTA-TOC PET showed a very clear image of the tumor, which was comparable to that of (18)F-FDG PET and very similar to that of (64)Cu

  14. Evaluation of 64Cu-labeled DOTA-D-Phe1-Tyr3-octreotide (64Cu-DOTA-TOC) for imaging somatostatin receptor-expressing tumors

    International Nuclear Information System (INIS)

    Hanaoka, Hirofumi; Tominaga, Hideyuki; Yamada, Keiich

    2009-01-01

    In-111 ( 111 In)-labeled octreotide has been clinically used for imaging somatostatin receptor-positive tumors, and radiolabeled octreotide analogs for positron emission tomography (PET) have been developed. Cu-64 ( 64 Cu; half-life, 12.7 h) is an attractive radionuclide for PET imaging and is produced with high specific activity using a small biomedical cyclotron. The aim of this study is to produce and fundamentally examine a 64 Cu-labeled octreotide analog, 64 Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-D-Phe 1 -Tyr 3 -octreotide ( 64 Cu-DOTA-TOC). 64 Cu produced using a biomedical cyclotron was reacted with DOTA-TOC for 30 min at 45 deg C. The stability of 64 Cu-DOTA-TOC was evaluated in vitro (incubated with serum) and in vivo (blood collected after administration) by high performance liquid chromatography (HPLC) analysis. Biodistribution studies were performed in normal mice by administration of mixed solution of 64 Cu-DOTA-TOC and 111 In-DOTA-TOC and somatostatin receptor-positive U87MG tumor-bearing mice by administration of 64 Cu-DOTA-TOC or 64 Cu-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid-octreotide ( 64 Cu-TETA-OC). The tumor was imaged using 64 Cu-DOTA-TOC, 64 Cu-TETA-OC, and fluorodeoxyglucose (FDG) with an animal PET scanner. 64 Cu-DOTA-TOC can be produced in amounts sufficient for clinical study with high radiochemical yield. 64 Cu-DOTA-TOC was stable in vitro, but time-dependent transchelation to protein was observed after injection into mice. In biodistribution studies, the radioactivity of 64 Cu was higher than that of 111 In in all organs except kidney. In tumor-bearing mice, 64 Cu-DOTA-TOC showed a high accumulation in the tumor, and the tumor-to-blood ratio reached as high as 8.81±1.17 at 6 h after administration. 64 Cu-DOTA-TOC showed significantly higher accumulation in the tumor than 64 Cu-TETA-OC. 64 Cu-DOTA-TOC PET showed a very clear image of the tumor, which was comparable to that of 18 F-FDG PET and

  15. IMMUNOHISTOCHEMICAL DETERMINATION OF EXPRESSION OF SOMATOSTATIN RECEPTORS TYPES 1, 2A, 3 AND 5 IN NEUROENDOCRINE TUMORS OF VARIOUS LOCALIZATION AND GRADE

    Directory of Open Access Journals (Sweden)

    L. E. Gurevich

    2016-01-01

    Full Text Available Background: Prediction of clinical benefits of somatostatin analogues in patients with neuroendocrine tumors (NET is very important prior to their administration. Data on immunohistochemical assessment of the expression of somatostatin receptors (SSR of various types, obtained from large samples of NET with various localization, functional activity and degree of malignancy, are scarce; therefore, the study was aimed at assessment of the latter.Materials and methods: We performed an immunohistochemical study with antibodies to SSR1, 2A, 3 and 5  types on tissue samples obtained during diagnostic and intra-operative biopsies from 399 NETs: 168 from pancreas, 120 from gastrointestinal tract (stomach, 48, from small intestine, 39, 14 of which being from duodenum; appendix, 6, colon and the rectum, 15 and 12, respectively, 84 from lung, 6 from thymus/mediastinum, and 21 from NET metastases of unknown primary localization.Results: Very high levels expression of receptors SSR2A preferentially binding to somatostatin analogues, which are currently used in clinical practice, were detected in the small intestine NETs (22/25, 88%, appendix (5/6, 83.3%, colon (10/15, 66.7%, thymus (4/6, 66.7%, atypical carcinoids of the lung (10/15, 66.7%, stomach (27/41, 65.8% and pancreas (105/165, 63.6%. The lowest expression was found in rectal NETs (5/12, 41.7% and small and large cell neuroendocrine lung carcinomas (20, 11.1%. Among functioning NETs, the highest level of SSR2A was found in gastrinomas (18/19, 94.7%, glucagonomas (15/16, 93.8%, small intestine carcinoids (31/35, 88.6%, and somatostatinomas (2/3, 66.7%. The lowest expression was detected in ACTH secreting tumors with Cushing's syndrome (11/12, 50%, and in insulinomas (34/69, 49.3%. SSR2A expression in functionally inactive pancreatic NETs was significantly higher than in insulinomas (57/82, 34/69 vs 69.5 and 49.3%, respectively. SSR2A expression was associated with the degree of malignancy and is

  16. Guideline for PET/CT imaging of neuroendocrine neoplasms with {sup 68}Ga-DOTA-conjugated somatostatin receptor targeting peptides and {sup 18}F-DOPA

    Energy Technology Data Exchange (ETDEWEB)

    Bozkurt, Murat Fani [Hacettepe University Faculty of Medicine Department of Nuclear Medicine, Ankara (Turkey); Virgolini, Irene; Decristoforo, Clemens [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Balogova, Sona [Comenius University and St. Elisabeth Oncology Institute, Department of Nuclear Medicine, Bratislava (Slovakia); Tenon Hospital AP-HP and Universite Pierre et Marie Curie, Department of Nuclear Medicine, Paris (France); Beheshti, Mohsen [St. Vincent' s Hospital, PET-CT Center, Department of Nuclear Medicine and Endocrinology, Linz (Austria); Paracelsus Medical University, Department of Nuclear Medicine, Salzburg (Austria); Rubello, Domenico [Santa Maria della Misericordia Hospital, Department of Nuclear Medicine, PET Center and Medical Physics and Radiology, Rovigo (Italy); Ambrosini, Valentina; Fanti, Stefano [University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Bologna (Italy); Kjaer, Andreas [National University Hospital and University of Copenhagen, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Delgado-Bolton, Roberto [San Pedro Hospital and Centre for Biomedical Research of La Rioja (CIBIR), Department of Diagnostic Imaging (Radiology) and Nuclear Medicine, Logrono (Spain); Kunikowska, Jolanta [Medical University of Warsaw, Nuclear Medicine, Warsaw (Poland); Oyen, Wim J.G. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London (United Kingdom); Chiti, Arturo [Humanitas University, Nuclear Medicine Department, Rozzano, MI (Italy); Giammarile, Francesco [University of Lyon, Nuclear Medicine, Lyon (France)

    2017-08-15

    Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using {sup 68}Ga-DOTA-conjugated peptides, as well as {sup 18}F-DOPA imaging for various neuroendocrine neoplasms. The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with {sup 68}Ga-conjugated peptides has been revised and updated with the relevant and recent literature in the field with contribution of distinguished experts. (orig.)

  17. Studies in rats on octreotide labelled with Ga-67: A potential radiopharmaceutical agent for the treatment of somatostatin receptor-positive tumours

    International Nuclear Information System (INIS)

    Lazniekova, A.; Laznieek, M.; Trejtnar, F.; Maecke, H.R.

    2001-01-01

    The paper presents the preparation, biodistribution and analysis of elimination mechanisms of 67 Ga-[DFO]-octreotide in rats. For labelling of the ligand with 67 Ga, desferrioxamine B (DFO) coupled to octreotide via the succinyl linker has been shown to form a stable chelating agent for binding of 67 Ga. The radiopharmaceutical was prepared by direct chelating of 67 Ga 3+ with [DFO]-octreotide in a slightly acidic reaction medium with high radiochemical purity. Pharmacokinetics of 67 Ga-[DFO]-octreotide of radioactivity in rats has shown relatively rapid elimination of the compound from the body with a long-term retention in the kidney and organs with high somatostatin receptor density. The agent was eliminated mostly by urine predominantly by the mechanism of glomerular filtration. (author)

  18. Preclinical evaluation of [99mTc/EDDA/tricine/HYNIC0, 1-Nal3, Thr8]-octreotide as a new analogue in the detection of somatostatin-receptor-positive tumors.

    Science.gov (United States)

    Gandomkar, Mostafa; Najafi, Reza; Shafiei, Mohammad; Mazidi, Mohammad; Ebrahimi, Sayed Esmaeil Sadat

    2007-08-01

    Radiolabeled somatostatin analogues are important tools for the in vivo localization and targeted radionuclide therapy of somatostatin-receptor-positive tumors. The aim of this study was to evaluate a new somatostatin analogue designed for the labeling with (99m)Tc: [6-hydrazinopyridine-3-carboxylic acid (HYNIC(0)), 1-Nal(3), Thr(8)]-octreotide ([HYNIC]-NATE), using ethylenediamine-N,N'-diacetic acid (EDDA) and tricine as coligands. Synthesis was preformed on a solid phase using a standard Fmoc strategy. Labeling with (99m)Tc was performed at 100 degrees C for 10 min using SnCl(2) as a reductant. Radiochemical analysis involved ITLC and high-performance liquid chromatography methods. Peptide conjugate affinity was determined in AR4-2J cell membranes. The internalization and externalization rates were studied in sstr(2)-expressing AR4-2J cells. Biodistribution of radiopeptide was studied in rats bearing the AR4-2J tumor. Radiolabeling was performed at high specific activities, and radiochemical purity was >95%. Peptide conjugate showed high affinity binding for sstr(2). The radioligand showed a moderate and specific internalization into AR4-2J cells (14.13+/-0.61% at 4 h). In animal biodistribution studies, a receptor-specific uptake of radioactivity was observed in somatostatin-receptor-positive organs. After 4 h, uptake in the AR4-2J tumor was 1.33+/-0.23%ID/g (percentage of injected dose per gram of tissue). These data show that [(99m)Tc/EDDA/tricine/HYNIC]-NATE is a specific radioligand for the somatostatin-receptor-positive tumors and is a suitable candidate for clinical studies.

  19. Preclinical evaluation of [99mTc/EDDA/tricine/HYNIC0, 1-Nal3, Thr8]-octreotide as a new analogue in the detection of somatostatin-receptor-positive tumors

    International Nuclear Information System (INIS)

    Gandomkar, Mostafa; Najafi, Reza; Shafiei, Mohammad; Mazidi, Mohammad; Ebrahimi, Sayed Esmaeil Sadat

    2007-01-01

    Purpose: Radiolabeled somatostatin analogues are important tools for the in vivo localization and targeted radionuclide therapy of somatostatin-receptor-positive tumors. The aim of this study was to evaluate a new somatostatin analogue designed for the labeling with 99m Tc: [6-hydrazinopyridine-3-carboxylic acid (HYNIC 0 ), 1-Nal 3 , Thr 8 ]-octreotide ([HYNIC]-NATE), using ethylenediamine-N,N'-diacetic acid (EDDA) and tricine as coligands. Methods: Synthesis was preformed on a solid phase using a standard Fmoc strategy. Labeling with 99m Tc was performed at 100 o C for 10 min using SnCl 2 as a reductant. Radiochemical analysis involved ITLC and high-performance liquid chromatography methods. Peptide conjugate affinity was determined in AR4-2J cell membranes. The internalization and externalization rates were studied in sstr 2 -expressing AR4-2J cells. Biodistribution of radiopeptide was studied in rats bearing the AR4-2J tumor. Results: Radiolabeling was performed at high specific activities, and radiochemical purity was >95%. Peptide conjugate showed high affinity binding for sstr 2 . The radioligand showed a moderate and specific internalization into AR4-2J cells (14.13±0.61% at 4 h). In animal biodistribution studies, a receptor-specific uptake of radioactivity was observed in somatostatin-receptor-positive organs. After 4 h, uptake in the AR4-2J tumor was 1.33±0.23%ID/g (percentage of injected dose per gram of tissue). Conclusion: These data show that [ 99m Tc/EDDA/tricine/HYNIC]-NATE is a specific radioligand for the somatostatin-receptor-positive tumors and is a suitable candidate for clinical studies

  20. Ectopic Expression of α6 and δ GABAA Receptor Subunits in Hilar Somatostatin Neurons Increases Tonic Inhibition and Alters Network Activity in the Dentate Gyrus

    Science.gov (United States)

    Tong, Xiaoping; Peng, Zechun; Zhang, Nianhui; Cetina, Yliana; Huang, Christine S.; Wallner, Martin; Otis, Thomas S.

    2015-01-01

    The role of GABAA receptor (GABAAR)-mediated tonic inhibition in interneurons remains unclear and may vary among subgroups. Somatostatin (SOM) interneurons in the hilus of the dentate gyrus show negligible expression of nonsynaptic GABAAR subunits and very low tonic inhibition. To determine the effects of ectopic expression of tonic GABAAR subtypes in these neurons, Cre-dependent viral vectors were used to express GFP-tagged GABAAR subunits (α6 and δ) selectively in hilar SOM neurons in SOM-Cre mice. In single-transfected animals, immunohistochemistry demonstrated strong expression of either the α6 or δ subunit; in cotransfected animals, both subunits were consistently expressed in the same neurons. Electrophysiology revealed a robust increase of tonic current, with progressively larger increases following transfection of δ, α6, and α6/δ subunits, respectively, indicating formation of functional receptors in all conditions and likely coassembly of the subunits in the same receptor following cotransfection. An in vitro model of repetitive bursting was used to determine the effects of increased tonic inhibition in hilar SOM interneurons on circuit activity in the dentate gyrus. Upon cotransfection, the frequency of GABAAR-mediated bursting in granule cells was reduced, consistent with a reduction in synchronous firing among hilar SOM interneurons. Moreover, in vivo studies of Fos expression demonstrated reduced activation of α6/δ-cotransfected neurons following acute seizure induction by pentylenetetrazole. The findings demonstrate that increasing tonic inhibition in hilar SOM interneurons can alter dentate gyrus circuit activity during strong stimulation and suggest that tonic inhibition of interneurons could play a role in regulating excessive synchrony within the network. SIGNIFICANCE STATEMENT In contrast to many hippocampal interneurons, somatostatin (SOM) neurons in the hilus of the dentate gyrus have very low levels of nonsynaptic GABAARs and exhibit

  1. Acute up-regulation of the rat brain somatostatin receptor-effector system by leptin is related to activation of insulin signaling and may counteract central leptin actions.

    Science.gov (United States)

    Perianes-Cachero, A; Burgos-Ramos, E; Puebla-Jiménez, L; Canelles, S; Frago, L M; Hervás-Aguilar, A; de Frutos, S; Toledo-Lobo, M V; Mela, V; Viveros, M P; Argente, J; Chowen, J A; Arilla-Ferreiro, E; Barrios, V

    2013-11-12

    Leptin and somatostatin (SRIF) have opposite effects on food seeking and ingestive behaviors, functions partially regulated by the frontoparietal cortex and hippocampus. Although it is known that the acute suppression of food intake mediated by leptin decreases with time, the counter-regulatory mechanisms remain unclear. Our aims were to analyze the effect of acute central leptin infusion on the SRIF receptor-effector system in these areas and the implication of related intracellular signaling mechanisms in this response. We studied 20 adult male Wister rats including controls and those treated intracerebroventricularly with a single dose of 5 μg of leptin and sacrificed 1 or 6h later. Density of SRIF receptors was unchanged at 1h, whereas leptin increased the density of SRIF receptors at 6h, which was correlated with an elevated capacity of SRIF to inhibit forskolin-stimulated adenylyl cyclase activity in both areas. The functional capacity of SRIF receptors was unaltered as cell membrane levels of αi1 and αi2 subunits of G inhibitory proteins were unaffected in both brain areas. The increased density of SRIF receptors was due to enhanced SRIF receptor subtype 2 (sst2) protein levels that correlated with higher mRNA levels for this receptor. These changes in sst2 mRNA levels were concomitant with increased activation of the insulin signaling, c-Jun and cyclic AMP response element-binding protein (CREB); however, activation of signal transducer and activator of transcription 3 was reduced in the cortex and unchanged in the hippocampus and suppressor of cytokine signaling 3 remained unchanged in these areas. In addition, the leptin antagonist L39A/D40A/F41A blocked the leptin-induced changes in SRIF receptors, leptin signaling and CREB activation. In conclusion, increased activation of insulin signaling after leptin infusion is related to acute up-regulation of the SRIF receptor-effector system that may antagonize short-term leptin actions in the rat brain

  2. Additional lesions detected in therapeutic scans with 177Lu-DOTATATE reflect higher affinity of 177Lu-DOTATATE for somatostatin receptors.

    Science.gov (United States)

    Mirzaei, Siroos; Bastati, Brigitte; Lipp, Rainer W; Knoll, Peter; Zojer, Niklas; Ludwig, Heinz

    2011-01-01

    Peptide receptor-targeted radionuclide therapy (PRRT) of somatostatin receptor (SR)-expressing neuroendocrine tumors (NETs) has become an established therapeutic option in patients with advanced NETs. The aim of this study was to compare the lesion detection rate of (99m)Tc-EDDA/HYNIC-TOC, a newly developed tracer for NET imaging, with (177)Lu-DOTATATE used for PRRT. 8 patients (4 women, 4 men, age range 46-76 years) with histologically proven NETs, who showed high SR loads by (99m)Tc-EDDA/HYNIC-TOC scintigraphy, were treated with (177)Lu-DOTATATE. After treatment, all patients were subjected to whole-body scintigraphy with additional low-dose single-photon emission computed tomography (SPECT-CT) of the chest and abdomen. All patients demonstrated (177)Lu-DOTATATE accumulation in all lesions previously detected by (99m)Tc- EDDA/HYNIC-TOC scintigraphy. Three patients showed additional lesions in the liver and lungs. SPECT-CT after (177)Lu-DOTATATE therapy may be helpful in detecting additional lesions not seen using (99m)Tc-EDDA/HYNIC-TOC. This could reflect the broader affinity of (177)Lu-DOTATATE for SRs compared with (99m)Tc-EDDA/HYNIC-TOC. Copyright © 2011 S. Karger AG, Basel.

  3. Radioautographic localization of somatostatin-14 and somatostatin-28 binding sites in the rat brain

    International Nuclear Information System (INIS)

    Leroux, P.; Pelletier, G.

    1984-01-01

    Somatostatin-14 (S14) and its precursor, somatostatin-28 (S28), are widely distributed throughout the rat brain, suggesting that they could act as neurotransmitter or neuromodulator in the central nervous system. The present study was undertaken to study the localization of S14 and S28 receptors in the rat brain determined by ''in vitro'' radioautography. The study performed on slide mounted frozen brain section with iodinated S14 and S28 analogs revealed an identical distribution of binding sites for the two forms of somatostatin. A good correlation could be observed between receptor distribution and immunohistologically localized neuropeptides except for striatum and hypothalamus. However, receptors were not detectable in the hypothalamus and were found in low concentration in the caudate-putamen nucleus, two regions containing high amounts of S28 and S14, suggesting a high occupancy of receptors in these areas by endogenous peptides or an inverse correlation between receptor and peptide concentrations

  4. 99mTc-N4-[Tyr3]Octreotate Versus 99mTc-EDDA/HYNIC-[Tyr3]Octreotide: an intrapatient comparison of two novel Technetium-99m labeled tracers for somatostatin receptor scintigraphy.

    Science.gov (United States)

    Gabriel, Michael; Decristoforo, Clemens; Maina, Theodosia; Nock, Berthold; vonGuggenberg, Elisabeth; Cordopatis, Paul; Moncayo, Roy

    2004-02-01

    Tetraamine-[Tyr3]octreotate (Demotate) is a somatostatin (SST) analogue that can be easily labeled with 99mTc at high specific activities and showed promising preclinical properties for SST receptor scintigraphy. This study reports on the first intra-patient comparison of 99mTc-Demotate and another 99mTc-labeled SST analogue, 99mTc-EDDA/HYNIC-TOC (HYNIC-TOC). Five patients with carcinoid tumors (n = 2) and endocrine pancreatic tumors (n = 3) were investigated with both radiopharmaceuticals. 99mTc-Demotate rapidly visualized somatostatin receptor positive tumors as early as 15 minutes post-injection (p.i.) with maximum tumor uptake and tumor/organ ratios already 1 hour p.i. Organs of predominant physiological uptake were the spleen and the kidneys with no intestinal excretion detectable up to 24 hours. 99mTc-Demotate exhibited faster pharmacokinetic properties compared to HYNIC-TOC. Tumor/organ ratios at equivalent time points were higher or comparable for 99mTc-Demotate in three patients with a matching scan result. Equivocal findings were observed in two patients, i.e. comparable uptake behavior in larger lesions with differences in smaller ones. 99mTc-Demotate is a promising agent for somatostatin receptor scintigraphy providing images of excellent quality as early as 1 hour after injection.

  5. Molecular imaging of neuroendocrine tumors using {sup 68}Ga-labeled peptides (Somatostatin receptor PET/CT); Molekulare Bildgebung neuroendokriner Tumoren mit {sup 68}Ga-markierten Peptiden (Somatostatinrezeptor-PET/CT)

    Energy Technology Data Exchange (ETDEWEB)

    Baum, R.P.; Prasad, V. [Zentralklinik Bad Berka GmbH (Germany). Klinik fuer Nuklearmedizin/PET-Zentrum; Hoersch, D. [Zentralklinik Bad Berka GmbH (Germany). Klinik fuer Innere Medizin, Gastroenterologie, Onkologie, Endokrionologie

    2009-06-15

    Receptor PET/CT using {sup 68}Ga-labeled somatostatin analogues (DOTA-NOC, DOTA-TOC or DOTA-TATE) enables the highly sensitive molecular imaging of neuroendocrine tumors (NETs) based on the expression of somatostatin receptors and even the detection of receptor subtypes. Our experience after more than 3000 studies shows that receptor PET/CT has a significantly higher tumor detection rate than conventional scintigraphy (even in SPECT/CT technique), and that tumor lesions can be very accurately localized. By calculating standardized uptake values (SUV) - which are reproducible and investigator-independent - patients can be selected for peptide receptor radiotherapy and also the course after therapy can be controlled. Receptor-PET/CT is the most sensitive imaging modality for the detection of unknown primary tumors (CUP syndrome), which is especially true for the detection of neuroendocrine tumors of the pancreas and small bowel; whole-body staging (''one stop shop'') as well as restaging and selection of patients for peptide receptor radiotherapy can be performed using a patient-friendly procedure (examination finished within one hour) exposing the patient to less radiation than whole-body CT scanning. The {sup 68}Ge/{sup 68}Ga generator has proved very reliable over the years - even in a hospital environment. The effective costs for {sup 68}Ga labeled somatostatin analogues might be less than for scintigraphic agents, provided a certain number of studies per year are performed. The development of new tumor-specific peptides as well as of other DOTA- or NOTA-coupled radiopharmaceuticals opens a new avenue into the future: finally, the {sup 68}Ga generator could play a similar important role for PET/CT as did the {sup 99m}Tc-Generator for conventional gamma camera imaging over the last decades. (orig.)

  6. Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with {sup 68}Ga-DOTA-octreotide: A potential PET tracer for beta cell mass measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Takeo [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Senda, Michio [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Watanabe, Yasuyoshi, E-mail: yywata@riken.jp [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)

    2013-12-06

    Highlights: •PET images showed high uptake of {sup 68}Ga-DOTA-octreotide in the normal pancreas. •{sup 68}Ga-DOTA-octreotide specifically binds to somatostatin receptors in the pancreas. •The pancreatic uptake of {sup 68}Ga-DOTA-octreotide was decreased in the diabetic rats. •{sup 68}Ga-DOTA-octreotide could be a candidate PET probe to measure the beta cell mass. -- Abstract: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with {sup 68}Gallium ({sup 68}Ga). After intravenous injection of {sup 68}Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that {sup 68}Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of {sup 68}Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with {sup 68}Ga-DOTA-octreotide could be a potential tool for evaluating BCM.

  7. Peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors: First comparative results using the somatostatin analogues Lu-177 DOTA-NOC and Lu-177 DOTA-TATE

    International Nuclear Information System (INIS)

    Wehrmann, C.; Senftleben, S.; Baum, R.P.

    2005-01-01

    Peptide receptor radionuclide therapy (PRRT) is used in our department since 5 years (approx. 400 applications) for the treatment of patients with metastatic neuroendocrine tumors. Of all known peptides, the somatostatin analogue DOTA-NOC shows in vitro the highest affinity to somatostatin receptors (sstr) 3 and 5 and a very high affinity to sstr 2. We studied the in vivo behaviour of the two peptides DOTA-NOC and DOTA-TATE (highest affinity to sstr 2) by the use of different parameters like tumor and organ uptake, effective half-lifes (kinetics) and mean absorbed organ and tumor doses. We studied 27 patients with metastatic neuroendocrine tumors with high somatostatin expression, as verified prior to treatment by Ga-68 DOTA-NOC receptor PET/CT or somatostatin receptor scintigraphy (Tc-99m EDDA-Hynic TOC or In-111 OctreoScan, planar and SPECT). 22 patients (8M and 14F; aged 619 years) were treated with 2500 6790 MBq Lu-177 DOTA-TATE. Another 5 patients (1M and 4F, aged 6310 years) were treated with 4000 7400 MBq Lu-177 DOTA-NOC. Labelling efficiency and radiochemical purity using Lutetium-177 chloride (obtained from PerkinElmer Life Sciences, USA) were constantly over 99.5%. Whole-body scans (anterior/posterior) were performed at 0.5h, 3h, 24h, 48h, 72h and 96h p.i. ROIs were drawn over the whole-body, organs, and different metastases (mainly in the liver). Blood samples were obtained in 12 patients after therapy with Lu-177 DOTA-TATE over 5 days for calculating the kinetics in blood. The ROI results were used to determine the uptake and effective half-life in different organs (kidney, spleen, liver, bone etc.) and the tumor residence times. By means of geometric mean, and after background correction, the ROI results were also used to calculate the estimated absorbed organ and tumor doses using the OLINDA software. Compared to Lu-177 DOTA-TATE (=100%), the uptake of Lu-177 DOTA-NOC was higher for the whole-body (45%) and for normal tissues (28%), and also in the

  8. [111In-DOTA]LTT-SS28, a first pansomatostatin radioligand for in vivo targeting of somatostatin receptor-positive tumors.

    Science.gov (United States)

    Maina, Theodosia; Cescato, Renzo; Waser, Beatrice; Tatsi, Aikaterini; Kaloudi, Aikaterini; Krenning, Eric P; de Jong, Marion; Nock, Berthold A; Reubi, Jean Claude

    2014-08-14

    Radiolabeled pansomatostatin-like analogues are expected to enhance the diagnostic sensitivity and to expand the clinical indications of currently applied sst2-specific radioligands. In this study, we present the somatostatin mimic [DOTA]LTT-SS28 {[(DOTA)Ser1,Leu8,D-Trp22,Tyr25]SS28} and its 111In radioligand. [DOTA]LTT-SS28 exhibited a pansomatostatin-like profile binding with high affinity to all five hsst1-hsst5 subtypes (IC50 values in the lower nanomolar range). Furthermore, [DOTA]LTT-SS28 behaved as an agonist at hsst2, hsst3, and hsst5, efficiently stimulating internalization of the three receptor subtypes. Radioligand [111In-DOTA]LTT-SS28 showed good stability in the mouse bloodstream. It displayed strong and specific uptake in AR42J tumors 4 h postinjection (9.3±1.6% ID/g vs 0.3±0.0% ID/g during sst2 blockade) in mice. Significant and specific uptake was also observed in HEK293-hsst2-, HEK293-hsst3-, and HEK293-hsst5-expressing tumors (4.43±1.5, 4.88±1.1, and DOTA]LTT-SS28 specifically localizes in sst2-, sst3-, and sst5-expressing xenografts in mice showing promise for multi-sst1-sst5 targeted tumor imaging.

  9. Altered Expression of Somatostatin Receptors in Pancreatic Islets from NOD Mice Cultured at Different Glucose Concentrations In Vitro and in Islets Transplanted to Diabetic NOD Mice In Vivo

    Directory of Open Access Journals (Sweden)

    Eva Ludvigsen

    2011-01-01

    Full Text Available Somatostatin acts via five receptors (sst1-5. We investigated if the changes in pancreatic islet sst expression in diabetic NOD mice compared to normoglycemic mice are a consequence of hyperglycemia or the ongoing immune reaction in the pancreas. Pancreatic islets were isolated from NOD mice precultured for 5 days and further cultured for 3 days at high or low glucose before examined. Islets were also isolated from NOD mice and transplanted to normal or diabetic mice in a number not sufficient to cure hyperglycemia. After three days, the transplants were removed and stained for sst1-5 and islet hormones. Overall, changes in sst islet cell expression were more common in islets cultured in high glucose concentration in vitro as compared to the islet transplantation in vivo to diabetic mice. The beta and PP cells exhibited more frequent changes in sst expression, while the alpha and delta cells were relatively unaffected by the high glucose condition. Our findings suggest that the glucose level may alter sst expressed in islets cells; however, immune mechanisms may counteract such changes in islet sst expression.

  10. An intrapatient comparison of 99mTc-EDDA/HYNIC-TOC with 111In-DTPA-octreotide for diagnosis of somatostatin receptor-expressing tumors.

    Science.gov (United States)

    Gabriel, Michael; Decristoforo, Clemens; Donnemiller, Eveline; Ulmer, Hanno; Watfah Rychlinski, Christine; Mather, Stephen J; Moncayo, Roy

    2003-05-01

    The aim of this study was to compare the imaging abilities of the recently developed somatostatin analog, (99m)Tc-hydrazinonicotinyl-Tyr(3)-octreotide ((99m)Tc-HYNIC-TOC [(99m)Tc-TOC]), with (111)In-diethylenediaminepentaacetic acid-D-Phe(1)-octreotide ((111)In-OCT [Octreoscan]) in patients undergoing routine somatostatin receptor (SSTR) scintigraphy. Forty-one patients (20 men, 21 women; age range, 29-75 y; mean age, 56.7 y) with either histologically proven or biologically and clinically suspected endocrine tumors were enrolled in the study. Four groups were distinguished: (a) patients being evaluated for the detection and localization of neuroendocrine tumors (n = 6), (b) tumor staging (n = 19), (c) patients being investigated to determine the SSTR status of tumor lesions (n = 11), and (d) patient follow-up studies (n = 5). Each patient received a mean activity of 150 MBq (111)In-OCT and 350-400 MBq (99m)Tc-TOC. Scintigraphy with (99m)Tc-TOC was performed 4 h after injection and scintigraphy with (111)In-OCT was performed 4 and 24 h after injection. SPECT studies of areas of interest were performed 4 h after injection for both tracers as well as at 24 h after injection for (111)In-OCT. The time interval between the studies using each tracer ranged from 2 to 22 d (mean interval, 9.3 d). (111)In-OCT and (99m)Tc-TOC showed an equivalent scan result in 32 patients (78%), 9 cases showed discrepancies (22%), false-negative results with (111)In-OCT were seen in 6 cases (14.6%), whereas (99m)Tc-TOC was false-positive in 2 cases (4.9%). (111)In-OCT was true-negative in both cases. The false-positive findings of the (99m)Tc-TOC studies were caused by nonspecific uptake in the bowel. In 1 case, (99m)Tc-TOC correctly identified a metastasis in the lumbar spine but both scan results were false-positive because of an inflammatory process. In 21 patients with SSTR-expressing tumors, the semiquantitative region-of-interest analysis showed that (99m)Tc-TOC achieved higher tumor

  11. The somatostatin receptor-targeted radiotherapeutic [{sup 90}Y-DOTA-dPhe{sup 1},Tyr{sup 3}]octreotide ({sup 90}Y-SMT 487) eradicates experimental rat pancreatic CA 20948 tumours

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, B.; Weckbecker, G.; Smith-Jones, P.M.; Albert, R.; Raulf, F.; Bruns, C. [Novartis Pharma AG, Basel (Switzerland)

    1998-07-01

    Somatostatin receptor-expressing tumours are potential targets for therapy with radiolabelled somatostatin analogues. We have synthesized a number of such analogues in the past and identified [DOTA-dPhe{sup 1}, Tyr{sup 3}]octreotide (SMT 487) as the most promising candidate molecule because of its advantageous properties in cellular and in vivo tumour models. In the current paper we describe the radiotherapeutic effect of yttrium-90 labelled SMT 487 in Lewis rats bearing the somatostatin receptor-positive rat pancreatic tumour CA 20948. SMT 487 binds with nanomolar affinity to both the human and the rat somatostatin receptor subtype 2 (sst{sub 2}) (human sst{sub 2} IC{sub 50}=0.9 nM, rat sst{sub 2} IC{sub 50}=0.5 nM). In vivo, {sup 90}Y-SMT 487 distributed rapidly to the sst{sub 2} expressing CA 20948 rat pancreatic tumour, with a tumour-to-blood ratio of 49.15 at 24 h post injection. A single intravenous administration of 10 mCi/kg {sup 90}Y-SMT 487 resulted in a complete remission of the tumours in five out of seven CA 20948 tumour-bearing Lewis rats. No regrowth of the tumours occurred 8 months post injection. Control animals that were treated with 30 {mu}g/kg of unlabelled SMT 487 had to be sacrificed 10 days post injection due to excessive growth or necrotic areas on the tumour surface. Upon re-inoculation of tumour cells into those rats that had shown complete remission, the tumours disappeared after 3-4 weeks of moderate growth without any further treatment. The present study shows for the first time the curative potential of {sup 90}Y-SMT 487-based radiotherapy for somatostatin receptor-expressing tumours. Clinical phase I studies with yttrium-labelled SMT 487 have started in September 1997. (orig.) With 4 figs., 2 tabs., 29 refs.

  12. Clinical Validation of a Pixon-Based Reconstruction Method Allowing a Twofold Reduction in Planar Images Time of 111In-Pentetreotide Somatostatin Receptor Scintigraphy

    Directory of Open Access Journals (Sweden)

    Philippe Thuillier

    2017-08-01

    Full Text Available ObjectiveThe objective of this study was to evaluate the diagnostic efficacy of Pixon-based reconstruction method on planar somatostatin receptor scintigraphy (SRS.MethodsAll patients with neuroendocrine tumors (NETs disease who were referred for SRS to our department during 1-year period from January to December 2015 were consecutively included. Three nuclear physicians independently reviewed all the data sets of images which included conventional images (CI; 15 min/view and processed images (PI obtained by reconstructing the first 450 s extracted data using Oncoflash® software package. Image analysis using a 3-point rating scale for abnormal uptake of 111 Indium-DTPA-Phe-octreotide in any lesion or organ was interpreted as positive, uncertain, or negative for the evidence of NET disease. A maximum grade uptake of the radiotracer in the lesion was assessed by the Krenning scale method. The results of image interpretation by the two methods were considered significantly discordant when the difference in organ involvement assessment was negative vs. positive or in lesion uptake was ≥2 grades. Agreement between the results of two methods and by different scan observers was evaluated using Cohen κ coefficients.ResultsThere was no significant (p = 0.403 correlation between data acquisition protocol and quality image. The rates of significant discrepancies for exam interpretation and organs involvement assessment were 2.8 and 2.6%, respectively. Mean κ values revealed a good agreement for concordance between CI and PI interpretation without difference of agreement for inter/intra-observer analysis.ConclusionOur results suggest the feasibility to use a Pixon-based reconstruction method for SRS planar images allowing a twofold reduction of acquisition time and without significant alteration of image quality or on image interpretation.

  13. Concordance between results of somatostatin receptor scintigraphy with 111In-DOTA-DPhe1-Tyr3-octreotide and chromogranin A assay in patients with neuroendocrine tumours

    International Nuclear Information System (INIS)

    Rodrigues, Margarida; Gabriel, Michael; Heute, Dirk; Putzer, Daniel; Virgolini, Irene; Griesmacher, Andrea

    2008-01-01

    Somatostatin receptor scintigraphy (SRS) and chromogranin A (CgA) assay have successfully been implemented in the clinical work-up and management of neuroendocrine tumour (NET) patients. However, there is still a lack of studies comparing results in these patients. Our aim was to compare directly in NET patients SRS and CgA assay results with special regard to tumour features such as grade of malignancy, primary origin, disease extent and function. One hundred twenty consecutive patients with histological confirmed NETs were investigated with 111 In-DOTA-DPhe 1 -Tyr 3 -octreotide ( 111 In-DOTA-TOC) SRS and CgA immunoradiometric assay. Tumours were classified by cell characteristics [well-differentiated NETs, well-differentiated neuroendocrine carcinomas, poorly differentiated neuroendocrine carcinomas (PDNECs)], primary origin (foregut, midgut, hindgut, undetermined), disease extent (limited disease, metastases, primary tumour and metastases) and functionality (secretory, nonsecretory). SRS was positive in 107 (89%) patients; CgA levels were increased in 95 (79%) patients. Overall, concordance between SRS and CgA results was found in 84 patients. Positive SRS but normal CgA level were found in 24 patients, with higher prevalence (p 111 In-DOTA-TOC SRS proved to be more sensitive than CgA in NETs patients. Tumour differentiation, disease extent and presence of liver metastases impact both SRS and CgA results, whereas nonsecretory activity is a negative predictor of only CgA increase. PDNECs and hindgut origin of tumours predispose to discrepancies with negative SRS but increased CgA levels. (orig.)

  14. Concordance between results of somatostatin receptor scintigraphy with 111In-DOTA-DPhe 1-Tyr 3-octreotide and chromogranin A assay in patients with neuroendocrine tumours.

    Science.gov (United States)

    Rodrigues, Margarida; Gabriel, Michael; Heute, Dirk; Putzer, Daniel; Griesmacher, Andrea; Virgolini, Irene

    2008-10-01

    Somatostatin receptor scintigraphy (SRS) and chromogranin A (CgA) assay have successfully been implemented in the clinical work-up and management of neuroendocrine tumour (NET) patients. However, there is still a lack of studies comparing results in these patients. Our aim was to compare directly in NET patients SRS and CgA assay results with special regard to tumour features such as grade of malignancy, primary origin, disease extent and function. One hundred twenty consecutive patients with histological confirmed NETs were investigated with (111)In-DOTA-DPhe(1)-Tyr(3)-octreotide ((111)In-DOTA-TOC) SRS and CgA immunoradiometric assay. Tumours were classified by cell characteristics [well-differentiated NETs, well-differentiated neuroendocrine carcinomas, poorly differentiated neuroendocrine carcinomas (PDNECs)], primary origin (foregut, midgut, hindgut, undetermined), disease extent (limited disease, metastases, primary tumour and metastases) and functionality (secretory, nonsecretory). SRS was positive in 107 (89%) patients; CgA levels were increased in 95 (79%) patients. Overall, concordance between SRS and CgA results was found in 84 patients. Positive SRS but normal CgA level were found in 24 patients, with higher prevalence (p<0.05) in patients with nonsecretory tumours. Conversely, negative SRS but CgA level increased were seen in 12 patients, with higher proportion (p<0.05) in patients with PDNECs and tumours of hindgut origin. Overall, (111)In-DOTA-TOC SRS proved to be more sensitive than CgA in NETs patients. Tumour differentiation, disease extent and presence of liver metastases impact both SRS and CgA results, whereas nonsecretory activity is a negative predictor of only CgA increase. PDNECs and hindgut origin of tumours predispose to discrepancies with negative SRS but increased CgA levels.

  15. Gastroenteropancreatic Neuroendocrine Tumors: Standardizing Therapy Monitoring with 68Ga-DOTATOC PET/CT Using the Example of Somatostatin Receptor Radionuclide Therapy

    Directory of Open Access Journals (Sweden)

    Wolfgang Luboldt

    2010-11-01

    Full Text Available The purpose of this study was to standardize therapy monitoring of hepatic metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs during the course of somatostatin receptor radionuclide therapy (SRRT. In 21 consecutive patients with nonresectable hepatic metastases of GEP-NETs, chromogranin A (CgA and 68Ga-DOTATOC PET/CT were compared before and after the last SRRT. On 68Ga-DOTATOC PET/CT, the maximum standard uptake values (SUVmax of normal liver and hepatic metastases were calculated. In addition, the volumes of hepatic metastases (volume of interest [VOI] were measured using four cut-offs to separate normal liver tissue from metastases (SUVmax of the normal liver plus 10% [VOIliver+10%], 20% [VOIliver+20%], 30% [VOIliver+30%] and SUV = 10 [VOI10SUV]. The SUVmaxof the normal liver was below 10 (7.2 ± 1.3 in all patients and without significant changes. Overall therapy changes (Δ per patient (mean [95% CI] were statistically significant with p < .01 for ΔCgA = −43 (−69 to −17, ΔSUVmax = −22 (−29 to −14, and ΔVOI10SUV = −53 (−68 to −38% and significant with p < .05 for ΔVOIliver+10% = −29 (−55 to −3%, ΔVOIliver+20% = −32 (−62 to −2 and ΔVOIliver+30% = −37 (−66 to −8. Correlations were found only between ΔCgA and ΔVOI10SUV (r = .595; p < .01, ΔSUVmax and ΔVOI10SUV (0.629, p < .01, and SUVmax and ΔSUVmax (r = .446; p < .05. 68Ga-DOTATOC PET/CT allows volumetric therapy monitoring via an SUV-based cut-off separating hepatic metastases from normal liver tissue (10 SUV recommended.

  16. Somatostatin-receptor-targeted α-emitting 213Bi is therapeutically more effective than β--emitting 177Lu in human pancreatic adenocarcinoma cells

    International Nuclear Information System (INIS)

    Nayak, Tapan K.; Norenberg, Jeffrey P.; Anderson, Tamara L.; Prossnitz, Eric R.; Stabin, Michael G.; Atcher, Robert W.

    2007-01-01

    Introduction: Advance clinical cancer therapy studies of patients treated with somatostatin receptor (sstr)-targeted [DOTA 0 -Tyr 3 ]octreotide (DOTATOC) labeled with low-linear-energy-transfer (LET) β - -emitters have shown overall response rates in the range of 15-33%. In order to improve outcomes, we sought to compare the therapeutic effectiveness of sstr-targeted high-LET α-emitting 213 Bi to that of low-LET β - -emitting 177 Lu by determining relative biological effectiveness (RBE) using the external γ-beam of 137 Cs as reference radiation. Methods: Sstr-expressing human pancreatic adenocarcinoma Capan-2 cells and A549 control cells were used for this study. The effects of different radiation doses of 213 Bi and 177 Lu labeled to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid and sstr-targeted DOTATOC were investigated with a clonogenic cell survival assay. Apoptosis was measured using the Cell Death Detection ELISA PLUS 10x kit. Results: Using equimolar DOTATOC treatment with concurrent irradiation with a 137 Cs source as reference radiation, the calculated RBE of [ 213 Bi]DOTATOC was 3.4, as compared to 1.0 for [ 177 Lu]DOTATOC. As measured in terms of absorbance units, [ 213 Bi]DOTATOC caused a 2.3-fold-greater release of apoptosis-specific mononucleosomes and oligonucleosomes than [ 177 Lu]DOTATOC at the final treatment time of 96 h (P 213 Bi]DOTATOC is therapeutically more effective in decreasing survival than is [ 177 Lu]DOTATOC in human pancreatic adenocarcinoma cells due to its comparatively higher RBE

  17. MIA PaCa-2 and PANC-1 - pancreas ductal adenocarcinoma cell lines with neuroendocrine differentiation and somatostatin receptors.

    Science.gov (United States)

    Gradiz, Rui; Silva, Henriqueta C; Carvalho, Lina; Botelho, Maria Filomena; Mota-Pinto, Anabela

    2016-02-17

    Studies using cell lines should always characterize these cells to ensure that the results are not distorted by unexpected morphological or genetic changes possibly due to culture time or passage number. Thus, the aim of this study was to describe those MIA PaCa-2 and PANC-1 cell line phenotype and genotype characteristics that may play a crucial role in pancreatic cancer therapeutic assays, namely neuroendocrine chemotherapy and peptide receptor radionuclide therapy. Epithelial, mesenchymal, endocrine and stem cell marker characterization was performed by immunohistochemistry and flow cytometry, and genotyping by PCR, gene sequencing and capillary electrophoresis. MIA PaCa-2 (polymorphism) expresses CK5.6, AE1/AE3, E-cadherin, vimentin, chromogranin A, synaptophysin, SSTR2 and NTR1 but not CD56. PANC-1 (pleomorphism) expresses CK5.6, MNF-116, vimentin, chromogranin A, CD56 and SSTR2 but not E-cadherin, synaptophysin or NTR1. MIA PaCA-1 is CD24(-), CD44(+/++), CD326(-/+) and CD133/1(-), while PANC-1 is CD24(-/+), CD44(+), CD326(-/+) and CD133/1(-). Both cell lines have KRAS and TP53 mutations and homozygous deletions including the first 3 exons of CDKN2A/p16(INK4A), but no SMAD4/DPC4 mutations or microsatellite instability. Both have neuroendocrine differentiation and SSTR2 receptors, precisely the features making them suitable for the therapies we propose to assay in future studies.

  18. Somatostatin receptor expression in the human spleen - Answer to an enigma by ex-vivo and in-vitro autoradiography after 177Lu-DOTA-octreotate administration

    International Nuclear Information System (INIS)

    Melis, M.; Swart, J. de; Groen, H.C.; Konijnenberg, M.W.; Van der Graaf, L.M.; Kaemmerer, D.; Kulkami, H.R.; Baum, R.P.; Lupp, A.; Saenger, J.; Jong, M. de

    2015-01-01

    Full text of publication follows. Aim: radiolabelled somatostatin analogues are being used for diagnostic and therapeutic (PRRT) purposes in patients with somatostatin receptor (SSTR) expressing tumours. During PRRT a significant spleen uptake may lead to radiation doses of > 20 Gy. Yet, the threshold dose for spleen radiation induced toxicity is currently unknown. Based on previous 68 Ga-DOTATOC PET/CT studies, demonstrating higher uptake in spleen than in splenosis, white pulp (WP) localization of radioactivity was suggested. This hypothesis was investigated in the current pilot study using the longer lived 177 Lu-DOTA-octreotate. Methods: a patient diagnosed with neuroendocrine neoplasm of the pancreatic tail (SUV max on 68 Ga-DOTATOC PET/CT 100.4) with liver metastasis (SUV 47.3, normal liver SUV 12.5) and uptake in the spleen (SUV 41.0) received 1 GBq 177 Lu-DOTA-octreotate. 2 h after administration whole-body planar scintigraphy and SPECT/CT of the upper abdomen was performed, followed by laparoscopic resection of the pancreatic tumour and splenectomy the next day. After spleen transport from Bad Berka to Rotterdam ex-vivo micro-SPECT of the removed spleen was acquired for 73 min using 2.5 mm diameter pinholes. Spleen fragments (∼10 * 10 * 5 mm) were either snap-frozen in liquid nitrogen or fixed in 10% formalin and paraffin embedded. Ex-vivo autoradiography of 10 μm cryo-sections was performed and serial sections were used for 111 In-DOTA-octreotate in-vitro autoradiography after decay of 177 Lu. FFPE sections were used for HE- and immunostaining for SSTR2A and cell subsets CD4 (Th-cell), CD8 (Ts-cell), CD20 (B-cell) and CD68 (macrophage). Results: 177 Lu-DOTA-octreotate scintigraphy and SPECT/CT demonstrated high uptake in the pancreatic tumor, hepatic metastasis and homogeneously in the normal spleen. High resolution micro-SPECT imaging of the isolated spleen also revealed a relatively homogeneous uptake (calculated rest activity 60 MBq 177 Lu). The

  19. Somatostatin receptor PET in neuroendocrine tumours: 68Ga-DOTA0,Tyr3-octreotide versus 68Ga-DOTA0-lanreotide

    International Nuclear Information System (INIS)

    Putzer, Daniel; Kroiss, Alexander; Waitz, Dietmar; Gabriel, Michael; Uprimny, Christian; Guggenberg, Elisabeth von; Decristoforo, Clemens; Warwitz, Boris; Virgolini, Irene Johanna; Traub-Weidinger, Tatjana; Widmann, Gerlig

    2013-01-01

    The aim of this study was to evaluate the impact of 68 Ga-labelled DOTA 0 -lanreotide ( 68 Ga-DOTA-LAN) on the diagnostic assessment of neuroendocrine tumour (NET) patients with low to moderate uptake on planar somatostatin receptor (SSTR) scintigraphy or 68 Ga-labelled DOTA 0 ,Tyr 3 -octreotide ( 68 Ga-DOTA-TOC) positron emission tomography (PET). Fifty-three patients with histologically confirmed NET and clinical signs of progressive disease, who had not qualified for peptide receptor radionuclide therapy (PRRT) on planar SSTR scintigraphy or 68 Ga-DOTA-TOC PET (n = 38) due to lack of tracer uptake, underwent 68 Ga-DOTA-LAN PET to evaluate a treatment option with 90 Y-labelled lanreotide according to the MAURITIUS trial. The included patients received 150 ± 30 MBq of each radiopharmaceutical intravenously. PET scans were acquired 60-90 min after intravenous bolus injection. Image results from both PET scans were compared head to head, focusing on the intensity of tracer uptake in terms of treatment decision. CT was used for morphologic correlation of tumour lesions. To further evaluate the binding affinities of each tracer, quantitative and qualitative values were calculated for target lesions. 68 Ga-DOTA-LAN and 68 Ga-DOTA-TOC both showed equivalent findings in 24/38 patients when fused PET/CT images were interpreted. The sensitivity, specificity and accuracy of 68 Ga-DOTA-LAN in comparison to CT were 0.63, 0.5 and 0.62 (n = 53; p 68 Ga-DOTA-TOC in comparison to CT 0.78, 0.5 and 0.76 (n = 38; p 68 Ga-DOTA-TOC showed a significantly higher maximum standardized uptake value (SUV max ) regarding the primary tumour in 25 patients (p 68 Ga-DOTA-LAN. Corresponding values of both PET scans for tumour and liver did not show any significant correlation. 68 Ga-DOTA-TOC revealed more tumour sites than 68 Ga-DOTA-LAN (106 vs 53). The tumour to background ratios for tumour and liver calculated from SUV max measurements were significantly higher for 68 Ga-DOTA-TOC than 68 Ga

  20. OctreoScan 111 for imaging of a somatostatin receptor-positive islet cell tumor in rat

    International Nuclear Information System (INIS)

    Bruns, C.; Stolz, B.; Albert, R.; Marbach, P.; Pless, J.

    1993-01-01

    We report here the in vitro characterization of SDZ 215-811 and the in vivo imaging of a islet cell tumor gown in rats using [ 111 In]SDZ 215-811. In vitro autoradiographies revelaed a high density of SRIF receptors on the pancreatic tumor tissue. As early as 5 min after intravenous injection of [ 111 In]SDZ 215-811 into tumour-bearing rats, the tumors were clearly localized by gamma-camera scintigraphy. Even 24 h post injection, the islet cell tumor was still detectable. The radioligand was mainly cleared from the circulation via the Kidneys, with a rapid α-phase (t 1/2 =5.6 min) and a slow elimination phase (t 1/2 =7.3 h). Biodistribution studies revealed a relatively high accumulation of radioactivity in the kidneys, but low uptake into the liver and the intestine. High uptake of [ 111 In]SDZ 215-811 was observed for the tumor tissue (0.92±0.07% ID/g; 1 h post injection). Interestingly, a tumor load of 0.14±0.01% ID/g was still measured after 24 h. The tumor/blood ratio was 4.93 after 24 h, indicating specific accumulation of radioactivity in the islet cell tumour. [ 111 In]SDZ 215-811 appears to be sensitive and specific ligand for SRIF receptorpositive tumors and offers an easy procedure for scintigraphic imaging of such tumors in man. (orig.)

  1. Therapy with radiolabelled somatostatin analogs in neuroendocrine tumors

    International Nuclear Information System (INIS)

    Kunikowska, J.; Krolicki, L.

    2007-01-01

    In the 80's the discovery of somatostatin receptors expression on NET cells enabled the application of somatostatin analogues in diagnosis and therapy. Initially, 'cold' somatostatin analogs were used for therapeutical purpose, with overall good clinical response, but with minimal anti-proliferation effect. Furthermore, radiolabelled receptor-binding peptides have been shown to be an important class of radiopharmaceuticals for tumor diagnosis and therapy with minimal side-effects. Specific binding between receptor on tumor cell and peptide with beta emitting radionuclide act not only on tumor related symptoms but also on tumor cell via radiotoxic effect of beta radiation. Discoveries of next receptor combinations, allow the work over synthesis and applications of next receptors' analogs both in diagnosis and in therapy. Due to complex characteristics of NET's, the use therapeutic 'cocktail' containing the variety analogs may be of great importance. (author)

  2. Technetium-99m labeled somatostatin and analogs: synthesis, characterization and in vivo evaluation

    International Nuclear Information System (INIS)

    Amartey, J.K.

    1993-01-01

    Technetium-99m complexes of somatostatin and analogs were synthesized following the introduction of sulfhydryl groups with 2-iminothiolane (Traut's Reagent). In rats the complex was taken up by the liver, kidneys, adrenals, lungs and the pancreas. Analysis of urine samples of treated rats showed that the radiochemicals have reasonably good in vivo stability. This implies that the complexes may be potentially useful for biochemical characterization of somatostatin receptors and also in scintigraphic detection of somatostatin receptor positive tumors, especially for metastatic deposits in patients on somatostatin therapy. (Author)

  3. 68Ga-DOTATOC PET/CT and somatostatin receptor (sst1-sst5) expression in normal human tissue: correlation of sst2 mRNA and SUVmax

    International Nuclear Information System (INIS)

    Boy, Christian; Poeppel, Thorsten D.; Jentzen, Walter; Brandau, Wolfgang; Bockisch, Andreas; Heusner, Till A.; Antoch, Gerald; Redmann-Bischofs, Anja; Unger, Nicole; Mann, Klaus; Petersenn, Stephan

    2011-01-01

    By targeting somatostatin receptors (sst) radiopeptides have been established for both diagnosis and therapy. For physiologically normal human tissues the study provides a normative database of maximum standardized uptake value (SUV max ) and sst mRNA. A total of 120 patients were subjected to diagnostic 68 Ga-DOTATOC positron emission tomography (PET)/CT (age range 19-83 years). SUV max values were measured in physiologically normal tissues defined by normal morphology, absence of surgical intervention and absence of metastatic spread during clinical follow-up. Expression of sst subtypes (sst1-sst5) was measured independently in pooled adult normal human tissue by real-time reverse transcriptase polymerase chain reaction (RT-PCR). SUV max revealed a region-specific pattern (e.g., mean ± SD, spleen 31.1 ± 10.9, kidney 16.9 ± 5.3, liver 12.8 ± 3.6, stomach 7.0 ± 3.1, head of pancreas 6.2 ± 2.3, small bowel 4.8 ± 1.8, thyroid 4.7 ± 2.2, bone 3.9 ± 1.3, large bowel 2.9 ± 0.8, muscle 2.1 ± 0.5, parotid gland 1.9 ± 0.6, axillary lymph node 0.8 ± 0.3 and lung 0.7 ± 0.3). SUV max was age independent. Gender differences were evident within the thyroid (female/male: 3.7 ± 1.6/5.5 ± 2.4, p max values exclusively correlated with sst2 expression (r = 0.846, p max with the expression of the other four subtypes. In normal human tissues 68 Ga-DOTATOC imaging has been related to the expression of sst2 at the level of mRNA. The novel normative database may improve diagnostics, monitoring and therapy of sst-expressing tumours or inflammation on a molecular basis. (orig.)

  4. Current knowledge on the sensitivity of the 68Ga-somatostatin receptor positron emission tomography and the SUVmax reference range for management of pancreatic neuroendocrine tumours

    International Nuclear Information System (INIS)

    Virgolini, Irene; Gabriel, Michael; Kroiss, Alexander; Guggenberg, Elisabeth von; Prommegger, Rupert; Warwitz, Boris; Nilica, Bernhard; Roig, Ilanos Geraldo; Rodrigues, Margarida; Uprimny, Christian

    2016-01-01

    Physiologically increased pancreatic uptake at the head/uncinate process is observed in more than one-third of patients after injection of one of the three 68 Ga-labelled octreotide-based peptides used for somatostatin (sst) receptor (r) imaging. There are minor differences between these 68 Ga-sstr-binding peptides in the imaging setting. On 68 Ga-sstr-imaging the physiological uptake can be diffuse or focal and usually remains stable over time. Differences in the maximal standardised uptake values (SUV max ) reported for the normal pancreas as well as for pancreatic neuroendocrine tumour (PNET) lesions may be related to several factors, including (a) differences in the peptide binding affinities as well as differences in sstr subtype expression of pancreatic α- and β-cells, and heterogeneity / density of tumour cells, (b) differences in scanner resolution, image reconstruction techniques and acquisition protocols, (c) mostly retrospective study designs, (d) mixed patient populations, or (e) interference with medications such as treatment with long-acting sst analogues. The major limitation in most of the studies lies in the lack of histopathological confirmation of abnormal findings. There is a significant overlap between the calculated SUV max -values for physiological pancreas and PNET-lesions of the head/uncinate process that do not favour the use of quantitative parameters in the clinical setting. Anecdotal long-term follow-up studies have even indicated that increased uptake in the head/uncinate process still can turn out to be malignant over years of follow up. SUV max -data for the pancreatic body and tail are limited. Therefore, any visible focal tracer uptake in the pancreas must be considered as suspicious for malignancy irrespective of quantitative parameters. In general, sstr-PET/CT has significant implications for the management of NET patients leading to a change in treatment decision in about one-third of patients. Therefore, follow-up with 68 Ga

  5. Current knowledge on the sensitivity of the (68)Ga-somatostatin receptor positron emission tomography and the SUVmax reference range for management of pancreatic neuroendocrine tumours.

    Science.gov (United States)

    Virgolini, Irene; Gabriel, Michael; Kroiss, Alexander; von Guggenberg, Elisabeth; Prommegger, Rupert; Warwitz, Boris; Nilica, Bernhard; Roig, Llanos Geraldo; Rodrigues, Margarida; Uprimny, Christian

    2016-10-01

    Physiologically increased pancreatic uptake at the head/uncinate process is observed in more than one-third of patients after injection of one of the three (68)Ga-labelled octreotide-based peptides used for somatostatin (sst) receptor (r) imaging. There are minor differences between these (68)Ga-sstr-binding peptides in the imaging setting. On (68)Ga-sstr-imaging the physiological uptake can be diffuse or focal and usually remains stable over time. Differences in the maximal standardised uptake values (SUVmax) reported for the normal pancreas as well as for pancreatic neuroendocrine tumour (PNET) lesions may be related to several factors, including (a) differences in the peptide binding affinities as well as differences in sstr subtype expression of pancreatic α- and β-cells, and heterogeneity / density of tumour cells, (b) differences in scanner resolution, image reconstruction techniques and acquisition protocols, (c) mostly retrospective study designs, (d) mixed patient populations, or (e) interference with medications such as treatment with long-acting sst analogues. The major limitation in most of the studies lies in the lack of histopathological confirmation of abnormal findings. There is a significant overlap between the calculated SUVmax-values for physiological pancreas and PNET-lesions of the head/uncinate process that do not favour the use of quantitative parameters in the clinical setting. Anecdotal long-term follow-up studies have even indicated that increased uptake in the head/uncinate process still can turn out to be malignant over years of follow up. SUVmax-data for the pancreatic body and tail are limited. Therefore, any visible focal tracer uptake in the pancreas must be considered as suspicious for malignancy irrespective of quantitative parameters. In general, sstr-PET/CT has significant implications for the management of NET patients leading to a change in treatment decision in about one-third of patients. Therefore, follow-up with (68)Ga

  6. Decision-tree model for health economic comparison of two long-acting somatostatin receptor ligand devices in France, Germany, and the UK.

    Science.gov (United States)

    Marty, Rémi; Roze, Stéphane; Kurth, Hannah

    2012-01-01

    Long-acting somatostatin receptor ligands (SRL) with product-specific formulation and means of administration are injected periodically in patients with acromegaly and neuroendocrine tumors. A simple decision-tree model aimed at comparing cost savings with ready-to-use Somatuline Autogel(®) (lanreotide) and Sandostatin LAR(®) (octreotide) for the UK, France, and Germany. The drivers of cost savings studied were the reduction of time to administer as well as a reduced baseline risk of clogging during product administration reported for Somatuline Autogel(®). The decision-tree model assumed two settings for SRL administration, ie, by either hospital-based or community-based nurses. In the case of clogging, the first dose was assumed to be lost and a second injection performed. Successful injection depended on the probability of clogging. Direct medical costs were included. A set of scenarios were run, varying the cost drivers, such as the baseline risk of clogging, SRL administration time, and percentage of patients injected during a hospital stay. Costs per successful injection were less for Somatuline Autogel(®)/Depot, ranging from Euros (EUR) 13-45, EUR 52-108, and EUR 127-151, respectively, for France, Germany, and the UK. The prices for both long-acting SRL were the same in France, and cost savings came to 100% from differences other than drug prices. For Germany and the UK, the proportion of savings due to less clogging and shorter administration time was estimated to be around 32% and 20%, respectively. Based on low and high country-specific patient cohort size estimations of individuals eligible for SRL treatment among the patient population with acromegaly and neuroendocrine tumors, annual savings were estimated to be up to EUR 2,000,000 for France, EUR 6,000,000 for Germany, and EUR 7,000,000 for the UK. This model suggests that increasing usage of the Somatuline device for injection of SRL might lead to substantial savings for health care providers

  7. Somatostatin receptor PET in neuroendocrine tumours: 68Ga-DOTA0,Tyr3-octreotide versus 68Ga-DOTA0-lanreotide.

    Science.gov (United States)

    Putzer, Daniel; Kroiss, Alexander; Waitz, Dietmar; Gabriel, Michael; Traub-Weidinger, Tatjana; Uprimny, Christian; von Guggenberg, Elisabeth; Decristoforo, Clemens; Warwitz, Boris; Widmann, Gerlig; Virgolini, Irene Johanna

    2013-02-01

    The aim of this study was to evaluate the impact of (68)Ga-labelled DOTA(0)-lanreotide ((68)Ga-DOTA-LAN) on the diagnostic assessment of neuroendocrine tumour (NET) patients with low to moderate uptake on planar somatostatin receptor (SSTR) scintigraphy or (68)Ga-labelled DOTA(0),Tyr(3)-octreotide ((68)Ga-DOTA-TOC) positron emission tomography (PET). Fifty-three patients with histologically confirmed NET and clinical signs of progressive disease, who had not qualified for peptide receptor radionuclide therapy (PRRT) on planar SSTR scintigraphy or (68)Ga-DOTA-TOC PET (n = 38) due to lack of tracer uptake, underwent (68)Ga-DOTA-LAN PET to evaluate a treatment option with (90)Y-labelled lanreotide according to the MAURITIUS trial. The included patients received 150 ± 30 MBq of each radiopharmaceutical intravenously. PET scans were acquired 60-90 min after intravenous bolus injection. Image results from both PET scans were compared head to head, focusing on the intensity of tracer uptake in terms of treatment decision. CT was used for morphologic correlation of tumour lesions. To further evaluate the binding affinities of each tracer, quantitative and qualitative values were calculated for target lesions. (68)Ga-DOTA-LAN and (68)Ga-DOTA-TOC both showed equivalent findings in 24/38 patients when fused PET/CT images were interpreted. The sensitivity, specificity and accuracy of (68)Ga-DOTA-LAN in comparison to CT were 0.63, 0.5 and 0.62 (n = 53; p < 0.0001) and for (68)Ga-DOTA-TOC in comparison to CT 0.78, 0.5 and 0.76 (n = 38; p < 0.013), respectively. (68)Ga-DOTA-TOC showed a significantly higher maximum standardized uptake value (SUV(max)) regarding the primary tumour in 25 patients (p < 0.003) and regarding the liver in 30 patients (p < 0.009) compared to (68)Ga-DOTA-LAN. Corresponding values of both PET scans for tumour and liver did not show any significant correlation. (68)Ga-DOTA-TOC revealed more tumour sites than (68)Ga

  8. Somatostatin receptor PET in neuroendocrine tumours: {sup 68}Ga-DOTA{sup 0},Tyr{sup 3}-octreotide versus {sup 68}Ga-DOTA{sup 0}-lanreotide

    Energy Technology Data Exchange (ETDEWEB)

    Putzer, Daniel; Kroiss, Alexander; Waitz, Dietmar; Gabriel, Michael; Uprimny, Christian; Guggenberg, Elisabeth von; Decristoforo, Clemens; Warwitz, Boris; Virgolini, Irene Johanna [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria); Traub-Weidinger, Tatjana [Vienna Medical University, Department of Nuclear Medicine, Vienna (Austria); Widmann, Gerlig [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria)

    2013-03-15

    The aim of this study was to evaluate the impact of {sup 68}Ga-labelled DOTA{sup 0}-lanreotide ({sup 68}Ga-DOTA-LAN) on the diagnostic assessment of neuroendocrine tumour (NET) patients with low to moderate uptake on planar somatostatin receptor (SSTR) scintigraphy or {sup 68}Ga-labelled DOTA{sup 0},Tyr{sup 3}-octreotide ({sup 68}Ga-DOTA-TOC) positron emission tomography (PET). Fifty-three patients with histologically confirmed NET and clinical signs of progressive disease, who had not qualified for peptide receptor radionuclide therapy (PRRT) on planar SSTR scintigraphy or {sup 68}Ga-DOTA-TOC PET (n = 38) due to lack of tracer uptake, underwent {sup 68}Ga-DOTA-LAN PET to evaluate a treatment option with {sup 90}Y-labelled lanreotide according to the MAURITIUS trial. The included patients received 150 {+-} 30 MBq of each radiopharmaceutical intravenously. PET scans were acquired 60-90 min after intravenous bolus injection. Image results from both PET scans were compared head to head, focusing on the intensity of tracer uptake in terms of treatment decision. CT was used for morphologic correlation of tumour lesions. To further evaluate the binding affinities of each tracer, quantitative and qualitative values were calculated for target lesions. {sup 68}Ga-DOTA-LAN and {sup 68}Ga-DOTA-TOC both showed equivalent findings in 24/38 patients when fused PET/CT images were interpreted. The sensitivity, specificity and accuracy of {sup 68}Ga-DOTA-LAN in comparison to CT were 0.63, 0.5 and 0.62 (n = 53; p < 0.0001) and for {sup 68}Ga-DOTA-TOC in comparison to CT 0.78, 0.5 and 0.76 (n = 38; p < 0.013), respectively. {sup 68}Ga-DOTA-TOC showed a significantly higher maximum standardized uptake value (SUV{sub max}) regarding the primary tumour in 25 patients (p < 0.003) and regarding the liver in 30 patients (p < 0.009) compared to {sup 68}Ga-DOTA-LAN. Corresponding values of both PET scans for tumour and liver did not show any significant correlation. {sup 68}Ga

  9. The somatostatin receptor 2 antagonist 64Cu-NODAGA-JR11 outperforms 64Cu-DOTA-TATE in a mouse xenograft model

    Science.gov (United States)

    Rylova, Svetlana N.; Stoykow, Christian; Del Pozzo, Luigi; Abiraj, Keelara; Tamma, Maria Luisa; Kiefer, Yvonne; Fani, Melpomeni; Maecke, Helmut R.

    2018-01-01

    Copper-64 is an attractive radionuclide for PET imaging and is frequently used in clinical applications. The aim of this study was to perform a side-by-side comparison of the in vitro and in vivo performance of 64Cu-NODAGA-JR11 (NODAGA = 1,4,7-triazacyclononane,1-glutaric acid,4,7-acetic acid, JR11 = p-Cl-Phe-cyclo(D-Cys-Aph(Hor)-D-Aph(cbm)-Lys-Thr-Cys)D-Tyr-NH2), a somatostatin receptor 2 antagonist, with the clinically used sst2 agonist 64Cu-DOTA-TATE ((TATE = D-Phe-cyclo(Cys-Tyr-D-Trp-Lys-Thr-Cys)Thr). In vitro studies demonstrated Kd values of 5.7±0.95 nM (Bmax = 4.1±0.18 nM) for the antagonist 64/natCu-NODAGA-JR11 and 20.1±4.4. nM (Bmax = 0.48±0.18 nM) for the agonist 64/natCu-DOTA-TATE. Cell uptake studies showed the expected differences between agonists and antagonists. Whereas 64Cu-DOTA-TATE (the agonist) showed very effective internalization in the cell culture assay (with 50% internalized at 4 hours post-peptide addition under the given experimental conditions), 64Cu-NODAGA-JR11 (the antagonist) showed little internalization but strong receptor-mediated uptake at the cell membrane. Biodistribution studies of 64Cu-NODAGA-JR11 showed rapid blood clearance and tumor uptake with increasing tumor-to-relevant organ ratios within the first 4 hours and in some cases, 24 hours, respectively. The tumor washout was slow or non-existent in the first 4 hours, whereas the kidney washout was very efficient, leading to high and increasing tumor-to-kidney ratios over time. Specificity of tumor uptake was proven by co-injection of high excess of non-radiolabeled peptide, which led to >80% tumor blocking. 64Cu-DOTA-TATE showed less favorable pharmacokinetics, with the exception of lower kidney uptake. Blood clearance was distinctly slower and persistent higher blood values were found at 24 hours. Uptake in the liver and lung was relatively high and also persistent. The tumor uptake was specific and similar to that of 64Cu-NODAGA-JR11 at 1 h, but release from the tumor

  10. 99mTc-EDDA/HYNIC-TOC: a new 99mTc-labelled radiopharmaceutical for imaging somatostatin receptor-positive tumours: first clinical results and intra-patient comparison with 111In-labelled octreotide derivatives

    International Nuclear Information System (INIS)

    Decristoforo, C.; Cholewinski, W.; Donnemiller, E.; Riccabona, G.; Moncayo, R.

    2000-01-01

    [ 111 In-diethylene triamine penta-acetic acid-d-Phe 1 ]-octreotide (DTPA-octreotide) scintigraphy has gained widespread acceptance as a diagnostic clinical procedure in oncology for imaging somatostatin receptor-positive tumours. However, indium-111 as a radiolabel has several drawbacks, including limited availability, suboptimal gamma energy and high radiation burden to the patient. We have recently reported on the preclinical development of 99m Tc-EDDA/HYNIC-TOC, a new octreotide derivative which showed promising results both in vitro and in vivo. We now report our initial clinical experiences with this new radiopharmaceutical in ten oncological patients. The clinical diagnoses were: carcinoid syndrome (n=5), thyroid cancer (n=3), pancreatic cancer (n=1) and pituitary tumour (n=1). The biodistribution and kinetics of 99m Tc-EDDA/HYNIC-TOC were compared with those of 111 In-DTPA-octreotide in six cases, and with those of 111 In-DOTA-TOC in five cases. With the new tracer tumours were imaged within 15 min after injection and showed the highest target/non-target ratios 4 h after injection. Tumour uptake persisted up to 20 h p.i. The rate of blood clearance was similar to that of 111 In-DTPA-octreotide but faster than that of 111 In-DOTA-TOC, while urinary excretion was lower compared with the 111 In derivatives. Semi-quantitative region of interest analysis showed that 99m Tc-EDDA/HYNIC-TOC produced higher tumour/organ (target/non-target) ratios than the 111 In derivatives, especially in relation to heart and muscle. Significantly more lesions could be detected in 99m Tc images. We conclude that 99m Tc-EDDA/HYNIC-TOC shows better imaging properties for the identification of somatostatin receptor-positive tumour sites than currently available 111 In-labelled octreotide derivatives. (orig.)

  11. 99mTc-EDDA/HYNIC-TOC: a new 99mTc-labelled radiopharmaceutical for imaging somatostatin receptor-positive tumours; first clinical results and intra-patient comparison with 111In-labelled octreotide derivatives.

    Science.gov (United States)

    Decristoforo, C; Mather, S J; Cholewinski, W; Donnemiller, E; Riccabona, G; Moncayo, R

    2000-09-01

    [111In-diethylene triamine penta-acetic acid-D-Phe1]-octreotide (DTPA-octreotide) scintigraphy has gained widespread acceptance as a diagnostic clinical procedure in oncology for imaging somatostatin receptor-positive tumours. However, indium-111 as a radiolabel has several drawbacks, including limited availability, suboptimal gamma energy and high radiation burden to the patient. We have recently reported on the preclinical development of 99mTc-EDDA/HYNIC-TOC, a new octreotide derivative which showed promising results both in vitro and in vivo. We now report our initial clinical experiences with this new radiopharmaceutical in ten oncological patients. The clinical diagnoses were: carcinoid syndrome (n=5), thyroid cancer (n=3), pancreatic cancer (n=1) and pituitary tumour (n=1). The biodistribution and kinetics of 99mTc-EDDA/HYNIC-TOC were compared with those of 111In-DTPA-octreotide in six cases, and with those of 111In-DOTA-TOC in five cases. With the new tracer tumours were imaged within 15 min after injection and showed the highest target/non-target ratios 4 h after injection. Tumour uptake persisted up to 20 h p.i. The rate of blood clearance was similar to that of 111In-DTPA-octreotide but faster than that of 111In-DOTA-TOC, while urinary excretion was lower compared with the 111In derivatives. Semi-quantitative region of interest analysis showed that 99mTc-EDDA/HYNIC-TOC produced higher tumour/organ (target/non-target) ratios than the 111In derivatives, especially in relation to heart and muscle. Significantly more lesions could be detected in 99mTc images. We conclude that 99mTcEDDA/HYNIC-TOC shows better imaging properties for the identification of somatostatin receptor-positive tumour sites than currently available 111In-labelled octreotide derivatives.

  12. Receptor scintigraphy using the Tc-99M-labelled somatostatin analogue EDDA-TRYCINE-HYNIC-TOC: clinical results in different tumor types and comparison with In-111 DOTATOC during Y-90 DOTATOC radioreceptor therapy

    International Nuclear Information System (INIS)

    Baum, R.P.; Schmuecking, M.; Fischer, S.; Przetak, C.; Niesen, A.; Maecke, H.R.

    2002-01-01

    Aim: To evaluate Tc-99m EDDA-TRYCINE-HYNIC-TOC in patients with somatostatin receptor positive tumours (staging, pre-therapeutic dosimetry for radioreceptor therapy and restaging after therapy) in comparison with In-111 DOTATOC. Material and Methods: The Tc-99m labelled somatostatin analogue was synthesized by an optimized procedure in our pharmaceutical laboratory using lyophilized kits (radiochemical purity by HPLC, TLC > 95%, product stability in vitro 4 to 6h). So far, 58 patients (60 examinations) were studied after injection of 580-890 MBq (median 673 MBq) EDDA-TRYCINE-HYNIC-TOC. The histologically proven tumours were neuroendocrine neoplasias, renal carcinomas, bronchial carcinoma, mesothelioma and malignant fibrous histiocytoma. The imaging protocol consisted of whole-body scans and planar images of the tumor region (15 min, 1 h, 2 h, 4 h, 8 h, 24 h p.i.) and additionally SPECT-images (1 h und 4 h p.i.). For semi-quantitative assessment, individual regions of interest (ROI) were drawn in order to generate time-activity curves and to calculate tumour-to-tissue/background ratios which were compared by visual grading (scala 0 to 3+). Furthermore, pharmacokinetic analyses were carried out (radioactivity kinetics in plasma and urine). In some selected patients, image fusion of whole-body scans was performed with CT and/or MRT and/or PET using a NUD software and a HERMES computer. Results: 10 out of 58 patients showed an intense tracer accumulation in the SSTR-positive tumours (visual 3+, tumour/background ratio >2,5). In these patients, radioreceptor therapy was carried out using Y-90 DOTATOC (simultaneous injection von 150 MBq In-111 DOTATOC). All pretherapeutic scans with the Tc-99m labelled ligand (4 h p.i.) showed a similar overall pattern of biodistribution and tumour uptake in comparison to the therapy scans with In-111 / Y-90 DOTATOC (24 h p.i.). The Tc-99m EDDA-TRYCINE-HYNIC-TOC scans (incl. SPECT) offered superior imaging properties with earlier tumour

  13. Receptor imaging with a new Tc-99m labelled somatostatin analogue (Tc-99m EDDA-TRYCINE-HYNIC-TOC): first clinical results and comparison with In-111 Dotatoc during radioreceptor therapy with Y-90 Dotatoc

    International Nuclear Information System (INIS)

    Baum, R.P.; Schmuecking, M.; Fischer, S.; Przetak, C.; Niesen, A.; Maecke, H.R.

    2002-01-01

    Full text: To evaluate Tc-99m EDDA-TRYCINE-HYNIC-TOC (TET-H-TOC) in patients with somatostatin receptor (SSTR)-positive tumors (staging, pretherapeutic indication for radioreceptor therapy and restaging after therapy) in comparison with In-111 DOTATOC. The Tc-99m labelled somatostatin analogue was synthesized by an optimized procedure in our pharmaceutical lab using lyophilized kits (radiochemical purity by HPLC, TLC > 95 %, product stability in vitro 4 to 6 h). So far, 46 patients (53 examinations) were studied after injection of 580-890 MBq (median 673 MBq) TET-H-TOC. The histologically proven tumors were endocrine neoplasias, renal carcinomas, bronchial carcinoma, mesothelioma and malignant fibrous histiocytoma. The imaging protocol consisted of whole-body scans and planar images of the tumor region (15 min, 1 h, 2 h, 4 h, 8 h, 24 h p.i.) and additionally SPECT-images (1 h and 4 h p.i.). For semi-quantitative assessment, individual regions of interest (ROI) were drawn in order to generate time-activity curves and to calculate tumor-to-tissue/background ratios which were compared by visual grading (scale 0 to 3+). Furthermore, pharmacokinetic analyses were carried out (radioactivity kinetics in plasma and urine). In some selected patients, image fusion of the whole-body scans was performed with CT and/or MRT and/or PET using a HERMES computer. 7 out of 46 patients showed an intense tracer accumulation in the SSTR-positive tumors (visual 3+, tumor / background ratio >2,5). In these patients, radioreceptor therapy was carried out using Y-90 DOTATOC (simultaneous injection of 150 MBq In-111 DOTATOC). All pretherapeutic scans with the Tc-99m labelled ligand (4 h p.i.) showed a similar overall pattern of biodistribution and tumor uptake in comparison to the therapy scans with In-111 / Y-90 DOTATOC 24 h p.i. The Tc-99m EDDA-HYNIC-TOC scans (incl. SPECT) offered superior imaging properties with earlier tumor visualization (all lesions were detected 1 h p.i.) as compared

  14. Monitoring of Biodistribution and Persistence of Conditionally Replicative Adenovirus in a Murine Model of Ovarian Cancer Using Capsid-Incorporated mCherry and Expression of Human Somatostatin Receptor Subtype 2 Gene

    Directory of Open Access Journals (Sweden)

    Igor P. Dmitriev

    2014-10-01

    Full Text Available A significant limiting factor to the human clinical application of conditionally replicative adenovirus (CRAd-based virotherapy is the inability to noninvasively monitor these agents and their potential persistence. To address this issue, we proposed a novel imaging approach that combines transient expression of the human somatostatin receptor (SSTR subtype 2 reporter gene with genetic labeling of the viral capsid with mCherry fluorescent protein. To test this dual modality system, we constructed the Ad5/3Δ24pIXcherry/SSTR CRAd and validated its capacity to generate fluorescent and nuclear signals in vitro and following intratumoral injection. Analysis of 64Cu-CB-TE2A-Y3-TATE biodistribution in mice revealed reduced uptake in tumors injected with the imaging CRAd relative to the replication-incompetent, Ad-expressing SSTR2 but significantly greater uptake compared to the negative CRAd control. Optical imaging demonstrated relative correlation of fluorescent signal with virus replication as determined by viral genome quantification in tumors. Positron emission tomography/computed tomography studies demonstrated that we can visualize radioactive uptake in tumors injected with imaging CRAd and the trend for greater uptake by standardized uptake value analysis compared to control CRAd. In the aggregate, the plasticity of our dual imaging approach should provide the technical basis for monitoring CRAd biodistribution and persistence in preclinical studies while offering potential utility for a range of clinical applications.

  15. Yttrium-90 and indium-111 labelling, receptor binding and biodistribution of [DOTA0,d-Phe1,Tyr3[octreotide, a promising somatostatin analogue for radionuclide therapy

    International Nuclear Information System (INIS)

    Jong, M. de; Bakker, W.H.; Krenning, E.P.; Breeman, W.A.P.; Pluijm, M.E. van der; Bernard, B.F.; Visser, T.J.; Jermann, E.; Behe, M.; Powell, P.; Maecke, H.R.

    1997-01-01

    In vitro octreotide receptor binding of [ 111 In-DOTA 0 ,d-Phe 1 ,Tyr 3 [octreotide ( 111 In-DOTATOC) and the in vivo metabolism of 90 Y- or 111 In-labelled DOTATOC were investigated in rats in comparison with [ 111 In-DTPA 0 [octreotide [ 111 In-DTPAOC). 111 In-DOTATOC was found to have an affinity similar to octreotide itself for the octreotide receptor in rat cerebral cortex microsomes. Twenty-four hours after injection of 90 Y- or 111 In-labelled DOTATOC, uptake of radioactivity in the octreotide receptor-expressing tissues pancreas, pituitary, adrenals and tumour was a factor of 2-6 that after injection of 111 In-DTPAOC. Uptake of labelled DOTATOC in pituitary, pancreas, adrenals and tumour was almost completely blocked by pretreatment with 0.5 mg unlabelled octreotide, indicating specific binding to the octreotide receptors. These findings strongly indicate that 90 Y-DOTATOC is a promising radiopharmaceutical for radiotherapy and that 111 In-DOTATOC is of potential value for diagnosis of patients with octreotide receptor-positive lesions, such as most neuroendocrine tumours. (orig.). With 3 figs., 2 tabs

  16. Union of {sup 99m} Tc-HYNIC-TOC at the somatostatin receptors in cells of pancreas cancer; Union del {sup 99m} Tc-HYNIC-TOC a los receptores de somatostatina en celulas de cancer de pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez C, J [Facultad de Medicina, UAEM, 50000 Toluca, Estado de Mexico (Mexico); Ramirez I, M T [INCMNSZ, Vasco de Quiroga Num. 15, Tlalpan, 14000 Mexico D.F. (Mexico); Ferro F, G; Pedraza L, M [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-07-01

    The radiation toxic effects have been used in therapy however much 50 years. The absorbed radiation dose can be determined at cellular level using cancerous cell cultures. If the deposited In vitro radiation dose coming from similar activities of several therapeutic radiopharmaceuticals it can compare it will be possible to choose the therapeutic radiopharmaceutical that it offers better dosimetric characteristics for the patient. The objective of this original investigation was to determine the union percentage of the octreotide {sup 99m}Tc-HYNlC-TOC to the somatostatin receivers in cells of cancer pancreas as well as the internalization, externalization and cellular viability. It was used the octapeptide, (octreotide, TOC) labelled with {sup 99m}Tc by means of the HYNIC chelating agent (6-hydrazine pyridine-3-carboxylic acid) and 3 cellular lines of murine pancreas cancer (AR42J), of cancer of human pancreas (CAPAN) and of one negative cellular line for somatostatin receivers (WRL-68). The {sup 99m}Tc-HYNIC-TOC was compared against two negative proofs for somatostatin receivers: the peptide {sup 99m}Tc-UBI and the {sup 99m}TcO{sub 4}. The cellular lines were conserved in the synthetic media Dulbecco-Eagle. After 2, 4 and 24 h of exhibition to the radiation, the cells are picked up and its are determined the viability by count in a Neubauer camera using tripan blue. In the same times it was calculated the union percentage of the radiopharmaceutical to the cells and the internalization (union to the cytoplasm) and the externalization (union to membrane receivers). With those figures it was calculated the absorbed radiation dose at cellular level. Results: At 4 hours the union percentage of the {sup 99m}Tc-HYNlC-TOC to the AR42-J cells was 6.83 times greater than for the WRL-68 control cells of human papilloma, (without receivers of the somatostatin) and for the CAPAN them 4 times greater than for the same cells used as negative control, for the case of the {sup 99m

  17. Union of {sup 99m} Tc-HYNIC-TOC at the somatostatin receptors in cells of pancreas cancer; Union del {sup 99m} Tc-HYNIC-TOC a los receptores de somatostatina en celulas de cancer de pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez C, J. [Facultad de Medicina, UAEM, 50000 Toluca, Estado de Mexico (Mexico); Ramirez I, M.T. [INCMNSZ, Vasco de Quiroga Num. 15, Tlalpan, 14000 Mexico D.F. (Mexico); Ferro F, G.; Pedraza L, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-07-01

    The radiation toxic effects have been used in therapy however much 50 years. The absorbed radiation dose can be determined at cellular level using cancerous cell cultures. If the deposited In vitro radiation dose coming from similar activities of several therapeutic radiopharmaceuticals it can compare it will be possible to choose the therapeutic radiopharmaceutical that it offers better dosimetric characteristics for the patient. The objective of this original investigation was to determine the union percentage of the octreotide {sup 99m}Tc-HYNlC-TOC to the somatostatin receivers in cells of cancer pancreas as well as the internalization, externalization and cellular viability. It was used the octapeptide, (octreotide, TOC) labelled with {sup 99m}Tc by means of the HYNIC chelating agent (6-hydrazine pyridine-3-carboxylic acid) and 3 cellular lines of murine pancreas cancer (AR42J), of cancer of human pancreas (CAPAN) and of one negative cellular line for somatostatin receivers (WRL-68). The {sup 99m}Tc-HYNIC-TOC was compared against two negative proofs for somatostatin receivers: the peptide {sup 99m}Tc-UBI and the {sup 99m}TcO{sub 4}. The cellular lines were conserved in the synthetic media Dulbecco-Eagle. After 2, 4 and 24 h of exhibition to the radiation, the cells are picked up and its are determined the viability by count in a Neubauer camera using tripan blue. In the same times it was calculated the union percentage of the radiopharmaceutical to the cells and the internalization (union to the cytoplasm) and the externalization (union to membrane receivers). With those figures it was calculated the absorbed radiation dose at cellular level. Results: At 4 hours the union percentage of the {sup 99m}Tc-HYNlC-TOC to the AR42-J cells was 6.83 times greater than for the WRL-68 control cells of human papilloma, (without receivers of the somatostatin) and for the CAPAN them 4 times greater than for the same cells used as negative control, for the case of the {sup 99m

  18. Sensitive radioimmunoassay for somatostatin using N-(/sup 125/I)-tyr-somatostatin as labelled antigen

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, A [CHUL, Quebec (Canada). Lab. of Molecular Endocrinology and Service of Gastro-Enterology; Coy, D H; Alvarado-Urbina, G; Cote, J; Meyers, C A; McManus, J; Barden, N; De Lean, A; Labrie, F

    1979-01-01

    A sensitive radioimmunoassay for somatostatin using N-(/sup 125/I)-Tyr-somatostatin is described and compared with using (/sup 125/I)-Tyr/sup 1/-somatostatin. The minimum detectable amount of somatostatin using N-(/sup 125/I)-Tyr-somatostatin as tracer was 0.1 to 0.5 pg, which is approximately 10-fold lower detection limit of the RIA using (/sup 125/I)-Tyr/sup 1/-somatostatin. Moreover, it was found that the shelf-life of N-(/sup 125/I)-Tyr-somatostatin was prolonged in comparison with labelled Tyr/sup 1/-somatostatin. Human pancreatic and gastric extracts displayed immunological similarity to synthetic somatostatin tetradecapeptide.

  19. Concordance between results of somatostatin receptor scintigraphy with {sup 111}In-DOTA-DPhe{sup 1}-Tyr{sup 3}-octreotide and chromogranin A assay in patients with neuroendocrine tumours

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Margarida [Medical University of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Hietzing Hospital, Institute of Nuclear Medicine, Vienna (Austria); Gabriel, Michael; Heute, Dirk; Putzer, Daniel; Virgolini, Irene [Medical University of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Griesmacher, Andrea [Medical University of Innsbruck, Central Institute of Medical and Chemical Laboratory Diagnostics, Innsbruck (Austria)

    2008-10-15

    Somatostatin receptor scintigraphy (SRS) and chromogranin A (CgA) assay have successfully been implemented in the clinical work-up and management of neuroendocrine tumour (NET) patients. However, there is still a lack of studies comparing results in these patients. Our aim was to compare directly in NET patients SRS and CgA assay results with special regard to tumour features such as grade of malignancy, primary origin, disease extent and function. One hundred twenty consecutive patients with histological confirmed NETs were investigated with {sup 111}In-DOTA-DPhe{sup 1}-Tyr{sup 3}-octreotide ({sup 111}In-DOTA-TOC) SRS and CgA immunoradiometric assay. Tumours were classified by cell characteristics [well-differentiated NETs, well-differentiated neuroendocrine carcinomas, poorly differentiated neuroendocrine carcinomas (PDNECs)], primary origin (foregut, midgut, hindgut, undetermined), disease extent (limited disease, metastases, primary tumour and metastases) and functionality (secretory, nonsecretory). SRS was positive in 107 (89%) patients; CgA levels were increased in 95 (79%) patients. Overall, concordance between SRS and CgA results was found in 84 patients. Positive SRS but normal CgA level were found in 24 patients, with higher prevalence (p<0.05) in patients with nonsecretory tumours. Conversely, negative SRS but CgA level increased were seen in 12 patients, with higher proportion (p < 0.05) in patients with PDNECs and tumours of hindgut origin. Overall, {sup 111}In-DOTA-TOC SRS proved to be more sensitive than CgA in NETs patients. Tumour differentiation, disease extent and presence of liver metastases impact both SRS and CgA results, whereas nonsecretory activity is a negative predictor of only CgA increase. PDNECs and hindgut origin of tumours predispose to discrepancies with negative SRS but increased CgA levels. (orig.)

  20. 99mTc-HYNIC-somatostatin analogues for imaging SST receptor positive tumours, preclinical evaluation and comparison with 111In-Octreotide

    International Nuclear Information System (INIS)

    Decristoforo, C.; Melendez-Alafort, L.; Sosabowski, J.K.; Mather, S.J.

    2001-01-01

    HYNIC-TOC and HYNIC-RC-160 were prepared and radiolabelled at high specific activities using tricine, EDDA and tricine/nicotinic acid as co-ligand systems. Radioligand binding assays were performed on membranes prepared from receptor-positive cell lines. Biodistribution and tumour uptake were determined in AR42J tumour bearing nude mice and compared to 99m Tc-MAG-3-RC-160 and 111 In-DTPA-Octreotide. Specific tumour uptake between 2.4 and 9.6%ID/g was found for the 99m Tc labelled HYNIC-conjugates compared to 0.2% for the 99m Tc-MAG-3-RC-160 and 4.3% ID/g for 111 In-DTPA-Octreotide. RC-160 conjugates showed lower tumour uptake and greater hepatobiliary excretion than TOC. Tricine as co-ligand showed higher levels of radioactivity in muscle, blood and liver, while tricine/NA produced significant levels of activity in the GI-tract. EDDA showed the most promising overall biodistribution profile with similar tumour: liver and GI-tract ratios to those obtained with 111 In-DTPA-Octreotide, lower ratios in blood and muscle but considerably higher tumour/kidney ratios. (author)

  1. Breast cancer imaging using radiolabelled somatostatin analogues

    International Nuclear Information System (INIS)

    Dalm, Simone U.; Melis, Marleen; Emmering, Jasper; Kwekkeboom, Dik J.; Jong, Marion de

    2016-01-01

    Imaging and therapy using radiolabelled somatostatin analogues are methods successfully used in patients with somatostatin receptor (SSTR)-expressing neuroendocrine tumours. Since these techniques were first introduced, many improvements have been made. SSTR expression has also been reported on breast cancer (BC). Currently mammography, magnetic resonance imaging and ultrasound are the most frequent methods used for BC imaging. Since SSTR expression on BC was demonstrated, clinical studies examining the feasibility of visualizing primary BC using SSTR radioligands have been performed. However, to date SSTR-mediated nuclear imaging is not used clinically in BC patients. The aim of this review is to assess whether recent improvements made within nuclear medicine may enable SSTR-mediated imaging to play a role in BC management. For this we critically analysed results of past studies and discussed the potential of the improvements made within nuclear medicine on SSTR-mediated nuclear imaging of BC. Seven databases were searched for publications on BC imaging with SSTR radioligands. The papers found were analysed by 3 individual observers to identify whether the studies met the pre-set inclusion criteria defined as studies in which nuclear imaging using radiolabelled SST analogues was performed in patients with breast lesions. Twenty-four papers were selected for this review including studies on SSTR-mediated nuclear imaging in BC, neuroendocrine BC and other breast lesions. The analysed studies were heterogeneous with respect to the imaging method, imaging protocol, patient groups and the radiolabelled SST analogues used. Despite the fact that the analysed studies were heterogeneous, sensitivity for primary BC ranged from 36–100%. In a subset of the studies LN lesions were visualized, but sensitivity was lower compared to that for primary tumours. A part of the studies included benign lesions and specificity ranged from 22–100%. Furthermore, false negatives and

  2. Improved safety and efficacy of 213Bi-DOTATATE-targeted alpha therapy of somatostatin receptor-expressing neuroendocrine tumors in mice pre-treated with L-lysine.

    Science.gov (United States)

    Chan, Ho Sze; Konijnenberg, Mark W; Daniels, Tamara; Nysus, Monique; Makvandi, Mehran; de Blois, Erik; Breeman, Wouter A; Atcher, Robert W; de Jong, Marion; Norenberg, Jeffrey P

    2016-12-01

    Targeted alpha therapy (TAT) offers advantages over current β-emitting conjugates for peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors. PRRT with 177 Lu-DOTATATE or 90 Y-DOTATOC has shown dose-limiting nephrotoxicity due to radiopeptide retention in the proximal tubules. Pharmacological protection can reduce renal uptake of radiopeptides, e.g., positively charged amino acids, to saturate in the proximal tubules, thereby enabling higher radioactivity to be safely administered. The aim of this preclinical study was to evaluate the therapeutic effect of 213 Bi-DOTATATE with and without renal protection using L-lysine in mice. Tumor uptake and kinetics as a function of injected mass of peptide (range 0.03-3 nmol) were investigated using 111 In-DOTATATE. These results allowed estimation of the mean radiation absorbed tumor dose for 213 Bi-DOTATATE. Pharmacokinetics and dosimetry of 213 Bi-DOTATATE was determined in mice, in combination with renal protection. A dose escalation study with 213 Bi-DOTATATE was performed to determine the maximum tolerated dose (MTD) with and without pre-administration of L-lysine as for renal protection. Neutrophil gelatinase-associated lipocalin (NGAL) served as renal biomarker to determine kidney injury. The maximum mean radiation absorbed tumor dose occurred at 0.03 nmol and the minimum at 3 nmol. Similar mean radiation absorbed tumor doses were determined for 0.1 and 0.3 nmol with a mean radiation absorbed dose of approximately 0.5 Gy/MBq 213 Bi-DOTATATE. The optimal mass of injected peptide was found to be 0.3 nmol. Tumor uptake was similar for 111 In-DOTATATE and 213 Bi-DOTATATE at 0.3 nmol peptide. Lysine reduced the renal uptake of 213 Bi-DOTATATE by 50% with no effect on the tumor uptake. The MTD was <13.0 ± 1.6 MBq in absence of L-lysine and 21.7 ± 1.9 MBq with L-lysine renal protection, both imparting an LD 50 mean renal radiation absorbed dose of 20 Gy. A correlation was found between the

  3. Current knowledge on the sensitivity of the {sup 68}Ga-somatostatin receptor positron emission tomography and the SUV{sub max} reference range for management of pancreatic neuroendocrine tumours

    Energy Technology Data Exchange (ETDEWEB)

    Virgolini, Irene; Gabriel, Michael; Kroiss, Alexander; Guggenberg, Elisabeth von; Prommegger, Rupert; Warwitz, Boris; Nilica, Bernhard; Roig, Ilanos Geraldo; Rodrigues, Margarida; Uprimny, Christian [Medical University of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria)

    2016-10-15

    Physiologically increased pancreatic uptake at the head/uncinate process is observed in more than one-third of patients after injection of one of the three {sup 68}Ga-labelled octreotide-based peptides used for somatostatin (sst) receptor (r) imaging. There are minor differences between these {sup 68}Ga-sstr-binding peptides in the imaging setting. On {sup 68}Ga-sstr-imaging the physiological uptake can be diffuse or focal and usually remains stable over time. Differences in the maximal standardised uptake values (SUV{sub max}) reported for the normal pancreas as well as for pancreatic neuroendocrine tumour (PNET) lesions may be related to several factors, including (a) differences in the peptide binding affinities as well as differences in sstr subtype expression of pancreatic α- and β-cells, and heterogeneity / density of tumour cells, (b) differences in scanner resolution, image reconstruction techniques and acquisition protocols, (c) mostly retrospective study designs, (d) mixed patient populations, or (e) interference with medications such as treatment with long-acting sst analogues. The major limitation in most of the studies lies in the lack of histopathological confirmation of abnormal findings. There is a significant overlap between the calculated SUV{sub max}-values for physiological pancreas and PNET-lesions of the head/uncinate process that do not favour the use of quantitative parameters in the clinical setting. Anecdotal long-term follow-up studies have even indicated that increased uptake in the head/uncinate process still can turn out to be malignant over years of follow up. SUV{sub max}-data for the pancreatic body and tail are limited. Therefore, any visible focal tracer uptake in the pancreas must be considered as suspicious for malignancy irrespective of quantitative parameters. In general, sstr-PET/CT has significant implications for the management of NET patients leading to a change in treatment decision in about one-third of patients

  4. Somatostatin Receptor Scintigraphy in Medullary Thyroid Cancer

    NARCIS (Netherlands)

    van der Horst-Schrivers, Anouk N. A.; Brouwers, Adrienne; Links, Thera; Hubalewska‐Dydejczyk, Alicja; Signore, Alberto; de Jong, Marion; Dierckx, Rudi A.; Buscombe, John; Van de Wiele, Christophe

    2015-01-01

    Medullary thyroid cancer (MTC) is a neuroendocrine tumor originating from the calcitonin‐secreting C cells. Surgery, consisting of a total thyroidectomy and an extensive lymph node dissection, is the only effective treatment in MTC; however, metastases are frequently found in the regional cervical

  5. Somatostatin in the caudal spinal cord

    DEFF Research Database (Denmark)

    Schrøder, H D

    1984-01-01

    . In all of these regions somatostatin-positive cell bodies were also observed. In the intermediate gray matter stained terminals were present around the central canal in a varying number. The most prominent stainability was found in the lumbosacral transition zone. Many terminals were also observed...... was particularly low in the motoneuron neuropil. However, a dense somatostatin network was found in the sixth lumbar segment in relation to the neurons in Onuf's nucleus X complex, the nucleus that innervates the small pelvic muscles including the striated sphincters. It is concluded that somatostatin, besides...

  6. Switch from antagonist to agonist after addition of a DOTA chelator to a somatostatin analog

    International Nuclear Information System (INIS)

    Reubi, Jean Claude; Cescato, Renzo; Waser, Beatrice; Erchegyi, Judit; Rivier, Jean E.

    2010-01-01

    Peptide receptor targeting has become an increasingly attractive method to target tumors diagnostically and radiotherapeutically. Peptides linked to a variety of chelators have been developed for this purpose. They have, however, rarely been tested for their agonistic or antagonistic properties. We report here on a somatostatin antagonist that switched to an agonist upon coupling to a DOTA chelator. Two novel somatostatin analogs, 406-040-15 and its DOTA-coupled counterpart 406-051-20, with and without cold Indium labeling, were tested for their somatostatin receptor subtypes 1-5 (sst 1 -sst 5 ) binding affinity using receptor autoradiography. Moreover, they were tested functionally for their ability to affect sst 2 and sst 3 internalization in vitro in HEK293 cells stably expressing the human sst 2 or sst 3 receptor, using an immunofluorescence microscopy-based internalization assay. All three compounds were characterized as pan-somatostatin analogs having a high affinity for all five sst. In the sst 2 internalization assay, all three compounds showed an identical behavior, namely, a weak agonistic effect complemented by a weak antagonistic effect, compatible with the behavior of a partial agonist. Conversely, in the sst 3 internalization assay, 406-040-15 was a full antagonist whereas its DOTA-coupled counterpart, 406-051-20, with and without Indium labeling, switched to a full agonist. Adding the DOTA chelator to the somatostatin analog 406-040-15 triggers a switch at sst 3 receptor from an antagonist to an agonist. This indicates that potential radioligands for tumor targeting should always be tested functionally before further development, in particular if a chelator is added. (orig.)

  7. Localisation and mechanism of renal retention of radiolabelled somatostatin analogues

    Energy Technology Data Exchange (ETDEWEB)

    Melis, Marleen; Krenning, Eric P.; Bernard, Bert F.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Barone, Raffaella [UCL, Centre of Nuclear Medicine and Laboratory of PET, Brussels (Belgium); Visser, Theo J. [Erasmus MC, Department of Internal Medicine, Rotterdam (Netherlands)

    2005-10-01

    Radiolabelled somatostatin analogues, such as octreotide and octreotate, are used for tumour scintigraphy and radionuclide therapy. The kidney is the most important critical organ during such therapy owing to the reabsorption and retention of radiolabelled peptides. The aim of this study was to investigate in a rat model both the localisation and the mechanism of renal uptake after intravenous injection of radiolabelled somatostatin analogues. The multi-ligand megalin/cubilin receptor complex, responsible for reabsorption of many peptides and proteins in the kidney, is an interesting candidate for renal endocytosis of these peptide analogues. For localisation studies, ex vivo autoradiography and micro-autoradiography of rat kidneys were performed 1-24 h after injection of radiolabelled somatostatin analogues and compared with the renal anti-megalin immunohistochemical staining pattern. To confirm a role of megalin in the mechanism of renal retention of [{sup 111}In-DTPA]octreotide, the effects of three inhibitory substances were explored in rats. Renal ex vivo autoradiography showed high cortical radioactivity and lower radioactivity in the outer medulla. The distribution of cortical radioactivity was inhomogeneous. Micro-autoradiography indicated that radioactivity was only retained in the proximal tubules. The anti-megalin immunohistochemical staining pattern showed a strong similarity with the renal [{sup 111}In-DTPA]octreotide ex vivo autoradiograms. Biodistribution studies showed that co-injection of positively charged d-lysine reduced renal uptake to 60% of control. Sodium maleate reduced renal [{sup 111}In-DTPA]octreotide uptake to 15% of control. Finally, cisplatin pre-treatment of rats reduced kidney uptake to 70% of control. Renal retention of [{sup 111}In-DTPA]octreotide is confined to proximal tubules in the rat kidney, in which megalin-mediated endocytosis may play an important part. (orig.)

  8. Radioimmunoassay of somatostatin: methodological problems and physiological investigations

    International Nuclear Information System (INIS)

    Penman, E.; Wass, J.A.H.

    1981-01-01

    Somatostatin, a tetradecapeptide, has a wide distribution throughout the central nervous system and the gastrointestinal tract and a broad spectrum of biological actions. In order to investigate its various physiological roles in man, a radioimmunoassay was developed for somatostatin in human blood plasma, which is described here. This RIA was used to investigate possible factors influencing somatostatin secretion. Changes in somatin levels produced by changes in insulin, glucagon and growth hormone levels were studied via the response of plasma immunoreactive somatostatin to hormonal stimuli in normal man. The influence of fasting and food consumption was studied; and the site of origin of circulating immunoreactive somatostatin was investigated in patients. (Auth.)

  9. Radiolabeled somatostatin analog scintigraphy in oncology and immune diseases: an overview

    International Nuclear Information System (INIS)

    Kwekkeboom, D.J.; Krenning, E.P.

    1997-01-01

    [ 111 In-DTPA-D-Phe 1 [-octreotide is a new radiopharmaceutical with a great potential for the visualization of somatostatin receptor-positive tumors, granulomas, and diseases in which activated leukocytes play a role. The overall sensitivity of [ 111 In-DTPA-D-Phe 1 [-octreotide scintigraphy to localize neuroendocrine tumors is high. In several neuroendocrine tumor types, inclusion of somatostatin receptor imaging in the localization or staging procedure may be very rewarding, either in terms of cost-effectiveness, patient management, or quality of life. In our opinion, this holds true for patients with carcinoids, gastrinomas, paragangliomas, small-cell lung carcinoma, and selected cases of patients with insulinomas. The value of [ 111 In-DTPA-D-Phe 1 [-octreotide scintigraphy in patients with other tumors, such as breast cancer, malignant lymphomas, or in patients with granulomatous diseases, has to be established. (orig.). With 4 figs., 1 tab

  10. Uptake kinetics of the somatostatin receptor ligand [86Y]DOTA-dPhe1-Tyr3-octreotide ([86Y]SMT487) using positron emission tomography in non-human primates and calculation of radiation doses of the 90Y-labelled analogue

    International Nuclear Information System (INIS)

    Roesch, F.; Brockmann, J.; Koehle, M.

    1999-01-01

    [ 90 Y]DOTA-dPhe 1 -Tyr 3 -octreotide ([ 90 Y]-SMT487) has been suggested as a promising radiotherapeutic agent for somatostatin receptor-expressing tumours. In order to quantify the in vivo parameters of this compound and the radiation doses delivered to healthy organs, the analogue [ 86 Y]DOTA-dPhe 1 -Tyr 3 -octreotide was synthesised and its uptake measured in baboons using positron emission tomography (PET). [ 86 Y]DOTA-dPhe 1 -Tyr 3 -octreotide was administered at two different peptide concentrations, namely 2 and 100 μg peptide per m 2 body surface. The latter concentration corresponded to a radiotherapeutic dose. In a third protocol [ 86 Y]DOTA-dPhe 1 -Tyr 3 -octreotide was injected in conjunction with a simultaneous infusion of an amino acid solution that was high in l-lysine in order to lower the renal uptake of radioyttrium. Quantitative whole-body PET scans were recorded to measure the uptake kinetics for kidneys, liver, lung and bone. The individual absolute uptake kinetics were used to calculate the radiation doses for [ 90 Y]DOTA-dPhe 1 -Tyr 3 -octreotide according to the MIRD recommendations extrapolated to a 70-kg human. The highest radiation dose was received by the kidneys, with 2.1-3.3 mGy per MBq [ 90 Y]DOTA-dPhe 1 -Tyr 3 -octreotide injected. For the 100 μg/m 2 SMT487 protocol with amino acid co-infusion this dose was about 20%-40% lower than for the other two treatment protocols. The liver and the red bone marrow received doses ranging from 0.32 to 0.53 mGy and 0.03 to 0.07 mGy per MBq [ 90 Y]DOTA-dPhe 1 -Tyr 3 -octreotide, respectively. The average effective dose equivalent amounted to 0.23-0.32 mSv/MBq. The comparatively low estimated radiation doses to normal organs support the initiation of clinical phase I trials with [ 90 Y]DOTA-dPhe 1 -Tyr 3 -octreotide in patients with somatostatin receptor-expressing tumours. (orig.)

  11. Uptake kinetics of the somatostatin receptor ligand [{sup 86}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide ([{sup 86}Y]SMT487) using positron emission tomography in non-human primates and calculation of radiation doses of the {sup 90}Y-labelled analogue

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, F.; Brockmann, J. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Nuklearchemie; Herzog, H.; Muehlensiepen, H.; Mueller-Gaertner, H.W. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Medizin; Stolz, B.; Marbach, P. [Novartis Pharma AG, Basel (Switzerland); Koehle, M. [Klinikum der Freien Universitaet Berlin (Germany)

    1999-04-29

    [{sup 90}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide ([{sup 90}Y]-SMT487) has been suggested as a promising radiotherapeutic agent for somatostatin receptor-expressing tumours. In order to quantify the in vivo parameters of this compound and the radiation doses delivered to healthy organs, the analogue [{sup 86}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide was synthesised and its uptake measured in baboons using positron emission tomography (PET). [{sup 86}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide was administered at two different peptide concentrations, namely 2 and 100 {mu}g peptide per m{sup 2} body surface. The latter concentration corresponded to a radiotherapeutic dose. In a third protocol [{sup 86}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide was injected in conjunction with a simultaneous infusion of an amino acid solution that was high in l-lysine in order to lower the renal uptake of radioyttrium. Quantitative whole-body PET scans were recorded to measure the uptake kinetics for kidneys, liver, lung and bone. The individual absolute uptake kinetics were used to calculate the radiation doses for [{sup 90}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide according to the MIRD recommendations extrapolated to a 70-kg human. The highest radiation dose was received by the kidneys, with 2.1-3.3 mGy per MBq [{sup 90}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide injected. For the 100 {mu}g/m{sup 2} SMT487 protocol with amino acid co-infusion this dose was about 20%-40% lower than for the other two treatment protocols. The liver and the red bone marrow received doses ranging from 0.32 to 0.53 mGy and 0.03 to 0.07 mGy per MBq [{sup 90}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide, respectively. The average effective dose equivalent amounted to 0.23-0.32 mSv/MBq. The comparatively low estimated radiation doses to normal organs support the initiation of clinical phase I trials with [{sup 90}Y]DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide in patients with somatostatin receptor-expressing tumours. (orig

  12. Somatostatin analogue scintigraphy and tuberculosis: case report

    International Nuclear Information System (INIS)

    Biancheri, I.; Rudenko, B.; Vautrin, P.; Raddoul, J.; Lamfichek, N.; Kantelip, B.; Mantion, G.

    2005-01-01

    Scintigraphy using a radiolabelled somatostatin analogue (111 In-pentetreotide) is useful in the detection of neuroendocrine tumors. But this radiopharmaceutical accumulates also in solid tumours or in inflammatory diseases such as granulomatosis. We present a case of 111 In-pentetreotide uptake in a tuberculous adenopathy. (author)

  13. Potentiation of peptide receptor radionuclide therapy by the PARP inhibitor olaparib

    NARCIS (Netherlands)

    J. Nonnekens (Julie); M. van Kranenburg (Melissa); C.E.M.T. Beerens (Cecile); M. Suker (Mustafa); M. Doukas (Michael); C.H.J. van Eijck (Casper); M. de Jong (Marcel); D.C. van Gent (Dik)

    2016-01-01

    textabstractMetastases expressing tumor-specific receptors can be targeted and treated by binding of radiolabeled peptides (peptide receptor radionuclide therapy or PRRT). For example, patients with metastasized somatostatin receptor-positive neuroendocrine tumors (NETs) can be treated with

  14. Synthesis, radiochemistry and biological evaluation of a new somatostatin analogue (SDZ 219-387) labelled with technetium-99m

    International Nuclear Information System (INIS)

    Maina, T.; Stolz, B.; Albert, R.; Bruns, C.; Koch, P.; Maecke, H.

    1994-01-01

    A new derivative of octreotide SDZ 219-387 [PnAO-(D)Phe 1 -octreotide] was synthesized, which binds specifically and with high affinity to somatostatin receptors in vitro (pK i =9.79±0.16). This new somatostatin analogue chelates technetium-99m under mild labelling conditions in good yields. The resulting [ 99m Tc]SDZ 219-387 was stable up to 6 h after labelling and could be isolated in a pure radiochemical and chemical form by high-perfomance liquid chromatographic purification. The intravenous administration of purified [ 99m Tc]SDZ 219-387 revealed that the radioligand was rapidly cleared from circulation, and tumour uptake of 0.38% ID/g was observed at 1.5 h post injection. [ 99m Tc]SDZ 219-387 specifically interacted with somatostatin binding sites on the tumour. However, the radioligand is highly lipophilic and excreted mainly through the hepatobiliary system. As a consequence, [ 99m Tc]SDZ 219-387 exhibits increased background activity and therefore is not appropriate for the in vivo visualization of somatostatin receptor-positive tumours and/or their metastases in the abdomen. (orig.)

  15. Effects of the single and combined treatment with dopamine agonist, somatostatin analog and mTOR inhibitors in a human lung carcinoid cell line: an in vitro study.

    Science.gov (United States)

    Pivonello, Claudia; Rousaki, Panagoula; Negri, Mariarosaria; Sarnataro, Maddalena; Napolitano, Maria; Marino, Federica Zito; Patalano, Roberta; De Martino, Maria Cristina; Sciammarella, Concetta; Faggiano, Antongiulio; Rocco, Gaetano; Franco, Renato; Kaltsas, Gregory A; Colao, Annamaria; Pivonello, Rosario

    2017-06-01

    Somatostatin analogues and mTOR inhibitors have been used as medical therapy in lung carcinoids with variable results. No data are available on dopamine agonists as treatment for lung carcinoids. The main aim of the current study was to evaluate the effect of the combined treatment of somatostatin analogue octreotide and the dopamine agonist cabergoline with mTOR inhibitors in an in vitro model of typical lung carcinoids: the NCI-H727 cell line. In NCI-H727 cell line, reverse transcriptase-quantitative polymerase chain reaction and immunofluorescence were assessed to characterize the expression of the somatostatin receptor 2 and 5, dopamine receptor 2 and mTOR pathway components. Fifteen typical lung carcinoids tissue samples have been used for somatostatin receptor 2, dopamine receptor 2, and the main mTOR pathway component p70S6K expression and localization by immunohistochemistry. Cell viability, fluorescence-activated cell sorting analysis and western blot have been assessed to test the pharmacological effects of octreotide, cabergoline and mTOR inhibitors, and to evaluate the activation of specific cell signaling pathways in NCI-H727 cell line. NCI-H727 cell line expressed somatostatin receptor 2, somatostatin receptor 5 and dopamine receptor 2 and all mTOR pathway components at messenger and protein levels. Somatostatin receptor 2, dopamine receptor 2, and p70S6K (non phosphorylated and phosphorylated) proteins were expressed in most typical lung carcinoids tissue samples. Octreotide and cabergoline did not reduce cell viability as single agents but, when combined with mTOR inhibitors, they potentiate mTOR inhibitors effect after long-term exposure, reducing Akt and ERK phosphorylation, mTOR escape mechanisms, and increasing the expression DNA-damage-inducible transcript 4, an mTOR suppressor. In conclusion, the single use of octreotide and cabergoline is not sufficient to block cell viability but the combined approach of these agents with mTOR inhibitors

  16. Immuno-reactive somatostatin in the cerebro-spinal fluid

    International Nuclear Information System (INIS)

    Kohler, J.

    1983-01-01

    In the present work the lumbar cerebro-spinal fluid of 178 patients with different neurological affections was examined with the aid of a specific radioimmunoassay for somatostatin. 18 patients without any pathologic neurological findings served as controls. In degenerative diseases of the brain, reduced somatostatin levels in the cerebro-spinal fluid as compared to the controls were measured. In 3 patients with isolated cerebellar atrophy no reduction of the somatostatin content was found; rather the values were highly normal. Huntington-Chorea also is a case apart. In patients with manifest affections, the somatostatin reduction, amounting to 54.6%, was particularly notable as compared to the controls. By contrast, degenerative diseases with predominant medullary and spastic affection are characterized by significantly increased somatostatin levels. Again, in non-spastic patients the values were not significantly different from those of the controls. Patients with inflammations of the brain and meminges as well as with tumors of the nervous system showed somatostatin levels increased by about 60.8% respectively 51.8% as compared to the controls. Epileptic patients normally exhibit a reduced somatostatin level in the cerebro-spinal fluid, but the reduction is not significant. Disseminated encephalomyclitis, whether chromic or acute, is not found to be associated with significant modifications of the somatostatin level in the cerebro-spinal fluid. Strikingly, however, patients in which the disease took a serious or very serious clinical course showed also the lowest somatostatin levels in the cerebro-spinal fluid. In patients exhibiting the roof compression symptom in consequence of a prolapse of the disk, no significant modifications were found. By contrast, in patients with the symptoms of a transverse lesion, significantly increased somatostatin values were measured. (orig./MG) [de

  17. Somatostatin-Immunoreactive Pancreaticoduodenal Neuroendocrine Neoplasms

    DEFF Research Database (Denmark)

    Engelund Luna, Iben; Monrad, Nina; Binderup, Tina

    2016-01-01

    , and biochemical features as well as treatment and prognosis. DESIGN: Twenty-three patients with p-dSOM (9 duodenal, 12 pancreatic, 2 unknown primary tumour) were identified from our prospective neuroendocrine tumour (NET) database, and data according to the study aims were recorded. RESULTS: Of the 9 patients...... with duodenal SOM the m/f ratio was 4/5. All males and one female had NF-1. Seven patients had stage 1A-B and 2 had stage 2B disease. The Ki-67 index was 1-5% (median 2%). Plasma somatostatin was elevated in patients with 2B disease. Of the 14 patients with pancreatic SOM or unknown primary tumour the m/f ratio...... was 2/12. One male had MEN-1. Five had stage 1A-2B and nine had stage 4. The Ki-67 index was 1-40% (median 7%). Plasma somatostatin was elevated in seven patients. Patients reported symptoms related to the somatostatinoma syndrome, but none fulfilled the criteria for a full syndrome. Primary tumour...

  18. The role of somatostatin in GLP-1-induced inhibition of glucagon secretion in mice

    DEFF Research Database (Denmark)

    Ørgaard, Anne; Holst, Jens J

    2017-01-01

    AIMS/HYPOTHESIS: Glucagon-like peptide-1 (GLP-1) receptor agonists are currently used for the treatment of type 2 diabetes. Their main mechanism of action is enhancement of glucose-induced insulin secretion (from increased beta cell glucose sensitivity) and inhibition of glucagon secretion...... on glucagon secretion is heavily debated. Glucagon inhibition is also said to be glucose-dependent, although it is unclear what is meant by this. We hypothesise here that GLP-1 does not inhibit glucagon secretion during hypoglycaemia because the inhibition depends on somatostatin secretion, which in turn...

  19. Calcitonin gene-related peptide and somatostatin releases correlated with the area under the lafutidine concentration-time curve in human plasma.

    Science.gov (United States)

    Ikawa, K; Shimatani, T; Azuma, Y; Inoue, M; Morikawa, N

    2006-08-01

    To examine the effects of the histamine H(2)-receptor antagonist, lafutidine, at clinical dosage (10 mg tablet after a standardized meal) on plasma levels of the gastrointestinal peptides, calcitonin gene-related peptide (CGRP), somatostatin and gastrin. Six healthy male volunteers ate a standardized meal, and received either lafutidine orally at a dose of 10 mg or water only (control). Blood samples were taken before and up to 4 h after the drug administration. Plasma lafutidine concentrations were determined by high pressure liquid chromatography. Pharmacokinetic analysis of lafutidine was performed using one-compartmental model. The levels of immunoreactive substances of plasma CGRP, somatostatin and gastrin were measured by enzyme immunoassay, and the amount of peptide release was calculated by the trapezoidal method. Lafutidine significantly increased plasma CGRP levels at 1, 1.5, 2.5 and 4 h and the total amount of CGRP release (192 +/- 14.0 pg.h/mL) compared with the control group (128 +/- 21.5 pg.h/mL). Lafutidine significantly increased the plasma somatostatin levels at 1 and 1.5 h, and the total amount of somatostatin released (107 +/- 18.2 pg.h/mL) compared with the control (78.4 +/- 7.70 pg.h/mL). The area under the drug concentration-time curve (AUC) from 0 to 4 h after administration correlated well with the Delta-CGRP and Delta-somatostatin release but not with total amount of gastrin released. However, plasma gastrin levels were significantly elevated at 1.5 h after drug administration. Lafutidine at clinical dosage increases plasma CGRP and the somatostatin. The amounts released correlated with the AUC of lafutidine in humans. These results suggest that the increased release of CGRP and somatostatin may contribute to its gastroprotective and anti-acid secretory effect.

  20. Cysteamine induces cholecystokinin release from the duodenum. Evidence for somatostatin as an inhibitory paracrine regulator of cholecystokinin secretion in the rat

    International Nuclear Information System (INIS)

    Abucham, J.; Reichlin, S.

    1990-01-01

    To determine whether cholecystokinin secretion is regulated by endogenous somatostatin, somatostatin deficiency was induced in vivo with cysteamine (250 mg/kg body wt, IV) or anti-somatostatin antiserum in anaesthetized rats and in vitro with cysteamine (30 micrograms/mL) in a rat duodenum-incubation system. Cholecystokinin secretion was assessed in vivo by measuring amylase in duodenal perfusates collected at 10-minute intervals for 1 hour and in vitro by a carboxy-terminal radioimmunoassay. Cysteamine induced a marked decrease in duodenal immunoreactive somatostatin both in vivo (50%) and in vitro (60%). The rate of amylase secretion increased from 9.7 +/- 2.1 U (mean +/- SE) to 28.0 +/- 4.8 U at 20 minutes (P less than 0.001). The cholecystokinin-receptor antagonist CR-1392 abolished amylase response for 30 minutes, whereas the more potent antagonists Asperlicin (18.0 mg/kg body wt, IV) and L-364,718 (0.25 mg/kg body wt, IV) caused prolonged blockade. The rate of amylase secretion in gastrectomized animals increased from 7.2 +/- 2.0 U to 15.0 +/- 2.2 U 20 minutes after cysteamine administration (P less than 0.01), indicating that the effect was not due to the presence of gastrin. In vitro, cysteamine caused a nearly fourfold increase in cholecystokinin secretion compared with controls (63.1 +/- 4.9 vs. 15.2 +/- 3.7, respectively; P less than 0.001). In vivo immunoneutralization of circulating somatostatin with a high-affinity and high-capacity antiserum produced no significant change in the rate of amylase secretion. These results suggest that cholecystokinin secretion is tonically inhibited by somatostatin and that this effect is mediated by locally secreted (paracrine) but not by circulating somatostatin

  1. Study of somatostatin in simple obesity

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Hafez, M A; El-Ghazaly, S; El-Feky, N A; Sayed, S N [Cairo Univ. (Egypt)

    1990-02-01

    C-peptide, as a marker for pancreatic beta cells function, and somatostatin (SS) in plasma of obese males (n = 15) and a corresponding normal weight control subjects (n = 10) are studied. Fasting plasma SS and serum C-peptide are significantly higher in obese vs lean group. This can be explained by hypertrophy of both D- and B-cells of the pancreatic islets reported by other investigators. Post-prandial plasma SS is insignificantly increased in obese vs the control group whereas the increase in C-peptide levels is significant suggesting unequal response of B- and D-cells to meal in the obese group. It is concluded that circulating SS may play an important role in the development if obesity. Hyperinsulinaemia documented in obesity may be due to hypersecretion of insulin. That may contribute to increased somatomedin-C in obesity. (author).

  2. Study of somatostatin in simple obesity

    International Nuclear Information System (INIS)

    Abdel-Hafez, M.A.; El-Ghazaly, S.; El-Feky, N.A.; Sayed, S.N.

    1990-01-01

    C-peptide, as a marker for pancreatic beta cells function, and somatostatin (SS) in plasma of obese males (n = 15) and a corresponding normal weight control subjects (n = 10) are studied. Fasting plasma SS and serum C-peptide are significantly higher in obese vs lean group. This can be explained by hypertrophy of both D- and B-cells of the pancreatic islets reported by other investigators. Post-prandial plasma SS is insignificantly increased in obese vs the control group whereas the increase in C-peptide levels is significant suggesting unequal response of B- and D-cells to meal in the obese group. It is concluded that circulating SS may play an important role in the development if obesity. Hyperinsulinaemia documented in obesity may be due to hypersecretion of insulin. That may contribute to increased somatomedin-C in obesity. (author)

  3. Preclinical evaluation of somatostatin analogs bearing two macrocyclic chelators for high specific activity labeling with radiometals

    International Nuclear Information System (INIS)

    Storch, D.; Schmitt, J.S.; Waldherr, C.; Maecke, H.R.; Waser, B.; Reubi, J.C.

    2007-01-01

    Radiometallated analogues of the regulatory peptide somatostatin are of interest in the in vivo localization and targeted radiotherapy of somatostatin receptor-overexpressing tumors. An important aspect of their use in vivo is a fast and efficient labeling (complexation) protocol for radiometals along with a high specific activity. We describe in this manuscript synthetic methods for the coupling of two chelators (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid = DOTA) to the bioactive peptide [Tyr 3 ,Thr 8 ]-octreotide (TATE) in order to increase the specific activity (radioactivity in Bq per mole peptide). The full chelator-linker-peptide conjugate was assembled on solid support using standard Fmoc chemistry. Two DOTA-chelators were linked to the peptide using lysine or N,N'-bis(3-aminopropyl)-glycine (Apg); in addition, pentasarcosine (Sar 5 ) was used as a spacer between the chelators and the peptide to probe its influence on biology and pharmacology. Complexation rates with In 3+ and Y 3+ salts and the corresponding radiometals were high, the bis-DOTA-derivatives showed higher complexation rates and gave higher specific activity than DOTA-TATE. Pharmacological and biological data of the complexed molecules did not show significant differences if compared to the parent peptide [ 111/nat In-DOTA]-TATE except for [( 111/nat In-DOTA) 2 -Apg]-TATE which showed a lower binding affinity and rate of internalization into tumor cells. The biodistribution of [( 111/nat In-DOTA)-Lys( 111/nat In-DOTA)]-TATE in the rat tumor model (AR4-2J) showed a high and specific (as shown by a blocking experiment) tracer uptake in somatostatin receptor-positive tissue but a lower tumor uptake compared to [ 111/nat In-DOTA]-TATE. (orig.)

  4. Experience with indium-111 and yttrium-90-labeled somatostatin analogs.

    Science.gov (United States)

    Virgolini, I; Traub, T; Novotny, C; Leimer, M; Füger, B; Li, S R; Patri, P; Pangerl, T; Angelberger, P; Raderer, M; Burggasser, G; Andreae, F; Kurtaran, A; Dudczak, R

    2002-01-01

    The high level expression of somatostatin receptors (SSTR) on various tumor cells has provided the molecular basis for successful use of radiolabeled octreotide / lanreotide analogs as tumor tracers in nuclear medicine. Other (nontumoral) potential indications for SSTR scintigraphy are based on an increased lymphocyte binding at sites of inflammatory or immunologic diseases such as thyroid-associated ophthalmology. The vast majority of human tumors seem to over-express the one or the other of five distinct hSSTR subtype receptors. Whereas neuroendocrine tumors frequently overexpress hSSTR2, intestinal adenocarcinomas seem to overexpress more often hSSTR3 or hSSTR4, or both of these hSSTR. In contrast to In-DTPA-DPhe(1)-octreotide (OctreoScan(R)) which binds to hSSTR2 and 5 with high affinity (Kd 0.1-5 nM), to hSSTR3 with moderate affinity (K(d) 10-100 nM) and does not bind to hSSTR1 and hSSTR4, (111)In / (90)Y-DOTA-lanreotide was found to bind to hSSTR2, 3, 4, and 5 with high affinity, and to hSSTR1 with lower affinity (K(d) 200 nM). Based on its unique hSSTR binding profile, (111)In-DOTA-lanreotide was suggested to be a potential radioligand for tumor diagnosis, and (90)Y-DOTA-lanreotide suitable for receptor-mediated radionuclide therapy. As opposed to (111)In-DTPA-DPhe(1)-octreotide and (111)In-DOTA-DPhe(1)-Tyr(3)-octreotide, discrepancies in the scintigraphic results were seen in about one third of (neuroendocrine) tumor patients concerning both the tumor uptake as well as detection of tumor lesions. On a molecular level, these discrepancies seem to be based on a "higherrdquuo; high-affinity binding of (111)In-DOTA-DPhe(1)-Tyr(3)-octreotide to hSSTR2 (K(d) 0.1-1 nM). Other somatostatin analogs with divergent affinity to the five known hSSTR subtype receptors have also found their way into the clinics, such as (99m)Tc-depreotide (NeoSpect(R); NeoTect(R)). Most of the imaging results are reported for neuroendocrine tumors (octreotide analogs) or nonsmall cell

  5. Are radiogallium-labelled DOTA-conjugated somatostatin analogues superior to those labelled with other radiometals?

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, P.; Ginj, M.; Zhang, H.; Maecke, H. [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Waser, B.; Reubi, J.C. [University of Bern, Institute of Pathology, Bern (Switzerland); Baum, R.P. [Zentralklinik Bad Berka, Department of Nuclear Medicine/PETCT-Center, Bad Berka (Germany)

    2007-07-15

    Gallium-68 is a metallic positron emitter with a half-life of 68 min that is ideal for the in vivo use of small molecules, such as [{sup 68}Ga-DOTA,Tyr{sup 3}]octreotide, in the diagnostic imaging of somatostatin receptor-positive tumours. In preclinical studies it has shown a striking superiority over its {sup 111}In-labelled congener. The purpose of this study was to evaluate whether third-generation somatostatin-based, radiogallium-labelled peptides show the same superiority. Peptides were synthesised on solid phase. The receptor affinity was determined by in vitro receptor autoradiography. The internalisation rate was studied in AR4-2J and hsst-HEK-transfected cell lines. The pharmacokinetics was studied in a rat xenograft tumour model, AR4-2J. All peptides showed high affinities on hsst2, with the highest affinity for the Ga{sup III}-complexed peptides. On hsst3 the situation was reversed, with a trend towards lower affinity of the Ga{sup III} peptides. A significantly increased internalisation rate was found in sst2-expressing cells for all {sup 67}Ga-labelled peptides. Internalisation into HEK-sst3 was usually faster for the {sup 111}In-labelled peptides. No internalisation was found into sst5. Biodistribution studies employing [{sup 67}Ga-DOTA,1-Nal{sup 3}]octreotide in comparison to [{sup 111}In-DOTA,1-Nal{sup 3}]octreotide and [{sup 67}Ga-DOTA,Tyr{sup 3}]octreotide showed a significantly higher and receptor-mediated uptake of the two{sup 67}Ga-labelled peptides in the tumour and somatostatin receptor-positive tissues. A patient study illustrated the potential advantage of a broad receptor subtype profile radiopeptide over a high-affinity sst2-selective radiopeptide. This study demonstrates that {sup 67/68}Ga-DOTA-octapeptides show distinctly better preclinical, pharmacological performances than the {sup 111}In-labelled peptides, especially on sst2-expressing cells and the corresponding animal models. They may be excellent candidates for further

  6. Are radiogallium-labelled DOTA-conjugated somatostatin analogues superior to those labelled with other radiometals?

    International Nuclear Information System (INIS)

    Antunes, P.; Ginj, M.; Zhang, H.; Maecke, H.; Waser, B.; Reubi, J.C.; Baum, R.P.

    2007-01-01

    Gallium-68 is a metallic positron emitter with a half-life of 68 min that is ideal for the in vivo use of small molecules, such as [ 68 Ga-DOTA,Tyr 3 ]octreotide, in the diagnostic imaging of somatostatin receptor-positive tumours. In preclinical studies it has shown a striking superiority over its 111 In-labelled congener. The purpose of this study was to evaluate whether third-generation somatostatin-based, radiogallium-labelled peptides show the same superiority. Peptides were synthesised on solid phase. The receptor affinity was determined by in vitro receptor autoradiography. The internalisation rate was studied in AR4-2J and hsst-HEK-transfected cell lines. The pharmacokinetics was studied in a rat xenograft tumour model, AR4-2J. All peptides showed high affinities on hsst2, with the highest affinity for the Ga III -complexed peptides. On hsst3 the situation was reversed, with a trend towards lower affinity of the Ga III peptides. A significantly increased internalisation rate was found in sst2-expressing cells for all 67 Ga-labelled peptides. Internalisation into HEK-sst3 was usually faster for the 111 In-labelled peptides. No internalisation was found into sst5. Biodistribution studies employing [ 67 Ga-DOTA,1-Nal 3 ]octreotide in comparison to [ 111 In-DOTA,1-Nal 3 ]octreotide and [ 67 Ga-DOTA,Tyr 3 ]octreotide showed a significantly higher and receptor-mediated uptake of the two 67 Ga-labelled peptides in the tumour and somatostatin receptor-positive tissues. A patient study illustrated the potential advantage of a broad receptor subtype profile radiopeptide over a high-affinity sst2-selective radiopeptide. This study demonstrates that 67/68 Ga-DOTA-octapeptides show distinctly better preclinical, pharmacological performances than the 111 In-labelled peptides, especially on sst2-expressing cells and the corresponding animal models. They may be excellent candidates for further development for clinical studies. (orig.)

  7. Somatostatin receptors and their ligands in the human immune system

    NARCIS (Netherlands)

    V.A.S.H. Dalm (Virgil)

    2003-01-01

    textabstractMaintenance of homeostasis is essential for survival of the mammalian organism. For a long time it was believed that the different systems in the human body act independently from each other to achieve this goal. However, during the last decades it has become more evident that the

  8. PET tracers for somatostatin receptor imaging of neuroendocrine tumors

    DEFF Research Database (Denmark)

    Johnbeck, Camilla Bardram; Knigge, Ulrich; Kjær, Andreas

    2014-01-01

    Neuroendocrine tumors have shown rising incidence mainly due to higher clinical awareness and better diagnostic tools over the last 30 years. Functional imaging of neuroendocrine tumors with PET tracers is an evolving field that is continuously refining the affinity of new tracers in the search...... these PET tracers further....

  9. [The scintigraphy of somatostatin receptors in the carcinoid tumor].

    Science.gov (United States)

    Banzo, J; Abós, M D; Prats, E; Delgado , M; Razola, P; García, S; Gomollón, F; García, F

    2001-02-01

    This study aimed to evaluate the diagnostic utility of 111In-DTPA-D-Phe1-octreotide scintigraphy in the different situations that can be present when an examination is requested during the clinical course of the carcinoid tumor (CT). We have performed 41 scintigraphies with 111In-octreotide (145-185 MBq) in 35 patients (19 females and 16 males) with clinically suspected or confirmed CT. The patients were classified into five groups: Group A: Indolent symptoms of CT (n=9); B: CT staging located in lung (n=4), stomach (n=2), cecum (n=1), thymus (n=1) and pancreas (n=1); C: Carcinoid syndrome (n=1); D: CT staging after surgery located in pancreas (n=1), ovary (n=1), cecum (n=1), stomach (n=1), appendix (n=1) and ileum (n=1); and E: Post-treatment follow-up (n=13), with CT located in bronchial tree (n=5), small intestine (n=3), appendix (n=2), thymus (n=1), ovary (n=1) and unknown primary tumor (n=1). Three patients of this group had one scintigraphic study before the treatment. Head and neck, thorax and abdomen images were obtained at 4 and 24 h in all of the patients and SPECT images of the abdomen (n=14), thorax (n=10), and brain (n=1) were obtained at 24 h in 25 patients. Group A: In the 3 patients with a positive scintigraphy, the definitive diagnosis was meningioma, Hurtle cell's carcinoma and lung adenocarcinoma. The clinical follow-up in the six other patients, at least during one year, did not show any evidence of CT. Group B: Six of the 9 CT were detected with the scintigraphy. In 2 cases of bronchial CT, the scan showed sarcoidotic regional lymph node involvement and CT hepatic and bone metastases, respectively. Group C: The scintigraphy detected hepatic metastases from an unknown primary tumor. Group D: The scintigraphy was positive in 3 cases (hepatic or/and abdominal metastases) and was normal in the other 3. The scintigraphy was negative in one patient with peritoneal metastases. Group E: The scintigraphy was normal in 7 patients in concordance with the clinical follow-up. In 3 patients with a scintigraphy performed prior to treatment, the scintigraphy detected recurrence (thymic CT), progression of the metastatic disease (ovarian CT) and partial regression of the hepatic metastases (carcinoid syndrome). In the three other patients, the scintigraphy showed metastases located in liver in one patient and hepatic and extra-hepatic metastases in the two other patients. The sensitivity and specificity of 111In-Octreotide in the detection of the primary tumor and metastases were 72% and 84% respectively. The 111In-Octreotide scintigraphy has a low diagnostic utility in patients with indolent symptoms of CT. However, it is the first line of diagnosis for the staging of the CT and to evaluate the follow up after therapy.

  10. Somatostatin analogues labelled with 99mTc

    International Nuclear Information System (INIS)

    Obenaus, E.; Crudo, J.; Edreira, M.; Viaggi, M.; De Castiglia, S.G.

    2001-01-01

    The aim of the present work was to study the biological and radiochemical behaviour of two somatostatin analogues, the RC-160 and Tyr3Octreotide(TOC) peptides when labelling with 99m Tc by two methods: direct and indirect using S-benzoyl- mercaptoacetyl triglycine (MAG-3) and hydrazinonicotinamide (HYNIC) as chelating agents. RC-160 was labelled with 125I (30% labelling yield) in order to examine its receptor specificity and to study the biodistribution in normal animals. A total binding of 30% and a non specific binding lower than 10% was obtained. On the other hand, the RC-160 was labelled with 99m Tc by a direct method (70% labelling yield), using sodium ascorbate and dithionite in order to reduce the peptide and 99m Tc, respectively. The synthesis of RC-160 with S-benzoyl MAG-3 and TOC with HYNIC, for labelling with 99m Tc are also described. The conjugates were prepared on a small scale and labelled with the radionuclide using tricine as co-ligands for HYNIC conjugates. Chromatographic studies were performed using HPLC system and radiochemical purities higher than 75% and 95% were obtained respectively. Biodistributions studies in normal Wistar rats were performed and results were correlated with chromatographic and protein binding properties. Lower lipophilicity of the labelled conjugates resulted in a higher renal excretion. HYNIC-TOC complex showed promising results when labelling with 99m Tc using tricine as co-ligand although higher stability should be found for ternary co-ligands compared to tricine. (author)

  11. Basal Forebrain Gating by Somatostatin Neurons Drives Prefrontal Cortical Activity.

    Science.gov (United States)

    Espinosa, Nelson; Alonso, Alejandra; Morales, Cristian; Espinosa, Pedro; Chávez, Andrés E; Fuentealba, Pablo

    2017-11-17

    The basal forebrain provides modulatory input to the cortex regulating brain states and cognitive processing. Somatostatin-expressing neurons constitute a heterogeneous GABAergic population known to functionally inhibit basal forebrain cortically projecting cells thus favoring sleep and cortical synchronization. However, it remains unclear if somatostatin cells can regulate population activity patterns in the basal forebrain and modulate cortical dynamics. Here, we demonstrate that somatostatin neurons regulate the corticopetal synaptic output of the basal forebrain impinging on cortical activity and behavior. Optogenetic inactivation of somatostatin neurons in vivo rapidly modified neural activity in the basal forebrain, with the consequent enhancement and desynchronization of activity in the prefrontal cortex, reflected in both neuronal spiking and network oscillations. Cortical activation was partially dependent on cholinergic transmission, suppressing slow waves and potentiating gamma oscillations. In addition, recruitment dynamics was cell type-specific, with interneurons showing similar temporal profiles, but stronger responses than pyramidal cells. Finally, optogenetic stimulation of quiescent animals during resting periods prompted locomotor activity, suggesting generalized cortical activation and increased arousal. Altogether, we provide physiological and behavioral evidence indicating that somatostatin neurons are pivotal in gating the synaptic output of the basal forebrain, thus indirectly controlling cortical operations via both cholinergic and non-cholinergic mechanisms. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Deficiencies in fat-soluble vitamins in long-term users of somatostatin analogue

    NARCIS (Netherlands)

    Fiebrich, H. -B.; van den Berg, G.; Kema, I. P.; Links, T. P.; Kleibeuker, J. H.; van Beek, A. P.; Walenkamp, A. M. E.; Sluiter, W. J.; de Vries, E. G. E.

    2010-01-01

    P>Background Somatostatin analogues are administered to control hormone hypersecretion in acromegaly and carcinoid patients. Somatostatin analogues can increase fat in the stools, which can lead to loss of fat-soluble vitamins. The effect of long-term somatostatin analogue use on vitamin levels

  13. Diet-Induced Growth Is Regulated via Acquired Leptin Resistance and Engages a Pomc-Somatostatin-Growth Hormone Circuit

    Directory of Open Access Journals (Sweden)

    Heiko Löhr

    2018-05-01

    Full Text Available Summary: Anorexigenic pro-opiomelanocortin (Pomc/alpha-melanocyte stimulating hormone (αMSH neurons of the hypothalamic melanocortin system function as key regulators of energy homeostasis, also controlling somatic growth across different species. However, the mechanisms of melanocortin-dependent growth control still remain ill-defined. Here, we reveal a thus-far-unrecognized structural and functional connection between Pomc neurons and the somatotropic hypothalamo-pituitary axis. Excessive feeding of larval zebrafish causes leptin resistance and reduced levels of the hypothalamic satiety mediator pomca. In turn, this leads to reduced activation of hypophysiotropic somatostatin (Sst-neurons that express the melanocortin receptor Mc4r, elevated growth hormone (GH expression in the pituitary, and enhanced somatic growth. Mc4r expression and αMSH responsiveness are conserved in Sst-expressing hypothalamic neurons of mice. Thus, acquired leptin resistance and attenuation of pomca transcription in response to excessive caloric intake may represent an ancient mechanism to promote somatic growth when food resources are plentiful. : The melanocortin system controls energy homeostasis and somatic growth, but the underlying mechanisms are elusive. Löhr et al. identify a functional neural circuit in which Pomc neurons stimulate hypothalamic somatostatin neurons, thereby inhibiting hypophyseal growth hormone production. Excessive feeding and acquired leptin resistance attenuate this pathway, allowing faster somatic growth when food resources are rich. Keywords: Pomc neuron, somatostatin neuron, somatic growth, growth hormone, melanocortin system, high-fat diet, obesity, leptin resistance, zebrafish, mouse

  14. Technetium-99m somatostatin analogues: effect of labelling methods and peptide sequence

    International Nuclear Information System (INIS)

    Decristoforo, C.; Mather, S.J.

    1999-01-01

    In this paper the preclinical evaluation of the somatostatin analogue RC160 labelled with technetium-99m using bifunctional chelators (BFCs) based on the hydrazinonicotinamide (HYNIC) and N 3 S system is described and a comparison made with [Tyr 3 ]-octreotide (TOC). Conjugates of both peptides with HYNIC, and of RC160 with benzoyl-MAG 3 and an N 3 S-adipate derivative were prepared and radiolabelling performed at high specific activities using tricine, tricine/nicotinic acid and ethylenediamine-N,N'-diacetic adic (EDDA) as co-ligands for HYNIC conjugates. All conjugates and 99m Tc-labelled peptides showed preserved binding affinity for the somatostatin receptor (IC50, Kd 99m Tc-RC160 derivatives compared with 99m Tc-EDDA/HYNIC-[Tyr 3 ]-octreotide (0.2%-3.5%ID/g vs 9.7%ID/g) and correlated well with the reduced internalisation rate for RC160 derivatives. Our results show that the selection of the labelling approach as well as the right choice of the peptide structure are crucial for labelling peptides with 99m Tc to achieve complexes with favourable biodistribution. Despite the relatively low tumour uptake compared with 99m Tc-EDDA/HYNIC-[Tyr 3 ]-octreotide, 99m Tc-RC160 could play a role in imaging tumours that do not bind octreotide derivatives. (orig.)

  15. Somatostatin-like peptide and regeneration capacities in planarians.

    Science.gov (United States)

    Bautz, A; Schilt, J

    1986-11-01

    The presence of a neuropeptide immunologically related to somatostatin (SRIF) has been investigated in the neurosecretory cells of two regenerating planarian species (Dugesia lugubris and Dendrocoelum lacteum). A correlation has been shown between the discharge of the SRIF-like-immunoreactive cells during the first hours after amputation and the capacity to regenerate, and between the persistence of numerous positive cells and the lack of regeneration. These results suggest that somatostatin might play a regulatory (inhibitory) role on the cellular proliferation which leads to the blastema edification.

  16. Regulation of somatostatin release in the nervous system of the rat

    International Nuclear Information System (INIS)

    Sheppard, M.

    1979-08-01

    This thesis represents the work done to study the release of somatostatin from the rat central nervous system in vitro, providing some evidence for a physiological role for somatostatin. Somatostatin was measured by a sensitive and specific radioimmunoassay devoloped in the laboratory. Chapter 2 reviews the literature on hypothalamic peptides and control of an anterior pituitary function, somatostatin, other central nervous system peptides and neurosecretion. Chapter 3 describes the central nervous system tissue dissection technique, the radioimmunoassay for somatostatin and the tissue levels of somatostatin immunoreactivity in different areas of the central nervous system. Chapter 4 deals with the release of immunoreactive somatostatin from incubated rat hypothalamus in vitro and the influence of other hormones and neuropeptides on this release. Chapter 5 describes the preparation of isolated nerve endings (synaptosomes) from four different areas of rat brain, the localisation of somatostatin to the synaptosome fraction of brain homogenates and the release of somatostatin from these synaptosomes. Chapter 6 deals with the release of somatostatin from incubated rat spinal cord in vitro. Chapter 7 presents the results of the characterisation of released immunoreactive material, the technique utilised being serial dilution of immunoreactive material and comparison to the standard curve, Sephadex gel chromatography, affinity chromatography, and the effect of released immunoreactive somatostatin on growth hormone release from perifused hemipituitaries in vitro, i.e. biological activity. Chapter 8 provides a summary of the main conclusions reached in this study and is followed by the Appendix describing chemical and biochemical methods, histological techniques, and statistical methods

  17. Hilar somatostatin interneuron loss reduces dentate gyrus inhibition in a mouse model of temporal lobe epilepsy.

    Science.gov (United States)

    Hofmann, Gabrielle; Balgooyen, Laura; Mattis, Joanna; Deisseroth, Karl; Buckmaster, Paul S

    2016-06-01

    In patients with temporal lobe epilepsy, seizures usually start in the hippocampus, and dentate granule cells are hyperexcitable. Somatostatin interneurons are a major subpopulation of inhibitory neurons in the dentate gyrus, and many are lost in patients and animal models. However, surviving somatostatin interneurons sprout axon collaterals and form new synapses, so the net effect on granule cell inhibition remains unclear. The present study uses optogenetics to activate hilar somatostatin interneurons and measure the inhibitory effect on dentate gyrus perforant path-evoked local field potential responses in a mouse model of temporal lobe epilepsy. In controls, light activation of hilar somatostatin interneurons inhibited evoked responses up to 40%. Epileptic pilocarpine-treated mice exhibited loss of hilar somatostatin interneurons and less light-induced inhibition of evoked responses. These findings suggest that severe epilepsy-related loss of hilar somatostatin interneurons can overwhelm the surviving interneurons' capacity to compensate by sprouting axon collaterals. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

  18. High molecular somatostatin, an interfering factor in radioimmunoassay

    International Nuclear Information System (INIS)

    Diel, F.; Schneider, E.; Baumann, H.

    1977-01-01

    Cyclic Tyr 1 -somatostatin (Tyr 1 -SRIF) is radioiodinated by the lactoperoxidase method. Purification is achieved by Sephadex G-25 adsorption chromatography. Specific anti-SRIF serum (FA1) has been raised in rabbits. A dose response curve is obtained in the range of 5 - 5,000 pg per tube using an antiserum dilution of 1:2,000. There is little cross-reaction with linear somatostatin and none with ocytocin, (lys-, arg-) vasopressin, valinomycin, polymyxin, insulin, glucagon, human growth hormone (hGH), and thyrotropin-releasing hormone (TRH). For recovery tests, extraction procedures are necessary. Thin-layer chromatography (TLC) and polyacrylamide-disc-electrophoresis (Disc-PAGE) are performed to identify the presumed high molecular 125 I-Tyr 1 -SRIF associate. This high molecular associate may represent an interfering factor in the radioimmunoassay for cyclic SRIF. (orig./AJ) [de

  19. PLGA nanoparticles for peptide receptor radionuclide therapy of neuroendocrine tumors: a novel approach towards reduction of renal radiation dose.

    Directory of Open Access Journals (Sweden)

    Geetanjali Arora

    Full Text Available BACKGROUND: Peptide receptor radionuclide therapy (PRRT, employed for treatment of neuroendocrine tumors (NETs is based on over-expression of Somatostatin Receptors (SSTRs on NETs. It is, however, limited by high uptake and retention of radiolabeled peptide in kidneys resulting in unnecessary radiation exposure thus causing nephrotoxicity. Employing a nanocarrier to deliver PRRT drugs specifically to the tumor can reduce the associated nephrotoxicity. Based on this, (177Lu-DOTATATE loaded PLGA nanoparticles (NPs were formulated in the present study, as a potential therapeutic model for NETs. METHODOLOGY AND FINDINGS: DOTATATE was labeled with Lutetium-177 ((177Lu (labeling efficiency 98%; R(f∼0.8. Polyethylene Glycol (PEG coated (177Lu-DOTATATE-PLGA NPs (50:50 and 75:25 formulated, were spherical with mean size of 304.5±80.8 and 733.4±101.3 nm (uncoated and 303.8±67.2 and 494.3±71.8 nm (coated for PLGA(50:50 and PLGA(75:25 respectively. Encapsulation efficiency (EE and In-vitro release kinetics for uncoated and coated NPs of PLGA (50:50 & 75:25 were assessed and compared. Mean EE was 77.375±4.98% & 67.885±5.12% (uncoated and 65.385±5.67% & 58.495±5.35% (coated. NPs showed initial burst release between 16.64-21.65% with total 42.83-44.79% over 21 days. The release increased with coating to 20.4-23.95% initially and 60.97-69.12% over 21 days. In-vivo studies were done in rats injected with (177Lu-DOTATATE and (177Lu-DOTATATE-NP (uncoated and PEG-coated by imaging and organ counting after sacrificing rats at different time points over 24 hr post-injection. With (177Lu-DOTATATE, renal uptake of 37.89±10.2%ID/g was observed, which reduced to 4.6±1.97% and 5.27±1.66%ID/g with uncoated and coated (177Lu-DOTATATE-NP. The high liver uptake with uncoated (177Lu-DOTATATE-NP (13.68±3.08% ID/g, reduced to 7.20±2.04%ID/g (p = 0.02 with PEG coating. CONCLUSION: PLGA NPs were easily formulated and modified for desired release properties. PLGA

  20. Somatostatin ontogenesis in the gastrointestinal and pancreatic tract: study in normal rats and during a induced diabetes in neonates rats

    International Nuclear Information System (INIS)

    Cunha, M.C.

    1980-01-01

    The ontogenic studies of somatostatin of pancreas, ileum and duodenum of Wistar rats and the rats with induced diabetes were done. The radioimmunologic method to dose the somatostatin was used. (L.M.J.)

  1. GH and IGF-I induction by passive immunization of rainbow trout Oncorhynchus mykiss Walbaum using a somatostatin 14 antibody

    Science.gov (United States)

    Inhibition of the growth axis by somatostatin was studied in juvenile rainbow trout using passive immunization with a previously isolated somatostatin antibody (antiSS-14). Upon subcutaneously injection of laying hens (Gallus domesticus) with conjugated somatostatin-14 (SS-14), the antiSS-14 was iso...

  2. Excessive grooming induced by somatostatin or its analog SMS 201-995

    NARCIS (Netherlands)

    Wimersma Greidanus, T.B. van; Maigret, C.; Krechting, B.

    1987-01-01

    Intracerebroventricular (i.c.v.) administration of somatostatin or SMS 201-995 induces excessive grooming behavior in rats. The grooming inducing effect of somatostatin is rather weak, as doses of 300 ng or less did not result in increased total grooming scores. In contrast a dose of 10 ng SMS

  3. Cholecystokinin inhibits gastrin secretion independently of paracrine somatostatin secretion in the pig

    DEFF Research Database (Denmark)

    Schmidt, P T; Hansen, L; Hilsted, L

    2004-01-01

    BACKGROUND: Cholecystokinin inhibits the secretion of gastrin from antral G cells, an effect that is speculated to be mediated by D cells secreting somatostatin. The aim of the study was to test directly whether cholecystokinin inhibition of antral gastrin secretion is mediated by somatostatin....... METHODS: The effects of CCK on gastrin and somatostatin secretion were studied in isolated vascularly perfused preparations of pig antrum before and after immunoneutralization brought about by infusion of large amounts of a high affinity monoclonal antibody against somatostatin. RESULTS: CCK infusion...... at 10(-9) M and 10(-8) M decreased gastrin output to 70.5% +/- 7.6% (n = 8) and 76.3% +/- 3.6% (n = 7) of basal output, respectively. CCK at 10(-10) M had no effect (n = 6). Somatostatin secretion was dose-dependently increased by CCK infusion and increased to 268 +/- 38.2% (n = 7) of basal secretion...

  4. Cell-to-cell communication and cellular environment alter the somatostatin status of delta cells

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Catriona, E-mail: catriona.kelly@qub.ac.uk [SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Coleraine (United Kingdom); Flatt, Peter R.; McClenaghan, Neville H. [SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Coleraine (United Kingdom)

    2010-08-20

    Research highlights: {yields} TGP52 cells display enhanced functionality in pseudoislet form. {yields} Somatostatin content was reduced, but secretion increased in high glucose conditions. {yields} Cellular interactions and environment alter the somatostatin status of TGP52 cells. -- Abstract: Introduction: Somatostatin, released from pancreatic delta cells, is a potent paracrine inhibitor of insulin and glucagon secretion. Islet cellular interactions and glucose homeostasis are essential to maintain normal patterns of insulin secretion. However, the importance of cell-to-cell communication and cellular environment in the regulation of somatostatin release remains unclear. Methods: This study employed the somatostatin-secreting TGP52 cell line maintained in DMEM:F12 (17.5 mM glucose) or DMEM (25 mM glucose) culture media. The effect of pseudoislet formation and culture medium on somatostatin content and release in response to a variety of stimuli was measured by somatostatin EIA. In addition, the effect of pseudoislet formation on cellular viability (MTT and LDH assays) and proliferation (BrdU ELISA) was determined. Results: TGP52 cells readily formed pseudoislets and showed enhanced functionality in three-dimensional form with increased E-cadherin expression irrespective of the culture environment used. However, culture in DMEM decreased cellular somatostatin content (P < 0.01) and increased somatostatin secretion in response to a variety of stimuli including arginine, calcium and PMA (P < 0.001) when compared with cells grown in DMEM:F12. Configuration of TGP52 cells as pseudoislets reduced the proliferative rate and increased cellular cytotoxicity irrespective of culture medium used. Conclusions: Somatostatin secretion is greatly facilitated by cell-to-cell interactions and E-cadherin expression. Cellular environment and extracellular glucose also significantly influence the function of delta cells.

  5. Cell-to-cell communication and cellular environment alter the somatostatin status of delta cells

    International Nuclear Information System (INIS)

    Kelly, Catriona; Flatt, Peter R.; McClenaghan, Neville H.

    2010-01-01

    Research highlights: → TGP52 cells display enhanced functionality in pseudoislet form. → Somatostatin content was reduced, but secretion increased in high glucose conditions. → Cellular interactions and environment alter the somatostatin status of TGP52 cells. -- Abstract: Introduction: Somatostatin, released from pancreatic delta cells, is a potent paracrine inhibitor of insulin and glucagon secretion. Islet cellular interactions and glucose homeostasis are essential to maintain normal patterns of insulin secretion. However, the importance of cell-to-cell communication and cellular environment in the regulation of somatostatin release remains unclear. Methods: This study employed the somatostatin-secreting TGP52 cell line maintained in DMEM:F12 (17.5 mM glucose) or DMEM (25 mM glucose) culture media. The effect of pseudoislet formation and culture medium on somatostatin content and release in response to a variety of stimuli was measured by somatostatin EIA. In addition, the effect of pseudoislet formation on cellular viability (MTT and LDH assays) and proliferation (BrdU ELISA) was determined. Results: TGP52 cells readily formed pseudoislets and showed enhanced functionality in three-dimensional form with increased E-cadherin expression irrespective of the culture environment used. However, culture in DMEM decreased cellular somatostatin content (P < 0.01) and increased somatostatin secretion in response to a variety of stimuli including arginine, calcium and PMA (P < 0.001) when compared with cells grown in DMEM:F12. Configuration of TGP52 cells as pseudoislets reduced the proliferative rate and increased cellular cytotoxicity irrespective of culture medium used. Conclusions: Somatostatin secretion is greatly facilitated by cell-to-cell interactions and E-cadherin expression. Cellular environment and extracellular glucose also significantly influence the function of delta cells.

  6. Somatostatin Negatively Regulates Parasite Burden and Granulomatous Responses in Cysticercosis

    Directory of Open Access Journals (Sweden)

    Mitra Khumbatta

    2014-01-01

    Full Text Available Cysticercosis is an infection of tissues with the larval cysts of the cestode, Taenia  solium. While live parasites elicit little or no inflammation, dying parasites initiate a granulomatous reaction presenting as painful muscle nodules or seizures when cysts are located in the brain. We previously showed in the T. crassiceps murine model of cysticercosis that substance P (SP, a neuropeptide, was detected in early granulomas and was responsible for promoting granuloma formation, while somatostatin (SOM, another neuropeptide and immunomodulatory hormone, was detected in late granulomas; SOM’s contribution to granuloma formation was not examined. In the current studies, we used somatostatin knockout (SOM−/− mice to examine the hypothesis that SOM downmodulates granulomatous inflammation in cysticercosis, thereby promoting parasite growth. Our results demonstrated that parasite burden was reduced 5.9-fold in SOM−/− mice compared to WT mice (P<0.05. This reduction in parasite burden in SOM−/− mice was accompanied by a 95% increase in size of their granulomas (P<0.05, which contained a 1.5-fold increase in levels of IFN-γ and a 26-fold decrease in levels of IL-1β (P<0.05 for both compared to granulomas from WT mice. Thus, SOM regulates both parasite burden and granulomatous inflammation perhaps through modulating granuloma production of IFN-γ and IL-1β.

  7. Active postoperative acromegaly: sustained remission after discontinuation of somatostatin analogues

    Directory of Open Access Journals (Sweden)

    Cristina Alvarez-Escola

    2016-11-01

    Full Text Available In patients with active acromegaly after pituitary surgery, somatostatin analogues are effective in controlling the disease and can even be curative in some cases. After treatment discontinuation, the likelihood of disease recurrence is high. However, a small subset of patients remains symptom-free after discontinuation, with normalized growth hormone (GH and insulin-like growth factor (IGF1 levels. The characteristics of patients most likely to achieve sustained remission after treatment discontinuation are not well understood, although limited evidence suggests that sustained remission is more likely in patients with lower GH and IGF1 levels before treatment withdrawal, in those who respond well to low-dose treatment, in those without evidence of adenoma on an MRI scan and/or in patients who receive long-term treatment. In this report, we describe the case of a 56-year-old female patient treated with lanreotide Autogel for 11 years. Treatment was successfully discontinued, and the patient is currently disease-free on all relevant parameters (clinical, biochemical and tumour status. The successful outcome in this case adds to the small body of literature suggesting that some well-selected patients who receive long-term treatment with somatostatin analogues may achieve sustained remission.

  8. Tumour uptake of the radiolabelled somatostatin analogue [DOTA0,TYR3]octreotide is dependent on the peptide amount

    International Nuclear Information System (INIS)

    Jong, M. de; Breeman, W.A.P.; Bernard, B.F.; Gameren, A. van; Bruin, E. de; Bakker, W.H.; Van der Pluijm, M.E.; Krenning, E.P.; Visser, T.J.; Maecke, H.R.

    1999-01-01

    Radiolabelled tumour receptor-binding peptides can be used for in vivo scintigraphic imaging. Recently, the somatostatin analogue [Tyr 3 ]octreotide (d-Phe-c(Cys-Tyr-d-Trp-Lys-Thr-Cys)-Thr(ol)) was derivatized with the chelator DOTA (tetra-azacyclododecane-tetra-acetic acid), enabling stable radiolabelling with both the high-energy beta particle-emitter yttrium-90 and the Auger electron-emitter indium-111. The thus produced radiolabelled compounds are promising for peptide receptor radionuclide therapy. Our previous in vitro and in vivo (rat) experiments with these radiolabelled compounds showed favourable binding and biodistribution characteristics with high uptake and retention in the target organs. We also demonstrated receptor-specific, time- and temperature-dependent internalization of radiolabelled [DOTA 0 ,Tyr 3 ]octreotide in somatostatin receptor subtype 2 (sst 2 )-positive rat pancreatic tumour cell lines. In this study we have investigated the effects of differences in the amount of injected peptide on tissue distribution of 111 In-labelled [DOTA 0 ,Tyr 3 ]octreotide in normal, i.e. non-tumour-bearing, and CA20948 tumour-bearing rats. This was done in order to find the amount of peptide at which the highest uptake in target tissues is achieved, and thereby to increase the potential of radionuclide therapy while simultaneously ensuring the lowest possible radiotoxicity in normal organs. Uptake of radiolabelled [DOTA 0 ,Tyr 3 ]octreotide in sst 2 -positive organs showed different bell-shaped functions of the amount of injected peptide, being highest at 0.05 (adrenals), 0.05-0.1 (pituitary and stomach) and 0.25 (pancreas) μg. Uptake in the tumour was highest at 0.5 μg injected peptide. The highest uptake was found at peptide amounts that were lower than those reported for [ 111 In-DTPA 0 ]octreotide (d-Phe-c(Cys-Phe-d-Trp-Lys-Thr-Cys)-Thr(ol), DTPA = diethylene-triamine-penta-acetic acid), consistent with the higher receptor affinity of the first compound

  9. Effects of the neuroprotective drugs somatostatin and brimonidine on retinal cell models of diabetic retinopathy.

    Science.gov (United States)

    Beltramo, Elena; Lopatina, Tatiana; Mazzeo, Aurora; Arroba, Ana I; Valverde, Angela M; Hernández, Cristina; Simó, Rafael; Porta, Massimo

    2016-12-01

    Diabetic retinopathy is considered a microvascular disease, but recent evidence has underlined early involvement of the neuroretina with interactions between microvascular and neural alterations. Topical administration of somatostatin (SST), a neuroprotective molecule with antiangiogenic properties, prevents diabetes-induced retinal neurodegeneration in animals. The α 2 -adrenergic receptor agonist brimonidine (BRM) decreases vitreoretinal vascular endothelial growth factor and inhibits blood-retinal barrier breakdown in diabetic rats. However, SST and BRM effects on microvascular cells have not yet been studied. We investigated the behaviour of these drugs on the crosstalk between microvasculature and neuroretina. Expression of SST receptors 1-5 in human retinal pericytes (HRP) was checked. We subsequently evaluated the effects of diabetic-like conditions (high glucose and/or hypoxia) with/without SST/BRM on HRP survival. Endothelial cells (EC) and photoreceptors were maintained in the above conditions and their conditioned media (CM) used to culture HRP. Vice versa, HRP-CM was used on EC and photoreceptors. Survival parameters were assessed. HRP express the SST receptor 1 (SSTR1). Glucose fluctuations mimicking those occurring in diabetic subjects are more damaging for pericytes and photoreceptors than stable high glucose and hypoxic conditions. SST/BRM added to HRP in diabetic-like conditions decrease EC apoptosis. However, neither SST nor BRM changed the response of pericytes and neuroretina-vascular crosstalk under diabetic-like conditions. Retinal pericytes express SSTR1, indicating that they can be a target for SST. Exposure to SST/BRM had no adverse effects, direct or mediated by the neuroretina, suggesting that these molecules could be safely evaluated for the treatment of ocular diseases.

  10. Novel sst2-selective somatostatin agonists. Three-dimensional consensus structure by NMR

    Science.gov (United States)

    Grace, Christy Rani R.; Erchegyi, Judit; Koerber, Steven C.; Reubi, Jean Claude; Rivier, Jean; Riek, Roland

    2008-01-01

    The three-dimensional NMR structures of six octapeptide agonist analogues of somatostatin (SRIF) in the free form are described. These analogues, with the basic sequence H-DPhe/Phe2-c[Cys3-Xxx7-DTrp8-Lys9-Thr10-Cys14]-Thr-NH2 (the numbering refers to the position in native SRIF), with Xxx7 being Ala/Aph, exhibit potent and highly selective binding to human SRIF type 2 (sst2) receptors. The backbone of these sst2-selective analogues have the usual type-II’ β-turn reported in the literature for sst2/3/5-subtype-selective analogues. Correlating biological results and NMR studies led to the identification of the side chains of DPhe2, DTrp8 and Lys9 as the necessary components of the sst2 pharmacophore. This is the first study to show that the aromatic ring at position 7 (Phe7) is not critical for sst2 binding and that it plays an important role in sst3 and sst5 binding. This pharmacophore is therefore different from that proposed by others for sst2/3/5 analogues. PMID:16854054

  11. The radioimmunoassay and physiology of somatostatin in the pancreas and gastrointestinal tract.

    Science.gov (United States)

    McIntosh, C; Arnold, R

    1978-05-01

    Radioimmunoassays for somatostain have demonstrated that high concentrations of the polypeptide are present in the pancreas and gastrointestinal tract of a number of species. Although measurement in tissue extracts is relatively unproblematic, detection and characterization of somatostatin-like material in plasma has proved technically difficult. Studies of pancreatic somatostatin release in vitro suggest a possible function in the regulation of islet hormone secretion, but the mode of action remains to be elucidated. Although, at present, no clinical relevance can be attributed to the somatostain radioimmunoassay reports of somatostatin secreting tumors and changes in stomach tissue content in patients with ulcer disease indicate a contributory role in the pathophysiology of certain disease states.

  12. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas

    Directory of Open Access Journals (Sweden)

    Wang JW

    2014-01-01

    Full Text Available Ji-wen Wang,1,2 Ying Li,3 Zhi-gang Mao,1,2 Bin Hu,1,2 Xiao-bing Jiang,1,2 Bing-bing Song,4 Xin Wang,4 Yong-hong Zhu,4 Hai-jun Wang1,21Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, 2Key Laboratory of Pituitary Adenoma in Guangdong Province, 3State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 4Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, People's Republic of ChinaAbstract: Excessive growth hormone (GH is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs and GH receptor antagonist; the former consists of lanreotide Autogel (ATG and octreotide long-acting release (LAR, and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4–6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated

  13. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  14. Somatostatin analogues labelled with 99mTc

    International Nuclear Information System (INIS)

    Obenaus, Esteban R.; Crudo, Jose L.; Edreira, Martin M.; Castiglia, Silvia G.

    1999-01-01

    Biological and radiochemical studies have been carried out on two labelled somatostatin analogues, the peptide RC-150 and the Tyr 3 -Octreotide. Both analogues have been labelled with 99m Tc using the direct and the indirect method and MAG-3 and HYNIC as chelating agents. By the direct method RC-150 was labelled using sodium ascorbate and dithionite as reducing agents. The radiochemical purity was 70%. By the indirect method, in the case of RC-160 with MAG-3 a radiochemical purity higher than 70% was attained while a purity of 100% was reached in the case of Tyr 3 -Octreotide with HYNIC. The biological distribution of HYNIC-Tyr 3 -Octreotide has been studied in rats. (author)

  15. Depletion of somatostatin-like immunoreactivity in the rat central nervous system by cysteamine

    International Nuclear Information System (INIS)

    Sagar, S.M.; Landry, D.; Millard, W.J.; Badger, T.M.; Arnold, M.A.; Martin, J.B.

    1982-01-01

    Selective neurotoxins have been of value in providing a means for specifically interfering with the actions of endogenous neurotransmitter candidates. Others have shown cysteamine (CSH) to deplete the gastrointestinal tract and hypothalamus of rats of immunoreactive somatostatin, suggesting a toxic action of that compound directed against somatostatin-containing cells. The present study further defines the actions of cysteamine on somatostatin in the central nervous system. (CNS). Cysteamine hydrochloride administered subcutaneously results in a depletion of somatostatin-like immunoreactivity (SLI) in the retina, brain, and cervical spinal cord of rats. The effect is demonstrable at doses of 30 mg/kg of body weight and above, occurs within 2 to 4 hr of a single injection of the drug, and is largely reversible within 1 week. The mean depletion of SLI observed within the CNS varies from 38% in cerebral cortex to 65% in cervical spinal cord 24 hr following administration of CSH, 300 mg/kg of body weight, s.c. By gel permeation chromatography, all molecular weight forms of SLI are affected, with the largest reductions in those forms that co-chromatograph with synthetic somatostatin-14 and somatostatin-28. These results indicate that CSH has a generalized, rapid, and largely reversible effect in depleting SLI from the rat CNS

  16. In vivo somatostatin, vasopressin, and oxytocin synthesis in diabetic rat hypothalamus

    International Nuclear Information System (INIS)

    Fernstrom, J.D.; Fernstrom, M.H.; Kwok, R.P.

    1990-01-01

    The in vivo labeling of somatostatin-14, somatostatin-28, arginine vasopressin, and oxytocin was studied in rat hypothalamus after third ventricular administration of [35S]cysteine to streptozotocin-diabetic and normal rats. Immunoreactive somatostatin levels in hypothalamus were unaffected by diabetes, as was the incorporation of [35S]cysteine into hypothalamic somatostatin-14 and somatostatin-28. In contrast, immunoreactive vasopressin levels in hypothalamus and posterior pituitary (and oxytocin levels in posterior pituitary) were below normal in diabetic rats. Moreover, [35S]cysteine incorporation into hypothalamic vasopressin and oxytocin (probably mainly in the paraventricular nucleus because of its proximity to the third ventricular site of label injection) was significantly above normal. The increments in vasopressin and oxytocin labeling were reversed by insulin administration. In vivo cysteine specific activity and the labeling of acid-precipitable protein did not differ between normal and diabetic animals; effects of diabetes on vasopressin and oxytocin labeling were therefore not caused by simple differences in cysteine specific activity. These results suggest that diabetes (1) does not influence the production of somatostatin peptides in hypothalamus but (2) stimulates the synthesis of vasopressin and oxytocin. For vasopressin at least, the increase in synthesis may be a compensatory response to the known increase in its secretion that occurs in uncontrolled diabetes

  17. Iodination and stability of somatostatin analogues: comparison of iodination techniques. A practical overview.

    Science.gov (United States)

    de Blois, Erik; Chan, Ho Sze; Breeman, Wouter A P

    2012-01-01

    For iodination ((125/127)I) of tyrosine-containing peptides, chloramin-T, Pre-Coated Iodo-Gen(®) tubes and Iodo-Beads(®) (Pierce) are commonly used for in vitro radioligand investigations and there have been reliant vendors hereof for decades. However, commercial availability of these radio-iodinated peptides is decreasing. For continuation of our research in this field we investigated and optimized (radio-)iodination of somatostatin analogues. In literature, radioiodination using here described somatostatin analogues and iodination techniques are described separately. Here we present an overview, including High Performance Liquid Chromatography (HPLC) separation and characterisation by mass spectrometry, to obtain mono- and di-iodinated analogues. Reaction kinetics of (125/127)I iodinated somatostatin analogues were investigated as function of reaction time and concentration of reactants, including somatostatin analogues, iodine and oxidizing agent. To our knowledge, for the here described somatostatin analogues, no (127)I iodination and optimization are described. (Radio-)iodinated somatostatin analogues could be preserved with a >90% radiochemical purity for 1 month after reversed phase HPLC-purification.

  18. Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Ming; Zhang, Qilin [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Liu, Wenjuan; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yang, Yeping [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Shanghai (China); Wang, Meng [Fudan University, Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Shanghai (China); Soochow University, Division of Endocrinology, the Second Affiliated Hospital, Suzhou (China); Zhu, Jingjing [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Neuropathology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Zhao, Yao; Wang, Yongfei [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Yao, Zhenwei [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Radiology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Lu, Yun [Fudan University, Department of Nuclear Medicine, Huashan Hospital, Shanghai Medical College, Shanghai (China)

    2016-11-15

    The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly. (orig.)

  19. An evaluation of the effects of somatostatin analogue therapy in non-functioning pituitary adenomas in comparison to acromegaly.

    Science.gov (United States)

    Zawada, Natalia Bożena; Kunert-Radek, Jolanta; Pawlikowski, Marek; Pisarek, Hanna; Radek, Maciej

    2016-01-01

    Non-functioning pituitary adenomas (NFPA) are often diagnosed late as invasive macroadenomas. The surgical resection is usually incomplete and about 50% of patients require additional surgery. Recent data suggest that somatostatin analogues (SSA), so important in the pharmacotherapy of acromegaly, can also be effective in the management of NFPA. We analysed data of patients who had been treated up to 10 years previously with SSA: 40 with acromegaly (23 - primary, 17 - recurrent tumours) and 22 with NFPA (4 - primary, 18 - recurrent tumours). Hormonal profile, dynamics of tumour size change, ophthalmic syndromes, somatostatin receptor (SSTR) scintigraphy, and immunohistochemistry of SSTR subtypes of operated tumours as well as side effects were investigated. Biochemical cure of acromegaly was achieved in 57.5% of patients, while reduction of tumour size was observed in 37% of patients and it was more frequent in not-operated cases. Regarding NFPA, stabilisation of tumour size was noticed in 68% of patients. Tumour shrinkage was reported in 9% of cases, but in 23% of the study group the adenoma size increased with indication for reoperation. The efficacy of SSA in NFPA is much lower in comparison to their well-established effects in the treatment of acromegaly. Stabilisation of tumour size, which is observed in the majority of NFPA, is significantly more frequent in comparison to the natural history of untreated NFPA and our previous studies as well. Analysis of SSTR subtypes is an argument in favour of introduction of novel broad-spectrum SSA that may be more effective in the treatment of NFPA. Referring to acromegaly, adenoma size decrease was reported more frequently in primary therapy. Considering recurrent tumours better outcomes were achieved in patients who were pre-treated with SSA before planned surgery. (Endokrynol Pol 2016; 67 (3): 292-298).

  20. Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly

    International Nuclear Information System (INIS)

    Shen, Ming; Zhang, Qilin; Liu, Wenjuan; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yang, Yeping; Wang, Meng; Zhu, Jingjing; Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Zhao, Yao; Wang, Yongfei; Yao, Zhenwei; Lu, Yun

    2016-01-01

    The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly. (orig.)

  1. Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly.

    Science.gov (United States)

    Shen, Ming; Zhang, Qilin; Liu, Wenjuan; Wang, Meng; Zhu, Jingjing; Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yao, Zhenwei; Lu, Yun; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Yang, Yeping; Zhao, Yao; Wang, Yongfei

    2016-11-01

    The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly.

  2. Development of 99mTc labelled somatostatin analogues and evaluation of their radiochemical and biological behaviour

    International Nuclear Information System (INIS)

    Gano, L.; Patricio, L.

    2001-01-01

    Conjugates of two somatostatin analogues, octreotide and RC-160, with HYNIC were synthesized, characterized and purified by reverse phase HPLC. Radiolabelling of the conjugates with 99m Tc was achieved using tricine as co-ligand. High labelling efficiencies were obtained and 99m Tc peptides with high radiochemical purity were found when analysed both by ITLC and HPLC. In vitro stability of 99m Tc-peptides in human serum and towards cysteine challenge was determined by Cellogel electrophoresis and HPLC after ultrafiltration of serum solution through a 20 kDa cut off membrane. Biodistribution studies were performed in healthy mice at 5 and 30 minutes and 1, 2, 4 and 24 h post-injection. Urine and blood samples were collected at sacrifice time. Samples of urine and ultrafiltrate murine serum were analysed by electrophoresis and reverse phase HPLC in order to get some information about radiocompounds metabolism. Biological distribution of 99m Tc octreotide was also assayed in mice pre-treated with an excess of unlabelled peptide. From our results we conclude that this labelling method led to stable 99m Tc complexes both in vitro and in vivo when high specific activities (37-72 GBq/μmole) were used. Biodistribution studies of both 99m Tc-peptides indicated a radioactivity distribution profile with significant differences especially in the liver uptake that is higher for 99m Tc RC-160. However, a rapid blood clearance was obtained for both radiolabelled peptides, and the urine analysis indicated that 99m Tc peptide is mostly excreted as the initial complex. Pre-treatment with unlabelled peptide did not affect renal excretion of 99m TOC but pancreas and intestine radioactive uptake was significantly lower, indicating saturation of somatostatin receptors and selective uptake. (author)

  3. Labelling and quality control of somatostatin analogues with 99mTc

    International Nuclear Information System (INIS)

    Verdera, S.; Balter, H.; Rodriguez, G.; Robles, A.; Oliver, P.; Laiz, J.; Souto, B.

    2001-01-01

    Techniques and methodologies for labelling peptides with 99m Tc and methods for their purification, chemical, radiochemical and biological controls were evaluated. With the purpose of gaining experience, labelling with 125 I was also studied. RC-160 was labelled with 125 I using iodogen as well as chloramine-T method. Higher yields were obtained with chloramine-T method (60%), rendering 125 I-peptide with 98% of radiochemical purity, with specific activity of 240 μCi/μg - 274 μCi/μg. The product was stable for five weeks (at -20 deg. C). For somatostatin receptors studies rat brain cortex membrane was prepared. Maximum binding capacity was 24.7% and Kaff for the binding of RC-160 to receptor was estimated as 2.0x10 10 M -1 . Other peptides as β-(2-Naphthyl)- D Ala-Cys-Tyr- D Trp-Lys-Val-Cys-Thr amide (N-9642, Σ) and mouse epidermal growth factor (mEGF) were also labelled by means of limiting chloramine-T method. In case of mEGF the availability of membrane receptors allowed us to experiment in mice as well as in vitro. The reaction yields were up to 60% and 70% respectively. Biodistribution of 125 I-mEGF in a mouse with adenoma demonstrated preferential uptake in tumour (21,7% injected dose). The radioimmunoassay system gave 39% maximum binding (MB) and 50% displacement (ED 50 ) for 10 ng/mL unlabelled mEGF. Direct method and BFC's for labelling peptides with 99m Tc were investigated and purification and quality controls studies were performed by TLC, HPLC (UV and gamma detection). RC-160 was labelled by a direct method using sodium dithionite as reducing agent with radiochemical purity >95%. The product was stable up to six hours (at RT). Considerable adsorption problems were observed. Biological behavior was in accordance with the compounds' lipophilicity. The synthesis of TOC conjugates with HYNIC as BFC was done with 45%±5% (n=3) yield. Labelling of HYNIC-TOC with tricine as co-ligand was conducted with up to 90% yield. Studies of RC-160 labelling using

  4. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas

    Science.gov (United States)

    Wang, Ji-wen; Li, Ying; Mao, Zhi-gang; Hu, Bin; Jiang, Xiao-bing; Song, Bing-bing; Wang, Xin; Zhu, Yong-hong; Wang, Hai-jun

    2014-01-01

    Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4–6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits. PMID:24421637

  5. Somatostatine analogs marked with 99m-TC

    International Nuclear Information System (INIS)

    Obenaus, E; Crudo, J; Edreira, M; Castiglia, S.G. de

    2003-01-01

    The aim of the present work was to study the biological and radiochemical behaviour of two somatostatin analogues, the RC-160 and Tyr 3 Octreotide(TOC) peptides when labeling with 99m Tc by an indirect method using S-Benzoyl- mercaptoacetyl triglycine (MAG3) and hydrazino nicotinamide (HYNIC) as chelating agents. The synthesis of RC160 with S-Benzoyl MAG3 and TOC with HYNIC, for labeling with 99m Tc are also described. The conjugates were prepared on a small scale and labeled with the radionuclide using tricine as coligands for HYNIC conjugates. Chromatographic studies were performed using an HPLC system and radiochemical purities higher than 75% and 95% were obtained respectively. Biodistributions studies in normal Wistar rats were performed and results were correlated with chromatographic and protein binding properties. Lower lipophilicity of the labeled conjugates resulted in a higher renal excretion. HYNIC-TOC complex showed promising results when labeling with 99m Tc using tricine as coligand although higher stability should be found for ternary coligands compared to tricine (Au)

  6. Somatostatin-expressing inhibitory interneurons in cortical circuits

    Directory of Open Access Journals (Sweden)

    Iryna Yavorska

    2016-09-01

    Full Text Available Cortical inhibitory neurons exhibit remarkable diversity in their morphology, connectivity, and synaptic properties. Here, we review the function of somatostatin-expressing (SOM inhibitory interneurons, focusing largely on sensory cortex. SOM neurons also comprise a number of subpopulations that can be distinguished by their morphology, input and output connectivity, laminar location, firing properties, and expression of molecular markers. Several of these classes of SOM neurons show unique dynamics and characteristics, such as facilitating synapses, specific axonal projections, intralaminar input, and top-down modulation, which suggest possible computational roles. SOM cells can be differentially modulated by behavioral state depending on their class, sensory system, and behavioral paradigm. The functional effects of such modulation have been studied with optogenetic manipulation of SOM cells, which produces effects on learning and memory, task performance, and the integration of cortical activity. Different classes of SOM cells participate in distinct disinhibitory circuits with different inhibitory partners and in different cortical layers. Through these disinhibitory circuits, SOM cells help encode the behavioral relevance of sensory stimuli by regulating the activity of cortical neurons based on subcortical and intracortical modulatory input. Associative learning leads to long-term changes in the strength of connectivity of SOM cells with other neurons, often influencing the strength of inhibitory input they receive. Thus despite their heterogeneity and variability across cortical areas, current evidence shows that SOM neurons perform unique neural computations, forming not only distinct molecular but also functional subclasses of cortical inhibitory interneurons.

  7. Effect of somatostatin on nonesterified fatty acid levels modifies glucose homeostasis during fasting

    International Nuclear Information System (INIS)

    Hendrick, G.K.; Frizzell, R.T.; Cherrington, A.D.

    1987-01-01

    In the 7-days fasted conscious dog, unlike the postabsorptive conscious dog, somatostatin infusion results in decreased levels of nonesterified fatty acids (NEFA) and increased glucose utilization (R d ) even when insulin and glucagon levels are held constant. The aim of this study was to determine whether NEFA replacement in such animals would prevent the increase in R d . In each of three protocols there was an 80-min tracer equilibration period, a 40-min basal period, and a 3-h test period. During the test period in the first protocol saline was infused, in the second protocol somatostatin was infused along with intraportal replacement amounts of insulin and glucagon (hormone replacement), while in the third protocol somatostatin plus the pancreatic hormones were infused with concurrent heparin plus Intralipid infusion. Glucose turnover was assessed using [3- 3 H]glucose. The peripheral levels of insulin, glucagon, and glucose were similar and constant in all three protocols; however, during somatostatin infusion, exogenous glucose infusion was necessary to maintain euglycemia. The NEFA level was constant during saline infusion and decreased in the hormone replacement protocol. In the hormone replacement plus NEFA protocol, the NEFA level did not change during the first 90-min period and then increased during the second 90-min period. After a prolonged fast in the dog, (1) somatostatin directly or indirectly inhibits adipose tissue NEFA release and causes a decrease in the plasma NEFA level, and (2) this decrease in the NEFA level causes an increase in R d

  8. Pertussis toxin inhibits somatostatin-induced K+ conductance in human pituitary tumor cells

    International Nuclear Information System (INIS)

    Yamashita, N.; Kojima, I.; Shibuya, N.; Ogata, E.

    1987-01-01

    The effect of pertussis toxin on somatostatin-induced K + current was examined in dissociated human pituitary tumor cells obtained from two acromegalic patients. Somatostatin-induced hyperpolarization or K + current was observed in 20 of 23 cells in adenoma 1 and 10 of 11 cells in adenoma 2. After treatment with pertussis toxin for 24 h, these responses were completely suppressed (0/14 in adenoma, 1, 0/10 in adenoma 2). Spontaneous action potentials, K + , Na + , and Ca 2+ currents were well preserved after pertussis toxin treatment. When crude membrane fraction was incubated with [ 32 P]NAD, a 41K protein was ADP-ribosylated by pertussis toxin. Hormone release was inhibited by somatostatin and this inhibition was blocked by pertussis toxin treatment

  9. In vitro effect of Δ9-tetrahydrocannabinol to stimulate somatostatin release and block that of luteinizing hormone-releasing hormone by suppression of the release of prostaglandin E2

    International Nuclear Information System (INIS)

    Rettori, V.; Aguila, M.C.; McCann, S.M.; Gimeno, M.F.; Franchi, A.M.

    1990-01-01

    Previous in vivo studies have shown that Δ 9 -tetrahydrocannabinol (THC), the principal active ingredient in marijuana, can suppress both luteinizing hormone (LH) and growth hormone (GH) secretion after its injection into the third ventricle of conscious male rats. The present studies were deigned to determine the mechanism of these effects. Various doses of THC were incubated with either stalk median eminence fragments (MEs) or mediobasal hypothalamic (MBH) fragments in vitro. Although THC (10 nM) did not alter basal release of LH-releasing hormone (LHRH) from MEs in vitro, it completely blocked the stimulatory action of dopamine or nonrepinephrine on LHRH release. The effective doses to block LHRH release were associated with a blockade of synthesis and release of prostaglandin E 2 (PGE 2 ) from MBH in vitro. In contrast to the suppressive effect of THC on LHRH release, somatostatin release from MEs was enhanced in a dose-related manner with a minimal effective dose of 1 nM. Since PGE 2 suppresses somatostatin release, this enhancement may also be related to the suppressive effect of THC on PGE 2 synthesis and release. The authors speculate that these actions are mediated by the recently discovered THC receptors in the tissue. The results indicate that the suppressive effect of THC on LH release is mediated by a blockade of LHRH release, whereas the suppressive effect of the compound on growth hormone release is mediated, at least in part, by a stimulation of somatostatin release

  10. Response, survival, and long-term toxicity after therapy with the radiolabeled somatostatin analogue [90Y-DOTA]-TOC in metastasized neuroendocrine cancers.

    Science.gov (United States)

    Imhof, Anna; Brunner, Philippe; Marincek, Nicolas; Briel, Matthias; Schindler, Christian; Rasch, Helmut; Mäcke, Helmut R; Rochlitz, Christoph; Müller-Brand, Jan; Walter, Martin A

    2011-06-10

    To investigate response, survival, and safety profile of the somatostatin-based radiopeptide (90)yttrium-labeled tetraazacyclododecane-tetraacetic acid modified Tyr-octreotide ([(90)Y-DOTA]-TOC) in neuroendocrine cancers. In a clinical phase II single-center open-label trial, patients with neuroendocrine cancers were treated with repeated cycles of [(90)Y-DOTA]-TOC. Each cycle consisted of a single intravenous injection of 3.7GBq/m(2) body-surface [(90)Y-DOTA]-TOC. Additional cycles were withheld in case of tumor progression and/or permanent toxicity. Overall, 1,109 patients received 2,472 cycles of [(90)Y-DOTA]-TOC (median, two; range, one to 10 cycles per patient). Of the 1,109 patients, 378 (34.1%) experienced morphologic response; 172 (15.5%), biochemical response; and 329 (29.7%), clinical response. During a median follow-up of 23 months, 491 patients (44.3%) died. Longer survival was correlated with each: morphologic (hazard ratio [HR], 0.46; 95% CI, 0.38 to 0.56; median survival, 44.7 v 18.3 months; P TOC treatment in a large cohort. Response to [(90)Y-DOTA]-TOC is associated with longer survival. Somatostatin receptor imaging is predictive for both survival after [(90)Y-DOTA]-TOC treatment and occurrence of renal toxicity.

  11. Somatostatin and serum gastrin in normal subjects and in patients with pernicious anaemia, chronic liver and renal disease

    Energy Technology Data Exchange (ETDEWEB)

    Le Roith, D; Vinik, A I; Epstein, S; Baron, P; Olkenitzky, M N; Pimstone, B L

    1975-09-13

    The effects of somatostatin (growth hormone release inhibiting hormone) on basal gastrin were studied in patients suffering from pernicious anaemia and chronic renal and liver disease, and during sequential arginine/insulin-stimulated gastrin release in normal subjects. When basal gastrin concentrations were normal (10-50 pg/ml) in controls and in patients who were in renal and liver failure, somatostatin had no effect on gastrin levels. Raised basal gastrin levels in pernicious anaemia and in 2 cases of chronic renal disease, were significantly inhibited by somatostatin with a half-life (T-half) of 3 to 4 minutes. Arginine infusion caused an insignificant rise in serum gastrin which was unaffected by somatostatin, whereas insulin hypoglycaemia significantly stimulated gastrin release, which was inhibited by somatostatin.

  12. Chemokine receptors and cortical interneuron dysfunction in schizophrenia.

    Science.gov (United States)

    Volk, David W; Chitrapu, Anjani; Edelson, Jessica R; Lewis, David A

    2015-09-01

    Alterations in inhibitory (GABA) neurons, including deficiencies in the GABA synthesizing enzyme GAD67, in the prefrontal cortex in schizophrenia are pronounced in the subpopulations of neurons that contain the calcium-binding protein parvalbumin or the neuropeptide somatostatin. The presence of similar illness-related deficits in the transcription factor Lhx6, which regulates prenatal development of parvalbumin and somatostatin neurons, suggests that cortical GABA neuron dysfunction may be related to disturbances in utero. Since the chemokine receptors CXCR4 and CXCR7 guide the migration of cortical parvalbumin and somatostatin neurons from their birthplace in the medial ganglionic eminence to their final destination in the neocortex, we sought to determine whether altered CXCR4 and/or CXCR7 mRNA levels were associated with disturbances in GABA-related markers in schizophrenia. Quantitative PCR was used to quantify CXCR4 and CXCR7 mRNA levels in the prefrontal cortex of 62 schizophrenia and 62 healthy comparison subjects that were previously characterized for markers of parvalbumin and somatostatin neurons and in antipsychotic-exposed monkeys. We found elevated mRNA levels for CXCR7 (+29%; pschizophrenia subjects but not in antipsychotic-exposed monkeys. CXCR7 mRNA levels were inversely correlated with mRNA levels for GAD67, parvalbumin, somatostatin, and Lhx6 in schizophrenia but not in healthy subjects. These findings suggest that higher mRNA levels for CXCR7, and possibly CXCR4, may represent a compensatory mechanism to sustain the migration and correct positioning of cortical parvalbumin and somatostatin neurons in the face of other insults that disrupt the prenatal development of cortical GABA neurons in schizophrenia. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Unique functional properties of somatostatin-expressing GABAergic neurons in mouse barrel cortex.

    NARCIS (Netherlands)

    Gentet, L.J.; Kremer, Y.; Taniguchi, H.; Huang, Z.J.; Staiger, J.F.; Petersen, C.C.H.

    2012-01-01

    Neocortical GABAergic neurons have diverse molecular, structural and electrophysiological features, but the functional correlates of this diversity are largely unknown. We found unique membrane potential dynamics of somatostatin-expressing (SOM) neurons in layer 2/3 of the primary somatosensory

  14. Effect of somatostatin on glucose homeostasis in conscious long-fasted dogs

    International Nuclear Information System (INIS)

    Stevenson, R.W.; Steiner, K.E.; Hendrick, G.K.; Cherrington, A.D.

    1987-01-01

    The effects of somatostatin plus intraportal insulin and glucagon replacement (pancreatic clamp) on carbohydrate metabolism were studied in conscious dogs fasted for 7 days so that gluconeogenesis was a major contributor to total glucose production. By use of [3- 3 H]glucose, glucose production (R a ) and utilization (R d ) and glucose clearance were assessed before and after implementation of the pancreatic clamp. After an initial control period, somatostatin (0.8 μg·kg -1 ·min -1 ) was infused with intraportal replacement amounts of glucagon and insulin. The insulin infusion rate was varied to maintain euglycemia and then kept constant for 250 min. Plasma glucagon was similar before and during somatostatin infusion, while plasma insulin was lower. Plasma glucose levels remained similar while R a and R d and the ratio of glucose clearance to plasma insulin were significantly increased. Net hepatic lactate uptake and [ 14 C]alanine plus [ 14 C]lactate conversion to [ 14 C]glucose increased. In conclusion, somatostatin alters glucose clearance in 7-day fasted dogs, resulting in changes in several indices of carbohydrate metabolism

  15. Somatostatin in the rat periventricular nucleus: sex differences and effect of gonadal steroids

    NARCIS (Netherlands)

    Vugt, van H.H.; Heijning, van de B.J.M.; Beek, van der E.M.

    2008-01-01

    In the rat, the sexual dimorphism in growth hormone release is driven by sex steroids, and is suggested to result mainly from differences in somatostatin (SOM) release patterns from the median eminence. We studied the effect of gonadal steroids on SOM peptide-containing cells in the periventricular

  16. Tissue-type plasminogen activator in somatostatin cells of rat pancreas and hypothalamus

    DEFF Research Database (Denmark)

    Kristensen, P; Larsson, L I; Danø, K

    1987-01-01

    -PA, and immunoblotting analysis demonstrated one band with a similar electrophoretic mobility. No urokinase-type PA immunoreactivity was found in the rat endocrine pancreas. A granular t-PA immunoreactivity resembling that found in adjacent sections with somatostatin antiserum was found in the median eminence...

  17. Pharmaceutical design and pharmacological characterization of Tc99m [99mTc] labelled somatostatin and gastrin analogues

    International Nuclear Information System (INIS)

    Guggenberg, E. von

    2004-10-01

    The development of regulatory peptide analogues radiolabelled with 99m Tc is of great interest for nuclear medicine applications, as 99m Tc shows very favourable imaging characteristics, such as low radiation burden to the patient, optimal image quality in SPECT, one-day-acquisition-protocol, availability on demand and cost effectiveness. In this work the principles of pharmaceutical design and preclinical pharmacological characterization of regulatory peptide analogues labelled with 99m Tc with possible application in tumour diagnosis are described. [ 99m Tc-EDDA-HYNIC0,Tyr3]octreotide ( 99m Tc-EDDA-HYNIC-TOC) is a promising new radiopharmaceutical with the potential to replace [ 111 In-DTPA0]octreotide in receptor scintigraphy of somatostatin receptor-positive tumours. Radiolabelling at high labelling yields and high specific activities could be obtained applying a coligand exchange labelling approach from tricine for EDDA under optimized conditions of pH, EDDA and stannous ion concentration. The resulting complex was characterized via HPLC, receptor binding and LC-MS. For the development of a freeze-dried kit formulation with long shelf-life, high stability of the final preparation and retained biological activity, the addition of bulking agent, the pH of the freeze-drying solution and the content of stannous chloride were of major importance. Different methods of radiochemical purity testing were evaluated to guarantee high quality of the preparation in a clinical setting, forming the basis for a further clinical evaluation of this promising new radiopharmaceutical. Radiolabelling of [D-Glu1]minigastrin (MG) with 99m Tc was studied applying two different labelling approaches. HYNIC-MG could be labelled using tricine and EDDA as coligands; and (Nalpha-His)Ac-MG was used as tridentate ligand for the 99m Tc carbonyl core. Stability experiments by HPLC analysis in PBS, serum, histidine- and cysteine-solutions as well as rat liver and kidney homogenates, receptor

  18. Synthesis and evaluation in vitro in cancer cells AR42J of the radiopharmaceutical 99mTc-Tyr3-Octreotide-dendrimer similar of somatostatin

    International Nuclear Information System (INIS)

    Orocio R, E.

    2013-01-01

    The objective of this project was preparing a multimeric system through the conjugation of several molecules of the peptide Tyr 3 -Octreotide to a dendrimer molecule based on Poly-amidoamine (PAMAM), as well as radiolabeled with 99m Tc and evaluating its behavior like new radiopharmaceutical similar of somatostatin. The dendrimer PAMAM generation 3.5 that possesses terminal groups of sodium carboxylate, was functionalized to peptide Tyr 3 -Octreotide through a reaction of peptide coupling with HATU (hexafluorophosphate (V) of 1-oxide-3-(bis(dimethylamino)methylene)-3H-[1,2,3]triazole[4,5-b]pyridine) as activating agent of carboxylate groups using the Size Exclusion Chromatography (Sec) as purification method. The product was characterized by Ultraviolet visible spectrophotometry, Mid-infrared and Far-infrared, Elemental analysis, Energy dispersive X-ray spectroscopy, Scanning electron microscopy, Thermogravimetry and Differential scanning calorimetry. The radiolabeled with 99m Tc was carried out using a direct method that involves the reduction of the anion TcO 4 - with stannous chloride, so that the dendrimer is capable of coordinating to the technetium forming a chelate compound. The radiochemical purity of the radiolabeled compound was determined by thin layer chromatography using a sodium chloride solution to 20% (m/v) as mobile phase and was verified by molecular exclusion chromatography. The radiolabeled compound was possible to obtain it with a radiochemical purity superior to 90%. Also, the specific and not specific union was evaluated of the synthesized compound in mouse pancreas cancer cells AR42J, positive to somatostatin receptors, showing specific recognition for this receptors type with high cellular internalization. The biodistribution studies were carried out in BALB/c mice at different post injection times and in nude mice with induced tumors AR42J. The results showed that the 99m Tc-PAMAM-Tyr 3 -Octreotide is excreted by via renal as hepatobiliary

  19. Somatostatin is required for masculinization of growth hormone–regulated hepatic gene expression but not of somatic growth

    Science.gov (United States)

    Low, Malcolm J.; Otero-Corchon, Veronica; Parlow, Albert F.; Ramirez, Jose L.; Kumar, Ujendra; Patel, Yogesh C.; Rubinstein, Marcelo

    2001-01-01

    Pulsatile growth hormone (GH) secretion differs between males and females and regulates the sex-specific expression of cytochrome P450s in liver. Sex steroids influence the secretory dynamics of GH, but the neuroendocrine mechanisms have not been conclusively established. Because periventricular hypothalamic somatostatin (SST) expression is greater in males than in females, we generated knockout (Smst–/–) mice to investigate whether SST peptides are necessary for sexually differentiated GH secretion and action. Despite marked increases in nadir and median plasma GH levels in both sexes of Smst–/– compared with Smst+/+ mice, the mutant mice had growth curves identical to their sibling controls and retained a normal sexual dimorphism in weight and length. In contrast, the liver of male Smst–/– mice was feminized, resulting in an identical profile of GH-regulated hepatic mRNAs between male and female mutants. Male Smst-/- mice show higher expression of two SST receptors in the hypothalamus and pituitary than do females. These data indicate that SST is required to masculinize the ultradian GH rhythm by suppressing interpulse GH levels. In the absence of SST, male and female mice exhibit similarly altered plasma GH profiles that eliminate sexually dimorphic liver function but do not affect dimorphic growth. PMID:11413165

  20. Preliminary PET/CT Imaging with Somatostatin Analogs [68Ga]DOTAGA-TATE and [68Ga]DOTAGA-TOC.

    Science.gov (United States)

    Satpati, Drishty; Shinto, Ajit; Kamaleshwaran, K K; Sarma, Haladhar Dev; Dash, Ashutosh

    2017-12-01

    Somatostatin receptor positron emission tomography/X-ray computed tomography (SSTR-PET/CT) is a well-established technique for staging and detection of neuroendocrine tumors (NETs). Ga-68-labeled DOTA-conjugated octreotide analogs are the privileged radiotracers for diagnosis and therapeutic monitoring of NETs. Hence, we were interested in assessing the influence of promising, newer variant DOTAGA on the hydrophilicity, pharmacokinetics, and lesion pick-up of somatostatin analogs. Herein, the potential of ([ 68 Ga]DOTAGA, Tyr 3 , Thr 8 ) octreotide ([ 68 Ga]DOTAGA-TATE) and ([ 68 Ga]DOTAGA, Tyr 3 ) octreotide ([ 68 Ga]DOTAGA-TOC) as NET imaging agents has been investigated. Amenability of [ 68 Ga]DOTAGA-(TATE/TOC) to kit-type formulation has been demonstrated. Biodistribution studies were carried out in normal rats at 1 h post-injection (p.i.). [ 68 Ga]DOTAGA-(TATE/TOC) PET/CT scans were carried out in patients (70-170 MBq, 1 h p.i.) with histologically confirmed well-differentiated NETs. [ 68 Ga]DOTAGA-TATE exhibited hydrophilicity similar to [ 68 Ga]DOTA-TATE (log P = -3.51 vs -3.69) whereas [ 68 Ga]DOTAGA-TOC was more hydrophilic than [ 68 Ga]DOTA-TOC (log P = -3.27 vs -2.93). [ 68 Ga]DOTAGA-TATE and [ 68 Ga]DOTA-TATE showed almost identical blood and kidney uptake in normal rats whereas significantly fast clearance (p TOC also demonstrated rapid clearance from blood and kidneys (p TOC. The metastatic lesions in NET patients were well identified by [ 68 Ga]DOTAGA-TATE and [ 68 Ga]DOTAGA-TOC. The phenomenal analogy was observed between [ 68 Ga]DOTAGA-TATE and [ 68 Ga]DOTA-TATE as well as between [ 68 Ga]DOTAGA-TOC and [ 68 Ga]DOTA-TOC in biodistribution studies in rats. The good lesion detection ability of the two radiotracers indicates their potential as NET imaging radiotracers.

  1. Effect of vasoactive intestinal polypeptide and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1984-01-01

    The effect of VIP and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands was investigated in the rat. Vasoactive intestinal polypeptide infused in doses of 10 and 100 ng/kg/h significantly increased epidermal growth factor and bicarbonate output......, but the concentrations did not change. Somatostatin infused at doses of 1, 10, 100 and 1000 ng/kg/h against a background of VIP 100 ng/kg/h inhibited in dose-dependent fashion the stimulated epidermal growth factor and bicarbonate outputs from rat Brunner's gland pouches. Also basal secretion was inhibited...... growth factor and bicarbonate from Brunner's glands, an effect which is inhibited by somatostatin. A possible role for somatostatin in the control of Brunner's gland secretion is suggested....

  2. Physiological expression of pancreatic somatostatin receptors in 99mTc-HYNIC-TOC scintigraphy.

    Science.gov (United States)

    de la Cueva, L; Lloro, P; Sangrós, M J; López Vélez, L; Navarro, P; Sarria, L; Álvarez, S; Abós, D

    2017-07-01

    To describe the frequency of head and/or pancreas uncinate process uptake of 99mTc-HYNIC-TOC, to study its nature, and analyze its diagnostic value. Retrospective evaluation of 47 consecutive 99mTc-HYNIC-TOC examinations was conducted. Head and/or pancreas uncinate process uptake was considered to be physiological in patients with normal CT at the same episode and in follow-up. It was analyzed if age or diabetes mellitus was justifying the existence or not of uptake. 32.5% patients showed uptake; 73% of them were mild. 84.6% patients with uptake have no pathology and 4% had neuroendocrine pancreatic disease at CT. Neither the age nor the diabetes mellitus established differences in patients without lesion. Near one-third of patients show physiological uptake by head and/or pancreas uncinate process at 99mTc-HYNIC-TOC scintigraphy. It seems that neither the diabetes nor the ages are factors that determine this physiological uptake.

  3. A Novel Molecular Fluorescent Technique for Imaging the Somatostatin Receptor 2, Using a DOTATOC Lanthanide Conjugate

    DEFF Research Database (Denmark)

    Andersen, Rune Wiik; Prakash, Vineet; Stensballe, Allan

    -functional DOTATOC component.                       METHOD AND MATERIALS            The chelation of Europium and Samarium to DOTATOC was proven using MALDI-TOF Mass Spectrometry. The rise in quantum yield between unchelated lanthanides and those bound by DOTATOC was examined using fluorescence spectroscopy...

  4. Somatostatin and dopamine receptors as molecular targets for the medical treatment of Cushing’s disease

    NARCIS (Netherlands)

    C. de Bruin (Christiaan)

    2009-01-01

    textabstractHarvey Williams Cushing (1869-1939) was born as the 10th child of a well-educated, puritanical medical family in Cleveland (figure 1). He attended Yale University, graduated cum laude from Harvard Medical School and was trained as a general surgeon at Johns Hopkins under the famous

  5. Somatostatin receptor-targeted organometallic iridium(III) complexes as novel theranostic agents

    Czech Academy of Sciences Publication Activity Database

    Novohradský, Vojtěch; Zamora, A.; Gandioso, A.; Brabec, Viktor; Ruiz, J.; Marchan, V.

    2017-01-01

    Roč. 53, č. 40 (2017), s. 5523-5526 ISSN 1359-7345 Institutional support: RVO:68081707 Keywords : anticancer activity * peptide- hormones * cancer-therapy Subject RIV: BO - Biophysics OBOR OECD: Biochemistry and molecular biology Impact factor: 6.319, year: 2016

  6. Synthesis and Quality Control of [18F]fluoropropanoyl-Gluc-Lys-TOCA for Somatostatine Receptors Imaging

    Czech Academy of Sciences Publication Activity Database

    Procházka, Libor; Kropáček, Martin; Bašta, Jiří; Melichar, František

    2012-01-01

    Roč. 39, P0310 (2012), S411-S411 ISSN 1619-7070. [25th Annual Congress of the European-Association-of-Nucelar Medicine. 27.10.2012-31.10.2012, Milan] Institutional support: RVO:61389005 Keywords : radiodiagnostic Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  7. Translational Advancement of Somatostatin Gene Delivery for Disease Modification and Cognitive Sparing in Intractable Epilepsy

    Science.gov (United States)

    2015-09-01

    seizures. A thoroughly characterized rodent epilepsy model will be used as a platform to test the hypotheses. In this model temporal lobe electrical...expression in the hippocampus resected from a young temporal lobe epilepsy patient. Post-baccalaureate student Andrew Moss has since expanded this project...somatostatin gene delivery persistently reduces seizure severity in a rat model of temporal lobe epilepsy , Gowri Natarajan, Jessica Anne McElroy

  8. Effect of treatment with depot somatostatin analogue octreotide on primary hyperparathyroidism (PHP) in multiple endocrine neoplasia type 1 (MEN1) patients.

    Science.gov (United States)

    Faggiano, Antongiulio; Tavares, Lidice Brandao; Tauchmanova, Libuse; Milone, Francesco; Mansueto, Gelsomina; Ramundo, Valeria; De Caro, Maria Laura Del Basso; Lombardi, Gaetano; De Rosa, Gaetano; Colao, Annamaria

    2008-11-01

    In patients with multiple endocrine neoplasia type 1 (MEN1), expression of somatostatin receptor (SST) in parathyroid adenomas and effectiveness of therapy with somatostatin analogues on primary hyperparathyroidism (PHP) have been scarcely investigated. To evaluate the effects of depot long acting octreotide (OCT-LAR) in patients with MEN1-related PHP. Eight patients with a genetically confirmed MEN1, presenting both PHP and duodeno-pancreatic neuroendocrine tumours (NET), were enrolled. The initial treatment was OCT-LAR 30 mg every 4 weeks. This therapy was established to stabilize the duodeno-pancreatic NET before to perform parathyroidectomy for PHP. Before OCT-LAR therapy, a SST scintigraphy was performed in all patients. SST subtype 2A immunohistochemistry was performed on parathyroid tumour samples from three patients undergone parathyroidectomy after OCT-LAR therapy. Serum concentrations of PTH, calcium and phosphorus as well as the 24-h urine calcium : creatinine ratio and the renal threshold phosphate concentration were evaluated before and after OCT-LAR. After OCT-LAR therapy, hypercalcaemia and hypercalciuria normalized in 75% and 62.5% of patients, respectively, and serum phosphorus and renal threshold phosphate significantly increased. Serum PTH concentrations significantly decreased in all patients and normalized in two of them. SST subtype 2A immunostaining was found in all parathyroid adenomas investigated, while SST scintigraphy showed a positive parathyroid tumour uptake in three of eight patients (37.5%). Six months of OCT-LAR therapy controlled hypercalcaemia and hypercalciuria in two-thirds of patients with MEN1-related PHP. Direct OCT-LAR effects mediated by binding to SST expression on parathyroid tumour cells are likely the main mechanism to explain the activity of this compound on calcium and phosphorus abnormalities in MEN1 PHP.

  9. Somatostatin-IRES-Cre Mice: Between Knockout and Wild-Type?

    Science.gov (United States)

    Viollet, Cécile; Simon, Axelle; Tolle, Virginie; Labarthe, Alexandra; Grouselle, Dominique; Loe-Mie, Yann; Simonneau, Michel; Martel, Guillaume; Epelbaum, Jacques

    2017-01-01

    The neuropeptide somatostatin (SOM) is widely expressed in rodent brain and somatostatin-IRES-Cre (SOM-cre) mouse strains are increasingly used to unravel the physiology of SOM-containing neurons. However, while knock-in targeting strategy greatly improves Cre-Lox system accuracy, recent reports have shown that genomic insertion of Cre construct per se can markedly affect physiological function. We show that Cre transgene insertion into the 3'UTR of the somatostatin gene leads to the selective and massive depletion of endogenous SOM in all tested brain regions. It also strongly impacts SOM-related neuroendocrine responses in a similar manner to what has been reported for SST KO mice: increased corticosterone levels after 30-min restraint stress, decreased amplitude and regularity of ultradian growth hormone secretory patterns accompanied by changes in sexually dimorphic liver gene expression ( serpina1, Cyp2b9, Cyp2a4, Cyp2d9, and Cyp7b1 ). In addition to demonstrating the need for examination of the consequences of Cre transgenesis, these results also reveal how this SOM-cre strain may be a useful tool in studying the functional consequences of moderate to low SOM levels as reported in neurological and psychiatric disorders.

  10. In vitro effect of. Delta. sup 9 -tetrahydrocannabinol to stimulate somatostatin release and block that of luteinizing hormone-releasing hormone by suppression of the release of prostaglandin E sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Rettori, V.; Aguila, M.C.; McCann, S.M. (Univ. of Texas Southwestern Medical Center at Dallas (United States)); Gimeno, M.F.; Franchi, A.M. (Centro de Estudios Farmacologicos y de Principios Naturales, Buenos Aires (Argentina))

    1990-12-01

    Previous in vivo studies have shown that {Delta}{sup 9}-tetrahydrocannabinol (THC), the principal active ingredient in marijuana, can suppress both luteinizing hormone (LH) and growth hormone (GH) secretion after its injection into the third ventricle of conscious male rats. The present studies were deigned to determine the mechanism of these effects. Various doses of THC were incubated with either stalk median eminence fragments (MEs) or mediobasal hypothalamic (MBH) fragments in vitro. Although THC (10 nM) did not alter basal release of LH-releasing hormone (LHRH) from MEs in vitro, it completely blocked the stimulatory action of dopamine or nonrepinephrine on LHRH release. The effective doses to block LHRH release were associated with a blockade of synthesis and release of prostaglandin E{sub 2} (PGE{sub 2}) from MBH in vitro. In contrast to the suppressive effect of THC on LHRH release, somatostatin release from MEs was enhanced in a dose-related manner with a minimal effective dose of 1 nM. Since PGE{sub 2} suppresses somatostatin release, this enhancement may also be related to the suppressive effect of THC on PGE{sub 2} synthesis and release. The authors speculate that these actions are mediated by the recently discovered THC receptors in the tissue. The results indicate that the suppressive effect of THC on LH release is mediated by a blockade of LHRH release, whereas the suppressive effect of the compound on growth hormone release is mediated, at least in part, by a stimulation of somatostatin release.

  11. Technetium-99m as alternative to produce somatostatin-labeled derivatives: comparative biodistribution evaluation with 111In-DTPA-octreotide

    International Nuclear Information System (INIS)

    Melo, Ivani B.; Buchpiguel, Carlos Alberto; Ueda, Laura T.; Araujo, Elaine B. de; Muramoto, Emiko; Barboza, Marycel F. de; Mengatti, Jair; Silva, Constancia P.G. da

    2008-01-01

    Synthetic somatostatin (SST) analogues have been used in the preparation of receptor-specific radiopharmaceuticals for diagnostic and therapy of neuroendocrine (NE) tumors. 111 In-DTPA-Octreotide (OctreoScan®) has found useful for imaging a range of tumors, including NE cancer, carcinoide and lymphoma. Unfortunately, 111 In is a high-cost cyclotron produced radioisotope with gamma emission not so suitable for scintigraphic images and for dosimetry like 99m Tc. This work studied the labeling conditions with 99m Tc and biological distribution in Swiss mice of two SST analogs (HYNIC-Tyr 3 -Octreotide and HYNICTyr 3 - Octreotate) and compared the biodistribution pattern with 111 In-DTPA-Octreotide. 99 mTc-HYNIC-Tyr 3 - Octreotate ( 99m Tc-HYNIC-TATE) and 99m Tc-HYNIC-Tyr 3 -Octreotide ( 99m Tc-HYNIC-OCT) were produced by labeling conditions using tricine and EDDA as coligands. 111 In-DTPA-Octreotide ( 111 In-DTPA-OCT) was produced by labeling DTPA-Octreotide with 111 InCl 3 (Nordion). Radiochemical purity of labeled preparations was determined by ITLC-SG. Biological distribution studies were performed after injection of radiopharmaceuticals on Swiss mice. Labeling procedures resulted on high radiochemical yield for all three preparations and the labeled products presented high in vitro stability. Biological distribution studies evidenced similar general biodistribution of 99m Tc-labeled peptides when compared with indium-labeled peptide with fast blood clearance and elimination by urinary tract. Kidneys uptake of 99 mTc-HYNIC-TATE are similar to 111 In-DTPA-Octreotide, and both are significantly higher than 99 mTc-HYNIC-OCT. All labeled peptides presented similar uptake on liver, but the retention in time at intestines, particularly at large intestine, was more expressive for 111 In-labeled peptide. The %ID of 99m Tc-HYNIC-OCT and 99m Tc-HYNIC-TATE in organs with high density of SST receptors like pancreas and adrenals were significant and similar to obtained for 111

  12. Effects of cysteamine on dopamine-mediated behaviors: evidence for dopamine-somatostatin interactions in the striatum

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Iverson, M.T.; Radke, J.M.; Vincent, S.R.

    1986-06-01

    The effects of prior treatment with cysteamine, a drug which appears to deplete selectively the neuropeptide somatostatin, on apomorphine-induced stereotypy and amphetamine-induced locomotor activity and conditioned place preferences were investigated. Twelve hours following systemic cysteamine injections apomorphine-induced stereotypy was attenuated and striatal somatostatin levels were reduced by half. Systemic cysteamine also decreased the motor stimulant effects of amphetamine, without influencing the rewarding properties as determined by the conditioned place preference procedure. Direct injections of cysteamine into the nucleus accumbens also decreased the locomotor response to amphetamine, and produced a local reduction in somatostatin levels in the accumbens. Cysteamine did not appear to alter monoamine turnover in the striatum after either systemic or intra-accumbens injections. These results suggest that somatostatin in the nucleus accumbens and caudate-putamen modulates the motor, but not the reinforcing properties of dopaminergic drugs, possibly via an action postsynaptic to dopamine-releasing terminals. Furthermore, it is evident from these results that cysteamine is an important tool with which to study the central actions of somatostatin.

  13. Not So Giants: Mice Lacking Both Somatostatin and Cortistatin Have High GH Levels but Show No Changes in Growth Rate or IGF-1 Levels.

    Science.gov (United States)

    Pedraza-Arévalo, S; Córdoba-Chacón, J; Pozo-Salas, A I; L-López, F; de Lecea, L; Gahete, M D; Castaño, J P; Luque, R M

    2015-06-01

    Somatostatin (SST) and cortistatin (CORT) are two highly related neuropeptides involved in the regulation of various endocrine secretions. In particular, SST and CORT are two primary negative regulators of GH secretion. Consequently, single SST or CORT knockout mice exhibit elevated GH levels; however, this does not lead to increased IGF-1 levels or somatic growth. This apparent lack of correspondence has been suggested to result from compensatory mechanisms between both peptides. To test this hypothesis, in this study we explored, for the first time, the consequences of simultaneously deleting endogenous SST and CORT by generating a double SST/CORT knockout mouse model and exploring its endocrine and metabolic phenotype. Our results demonstrate that simultaneous deletion of SST and CORT induced a drastic elevation of endogenous GH levels, which, surprisingly, did not lead to changes in growth rate or IGF-1 levels, suggesting the existence of additional factors/systems that, in the absence of endogenous SST and CORT, could counteract GH actions. Notably, elevation in circulating GH levels were not accompanied by changes in pituitary GH expression or by alterations in the expression of its main regulators (GHRH and ghrelin) or their receptors (GHRH receptor, GHS receptor, or SST/CORT receptors) at the hypothalamic or pituitary level. However, although double-SST/CORT knockout male mice exhibited normal glucose and insulin levels, they had improved insulin sensitivity compared with the control mice. Therefore, these results suggest the existence of an intricate interplay among the known (SST/CORT), and likely unknown, inhibitory components of the GH/IGF-1 axis to regulate somatic growth and glucose/insulin homeostasis.

  14. Regulation of ATP-sensitive K+ channels in insulinoma cells: Activation by somatostatin and protein kinase C and the role of cAMP

    International Nuclear Information System (INIS)

    De Weille, J.R.; Schmid-Antomarchi, H.; Fosset, M.; Lazdunski, M.

    1989-01-01

    The actions of somatostatin and of the phorbol ester 4β-phorbol 12-myristate 13-acetate (PMA) were studied in rat insulinoma (RINm5F) cells by electrophysiological and 86 Rb + flux techniques. Both PMA and somatostatin hyperpolarize insulinoma cells by activating ATP-sensitive K + channels. The presence of intracellular GTP is required for the somatostatin effects. PMA- and somatostatin-induced hyperpolarization and channel activity are inhibited by the sulfonylurea glibenclamide. Glibenclamide-sensitive 86 Rb + efflux from insulinoma cells is stimulated by somatostatin in a dose-dependent manner (half maximal effect at 0.7 nM) and abolished by pertussis toxin pretreatment. Mutual roles of a GTP-binding protein, of protein kinase C, and of cAMP in the regulation of ATP-sensitive K + channels are discussed

  15. Seven transmembrane G protein-coupled receptor repertoire of gastric ghrelin cells

    DEFF Research Database (Denmark)

    Engelstoft, Maja S; Park, Won-Mee; Sakata, Ichiro

    2013-01-01

    The molecular mechanisms regulating secretion of the orexigenic-glucoregulatory hormone ghrelin remain unclear. Based on qPCR analysis of FACS-purified gastric ghrelin cells, highly expressed and enriched 7TM receptors were comprehensively identified and functionally characterized using in vitro......, ex vivo and in vivo methods. Five Gαs-coupled receptors efficiently stimulated ghrelin secretion: as expected the β1-adrenergic, the GIP and the secretin receptors but surprisingly also the composite receptor for the sensory neuropeptide CGRP and the melanocortin 4 receptor. A number of Gαi....../o-coupled receptors inhibited ghrelin secretion including somatostatin receptors SSTR1, SSTR2 and SSTR3 and unexpectedly the highly enriched lactate receptor, GPR81. Three other metabolite receptors known to be both Gαi/o- and Gαq/11-coupled all inhibited ghrelin secretion through a pertussis toxin-sensitive Gαi...

  16. Targeting either GH or IGF-I during somatostatin analogue treatment in patients with acromegaly

    DEFF Research Database (Denmark)

    Dal, Jakob; Klose, Marianne; Heck, Ansgar

    2018-01-01

    CONTEXT: Discordant GH and IGF-I values are frequent in acromegaly. The clinical significance and its dependence on treatment modality and of glucose-suppressed GH (GHnadir) measurements remain uncertain. OBJECTIVE: To evaluate the effects of targeting either IGF-I or GH during somatostatin analog...... (SA) treatment. PATIENTS AND METHODS: 84 patients with controlled acromegaly after surgery (n=23) or SA (n=61) underwent a GH-profile including an OGTT, at baseline and after 12 months. SA patients were randomized to monitoring according to either IGF-I (n= 33) or GHnadir (n=28). SA dose escalation...

  17. Gene transcript analysis blood values correlate with {sup 68}Ga-DOTA-somatostatin analog (SSA) PET/CT imaging in neuroendocrine tumors and can define disease status

    Energy Technology Data Exchange (ETDEWEB)

    Bodei, L. [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Kidd, M.; Modlin, I.M.; Drozdov, I. [Wren Laboratories, Branford, CT (United States); Prasad, V. [Charite University Hospital, Department of Nuclear Medicine, Berlin (Germany); Severi, S.; Paganelli, G. [Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Nuclear Medicine and Radiometabolic Units, Meldola (Italy); Ambrosini, V. [S. Orsola-Malpighi University Hospital, Nuclear Medicine, Bologna (Italy); Kwekkeboom, D.J.; Krenning, E.P. [Erasmus Medical Center Rotterdam, Nuclear Medicine Department, Rotterdam (Netherlands); Baum, R.P. [Zentralklinik Bad Berka, THERANOSTICS Center for Molecular Radiotherapy and Imaging, Bad Berka (Germany)

    2015-08-15

    Precise determination of neuroendocrine tumor (NET) disease status and response to therapy remains a rate-limiting concern for disease management. This reflects limitations in biomarker specificity and resolution capacity of imaging. In order to evaluate biomarker precision and identify if combinatorial blood molecular markers and imaging could provide added diagnostic value, we assessed the concordance between {sup 68}Ga-somatostatin analog (SSA) positron emission tomography (PET), circulating NET gene transcripts (NETest), chromogranin A (CgA), and Ki-67 in NETs. We utilized two independent patient groups with positive {sup 68}Ga-SSA PET: data set 1 ({sup 68}Ga-SSA PETs undertaken for peptide receptor radionuclide therapy (PRRT), as primary or salvage treatment, n = 27) and data set 2 ({sup 68}Ga-SSA PETs performed in patients referred for initial disease staging or restaging after various therapies, n = 22). We examined the maximum standardized uptake value (SUV{sub max}), circulating gene transcripts, CgA levels, and baseline Ki-67. Regression analyses, generalized linear modeling, and receiver-operating characteristic (ROC) analyses were undertaken to determine the strength of the relationships. SUV{sub max} measured in two centers were mathematically evaluated (regression modeling) and determined to be comparable. Of 49 patients, 47 (96 %) exhibited a positive NETest. Twenty-six (54 %) had elevated CgA (χ{sup 2} = 20.1, p < 2.5 x 10{sup -6}). The majority (78 %) had Ki-67 < 20 %. Gene transcript scores were predictive of imaging with >95 % concordance and significantly correlated with SUV{sub max} (R {sup 2} = 0.31, root-mean-square error = 9.4). The genes MORF4L2 and somatostatin receptors SSTR1, 3, and 5 exhibited the highest correlation with SUV{sub max}. Progressive disease was identified by elevated levels of a quotient of MORF4L2 expression and SUV{sub max} [ROC-derived AUC (R {sup 2} = 0.7, p < 0.05)]. No statistical relationship was identified

  18. Gene transcript analysis blood values correlate with 68Ga-DOTA-somatostatin analog (SSA) PET/CT imaging in neuroendocrine tumors and can define disease status

    International Nuclear Information System (INIS)

    Bodei, L.; Kidd, M.; Modlin, I.M.; Drozdov, I.; Prasad, V.; Severi, S.; Paganelli, G.; Ambrosini, V.; Kwekkeboom, D.J.; Krenning, E.P.; Baum, R.P.

    2015-01-01

    Precise determination of neuroendocrine tumor (NET) disease status and response to therapy remains a rate-limiting concern for disease management. This reflects limitations in biomarker specificity and resolution capacity of imaging. In order to evaluate biomarker precision and identify if combinatorial blood molecular markers and imaging could provide added diagnostic value, we assessed the concordance between 68 Ga-somatostatin analog (SSA) positron emission tomography (PET), circulating NET gene transcripts (NETest), chromogranin A (CgA), and Ki-67 in NETs. We utilized two independent patient groups with positive 68 Ga-SSA PET: data set 1 ( 68 Ga-SSA PETs undertaken for peptide receptor radionuclide therapy (PRRT), as primary or salvage treatment, n = 27) and data set 2 ( 68 Ga-SSA PETs performed in patients referred for initial disease staging or restaging after various therapies, n = 22). We examined the maximum standardized uptake value (SUV max ), circulating gene transcripts, CgA levels, and baseline Ki-67. Regression analyses, generalized linear modeling, and receiver-operating characteristic (ROC) analyses were undertaken to determine the strength of the relationships. SUV max measured in two centers were mathematically evaluated (regression modeling) and determined to be comparable. Of 49 patients, 47 (96 %) exhibited a positive NETest. Twenty-six (54 %) had elevated CgA (χ 2 = 20.1, p < 2.5 x 10 -6 ). The majority (78 %) had Ki-67 < 20 %. Gene transcript scores were predictive of imaging with >95 % concordance and significantly correlated with SUV max (R 2 = 0.31, root-mean-square error = 9.4). The genes MORF4L2 and somatostatin receptors SSTR1, 3, and 5 exhibited the highest correlation with SUV max . Progressive disease was identified by elevated levels of a quotient of MORF4L2 expression and SUV max [ROC-derived AUC (R 2 = 0.7, p < 0.05)]. No statistical relationship was identified between CgA and Ki-67 and no relationship with imaging parameters

  19. Application of single-vial ready-for-use formulation of 111In- or 177Lu-labelled somatostatin analogs.

    Science.gov (United States)

    de Blois, Erik; Chan, Ho Sze; de Zanger, Rory; Konijnenberg, Mark; Breeman, Wouter A P

    2014-02-01

    For the sake of safety it would be desirable to store and transport the ready-for-use liquid formulation (diagnostics and therapeutics) of radiolabelled peptides. The use of ethanol, in combination with a mixture of gentisic- and ascorbic acid, has superior effects on stabilizing radiolabelled somatostatin analogs. As a consequence, (111)In- and (177)Lu-labelled somatostatin analogs can be stored and transported in a single-vial ready-for-use liquid formulation up to 7 days after radiolabelling. © 2013 Published by Elsevier Ltd.

  20. Ultrastructural autoradiographic localization of somatostatin-28 in the rat pituitary gland

    International Nuclear Information System (INIS)

    Morel, G.; Leroux, P.; Pelletier, G.

    1985-01-01

    To identify the anterior pituitary cell type(s) containing somatostatin-28 (SS-28)-binding sites and to study the internalization processes of this peptide by the target cells, autoradiography was performed on rat anterior pituitaries removed at specific intervals (2-60 min) after iv injection of the [ 125 I]iodo-SS-28 agonist [Leu8,D-Trp22,Tyr25]SS-28 into intact, adrenalectomized, or castrated male rats. At the light microscopic level, the silver grains were found in 75% of cells. Concomitant injection of an excess of unlabeled peptide prevented the binding of label, verifying the specificity of binding. No specific labeling could be detected in the adrenocorticotrophs of adrenalectomized rats or gonadotrophs (castration cells) of castrated rats. At the electron microscopic level, three cell types (somatotrophs, thyrotrophs, and mammotrophs) appear to contain radiolabeled SS-28. The time-course study in somatotrophs of intact animals showed that 2 min after injection, most silver grains were associated with the plasma membrane. Five to 15 min after injection, label was found over both the plasma membrane and cytoplasmic organelles, especially the Golgi apparatus, lysosomes, and secretory granules. At the longest time interval (60 min), labeling was mostly associated with the cytoplasmic organelles. These results indicate that SS-28-binding sites are present only in those cell types in which somatostatin is known to regulate secretory functions. The present data also show that a rapid internalization of the radiolabeled peptide occurs

  1. THE EFFECT OF THE SOMATOSTATIN ANALOGUE OCTREOTIDE ON EXPERIMENTAL INTESTINAL OBSTRUCTION IN RATS

    Directory of Open Access Journals (Sweden)

    Paran Haim

    1998-01-01

    Full Text Available Background: Somatostatin has an inhibitory effect on the endocrine and exocrine secretions of the gut. It may have a beneficial effect in the conservative treatment of intestinal obstruction. The aim of the present study is to investigate the effect of octreotide in mechanical intestinal obstruction in rats. Method: Intestinal obstruction was induced in rats by ligation of a segment of the distal ileum. Animals were treated with the somatostatin analogue octreotide (n=16, or saline (n=16. Eight rats were operated but their intestine was not ligated (n=8 serving as sham controls. Forty eight hours after the operation, the animals were operated upon again and blood samples from the femoral vein were tested for electrolytes, urea, glucose, lactic acid, amylase, ph and bicarbonate. Portal vein blood samples were also obtained and tested for lactic acid and amylase. Results: Intestinal obstruction resulted, after 48 hours, in severe dilatation of bowel loops. A significant increase in plasma levels of urea, amylase and lactic acid was observed. Plasma pH decreased. In blood samples from the portal vein, a significant increase in lactic acid was observed, indicating metabolic acidosis, probably secondary to bowel ischemia. Octreotide treatment, resulted in less acidosis, with concomitant lower urea and lactic acid levels in the plasma and especially in the portal vein. Conclusion: Octreotide treatment may have a beneficial effect in the conservative treatment of selected cases of intestinal obstruction.

  2. Long-term Primary Medical Therapy with Somatostatin Analogs in Acromegaly

    Directory of Open Access Journals (Sweden)

    Deng-Huang Su

    2006-01-01

    Full Text Available To cure acromegalic patients, transsphenoidal surgery is considered first, especially for microadenoma. However, less than 50% of patients with macroadenoma achieve satisfactory biochemical control. Moreover, surgery may cause hypopituitarism. Medical therapy may offer the prospect of near normalization of growth hormone (GH/insulin-like growth factor-1 levels with substantial tumor shrinkage in a significant number of patients. Here, we report two cases of acromegaly under treatment with somato-statin analogs alone for more than 10 years. Case 1 was a 54-year-old man with a pituitary macro-adenoma. He received 4 years of octreotide treatment followed by 6 years of prolonged-release (PR lanreotide resulting in normal GH level. Case 2 was a 60-year-old woman with a 1.3 cm pituitary tumor. She received 8 years of octreotide treatment followed by 6 years of PR lanreotide resulting in subnormal GH level and gallbladder sludge. She had received bilateral total hip replacement for hip osteoarthritis at the age of 59 years. These cases illustrate that long-term treatment with somatostatin analogs offers an alternative choice in selected acromegalic patients, such as those with pituitary tumor who cannot be cured by surgery, those who have unacceptable anesthetic risk and those who refuse surgery.

  3. Immunohistochemical expression of insulin, glucagon, and somatostatin in pancreatic islets of horses with and without insulin resistance.

    Science.gov (United States)

    Newkirk, Kim M; Ehrensing, Gordon; Odoi, Agricola; Boston, Raymond C; Frank, Nicholas

    2018-02-01

    OBJECTIVE To assess insulin, glucagon, and somatostatin expression within pancreatic islets of horses with and without insulin resistance. ANIMALS 10 insulin-resistant horses and 13 insulin-sensitive horses. PROCEDURES For each horse, food was withheld for at least 10 hours before a blood sample was collected for determination of serum insulin concentration. Horses with a serum insulin concentration horses with a serum insulin concentration > 20 μU/mL underwent a frequently sampled IV glucose tolerance test to determine sensitivity to insulin by minimal model analysis. Horses with a sensitivity to insulin horses were euthanized with a barbiturate overdose, and pancreatic specimens were harvested and immunohistochemically stained for determination of insulin, glucagon, and somatostatin expression in pancreatic islets. Islet hormone expression was compared between insulin-resistant and insulin-sensitive horses. RESULTS Cells expressing insulin, glucagon, and somatostatin made up approximately 62%, 12%, and 7%, respectively, of pancreatic islet cells in insulin-resistant horses and 64%, 18%, and 9%, respectively, of pancreatic islet cells in insulin-sensitive horses. Expression of insulin and somatostatin did not differ between insulin-resistant and insulin-sensitive horses, but the median percentage of glucagon-expressing cells in the islets of insulin-resistant horses was significantly less than that in insulin-sensitive horses. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that, in insulin-resistant horses, insulin secretion was not increased but glucagon production might be downregulated as a compensatory response to hyperinsulinemia.

  4. Gastrin (G) cells and somatostatin (D) cells in patients with dyspeptic symptoms: Helicobacter pylori associated and non-associated gastritis

    NARCIS (Netherlands)

    Liu, Y.; Vosmaer, G. D. C.; Tytgat, G. N. J.; Xiao, S.-D.; ten Kate, F. J. W.

    2005-01-01

    Background: Gastrin G cells and somatostatin D cells are important regulators of gastric acid secretion and alterations in their relative numbers may play a key role in gastroduodenal disease. Aim: To investigate the effect of Helicobacter pylori infection on the density of immunoreactive G and D

  5. Central nervous system immunoreactive somatostatin, substance P and met-enkephalin concentrations in experimental hepatic encephalopathy in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.L.; Millar, R.P.; Kirsch, R. (Cape Town Univ. (South Africa))

    1982-06-12

    Immunoreactive somatostatin, substance P and met-enkephalin concentrations were measured in various regions of the rat brain 65 hours after portacaval shunt and compared with concentrations in sham-operated animals. No significant difference was detected in any of the three peptides in the regions studied, suggesting that these peptides do not play a role in the pathogenesis of hepatic encephalopathy.

  6. Effect of somatostatin on repair of ionizing radiation-induced DNA damage in pituitary adenoma cells GH3

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, M.; Čáp, J.; Vokurková, D.; Lukášová, Emilie; Vávrová, J.; Cerman, J.; Mašín, V.; Mazánková, N.

    2008-01-01

    Roč. 57, č. 2 (2008), s. 225-235 ISSN 0862-8408 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : acromegaly * somatostatin * ionizing radiation Subject RIV: BO - Biophysics Impact factor: 1.653, year: 2008

  7. Long-term effects of cholinergic basal forebrain lesions on neuropeptide Y and somatostatin immunoreactivity in rat neocortex

    NARCIS (Netherlands)

    Gaykema, R.P.A.; Compaan, J.C.; Nyakas, C.; Horvath, E.; Luiten, P.G.M.

    1989-01-01

    The effect of cholinergic basal forebrain lesions on immunoreactivity to somatostatin (SOM-i) and neuropeptide-Y (NPY-i) was investigated in the rat parietal cortex, 16-18 months after multiple bilateral ibotenic acid injections in the nucleus basalis complex. As a result of the lesion, the

  8. Conversion of daily pegvisomant to weekly pegvisomant combined with long-acting somatostatin analogs, in controlled acromegaly patients

    NARCIS (Netherlands)

    S.J.C.M.M. Neggers (Bas); W.W. de Herder (Wouter); R.A. Feelders (Richard); A-J. van der Lely (Aart-Jan)

    2011-01-01

    textabstractThe efficacy of combined treatment in active acromegaly with both long-acting somatostatin analogs (SRIF) and pegvisomant (PEG-V) has been well established. The aim was to describe the PEG-V dose reductions after the conversion from daily PEG-V to combination treatment. To clarify the

  9. GLP-1 regulation of glucagon, somatostatin and insulin in naidm patients: evidence of direct inhibition of A - cells by GLP - 1

    International Nuclear Information System (INIS)

    Naveed, A.K.; Khan, F.A.

    2006-01-01

    Glucagon-like peptide-1 (7-36) amide (GLP-1) is released from the gut into the circulation after meals and is the most potent physiological insulinotropic hormone in man. In contrast to presently available therapeutic agents for non-insulin dependent diabetes mellitus (NIDDM), GLP-1 has the advantages of both suppressing glucagon secretion and delaying gastric emptying. We report first study of subcutaneous GLP-1 treatment to determine the optimum dose required to control the NIDDM. Seven patients, with poorly controlled NIDDM were entered in the study who visited at four visits with intervals of 2-4 days and received saline, 40, 100 and 200 nmol subcutaneous GLP-1, immediately after meals. A standerdized test meal was given. A significant hypoglycaemic response (p<0.05) was achieved in patients given 40, 100 and 200 nmol GLP-1. An increase in insulin levels (p<0.05) was observed as compared to control, when 100 and 200 nmol GLP-1 was given. There was no significant difference between insulin and glucose responses when 100 and 200 nmol of GLP-1 were compared with each. The glucagon levels were significant less (p< 0.05) in patients, given 100 and 200 nmol doses as compared to control. Glucagon inhibitory response to GLP-1, when given in doses of 200 nmol was more (p< 0.05) than 100 nmol GLP-1. Somatostatin levels decreased dose dependently by GLP-1 infusions. It is concluded that suppression of glucagon secretion and inhibition of somatostatin corresponded to dose of GLP-1 used. There was no significant difference in glucose and insulin levels between 100 and 200 nmol GLP-1 doses. Therefore, present study has helped in ascertaining the optimum dose for GLP-1 i.e. 100 nmol. Down regulation of GLP-1 receptors on cells occurred at higher dose while, A and D cells inhibition occurred dose dependently. These results revealed that GLP-1 affects A and D cells directly and also through stimulation of cells. These findings will significantly contribute in the possible role

  10. Human adipose tissue-derived mesenchymal stem cells differentiate into insulin, somatostatin, and glucagon expressing cells

    International Nuclear Information System (INIS)

    Timper, Katharina; Seboek, Dalma; Eberhardt, Michael; Linscheid, Philippe; Christ-Crain, Mirjam; Keller, Ulrich; Mueller, Beat; Zulewski, Henryk

    2006-01-01

    Mesenchymal stem cells (MSC) from mouse bone marrow were shown to adopt a pancreatic endocrine phenotype in vitro and to reverse diabetes in an animal model. MSC from human bone marrow and adipose tissue represent very similar cell populations with comparable phenotypes. Adipose tissue is abundant and easily accessible and could thus also harbor cells with the potential to differentiate in insulin producing cells. We isolated human adipose tissue-derived MSC from four healthy donors. During the proliferation period, the cells expressed the stem cell markers nestin, ABCG2, SCF, Thy-1 as well as the pancreatic endocrine transcription factor Isl-1. The cells were induced to differentiate into a pancreatic endocrine phenotype by defined culture conditions within 3 days. Using quantitative PCR a down-regulation of ABCG2 and up-regulation of pancreatic developmental transcription factors Isl-1, Ipf-1, and Ngn3 were observed together with induction of the islet hormones insulin, glucagon, and somatostatin

  11. Oral curcumin has anti-arthritic efficacy through somatostatin generation via cAMP/PKA and Ca(2+)/CaMKII signaling pathways in the small intestine.

    Science.gov (United States)

    Yang, Yan; Wu, Xin; Wei, Zhifeng; Dou, Yannong; Zhao, Di; Wang, Ting; Bian, Difei; Tong, Bei; Xia, Ying; Xia, Yufeng; Dai, Yue

    2015-01-01

    Curcumin (CUR) has been proven to be clinically effective in rheumatoid arthritis (RA) therapy, but its low oral bioavailability eclipses existent evidence that attempts to explain the underlying mechanism. Small intestine, the only organ exposed to a relatively high concentration of CUR, is the main site that generates gut hormones which are involved in the pathogenesis of RA. This study aims at addressing the hypothesis that one or more gut hormones serve as an intermediary agent for the anti-arthritic action of CUR. The protein and mRNA levels of gut hormones in CUR-treated rats were analyzed by ELISA and RT-PCR. Somatostatin (SOM) depletor and receptor antagonist were used to verify the key role of SOM in CUR-mediated anti-arthritic effect. The mechanisms underlying CUR-induced upregulation of SOM levels were explored by cellular experiments and immunohistochemical staining. The data showed that oral administration of CUR (100 mg/kg) for consecutive two weeks in adjuvant-induced arthritis rats still exhibited an extremely low plasma exposure despite of a dramatic amelioration of arthritis symptoms. When injected intraperitoneally, CUR lost anti-arthritic effect in rats, suggesting that it functions in an intestine-dependent manner. CUR elevated SOM levels in intestines and sera, and SOM depletor and non-selective SOM receptor antagonist could abolish the inhibitory effect of CUR on arthritis. Immunohistochemical assay demonstrated that CUR markedly increased the number of SOM-positive cells in both duodenum and jejunum. In vitro experiments demonstrated that CUR could augment SOM secretion from intestinal endocrine cells, and this effect could be hampered by either MEK1/2 or Ca(2+)/calmodulin-dependent kinase II (CAMKII) inhibitor. In summary, oral administration of CUR exhibits anti-arthritic effect through augmenting SOM secretion from the endocrine cells in small intestines via cAMP/PKA and Ca(2+)/CaMKII signaling pathways. Copyright © 2015 Elsevier Ltd

  12. Receptor-mediated radiotherapy with Y-DOTA-DPhe-Tyr-octreotide: the experience of the European Institute of Oncology Group.

    Science.gov (United States)

    Chinol, Marco; Bodei, Lisa; Cremonesi, Marta; Paganelli, Giovanni

    2002-04-01

    High concentrations of subtype 2 somatostatin tumor receptors (sst(2)) are expressed in numerous tumors, enabling primary and metastatic masses to be localized by scintigraphy after injecting (111)In-labeled somatostatin analogue octreotide. In addition to neuroendocrine tumors, somatostatin receptors have been identified on cancers of the central nervous system, breast, lung, and lymphatic tissue, and the use of radionuclide-labeled somatostatin analogues appeared promising for therapy as well as for diagnosis of such malignancies. The somatostatin analogue [DOTA-(D)Phe(1)-Tyr(3)] octreotide (DOTATOC) possesses favorable characteristics for its potential therapeutic use in that it shows high affinity for sst(2), moderately high affinity for sst(5), and intermediate affinity for sst(3), high hydrophilicity, stable and facile labeling with (111)In and (90)Y. We began to investigate the potential therapeutic applications of (90)Y DOTATOC in 1997 by performing a thorough dosimetric study in 18 patients who were administered (111)In DOTATOC to estimate the absorbed doses during(90)Y-DOTATOC therapy. Then, we moved on and treated an overall number of 256 patients, mostly recruited in 2 distinct protocols with and without the administration of kidney protecting agents, with (90)Y DOTATOC. No major acute reactions were observed up to the activity of 5.55 GBq per cycle. The MTD per cycle was defined as 5.18 GBq. Objective therapeutic responses were documented in more than 20% of patients in terms of partial and complete responses. The present article reports in details our clinical experience (still ongoing) and outcomes with the use of (90)Y DOTATOC. Copyright 2002, Elsevier Science (USA). All rights reserved.

  13. Glycine-extended gastrin enhances somatostatin release from cultured rabbit fundic D-cells [v1; ref status: indexed, http://f1000r.es/8n

    Directory of Open Access Journals (Sweden)

    Ian LP Beales

    2013-02-01

    Full Text Available The role of the peptide hormone gastrin in stimulating gastric acid secretion is well established. Mature amidated gastrin is processed from larger peptide precursor forms. Increasingly these processing intermediates, such as glycine-extended gastrin (G-Gly and progastrin, have been shown to have biological activities of their own, often separate and complementary to gastrin. Although G-Gly is synthesized and secreted by gastric antral G-cells, the physiological functions of this putative mediator are unclear. Gastrin and cholecystokinin (CCK stimulate the secretion of somatostatin from gastric D-cells as part of the feedback control of gastric acid. In this study the effect of G-Gly and gastrin on the release of somatostatin from rabbit fundic D-cells was examined. D-cells were obtained by collagenase-EDTA digestion and elutriation and cultured for 48 hours. With a 2 hour exposure to the peptides, gastrin but not G-Gly stimulated somatostatin release. Treatment of D-cells for 24 hours with gastrin or G-Gly individually, significantly enhanced subsequent basal as well as CCK- and GLP-1-stimulated somatostatin release. Twenty four hours exposure to gastrin combined with G-Gly synergistically enhanced basal and agonist-stimulated somatostatin release and cellular somatostatin content. Gastrin and G-Gly may be important in the longer term regulation of D-cell function.

  14. Somatostatin-immunoreactive senile plaque-like structures in the frontal cortex and nucleus accumbens of aged tree shrews and Japanese macaques.

    Science.gov (United States)

    Yamashita, Akiko; Fuchs, Eberhard; Taira, Masato; Yamamoto, Takamitsu; Hayashi, Motoharu

    2012-06-01

    Previously, we demonstrated decreased expression of somatostatin mRNA in aged macaque brain, particularly in the prefrontal cortex. To investigate whether or not this age-dependent decrease in mRNA is related to morphological changes, we analyzed somatostatin cells in the cerebra of aged Japanese macaques and compared them with those in rats and tree shrews, the latter of which are closely related to primates. Brains of aged macaques, tree shrews, and rats were investigated by immunohistochemistry with special emphasis on somatostatin. We observed degenerating somatostatin-immunoreactive cells in the cortices of aged macaques and tree shrews. Somatostatin-immunoreactive senile plaque-like structures were found in areas 6 and 8 and in the nucleus accumbens of macaques, as well as in the nucleus accumbens and the cortex of aged tree shrews, where amyloid accumulations were observed. Somatostatin degenerations may be related to amyloid accumulations and may play roles in impairments of cognitive functions during aging. © 2012 John Wiley & Sons A/S.

  15. 99mTc labelled peptides for imaging of peripheral receptors

    International Nuclear Information System (INIS)

    Mustanser, J.; Anjum, A.

    2001-01-01

    Several peptides are being used as radiopharmaceuticals for receptor imaging scintigraphy. The peptide receptors are found in the tumours of various sites in the human body. Somatostatin is one of those, which is expressed by a variety of tumours say in brain cortex, medullary carcinoma of thyroid, adrenal glands, pancreas and gut. Therefore neuropeptides based on somatostatin analogues are labelled with different radionuclide, 123 I and 111 In. Efforts are underway to label RC-160 (an analogue of somatostatin) with 99m Tc because of its favourable radiation dosimetry, short half-life, low price, high count rate and better diagnostic efficacy. In this project various methods of labelling RC-160 with different radionuclides 125 I and 99m Tc have been studied in detail. Radioiodination of RC-160 was tried with 125 I using the iodogen method as directed and then with Chloramine T method. Labelling of RC-160 peptide with 99m Tc was done using two different aspects. Direct labelling with 99m Tc and indirect labelling with 99m Tc using double chelating agents. Radiochemical quality control was carried out applying instant thin layer chromatography using ITLC-SG strips in 85% of methanol. Later the HPLC analysis was used for its evaluation. To label RC-160 with 99m Tc the approach of direct labelling was attempted first. 46% labelling could be achieved with 95% of radiochemical purity. The biodistribution of 99m Tc-RC-160 complex in rats has also been studied to determine uptake in various sites of somatostatin receptors. Eventually, attempt was made to synthesize biomolecule by conjugating Boc protected RC-160 with benzoyl MAG-3. As a result 80% of Boc-RC-160 went under conjugation with benzoyl MAG-3. (author)

  16. Breast fibroadenoma with increased activity on 68Ga-DOTATATE PET/CT

    Science.gov (United States)

    Papadakis, Georgios Z.; Millo, Corina; Sadowski, Samira M.; Karantanas, Apostolos H.; Bagci, Ulas; Patronas, Nicholas J.

    2016-01-01

    Fibroadenoma is the most common benign breast tumor in women of reproductive age, carrying little to no risk of breast cancer development. We report on a case of a woman with history of neuroendocrine tumor (NET), who on follow-up imaging tests underwent whole-body PET/CT study using 68Ga-DOTATATE. The scan showed increased focal activity in the right breast, which was biopsied revealing a fibroadenoma. The presented data suggests cell surface over-expression of somatostatin receptors (SSTRs) by this benign breast tumor. Moreover, this finding emphasizes the need for cautious interpretation of 68Ga-DOTATATE avid breast lesions which could mimic malignancy in NET patients. PMID:27879489

  17. Somatostatin-based Radiopeptide Therapy with [177Lu-DOTA]-TOC versus [90Y-DOTA]-TOC in Neuroendocrine Tumors

    OpenAIRE

    Romer A Seiler D Marincek N Brunner P Koller MT Ng QK Maecke HR Muller-Brand J Rochlitz C B

    2014-01-01

    PURPOSE: Somatostatin based radiopeptide treatment is generally performed using the ß emitting radionuclides (90)Y or (177)Lu. The present study aimed at comparing benefits and harms of both therapeutic approaches. METHODS: In a comparative cohort study patients with advanced neuroendocrine tumours underwent repeated cycles of [(90)Y DOTA] TOC or [(177)Lu DOTA] TOC until progression of disease or permanent adverse events. Multivariable Cox regression and competing risks regression were emplo...

  18. Quantum Dot Immunocytochemical Localization of Somatostatin in Somatostatinoma by Widefield Epifluorescence, Super-resolution Light, and Immunoelectron Microscopy

    Science.gov (United States)

    Lai, Ken; Wu, Xiaojuan; Yong, Jim L. C.; Lee, C. Soon

    2012-01-01

    Quantum dot nanocrystal probes (QDs) have been used for detection of somatostatin hormone in secretory granules of somatostatinoma tumor cells by immunofluorescence light microscopy, super-resolution light microscopy, and immunoelectron microscopy. Immunostaining for all modalities was done using sections taken from an epoxy resin-embedded tissue specimen and a similar labeling protocol. This approach allowed assessment of labeling at light microscopy level before examination at super-resolution and electron microscopy level and was a significant aid in interpretation. Etching of ultrathin sections with saturated sodium metaperiodate was a critical step presumably able to retrieve some tissue antigenicity masked by processing in epoxy resin. Immunofluorescence microscopy of QD-immunolabeled sections showed somatostatin hormone localization in cytoplasmic granules. Some variable staining of tumor gland-like structures appeared related to granule maturity and dispersal of granule contents within the tumor cell cytoplasm. Super-resolution light microscopy demonstrated localization of somatostatin within individual secretory granules to be heterogeneous, and this staining pattern was confirmed by immunoelectron microscopy. PMID:22899862

  19. Quantum dot immunocytochemical localization of somatostatin in somatostatinoma by Widefield Epifluorescence, super-resolution light, and immunoelectron microscopy.

    Science.gov (United States)

    Killingsworth, Murray C; Lai, Ken; Wu, Xiaojuan; Yong, Jim L C; Lee, C Soon

    2012-11-01

    Quantum dot nanocrystal probes (QDs) have been used for detection of somatostatin hormone in secretory granules of somatostatinoma tumor cells by immunofluorescence light microscopy, super-resolution light microscopy, and immunoelectron microscopy. Immunostaining for all modalities was done using sections taken from an epoxy resin-embedded tissue specimen and a similar labeling protocol. This approach allowed assessment of labeling at light microscopy level before examination at super-resolution and electron microscopy level and was a significant aid in interpretation. Etching of ultrathin sections with saturated sodium metaperiodate was a critical step presumably able to retrieve some tissue antigenicity masked by processing in epoxy resin. Immunofluorescence microscopy of QD-immunolabeled sections showed somatostatin hormone localization in cytoplasmic granules. Some variable staining of tumor gland-like structures appeared related to granule maturity and dispersal of granule contents within the tumor cell cytoplasm. Super-resolution light microscopy demonstrated localization of somatostatin within individual secretory granules to be heterogeneous, and this staining pattern was confirmed by immunoelectron microscopy.

  20. Oligomerisation of C. elegans Olfactory Receptors, ODR-10 and STR-112, in Yeast

    KAUST Repository

    Tehseen, Muhammad

    2014-09-25

    It is widely accepted that vertebrate G-Protein Coupled Receptors (GPCRs) associate with each other as homo- or hetero-dimers or higher-order oligomers. The C. elegans genome encodes hundreds of olfactory GPCRs, which may be expressed in fewer than a dozen chemosensory neurons, suggesting an opportunity for oligomerisation. Here we show, using three independent lines of evidence: co-immunoprecipitation, bioluminescence resonance energy transfer and a yeast two-hybrid assay that nematode olfactory receptors (ORs) oligomerise when heterologously expressed in yeast. Specifically, the nematode receptor ODR-10 is able to homo-oligomerise and can also form heteromers with the related nematode receptor STR-112. ODR-10 also oligomerised with the rat I7 OR but did not oligomerise with the human somatostatin receptor 5, a neuropeptide receptor. In this study, the question of functional relevance was not addressed and remains to be investigated.

  1. Oligomerisation of C. elegans Olfactory Receptors, ODR-10 and STR-112, in Yeast

    KAUST Repository

    Tehseen, Muhammad; Liao, Chunyan; Dacres, Helen; Dumancic, Mira; Trowell, Stephen; Anderson, Alisha

    2014-01-01

    It is widely accepted that vertebrate G-Protein Coupled Receptors (GPCRs) associate with each other as homo- or hetero-dimers or higher-order oligomers. The C. elegans genome encodes hundreds of olfactory GPCRs, which may be expressed in fewer than a dozen chemosensory neurons, suggesting an opportunity for oligomerisation. Here we show, using three independent lines of evidence: co-immunoprecipitation, bioluminescence resonance energy transfer and a yeast two-hybrid assay that nematode olfactory receptors (ORs) oligomerise when heterologously expressed in yeast. Specifically, the nematode receptor ODR-10 is able to homo-oligomerise and can also form heteromers with the related nematode receptor STR-112. ODR-10 also oligomerised with the rat I7 OR but did not oligomerise with the human somatostatin receptor 5, a neuropeptide receptor. In this study, the question of functional relevance was not addressed and remains to be investigated.

  2. Patient-specific dosimetry in peptide receptor radionuclide therapy: a clinical review

    International Nuclear Information System (INIS)

    Chalkia, M.T.; Stefanoyiannis, A.P.; Chatziioannou, S.N.; Efstathopoulos, E.P.; Round, W.H.; Nikiforidis, G.C.

    2015-01-01

    Neuroendocrine tumours (NETs) belong to a relatively rare class of neoplasms. Nonetheless, their prevalence has increased significantly during the last decades. Peptide receptor radionuclide therapy (PRRT) is a relatively new treatment approach for inoperable or metastasised NETs. The therapeutic effect is based on the binding of radiolabelled somatostatin analogue peptides with NETs’ somatostatin receptors, resulting in internal irradiation of tumours. Pre-therapeutic patient-specific dosimetry is essential to ensure that a treatment course has high levels of safety and efficacy. This paper reviews the methods applied for PRRT dosimetry, as well as the dosimetric results presented in the literature. Focus is given on data concerning the therapeutic somatostatin analogue radiopeptides 111 In-[DTPA o , D -Phe 1 ]-octreotide ( 111 In-DTPA-octreotide), 90 Y-[DOTA o ,Tyr 3 ]-octreotide ( 90 Y-DOTATOC) and 177 Lu-[DOTA o ,Tyr 3 ,Thr 8 ]-octreotide ( 177 Lu-DOTATATE). Following the Medical Internal Radiation Dose (MIRD) Committee formalism, dosimetric analysis demonstrates large interpatient variability in tumour and organ uptake, with kidneys and bone marrow being the critical organs. The results are dependent on the image acquisition and processing protocol, as well as the dosimetric imaging radiopharmaceutical.

  3. [Construction and immunogenicity of recombinant porcine parvovirus-like particles with somatostatin].

    Science.gov (United States)

    Zhang, Xuehua; Zheng, Qisheng; Chen, Jin; Xue, Gang; Hou, Hongyan; Hou, Jibo

    2010-08-01

    In order to obtain a virus-like particle vaccine both for porcine parvovirus (PPV) prevention and growth-promotion, VP2 gene of PPV NJ-a strain was amplified with PCR, and four copies of synthetic somatostatin gene were fused to the N-terminal of VP2 gene. The fused gene was cloned into pFast-HT A to construct the recombinant plasmid pFast-SS4-VP2, then the pFast-SS4-VP2 was transformed into DH10Bac competent cells and recombined with shuttle vector Bacmid, followed by identification with blue-white screening and PCR analysis for three cycles, and the positive recombinant was named as rBacmid-SS4-VP2. The positive Sf-9 cells were transfected with rBacmid-SS4-VP2 by Lipofectamine to produce recombinant baculovirus. When the cytopathic effect (CPE) was obvious, the transfected Sf-9 cell was harvested, and the positive recombinant virus was named as rBac-SS4-VP2. The insertion for the target gene into baculovirus genome was confirmed with PCR. SDS-PAGE and Western blotting revealed that the calculated protein of approximately 68 kDa was in the expressed in the insect cells. The Sf-9 cells infected with rBac-SS4-VP2 were stained positive against PPV antibody using the indirect immunofluorescence assay (IFA). Moreover, the virus particle self-assembly was observed under electron microscopy. 90 four-week-old mice were immunized by the recombinant protein coupled with different adjuvants alhydrogel, IMS and oil. VP2-specific ELISA antibodies, PPV-specific neutralizing antibody, somatostatin antibody and growth hormone levels were examined to evaluate the immunogenicity of this virus like particle. Results indicated that mice groups immunized rSS4-VP2 protein with alhydrogel and IMS developed similar humoral immune response comparing with inactived PPV vaccine. Mice group immunized with rSS4-VP2 generated higher level of SS antibody and growth hormone comparing with negative control, mice receiving rSS4-VP2 with alhydrogel developed the highest antibody titre than all

  4. Study of pharmacokinetics and biodistribution of radiolabelled receptor specific peptides in laboratory animals

    International Nuclear Information System (INIS)

    Laznickova, A.; Laznicek, M.; Trejtnar, F.; Maecke, H.R.; Mather, S.J.

    2001-01-01

    Somatostatin analogues labelled with different radionuclides could be employed for visualization or treatment of somatostatin receptor-positive tumours. An octapeptide 111 In [DTPA] octreotide is a synthetic radiolabelled somatostatin analogue which is currently in clinical use for detecting small neuroendocrine tumours and metastases not detectable by conventional means. However, several other somatostatin analogues have been under development and testing. The aim of this study was to radiolabel selected somatostatin receptor-binding octapeptides by different radionuclides and to report the results of their biodistribution in rats. The study was focused on the direct labelling of vapreotide (RC-160) with 99m Tc, on the conjugates of octreotide with DFO (desferrioxamine) for labelling with 67 Ga, and on the conjugates of octreotide and TOC with DOTA (tetraazacyclo-dodecane tetraacetic acid) for labelling with 88 Y. In the present study, 88 Y isotope instead of 90 Y was used as a label as 88 Y exhibits a longer half life of decay and emits gamma radiation which can be much more easily detected in biological samples than beta emission. The labelling of octreotide analogues with metal radionuclides using derived bifunctional chelates was simple, straightforward and consistently resulted in high radiochemical purity of the product. On the other hand, the application of the direct labelling method for labelling of RC-160 with 99m Tc was difficult because all procedures had to be made under nitrogen atmosphere and an attainment of high yield proved to be highly dependent on the accurate observation of reaction conditions. The labelling efficiency makes an immediate use of the radiolabelled RC-160 for biological studies impossible and it is necessary to involve the purification step into the labelling procedure. All radiolabelled receptor specific peptides under study exhibited rapid radioactivity clearance from the blood and most organs and tissues. On the other hand

  5. 99mTc labelled peptide for imaging of peripheral receptors

    International Nuclear Information System (INIS)

    Mishra, A.K.; Mishra, P.; Chuttani, K.; Sharma, R.K.; Lazar Mathew, T.

    2001-01-01

    Conjugates of somatostatin analogues, RC-160 with different bifunctional chelators to label with 99m Tc, were synthesized. Conjugates with hydrazinonicotinamide (HYNIC) and compounds (benzoyl MAG-3 and CITC-DTPA) were prepared on a small scale with high purity and evaluated as different types of chelators on RC-160. Stability studies performed under physiological conditions showed high stability. Peptide conjugates could be labelled at high specific activities (307inCi/umol) with 99m Tc and different transchelator were used for the HYNIC conjugates. The resulting radiolabelled with ( 99m Tc and 1251) complexes were highly stable and showed binding affinity to somatostatin receptors in the nanomolar range. The radioconjugates were administered to rabbits and mice in order to study their in vivo stability, biokinetics and biodistribution. (author)

  6. Obesity alters gene expression for GH/IGF-I axis in mouse mammary fat pads: differential role of cortistatin and somatostatin.

    Directory of Open Access Journals (Sweden)

    Alicia Villa-Osaba

    Full Text Available Locally produced growth hormone (GH and IGF-I are key factors in the regulation of mammary gland (MG development and may be important in breast cancer development/progression. Somatostatin (SST and cortistatin (CORT regulate GH/IGF-I axis at various levels, but their role in regulating GH/IGF-I in MGs remains unknown. Since obesity alters the expression of these systems in different tissues and is associated to MG (patho physiology, we sought to investigate the role of SST/CORT in regulating GH/IGF-I system in the MGs of lean and obese mice. Therefore, we analyzed GH/IGF-I as well as SST/CORT and ghrelin systems expression in the mammary fat pads (MFPs of SST- or CORT-knockout (KO mice and their respective littermate-controls fed a low-fat (LF or a high-fat (HF diet for 16 wks. Our results demonstrate that the majority of the components of GH/IGF-I, SST/CORT and ghrelin systems are locally expressed in mouse MFP. Expression of elements of the GH/IGF-I axis was significantly increased in MFPs of HF-fed control mice while lack of endogenous SST partially suppressed, and lack of CORT completely blunted, the up-regulation observed in obese WT-controls. Since SST/CORT are known to exert an inhibitory role on the GH/IGFI axis, the increase in SST/CORT-receptor sst2 expression in MFPs of HF-fed CORT- and SST-KOs together with an elevation on circulating SST in CORT-KOs could explain the differences observed. These results offer new information on the factors (GH/IGF-I axis involved in the endocrine/metabolic dysregulation of MFPs in obesity, and suggest that CORT is not a mere SST sibling in regulating MG physiology.

  7. Changes in pancreatic somatostatin content in spontaneously diabetic mice, as determined by radioimmunoassay and immunohistochemical methods

    International Nuclear Information System (INIS)

    Makino, H.; Matsushima, Y.; Kanatsuka, A.; Yamamoto, M.; Kumagai, A.; Nishimura, M.

    1979-01-01

    A specific RIA for somatostatin (SRIF) was used to determine the SRIF content of the pancreas and hypothalamus in spontaneously diabetic C57BL/KsJ dbdb and C57BL/6J obob mice. In addition, SRIF- and glucagon-containing cells were examined in the pancreatic islets with an immunohistochemical technique. In dbdb mice, immunoassayable pancreatic SRIF content was increased, as was the number of SRIF- or glucagon-containing cells. In obob mice, immunoassayable pancreatic SRIF content was also increased, but no increase was noted in the number of SRIF- or glucagon-containing cells. The hypothalamic SRIF content of either strain was not different from that of controls. These results regarding pancreatic SRIF content were in accord with some but not all previous reports. These differences may be related to the age of the mice or to the conditions in which they were bred. The pancreatic SRIF increase in both dbdb and obob mice may be attributable to hyperglucagonemia, hyperglycemia, or a decrease in insulin action. Further work is necessary to clearly delineate the mechanism

  8. Vasoactive intestinal peptide and somatostatin in the plasma and sigmoid mucosa in irritable bowel syndrome

    International Nuclear Information System (INIS)

    Zhang Ru; Wang Fuxian

    2004-01-01

    To investigate the possible role and clinical significance of vasoactive intestinal peptide (VIP) and somatostatin(SS) in the irritable bowel syndrome (IBS), the VIP and SS in the plasma and sigmoid mucosa were measured by radioimmunoassay in the control group and the IBS group. The VIP concentration in the plasma and sigmoid mucosa of the IBS patients with constipation was significantly higher than that of the control group (P<0.01), while that of the IBS patients with diarrhea was significantly lower than that of the control group (P<0.05). The SS concentration in two sites was significantly elevated in IBS patients of both types and was significantly higher in IBS with constipation than in IBS with diarrhea (P<0.05). Conclusion: The VIP and SS in IBS are abnormal, which might play a role in the pathogenesis of IBS. The plasma and mucosa concenration of VIP and SS in two kinds of IBS patients are significantly different, which indicates that there might be different pathophysiological basis involved in the pathogenesis of the two kinds of IBS patients. (authors)

  9. Differential Receptive Field Properties of Parvalbumin and Somatostatin Inhibitory Neurons in Mouse Auditory Cortex.

    Science.gov (United States)

    Li, Ling-Yun; Xiong, Xiaorui R; Ibrahim, Leena A; Yuan, Wei; Tao, Huizhong W; Zhang, Li I

    2015-07-01

    Cortical inhibitory circuits play important roles in shaping sensory processing. In auditory cortex, however, functional properties of genetically identified inhibitory neurons are poorly characterized. By two-photon imaging-guided recordings, we specifically targeted 2 major types of cortical inhibitory neuron, parvalbumin (PV) and somatostatin (SOM) expressing neurons, in superficial layers of mouse auditory cortex. We found that PV cells exhibited broader tonal receptive fields with lower intensity thresholds and stronger tone-evoked spike responses compared with SOM neurons. The latter exhibited similar frequency selectivity as excitatory neurons. The broader/weaker frequency tuning of PV neurons was attributed to a broader range of synaptic inputs and stronger subthreshold responses elicited, which resulted in a higher efficiency in the conversion of input to output. In addition, onsets of both the input and spike responses of SOM neurons were significantly delayed compared with PV and excitatory cells. Our results suggest that PV and SOM neurons engage in auditory cortical circuits in different manners: while PV neurons may provide broadly tuned feedforward inhibition for a rapid control of ascending inputs to excitatory neurons, the delayed and more selective inhibition from SOM neurons may provide a specific modulation of feedback inputs on their distal dendrites. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. SPECT/CT with radiolabeled somatostatin analogues in the evaluation of systemic granulomatous infections.

    Science.gov (United States)

    Monteiro, Paulo Henrique Silva; de Souza, Thiago Ferreira; Moretti, Maria Luiza; Resende, Mariangela Ribeiro; Mengatti, Jair; de Lima, Mariana da Cunha Lopes; Santos, Allan Oliveira; Ramos, Celso Darío

    2017-01-01

    To evaluate SPECT/CT with radiolabeled somatostatin analogues (RSAs) in systemic granulomatous infections in comparison with gallium-67 ( 67 Ga) citrate scintigraphy. We studied 28 patients with active systemic granulomatous infections, including tuberculosis, paracoccidioidomycosis, pneumocystosis, cryptococcosis, aspergillosis, leishmaniasis, infectious vasculitis, and an unspecified opportunistic infection. Of the 28 patients, 23 had started specific treatment before the study outset. All patients underwent whole-body SPECT/CT imaging: 7 after injection of 99m Tc-EDDA-HYNIC-TOC, and 21 after injection of 111 In-DTPA-octreotide. All patients also underwent 67 Ga citrate imaging, except for one patient who died before the 67 Ga was available. In 20 of the 27 patients who underwent imaging with both tracers, 27 sites of active disease were detected by 67 Ga citrate imaging and by SPECT/CT with an RSA. Both tracers had negative results in the other 7 patients. RSA uptake was visually lower than 67 Ga uptake in 11 of the 20 patients with positive images and similar to 67 Ga uptake in the other 9 patients. The only patient who did not undergo 67 Ga scintigraphy underwent 99m Tc-EDDA-HYNIC-TOC SPECT/CT-guided biopsy of a lung cavity with focal RSA uptake, which turned to be positive for aspergillosis. SPECT/CT with 99m Tc-EDDA-HYNIC-TOC or 111 In-DTPA-octreotide seems to be a good alternative to 67 Ga citrate imaging for the evaluation of patients with systemic granulomatous disease.

  11. Circadian modulation of anxiety: a role for somatostatin in the amygdala.

    Directory of Open Access Journals (Sweden)

    Anne Albrecht

    Full Text Available Pharmacological evidence suggests that the neuropeptide somatostatin (SST exerts anxiolytic action via the amygdala, but findings concerning the putative role of endogenous SST in the regulation of emotional responses are contradictory. We hypothesized that an endogenous regulation of SST expression over the course of the day may determine its function and tested both SST gene expression and the behavior of SST knock out (SST⁻/⁻ mice in different aversive tests in relation to circadian rhythm. In an open field and a light/dark avoidance test, SST⁻/⁻ mice showed significant hyperactivity and anxiety-like behavior during the second, but not during the first half of the active phase, failing to show the circadian modulation of behavior that was evident in their wild type littermates. Behavioral differences occurred independently of changes of intrinsically motivated activity in the home cage. A circadian regulation of SST mRNA and protein expression that was evident in the basolateral complex of the amygdala of wild type mice may provide a neuronal substrate for the observed behavior. However, fear memory towards auditory cue or the conditioning context displayed neither a time- nor genotype-dependent modulation. Together this indicates that SST, in a circadian manner and putatively via its regulation of expression in the amygdala, modulates behavior responding to mildly aversive conditions in mice.

  12. The liver plays an important role in the regulation of somatostatin-14 in the rat

    International Nuclear Information System (INIS)

    Raper, S.E.; Kothary, P.C.; Kokudo, N.; DelValle, J.; Eckhauser, F.E.

    1991-01-01

    Since little is known about the in vivo disposition of circulating somatostatin-14 (SRIF-14), we examined hepatic processing of SRIF-14 in the rat. Three minutes after the intraportal injection of iodine 125 ( 125 I)-labeled SRIF-14, 16.0 +/- 2.0% of the injected dose is localized to the liver. In the presence of unlabeled SRIF-14, hepatic uptake can be decreased by 68%. Five minutes after the intraportal injection of 125 I-SRIF-14, 9.5 +/- 1.4% of the tracer is localized to the liver, more than any other organ tested. Serial collections of bile reveal peak radioactivity at between 10 and 20 minutes. Simultaneous administration of unlabeled SRIF-14 decreases biliary radioactivity by 40%. HPLC analysis of radioactive bile reveals a chromatographic profile similar to that of intact SRIF and is 73% immunoprecipitable by an anti-SRIF antibody. Pretreatment with chloroquine, a lysosomal enzyme inhibitor, does not significantly decrease biliary radioactivity. We conclude that the data are consistent with saturable hepatic uptake and predominantly nonlysosomal transcellular transport

  13. Peripheral nervous system assessment in acromegaly patients under somatostatin analogue therapy.

    Science.gov (United States)

    Alibas, H; Gogas Yavuz, D; Kahraman Koytak, P; Uygur, M; Tanridag, T; Uluc, K

    2017-01-01

    Acromegaly is known to affect peripheral nervous system (PNS) causing carpal tunnel syndrome (CTS) and polyneuropathy. The frequency of these disorders and the evaluation methods vary among studies. In the present study, we aimed to examine PNS of acromegaly patients under somatostatin analogue (SSA) therapy. Forty-eight acromegaly patients (26 F/22 M, 45.58 ± 11.6 years) under SSA treatment and 44 healthy controls (25 F/19 M, 47.46 ± 8.7 years) were assessed by symptom questionnaires, neurologic examination and electrophysiological studies. 87.5 % of the acromegaly patients had at least one abnormal finding regarding PNS. With the incorporation of palm-wrist median nerve conduction velocity method, we detected CTS in 50 % of patients. Polyneuropathy was less frequent (29.2 %). Both conditions were independent from the coexisting diabetes mellitus (p = 0.22 for CTS, p = 0.71 for polyneuropathy). Polyneuropathy but not CTS was more common among biochemically uncontrolled acromegaly patients rather than those under control (p = 0.03; p = 0.68, respectively). Our findings emphasize the high prevalence of peripheral nervous system involvement in acromegaly patients under SSA therapy and importance of neurological evaluation of these patients. Early diagnosis and treatment of the disease may reduce the PNS involvement.

  14. Insulin receptors

    International Nuclear Information System (INIS)

    Kahn, C.R.; Harrison, L.C.

    1988-01-01

    This book contains the proceedings on insulin receptors. Part A: Methods for the study of structure and function. Topics covered include: Method for purification and labeling of insulin receptors, the insulin receptor kinase, and insulin receptors on special tissues

  15. CXCL14-like Immunoreactivity Exists in Somatostatin-containing Endocrine Cells, and in the Lamina Propria and Submucosal Somatostatinergic Nervous System of Mouse Alimentary Tract.

    Science.gov (United States)

    Suzuki, Hirohumi; Yamada, Kentaro; Matsuda, Yasuhiro; Onozuka, Minoru; Yamamoto, Toshiharu

    2017-12-26

    In the present study, we investigated the distribution of CXCL14 immunoreactive endocrine cells and neurons in mouse alimentary tract by immunohistochemistry. CXCL14 immunoreactive endocrine cells were found as closed-type cells in the stomach and open-type cells in the small intestine. The immunostaining of these endocrine cells corresponded with that of the somatostatin-containing endocrine cells. Only a few CXCL14 immunoreactive endocrine cells were seen in the large intestine. CXCL14 immunoreactive fibers were observed in the muscular layer from the stomach to the rectum with most abundance in the rectum. Many CXCL14 immunoreactive fibers were observed in the lamina propria and submucosal layer from the duodenum to the rectum with most abundance in the rectum; these fibers corresponded to the somatostatin-containing nerve fibers. Some CXCL14 immunoreactive neuronal somata that were also immuno-positive for somatostatin, were noted in the submucosal layer of the rectum. However, the remaining parts of the alimentary tract presented with almost negligible immunoreactive somata. The co-localization of CXCL14 and somatostatin suggests that CXCL14 contributes to the function of somatostatin, which include the inhibition of other endocrine and exocrine cells and the enteric nervous systems.

  16. Towards kit formulation of 99mTc labelled somatostatin receptor binding peptides of high specific activity for tumour localization

    International Nuclear Information System (INIS)

    Behe, M.; Powell, P.; Maecke, H.R.

    2001-01-01

    The project aimed to develop 99m Tc octreotide analogue for use in nuclear oncology. Several attempts to label SRIF analogues with 99m Tc have used a direct labelling approach but, for this project, HYNIC was chosen as a technetium ligand. A comparison of two different SRIF analogues designed for high specific activity labelling with 99m Tc was done. HYNIC-Octreotide and HYNIC-TOC were prepared and a kit formulation that can be labelled conveniently is currently being studied in a clinical setting. (author)

  17. Contribution of somatostatin, cortistatin, their receptors and other peptides to the regulation of growth hormone in primates and mice

    OpenAIRE

    Córdoba-Chacón, José

    2011-01-01

    La regulación de la secreción de hormona del crecimiento (GH) se ha considerado clásicamente como resultado de la acción conjunta y coordinada de dos péptidos hipotalámicos: la hormona liberadora de GH (GHRH) y el factor inhibidor de la secreción de GH (somatostatina, SST). Sin embargo, actualmente el control de la GH se concibe más como un fenómeno multifactorial, en el que se combinan señales reguladoras adicionales, tanto de origen central, como la cortistatina (CST o CORT) y la ghrelina h...

  18. Positron emission tomography evaluation of somatostatin receptor targeted (64)Cu-TATE-liposomes in a human neuroendocrine carcinoma mouse model

    DEFF Research Database (Denmark)

    Petersen, Anncatrine Luisa; Binderup, Tina; Jølck, Rasmus Irming

    2012-01-01

    -liposomes without TATE. PEGylated liposomes with or without TATE accumulated at significantly higher quantities in NETs (5.1±0.3 and 5.8±0.2 %ID/g, respectively) than the free peptide (64)Cu-DOTA-TATE (1.4±0.3 %ID/g) 24h post-injection. Importantly, (64)Cu-loaded PEGylated liposomes with TATE showed significantly...... higher tumor-to-muscle (T/M) ratio (12.7±1.0) than the control-liposomes without TATE (8.9±0.9) and the (64)Cu-DOTA-TATE free peptide (7.2±0.3). The higher T/M ratio of the PEGylated liposomes with TATE suggests some advantage of active targeting of NETs, although no absolute benefit in tumor...... to image NETs was evaluated using PET. Additionally, the liposome accumulation and imaging capability was compared with free radiolabelled TATE peptide administered as (64)Cu-DOTA-TATE. The presence of TATE on the liposomes resulted in a significantly faster initial blood clearance in comparison to control...

  19. Peptide receptor radionuclide therapy for neuroendocrine tumors in Germany: first results of a multi-institutional cancer registry.

    Science.gov (United States)

    Hörsch, Dieter; Ezziddin, Samer; Haug, Alexander; Gratz, Klaus Friedrich; Dunkelmann, Simone; Krause, Bernd Joachim; Schümichen, Carl; Bengel, Frank M; Knapp, Wolfram H; Bartenstein, Peter; Biersack, Hans-Jürgen; Plöckinger, Ursula; Schwartz-Fuchs, Sabine; Baum, R P

    2013-01-01

    Peptide receptor radionuclide therapy is an effective treatment option for patients with well-differentiated somatostatin receptor-expressing neuroendocrine tumors. However, published data result mainly from retrospective monocentric studies. We initiated a multi-institutional, prospective, board-reviewed registry for patients treated with peptide receptor radionuclide therapy in Germany in 2009. In five centers, 297 patients were registered. Primary tumors were mainly derived from pancreas (117/297) and small intestine (80/297), whereas 56 were of unknown primary. Most tumors were well differentiated with median Ki67 proliferation rate of 5% (range 0.9-70%). Peptide receptor radionuclide therapy was performed using mainly yttrium-90 and/or lutetium-177 as radionuclides in 1-8 cycles. Mean overall survival was estimated at 213 months with follow-up between 1 and 230 months after initial diagnosis, and 87 months with follow-up between 1 and 92 months after start of peptide receptor radionuclide therapy. Median overall survival was not yet reached. Subgroup analysis demonstrated that best results were obtained in neuroendocrine tumors with proliferation rate below 20%. Our results indicate that peptide receptor radionuclide therapy is an effective treatment for well- and moderately differentiated neuroendocrine tumors irrespective of previous therapies and should be regarded as one of the primary treatment options for patients with somatostatin receptor-expressing neuroendocrine tumors.

  20. Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

    Energy Technology Data Exchange (ETDEWEB)

    Waser, Beatrice; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, PO Box 62, Berne (Switzerland)

    2014-06-15

    Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. For the somatostatin receptor targeting of tumours, however, it was recently reported that antagonist tracers were superior to agonist tracers. The present study therefore evaluated various forms of the {sup 125}iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracer for the in vitro visualization of GLP-1 receptor-expressing tissues in rats and humans and compared it with the agonist tracer {sup 125}I-GLP-1(7-36)amide. Receptor autoradiography studies with {sup 125}I-GLP-1(7-36)amide agonist or {sup 125}I-BH-exendin(9-39) antagonist radioligands were performed in human and rat tissues. The antagonist {sup 125}I-BH-exendin(9-39) labelled at lysine 19 identifies all human and rat GLP-1 target tissues and GLP-1 receptor-expressing tumours. Binding is of high affinity and is comparable in all tested tissues in its binding properties with the agonist tracer {sup 125}I-GLP-1(7-36)amide. For comparison, {sup 125}I-BH-exendin(9-39) with the BH labelled at lysine 4 did identify the GLP-1 receptor in rat tissues but not in human tissues. The GLP-1 receptor antagonist exendin(9-39) labelled with {sup 125}I-BH at lysine 19 is an excellent GLP-1 radioligand that identifies human and rat GLP-1 receptors in normal and tumoural tissues. It may therefore be the molecular basis to develop suitable GLP-1 receptor antagonist radioligands for in vivo imaging of GLP-1 receptor-expressing tissues in patients. (orig.)

  1. Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

    International Nuclear Information System (INIS)

    Waser, Beatrice; Reubi, Jean Claude

    2014-01-01

    Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. For the somatostatin receptor targeting of tumours, however, it was recently reported that antagonist tracers were superior to agonist tracers. The present study therefore evaluated various forms of the 125 iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracer for the in vitro visualization of GLP-1 receptor-expressing tissues in rats and humans and compared it with the agonist tracer 125 I-GLP-1(7-36)amide. Receptor autoradiography studies with 125 I-GLP-1(7-36)amide agonist or 125 I-BH-exendin(9-39) antagonist radioligands were performed in human and rat tissues. The antagonist 125 I-BH-exendin(9-39) labelled at lysine 19 identifies all human and rat GLP-1 target tissues and GLP-1 receptor-expressing tumours. Binding is of high affinity and is comparable in all tested tissues in its binding properties with the agonist tracer 125 I-GLP-1(7-36)amide. For comparison, 125 I-BH-exendin(9-39) with the BH labelled at lysine 4 did identify the GLP-1 receptor in rat tissues but not in human tissues. The GLP-1 receptor antagonist exendin(9-39) labelled with 125 I-BH at lysine 19 is an excellent GLP-1 radioligand that identifies human and rat GLP-1 receptors in normal and tumoural tissues. It may therefore be the molecular basis to develop suitable GLP-1 receptor antagonist radioligands for in vivo imaging of GLP-1 receptor-expressing tissues in patients. (orig.)

  2. Neurotensin receptors in human neoplasms: high incidence in Ewing's sarcomas.

    Science.gov (United States)

    Reubi, J C; Waser, B; Schaer, J C; Laissue, J A

    1999-07-19

    Receptors for regulatory peptides, such as somatostatin or vasoactive intestinal peptide (VIP), expressed at high density by neoplastic cells, can be instrumental for tumor diagnosis and therapy. Little is known about the expression of neurotensin receptors in human tumors. In the present study, 464 human neoplasms of various types were investigated for their neurotensin receptor content by in vitro receptor autoradiography on tissue sections using 125I-[Tyr3]-neurotensin as radioligand. Neurotensin receptors were identified and localized in tumor cells of 11/17 Ewing's sarcomas, 21/40 meningiomas, 10/23 astrocytomas, 5/13 medulloblastomas, 7/24 medullary thyroid cancers and 2/8 small cell lung cancers. They were rarely found in non-small cell lung cancers and breast carcinomas; they were absent in prostate, ovarian, renal cell and hepatocellular carcinomas, neuroendocrine gut tumors, pituitary adenomas, schwannomas, neuroblastomas and lymphomas. When present, the receptors bound with nanomolar affinity neurotensin and acetyl-neurotensin-(8-13), with lower affinity neuromedin N, diethylenetriamine penta-acetic acidneurotensin-(8-13) and SR 48692, but not neurotensin-(1-11). They were all of the NT1 type, without high affinity for levocabastine. Further, in 2 receptor-positive Ewing's sarcomas, neurotensin mRNA was detected by in situ hybridization techniques. Since neurotensin is known to stimulate cell proliferation, the presence of neurotensin receptors in human neoplasia may be of biological relevance, possibly as an integrative part of an autocrine feedback mechanism of tumor growth stimulation.

  3. Study on the changes of serum levels of polypeptide growth factors (EGF, TGF-α) and related hormones (gastrin, somatostatin) in patients with peptic ulcer

    International Nuclear Information System (INIS)

    Cao Jianfan; Ma Yunbao; Zhang Xiaoyi

    2005-01-01

    Objective: To study the possible roles of EGF, TGF-α, gastrin and somatostatin in the pathogenesis of peptic ulcer by measuring the changes of serum levels of those four parameters in the patients with peptic ulcer. Methods: Serum levels of epidermal growth factor (EGF), transforming growth factor-α (TGF-α), gastrin (Gas) and somatostatin (SS) were measured with RIA in 30 patients with gastric ulcer, 32 patients with duodenal ulcer and 30 controls. Results: Serum levels of gastrin and EGF were significantly higher in the patients with peptic ulcer than those in the controls (both P 0.05). However, serum TGF-α levels were significantly lower in the ulcer patients than those in the controls (P<0.01). Conclusion: Changes of serum levels of gastrin, EGF and TGF-α were quite significant in the ulcer patients and determining of which might be of clinical meanings. Determination of somatostatin changes seemed to be of less importance. (authors)

  4. Growth-hormone and somatostatin effects on [75Se]selenomethionine uptake by the pancreas

    International Nuclear Information System (INIS)

    Atkins, H.L.; Som, P.

    1979-01-01

    The imaging of the pancreas with [ 75 Se]selenomethionine has a low rate of reliability. This study was carried out in order to elucidate some factors that may be important in affecting the degree of uptake of the tracer by the pancreas. Studies were carried out in animals to observe the effects of growth-hormone (GH), somatostatin (SRIF), L-DOPA, and apomorphine administration on the distribution of [ 75 Se]selenomethionine. Intravenously administered GH significantly depressed pancreatic uptake of Se-75 in mice and dogs and depressed the pancreas-to-liver concentration ratio (P/L). The effect of i.p. GH in mice was to decrease the P/L ratio, but the decrease in pancreatic uptake was not statistically significant. There was also a greater effect of GH in dogs than in mice, with pancreatic uptake decreasing from 5.60 +- 2.17% to 1.24 +- 0.96% and the P/L from 4.78 +- 1.85 to 0.97 +- 0.73. L-DOPA and apomorphine produced effects similar to GH in mice. SRIF in small doses had little effect, but in larger doses it enhanced pancreatic uptake, although not affecting P/L. The results indicate that hypothalamic factors may be important in affecting the function of the exocrine pancreas. Both L-DOPA and apomorphine are known to stimulate GH production through hypothalamic-pituitary pathways. In addition to suppressing GH release, SRIF may have direct effects on the exocrine pancreas

  5. SPECT/CT with radiolabeled somatostatin analogues in the evaluation of systemic granulomatous infections

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Silva Monteiro

    2017-10-01

    Full Text Available Abstract Objective: To evaluate SPECT/CT with radiolabeled somatostatin analogues (RSAs in systemic granulomatous infections in comparison with gallium-67 (67Ga citrate scintigraphy. Materials and Methods: We studied 28 patients with active systemic granulomatous infections, including tuberculosis, paracoccidioidomycosis, pneumocystosis, cryptococcosis, aspergillosis, leishmaniasis, infectious vasculitis, and an unspecified opportunistic infection. Of the 28 patients, 23 had started specific treatment before the study outset. All patients underwent whole-body SPECT/CT imaging: 7 after injection of 99mTc-EDDA-HYNIC-TOC, and 21 after injection of 111In-DTPA-octreotide. All patients also underwent 67Ga citrate imaging, except for one patient who died before the 67Ga was available. Results: In 20 of the 27 patients who underwent imaging with both tracers, 27 sites of active disease were detected by 67Ga citrate imaging and by SPECT/CT with an RSA. Both tracers had negative results in the other 7 patients. RSA uptake was visually lower than 67Ga uptake in 11 of the 20 patients with positive images and similar to 67Ga uptake in the other 9 patients. The only patient who did not undergo 67Ga scintigraphy underwent 99mTc-EDDA-HYNIC-TOC SPECT/CT-guided biopsy of a lung cavity with focal RSA uptake, which turned to be positive for aspergillosis. Conclusion: SPECT/CT with 99mTc-EDDA-HYNIC-TOC or 111In-DTPA-octreotide seems to be a good alternative to 67Ga citrate imaging for the evaluation of patients with systemic granulomatous disease.

  6. The utility of two somatostatin analog radiopharmaceuticals in assessment of radiologically indeterminate pulmonary lesions.

    Science.gov (United States)

    Sobic-Saranovic, Dragana P; Pavlovic, Smiljana V; Artiko, Vera M; Saranovic, Djordjije Z; Jaksic, Emilija D; Subotic, Dragan; Nagorni-Obradovic, Ljudmila; Kozarevic, Nebojsa; Petrovic, Nebojsa; Grozdic, Isidora T; Obradovic, Vladimir B

    2012-01-01

    The aim of our study was to assess diagnostic accuracy of Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC scintigraphy for evaluation of pulmonary lesions that appeared ambiguous on computed tomography (CT). Forty-nine consecutive patients (37 men and 12 women; mean age, 60 ± 11 years) with 60 pulmonary lesions on chest radiography and CT were referred for nuclear imaging. They were prospectively allocated to undergo whole-body scintigraphy (WBS) and single photon emission computed tomography (SPECT) using either Tc-99m depreotide (26 patients, group 1) or Tc-99m-EDDA/HYNIC-TOC imaging (23 patients, group 2). Histologic findings after tissue biopsy served as a gold standard for determining diagnostic accuracy of the 2 somatostatin analogs. Visual assessment was complemented by semiquantitative analysis based on target to background ratio. Among the 32 pulmonary lesions scanned with Tc-99m depreotide, focal uptake was increased in 22 of 25 malignancies, whereas no uptake was found in 6 of 7 benign lesions (88% sensitivity, 85% specificity, and 88% accuracy) on both WBS and SPECT. Imaging of 28 pulmonary lesions with Tc-99m-EDDA/HYNIC-TOC had a similar diagnostic yield (sensitivity 87%, specificity 84%, and accuracy 86%). Overall, target to background ratios were higher on SPECT than WBS but not significantly different between groups 1 and 2 (SPECT 2.72 ± 0.70 vs. 2.71 ± 0.50, WBS 1.61 ± 0.32 vs. 1.62 ± 0.28, respectively). This study demonstrates that Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC have similar diagnostic value for characterizing pulmonary lesions that appear ambiguous on CT.

  7. Comparison of somatostatin analogue and metaiodobenzylguanidine scintigraphy for the detection of carcinoid tumours

    International Nuclear Information System (INIS)

    Nocaudie-Calzada, M.; Huglo, D.; Carnaille, B.; Proye, C.; Marchandise, X.

    1996-01-01

    The purpose of this prospective study was to compare the ability of radiolabelled somatostatin analogue (RSA) and metaiodobenzylguanidine (MIBG) scintigraphy to display carcinoid tumours. Forty patients were studied after radiological assessment based on clinical symptomatology. These patients had radiologically demonstrated tumours (n=28), resected tumours discovered to be of the carcinoid type (n=5) or clinically and biologically suspected carcinoid tumours (n=7). They underwent indium-111 DTPA-pentetreotide or iodine-123-Tyr-3-octreotide and 131 I-MIBG scintigraphy. The results were compared with those of complementary surgical or morphological examinations and analysed according to the site of the tumour and the symptomatology. In the case of 31 patients with a total of 55 tumoral sites, the sensitivity of the initial radiological assessment, of RSA and of MIBG was 96%, 86% and 64%, respectively, for the detection of at least one tumour per patient, but 51%, 85% and 51%, respectively, for the total number of sites. No site was detected solely by MIBG. The concordance between RSA and MIBG was better when all sites were considered (kappa index+0.44) than for only extrahepatic abdominal tumoral sites (kappa index+0.095). Abdominal, thoracic or bone marrow tumours were more easily detected with RSA than with MIBG. Hepatic invasion (21 cases) was more easily detected by radiology (sensitivity 100%) than by RSA and MIBG, both of which displayed a sensitivity of 80%, but with differences in uptake intensity. Tumour detection using MIBG was more significantly linked with flush (P 0.10). In the assessment of carcinoid tumours, RSA scintigraphy should be carried out initially (just after hepatic ultrasonography) and supplemented by MIBG, as comparison of the studies serves to guide therapeutic options and might be valuable for prognosis. (orig.). With 2 figs., 3 tabs

  8. SPECT/CT with radiolabeled somatostatin analogues in the evaluation of systemic granulomatous infections

    International Nuclear Information System (INIS)

    Monteiro, Paulo Henrique Silva; Souza, Thiago Ferreira de; Moretti, Maria Luiza; Resende, Mariangela Ribeiro; Lima, Mariana da Cunha Lopes de; Santos, Allan Oliveira; Ramos, Celso Darío

    2017-01-01

    Objective: To evaluate SPECT/CT with radiolabeled somatostatin analogues (RSAs) in systemic granulomatous infections in comparison with gallium-67 ( 67 Ga) citrate scintigraphy. Materials And Methods: We studied 28 patients with active systemic granulomatous infections, including tuberculosis, paracoccidioidomycosis, pneumocystosis, cryptococcosis, aspergillosis, leishmaniasis, infectious vasculitis, and an unspecified opportunistic infection. Of the 28 patients, 23 had started specific treatment before the study outset. All patients underwent whole-body SPECT/CT imaging: 7 after injection of 99m Tc-EDDA-HYNIC-TOC, and 21 after injection of 111 In-DTPA-octreotide. All patients also underwent 67 Ga citrate imaging, except for one patient who died before the 67 Ga was available. Results: In 20 of the 27 patients who underwent imaging with both tracers, 27 sites of active disease were detected by 67 Ga citrate imaging and by SPECT/CT with an RSA. Both tracers had negative results in the other 7 patients. RSA uptake was visually lower than 67 Ga uptake in 11 of the 20 patients with positive images and similar to 67 Ga uptake in the other 9 patients. The only patient who did not undergo 67 Ga scintigraphy underwent 99m Tc-EDDA-HYNIC-TOC SPECT/CT-guided biopsy of a lung cavity with focal RSA uptake, which turned to be positive for aspergillosis. Conclusion: SPECT/CT with 99m Tc-EDDA-HYNIC-TOC or 111 In-DTPA-octreotide seems to be a good alternative to 67 Ga citrate imaging for the evaluation of patients with systemic granulomatous disease. (author)

  9. Attitudes and preferences in patients with acromegaly on long-term treatment with somatostatin analogues

    Directory of Open Access Journals (Sweden)

    Cecilia Follin

    2016-08-01

    Full Text Available Introduction: Patients with acromegaly can be treated with surgery, medical therapy and/or radiation therapy. For the patients not being cured with surgery, treatment with somatostatin analogues (SSAs is the primary therapy. SSA can be taken by self- or partner-administered injections in addition to being given by a nurse at a clinic. The aim was to assess if patients with acromegaly prefer self-injections and to investigate their attitudes towards long-term medical therapy. Method: All patients in the southern medical region of Sweden with a diagnosis of acromegaly and treated with SSA were eligible for the study (n = 24. The study is based on a questionnaire asking about the patients’ attitudes and preferences for injections with SSA, including their attitudes towards self-injection with SSA. Results: The patients’ (23 included median age was 68.5 years and the patients had been treated with SSA for 13 (1–38 years. One patient was currently self-injecting. All of the other patients were receiving injections from a nurse at a clinic. Three patients preferred self-injections, one preferred partner injections and 19 patients did not prefer self- or partner injections. The most frequent arguments to not preferring self-injections were ‘feeling more secure with an educated nurse’ and ‘preferring regular contact with a specialised nurse’. Conclusion: Patients with acromegaly prefer regular contact with the endocrine team to the independence offered by self-injections. These findings might mirror the patients’ desires for continuity and safety. We need to address patients’ concerns regarding injections with SSA and support them in their choices.

  10. Somatostatin-Positive Gamma-Aminobutyric Acid Interneuron Deficits in Depression: Cortical Microcircuit and Therapeutic Perspectives.

    Science.gov (United States)

    Fee, Corey; Banasr, Mounira; Sibille, Etienne

    2017-10-15

    The functional integration of external and internal signals forms the basis of information processing and is essential for higher cognitive functions. This occurs in finely tuned cortical microcircuits whose functions are balanced at the cellular level by excitatory glutamatergic pyramidal neurons and inhibitory gamma-aminobutyric acidergic (GABAergic) interneurons. The balance of excitation and inhibition, from cellular processes to neural network activity, is characteristically disrupted in multiple neuropsychiatric disorders, including major depressive disorder (MDD), bipolar disorder, anxiety disorders, and schizophrenia. Specifically, nearly 3 decades of research demonstrate a role for reduced inhibitory GABA level and function across disorders. In MDD, recent evidence from human postmortem and animal studies suggests a selective vulnerability of GABAergic interneurons that coexpress the neuropeptide somatostatin (SST). Advances in cell type-specific molecular genetics have now helped to elucidate several important roles for SST interneurons in cortical processing (regulation of pyramidal cell excitatory input) and behavioral control (mood and cognition). Here, we review evidence for altered inhibitory function arising from GABAergic deficits across disorders and specifically in MDD. We then focus on properties of the cortical microcircuit, where SST-positive GABAergic interneuron deficits may disrupt functioning in several ways. Finally, we discuss the putative origins of SST cell deficits, as informed by recent research, and implications for therapeutic approaches. We conclude that deficits in SST interneurons represent a contributing cellular pathology and therefore a promising target for normalizing altered inhibitory function in MDD and other disorders with reduced SST cell and GABA functions. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  11. Topography of somatostatin gene expression relative to molecular progenitor domains during ontogeny of the mouse hypothalamus

    Directory of Open Access Journals (Sweden)

    Nicanor eMorales-Delgado

    2011-02-01

    Full Text Available The hypothalamus comprises alar, basal and floor plate developmental compartments. Recent molecular data support a rostro-caudal subdivision into rostral (terminal and caudal (peduncular halves. In this context, the distribution of neuronal populations expressing somatostatin (Sst mRNA was analyzed in the developing mouse hypothalamus, comparing with the expression pattern of the genes Orthopedia (Otp, Distal-less 5 (Dlx5, Sonic Hedgehog (Shh and Nk2 homeobox 1 (Nkx2.1. At embryonic day 10.5 (E10.5, Sst mRNA was first detectable in the anterobasal nucleus, a Nkx2.1-, Shh- and Otp- positive basal domain. By E13.5, nascent Sst expression was also related to two additional Otp-positive domains within the alar plate and one in the basal plate. In the alar plate, Sst-positive cells were observed in rostral and caudal ventral subdomains of the Otp-positive paraventricular complex. An additional basal Sst-expressing cell group was found within a longitudinal Otp-positive periretromamillary band that separates the retromamillary area from tuberal areas. Apart of subsequent growth of these initial populations, at E13.5 and E15.5 some Sst-positive derivatives migrate tangentially into neighboring regions. A subset of cells produced at the anterobasal nucleus disperses ventralwards into the shell of the ventromedial hypothalamic nucleus and the arcuate nucleus. Cells from the rostroventral paraventricular subdomain reach the suboptic nucleus, whereas a caudal contingent migrates radially into lateral paraventricular, perifornical and entopeduncular nuclei. Our data provide a topologic map of molecularly-defined progenitor areas originating a specific neuron type during early hypothalamic development. Identification of four main separate sources helps to understand causally its complex adult organization.

  12. Preliminary research on relationship between the somatostatin level and diabetes mellitus

    International Nuclear Information System (INIS)

    Shi Hongzhen; Wang Zizheng; Du Tongxin; Liu Jiaqin; Wei Jin; Qi Shaokang

    1996-01-01

    To study the relationship between somatostatin (SS) and diabetes mellitus (DM), and also among SS, C-peptide (C-P), insulin (INS), and glucagon (Gluc). Fasting and postprandial 2h plasma SS, INS, C-P and Gluc in 17 patients of IDDM, 22 patients of NIDDM and 23 normal controls were detected simultaneously by RIA. Dynamic assessment of above parameters was performed at 0,30,60,120,180 min in 8 cases of NIDDM with oral glucose tolerance test (OGTT). Fasting and postprandial 2h SS and Gluc levels were significantly higher in DM than in normal controls. The ratios of SS/INS and Gluc/SS in IDDM were higher than those in NIDDM and normal controls, while no difference was found in NIDDM and normal controls. Fasting Gluc/SS was similar in three groups, but increased significantly in DM after oral glucose intake and postprandial state. OGTT found that the levels of SS both in patients of nIDDM and normal controls reached its maximum at 30 min with a smaller amplitude in peak value in patient group, while the levels of INS, C-P and Gluc attained its climax at 60 min, lagging behind the normal controls (30 min), with a sustained high levels at 180 min. There was a difference of SS-secreting phase between DM and normal controls. The ratios of SS/INS, Gluc/INS provided an important reference value for diagnosis of DM. A relative insufficiency of SS secretion and Gluc/SS imbalance under glucose-loading may play an important role in the etiology of DM

  13. SPECT/CT with radiolabeled somatostatin analogues in the evaluation of systemic granulomatous infections

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Paulo Henrique Silva; Souza, Thiago Ferreira de; Moretti, Maria Luiza; Resende, Mariangela Ribeiro; Lima, Mariana da Cunha Lopes de; Santos, Allan Oliveira; Ramos, Celso Darío, E-mail: paulohsm42@gmail.com [Universidade de Campinas (UNICAMP), SP (Brazil). Escola de Medicina; Mengatti Jair [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-11-15

    Objective: To evaluate SPECT/CT with radiolabeled somatostatin analogues (RSAs) in systemic granulomatous infections in comparison with gallium-67 ({sup 67}Ga) citrate scintigraphy. Materials And Methods: We studied 28 patients with active systemic granulomatous infections, including tuberculosis, paracoccidioidomycosis, pneumocystosis, cryptococcosis, aspergillosis, leishmaniasis, infectious vasculitis, and an unspecified opportunistic infection. Of the 28 patients, 23 had started specific treatment before the study outset. All patients underwent whole-body SPECT/CT imaging: 7 after injection of {sup 99m}Tc-EDDA-HYNIC-TOC, and 21 after injection of {sup 111}In-DTPA-octreotide. All patients also underwent {sup 67}Ga citrate imaging, except for one patient who died before the {sup 67}Ga was available. Results: In 20 of the 27 patients who underwent imaging with both tracers, 27 sites of active disease were detected by {sup 67}Ga citrate imaging and by SPECT/CT with an RSA. Both tracers had negative results in the other 7 patients. RSA uptake was visually lower than {sup 67}Ga uptake in 11 of the 20 patients with positive images and similar to {sup 67}Ga uptake in the other 9 patients. The only patient who did not undergo {sup 67}Ga scintigraphy underwent {sup 99m}Tc-EDDA-HYNIC-TOC SPECT/CT-guided biopsy of a lung cavity with focal RSA uptake, which turned to be positive for aspergillosis. Conclusion: SPECT/CT with {sup 99m}Tc-EDDA-HYNIC-TOC or {sup 111}In-DTPA-octreotide seems to be a good alternative to {sup 67}Ga citrate imaging for the evaluation of patients with systemic granulomatous disease. (author)

  14. Crosstalks between kisspeptin neurons and somatostatin neurons are not photoperiod dependent in the ewe hypothalamus.

    Science.gov (United States)

    Dufourny, Laurence; Lomet, Didier

    2017-12-01

    Seasonal reproduction is under the control of gonadal steroid feedback, itself synchronized by day-length or photoperiod. As steroid action on GnRH neurons is mostly indirect and therefore exerted through interneurons, we looked for neuroanatomical interactions between kisspeptin (KP) neurons and somatostatin (SOM) neurons, two populations targeted by sex steroids, in three diencephalic areas involved in the central control of ovulation and/or sexual behavior: the arcuate nucleus (ARC), the preoptic area (POA) and the ventrolateral part of the ventromedial hypothalamus (VMHvl). KP is the most potent secretagogue of GnRH secretion while SOM has been shown to centrally inhibit LH pulsatile release. Notably, hypothalamic contents of these two neuropeptides vary with photoperiod in specific seasonal species. Our hypothesis is that SOM inhibits KP neuron activity and therefore indirectly modulate GnRH release and that this effect may be seasonally regulated. We used sections from ovariectomized estradiol-replaced ewes killed after photoperiodic treatment mimicking breeding or anestrus season. We performed triple immunofluorescent labeling to simultaneously detect KP, SOM and synapsin, a marker for synaptic vesicles. Sections from the POA and from the mediobasal hypothalamus were examined using a confocal microscope. Randomly selected KP or SOM neurons were observed in the POA and ARC. SOM neurons were also observed in the VMHvl. In both the ARC and POA, nearly all KP neurons presented numerous SOM contacts. SOM neurons presented KP terminals more frequently in the ARC than in the POA and VMHvl. Quantitative analysis failed to demonstrate major seasonal variations of KP and SOM interactions. Our data suggest a possible inhibitory action of SOM on all KP neurons in both photoperiodic statuses. On the other hand, the physiological significance of KP modulation of SOM neuron activity and vice versa remain to be determined. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Diversity and overlap of Parvalbumin and Somatostatin expressing interneurons in mouse presubiculum

    Directory of Open Access Journals (Sweden)

    Mérie eNassar

    2015-05-01

    Full Text Available The presubiculum, located between hippocampus and entorhinal cortex, plays a fundamental role in representing spatial information, notably head direction. Little is known about GABAergic interneurons of this region. Here, we used three transgenic mouse lines, Pvalb-Cre, Sst-Cre and X98, to examine distinct interneurons labeled with tdTomato or green fluorescent protein. The distribution of interneurons in presubicular lamina for each animal line was compared to that in the GAD67-GFP knock-in animal line. Labelling was specific in the Pvalb-Cre line with 87% of labeled interneurons immunopositive for (PV. Immunostaining for somatostatin (SOM revealed good specificity in the X98 line with 89% of fluorescent cells, but a lesser specificity in Sst-Cre animals where only 71% of labeled cells were immunopositive. A minority of ~ 6% of interneurons co-expressed PV and SOM in the presubiculum of Sst-Cre animals. The electrophysiological and morphological properties of fluorescent interneurons from Pvalb-Cre, Sst-Cre and X98 mice differed. Distinct physiological groups of presubicular interneurons were resolved by unsupervised cluster analysis of parameters describing passive properties, firing patterns and AP shapes. One group consisted of SOM-positive, Martinotti type neurons with a low firing threshold (cluster 1. Fast spiking basket cells, mainly from the Pvalb-Cre line, formed a distinct group (cluster 3. Another group (cluster 2 contained interneurons of intermediate electrical properties and basket-cell like morphologies. These labeled neurons were recorded from both Sst-Cre and Pvalb-Cre animals. Thus, our results reveal a wide variation in anatomical and physiological properties for these interneurons, a real overlap of interneurons immuno-positive for both PV and SOM as well as an off-target recombination in the Sst-Cre line, possibly linked to maternal cre inheritance.

  16. Age-related changes in Serum Growth Hormone, Insulin-like Growth Factor-1 and Somatostatin in System Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Malemud Charles J

    2004-10-01

    Full Text Available Abstract Background Systemic lupus erythematosus is an age- and gender-associated autoimmune disorder. Previous studies suggested that defects in the hypothalamic/pituitary axis contributed to systemic lupus erythematosus disease progression which could also involve growth hormone, insulin-like growth factor-1 and somatostatin function. This study was designed to compare basal serum growth hormone, insulin-like growth factor-1 and somatostatin levels in female systemic lupus erythematosus patients to a group of normal female subjects. Methods Basal serum growth hormone, insulin-like growth factor-1 and somatostatin levels were measured by standard radioimmunoassay. Results Serum growth hormone levels failed to correlate with age (r2 = 3.03 in the entire group of normal subjects (i.e. 20 – 80 years. In contrast, serum insulin-like growth factor-1 levels were inversely correlated with age (adjusted r2 = 0.092. Of note, serum growth hormone was positively correlated with age (adjusted r2 = 0.269 in the 20 – 46 year range which overlapped with the age range of patients in the systemic lupus erythematosus group. In that regard, serum growth hormone levels were not significantly higher compared to either the entire group of normal subjects (20 – 80 yrs or to normal subjects age-matched to the systemic lupus erythematosus patients. Serum insulin-like growth factor-1 levels were significantly elevated (p 55 yrs systemic lupus erythematosus patients. Conclusions These results indicated that systemic lupus erythematosus was not characterized by a modulation of the growth hormone/insulin-like growth factor-1 paracrine axis when serum samples from systemic lupus erythematosus patients were compared to age- matched normal female subjects. These results in systemic lupus erythematosus differ from those previously reported in other musculoskeletal disorders such as rheumatoid arthritis, osteoarthritis, fibromyalgia, diffuse idiopathic skeletal

  17. Proghrelin-derived peptides influence the secretion of insulin, glucagon, pancreatic polypeptide and somatostatin: a study on isolated islets from mouse and rat pancreas

    DEFF Research Database (Denmark)

    Qader, S.S.; Hakanson, R.; Lundquist, I.

    2008-01-01

    ghrelin, and to the 23-amino acid peptide obestatin, claimed to be a physiological opponent of acyl ghrelin. This study examines the effects of the proghrelin products, alone and in combinations, on the secretion of insulin, glucagon, pancreatic polypeptide (PP) and somatostatin from isolated islets...... times higher concentration than acyl ghrelin (corresponding to the ratio of the two peptides in circulation), desacyl ghrelin abolished the effects of acyl ghrelin but not those of obestatin. Acyl ghrelin and obestatin affected the secretion of glucagon, PP and somatostatin at physiologically relevant...

  18. Alterations in Somatostatin Cells and Biochemical Parameters Following Zinc Supplementation in Gastrointestinal Tissue of St reptozotocin-Induced Diabetic Rats

    International Nuclear Information System (INIS)

    Bolkent, Sema; Bolkent, Sehnaz; Yanardag, Refiye; Mutlu, Ozgur; Yildirim, Sukriye

    2006-01-01

    Chronic hyperglycemia in diabetes is a major causative factor of free radical generation which further leads to many secondary diabetic complications via the damage to cellular proteins, membrane lipids, and nucleic acids. Zinc is an essential trace element in all living systems and plays a structural role in many proteins and enzymes. Somatostatin is known to have inhibitory effects on various gastrointestinal functions. Therefore, we determined somatostatin protein production and secretion levels, and biochemical and light microscopical changes following zinc supplementation in the gastrointestinal tract of streptozotocin (STZ)-diabetic rats. The animals were divided into four groups: Group I: control (untreated) animals; Group II: control animals given zinc sulfate; Group III: diabetic animals; and Group IV: diabetic animals given zinc sulfate. Zinc sulfate was given to the animals by gavage at a daily dose of 100 mg/kg body weight for 60 days. Diabetes was induced by intraperitoneal (i.p.) injection of STZ in a single dose of 65 mg/kg. For histological studies, stomach and duodenum tissues were fixed in Bouin solution and sections stained with Masson’s trichrome and Periodic-Acid-Schiff. Tissue homogenates were used for protein, lipid peroxidation (LPO), glutathione (GSH), and nonenzymatic glycosylation (NEG) analyses. Zinc supplementation to the STZ-diabetic rats revealed the protective effect of zinc on these parameters. Zinc supplementation may contribute to prevent at least some complications of diabetes mellitus

  19. Analysis of 125I-[Tyr3] octreotide receptors of NCI-H466 cell line

    International Nuclear Information System (INIS)

    Sun Junjie; Fan Wo; Xu Yujie; Zhang Youjiu; Zhu Ran

    2002-01-01

    Objective: To study the affinity of small cell lung carcinoma to [Tyr 3 ] octreotide (TOC). Methods: Taking 125 I-[Tyr 3 ] octreotide (labeled by chloramine-T method), as the ligand, small cell lung carcinoma NCI-H466 cell line was inspected for the receptor-binding points and affinity constant. Results: The radio-chemical purity of 125 I-TOC purified through sephadex G-10 was higher than 95%. Receptor analysis study showed that the expression of somatostatin receptors on NCI-H446 cells was numerous (Bmax = 1.17 x 10 5 /cell) with strong affinity to 125 I-TOC (Kd = 0.56 nM). Conclusion: Labeled TOC could be used for small cell lung carcinoma receptor imaging and radio-pharmaceutical therapy

  20. Receptors for sensory neuropeptides in human inflammatory diseases: Implications for the effector role of sensory neurons

    International Nuclear Information System (INIS)

    Mantyh, P.W.; Catton, M.D.; Boehmer, C.G.; Welton, M.L.; Passaro, E.P. Jr.; Maggio, J.E.; Vigna, S.R.

    1989-01-01

    Glutamate and several neuropeptides are synthesized and released by subpopulations of primary afferent neurons. These sensory neurons play a role in regulating the inflammatory and immune responses in peripheral tissues. Using quantitative receptor autoradiography we have explored what changes occur in the location and concentration of receptor binding sites for sensory neurotransmitters in the colon in two human inflammatory diseases, ulcerative colitis and Crohn's disease. The sensory neurotransmitter receptors examined included bombesin, calcitonin gene related peptide-alpha, cholecystokinin, galanin, glutamate, somatostatin, neurokinin A (substance K), substance P, and vasoactive intestinal polypeptide. Of the nine receptor binding sites examined only substance P binding sites associated with arterioles, venules and lymph nodules were dramatically up-regulated in the inflamed tissue. These data suggest that substance P is involved in regulating the inflammatory and immune responses in human inflammatory diseases and indicate a specificity of efferent action for each sensory neurotransmitter in peripheral tissues

  1. Budget impact of somatostatin analogs as treatment for metastatic gastroenteropancreatic neuroendocrine tumors in US hospitals

    Directory of Open Access Journals (Sweden)

    Ortendahl JD

    2017-08-01

    Full Text Available Jesse D Ortendahl,1 Sonia J Pulgar,2 Beloo Mirakhur,3 David Cox,3 Tanya GK Bentley,1 Alexandria T Phan4 1Health Economics, Partnership for Health, LLC, Beverly Hills, CA, USA; 2Health Economics and Outcomes Research, Ipsen Biopharmaceuticals, Basking Ridge, NJ, USA; 3Medical Affairs, Oncology, Ipsen Biopharmaceuticals, Basking Ridge, NJ, USA; 4GI Medical Oncology, University of New Mexico Comprehensive Cancer Center, Albuquerque, NM, USA Objective: With the introduction of new therapies, hospitals have to plan spending limited resources in a cost-effective manner. To assist in identifying the optimal treatment for patients with locally advanced or metastatic gastroenteropancreatic neuroendocrine tumors, budget impact modeling was used to estimate the financial implications of adoption and diffusion of somatostatin analogs (SSAs. Patients and methods: A hypothetical cohort of 500 gastroenteropancreatic neuroendocrine tumor patients was assessed in an economic model, with the proportion with metastatic disease treated with an SSA estimated using published data. Drug acquisition, preparation, and administration costs were based on national pricing databases and published literature. Octreotide dosing was based on published estimates of real-world data, whereas for lanreotide, real-world dosing was unavailable and we therefore used the highest indicated dosing. Alternative scenarios reflecting the proportion of patients receiving lanreotide or octreotide were considered to estimate the incremental budget impact to the hospital. Results: In the base case, 313 of the initial 500 gastroenteropancreatic neuroendocrine tumor patients were treated with an SSA. The model-predicted per-patient cost was US$83,473 for lanreotide and US$89,673 for octreotide. With a hypothetical increase in lanreotide utilization from 5% to 30% of this population, the annual model-projected hospital costs decreased by US$488,615. When varying the inputs in one-way sensitivity

  2. Quality of life is impaired in association with the need for prolonged postoperative therapy by somatostatin analogs in patients with acromegaly

    NARCIS (Netherlands)

    Postma, Mark R; Netea-Maier, Romana T; van den Berg, Gerrit; Homan, Jens; Sluiter, Wim J; Wagenmakers, Margreet A; van den Bergh, Alfons C M; Wolffenbuttel, Bruce H R; Hermus, Ad R M M; van Beek, André P

    OBJECTIVE: To assess the influence of long-acting somatostatin analogs (SSTA) after initial pituitary surgery on long-term health-related quality of life (HR-QoL) in relation to disease control in patients with acromegaly. DESIGN: This is a cross-sectional study in two tertiary referral centers in

  3. Quality of life is impaired in association with the need for prolonged postoperative therapy by somatostatin analogs in patients with acromegaly.

    NARCIS (Netherlands)

    Postma, M.R.; Netea-Maier, R.T.; Berg, G. van den; Homan, J.; Sluiter, W.J.; Wagenmakers, M.A.E.M.; Bergh, A.C. van den; Wolffenbuttel, B.H.R.; Hermus, A.R.M.M.; Beek, A.P. van

    2012-01-01

    OBJECTIVE: To assess the influence of long-acting somatostatin analogs (SSTA) after initial pituitary surgery on long-term health-related quality of life (HR-QoL) in relation to disease control in patients with acromegaly. DESIGN: This is a cross-sectional study in two tertiary referral centers in

  4. Synthesis and evaluation in vitro in cancer cells AR42J of the radiopharmaceutical {sup 99m}Tc-Tyr{sup 3}-Octreotide-dendrimer similar of somatostatin; Sintesis y evaluacion in vitro en celulas de cancer AR42J del radiofarmaco {sup 99m}Tc-Tyr{sup 3}-Octreotido-dendrimero analogo de la somatostatina

    Energy Technology Data Exchange (ETDEWEB)

    Orocio R, E.

    2013-07-01

    The objective of this project was preparing a multimeric system through the conjugation of several molecules of the peptide Tyr{sup 3}-Octreotide to a dendrimer molecule based on Poly-amidoamine (PAMAM), as well as radiolabeled with {sup 99m}Tc and evaluating its behavior like new radiopharmaceutical similar of somatostatin. The dendrimer PAMAM generation 3.5 that possesses terminal groups of sodium carboxylate, was functionalized to peptide Tyr{sup 3}-Octreotide through a reaction of peptide coupling with HATU (hexafluorophosphate (V) of 1-oxide-3-(bis(dimethylamino)methylene)-3H-[1,2,3]triazole[4,5-b]pyridine) as activating agent of carboxylate groups using the Size Exclusion Chromatography (Sec) as purification method. The product was characterized by Ultraviolet visible spectrophotometry, Mid-infrared and Far-infrared, Elemental analysis, Energy dispersive X-ray spectroscopy, Scanning electron microscopy, Thermogravimetry and Differential scanning calorimetry. The radiolabeled with {sup 99m}Tc was carried out using a direct method that involves the reduction of the anion TcO{sub 4}{sup -} with stannous chloride, so that the dendrimer is capable of coordinating to the technetium forming a chelate compound. The radiochemical purity of the radiolabeled compound was determined by thin layer chromatography using a sodium chloride solution to 20% (m/v) as mobile phase and was verified by molecular exclusion chromatography. The radiolabeled compound was possible to obtain it with a radiochemical purity superior to 90%. Also, the specific and not specific union was evaluated of the synthesized compound in mouse pancreas cancer cells AR42J, positive to somatostatin receptors, showing specific recognition for this receptors type with high cellular internalization. The biodistribution studies were carried out in BALB/c mice at different post injection times and in nude mice with induced tumors AR42J. The results showed that the {sup 99m}Tc-PAMAM-Tyr{sup 3}-Octreotide is

  5. Somatostatin-based radiotherapy with [90Y-DOTA]-TOC in neuroendocrine tumors: long-term outcome of a phase I dose escalation study.

    Science.gov (United States)

    Marincek, Nicolas; Jörg, Ann-Catherine; Brunner, Philippe; Schindler, Christian; Koller, Michael T; Rochlitz, Christoph; Müller-Brand, Jan; Maecke, Helmut R; Briel, Matthias; Walter, Martin A

    2013-01-15

    We describe the long-term outcome after clinical introduction and dose escalation of somatostatin receptor targeted therapy with [90Y-DOTA]-TOC in patients with metastasized neuroendocrine tumors. In a clinical phase I dose escalation study we treated patients with increasing [90Y-DOTA]-TOC activities. Multivariable Cox regression and competing risk regression were used to compare efficacy and toxicities of the different dosage protocols. Overall, 359 patients were recruited; 60 patients were enrolled for low dose (median: 2.4 GBq/cycle, range 0.9-7.8 GBq/cycle), 77 patients were enrolled for intermediate dose (median: 3.3 GBq/cycle, range: 2.0-7.4 GBq/cycle) and 222 patients were enrolled for high dose (median: 6.7 GBq/cycle, range: 3.7-8.1 GBq/cycle) [90Y-DOTA]-TOC treatment. The incidences of hematotoxicities grade 1-4 were 65.0%, 64.9% and 74.8%; the incidences of grade 4/5 kidney toxicities were 8.4%, 6.5% and 14.0%, and the median survival was 39 (range: 1-158) months, 34 (range: 1-118) months and 29 (range: 1-113) months. The high dose protocol was associated with an increased risk of kidney toxicity (Hazard Ratio: 3.12 (1.13-8.59) vs. intermediate dose, p = 0.03) and a shorter overall survival (Hazard Ratio: 2.50 (1.08-5.79) vs. low dose, p = 0.03). Increasing [90Y-DOTA]-TOC activities may be associated with increasing hematological toxicities. The dose related hematotoxicity profile of [90Y-DOTA]-TOC could facilitate tailoring [90Y-DOTA]-TOC in patients with preexisting hematotoxicities. The results of the long-term outcome suggest that fractionated [90Y-DOTA]-TOC treatment might allow to reduce renal toxicity and to improve overall survival. (ClinicalTrials.gov number NCT00978211).

  6. Somatostatin-based radiotherapy with [90Y-DOTA]-TOC in neuroendocrine tumors: long-term outcome of a phase I dose escalation study

    Directory of Open Access Journals (Sweden)

    Marincek Nicolas

    2013-01-01

    Full Text Available Abstract Background We describe the long-term outcome after clinical introduction and dose escalation of somatostatin receptor targeted therapy with [90Y-DOTA]-TOC in patients with metastasized neuroendocrine tumors. Methods In a clinical phase I dose escalation study we treated patients with increasing [90Y-DOTA]-TOC activities. Multivariable Cox regression and competing risk regression were used to compare efficacy and toxicities of the different dosage protocols. Results Overall, 359 patients were recruited; 60 patients were enrolled for low dose (median: 2.4 GBq/cycle, range 0.9-7.8 GBq/cycle, 77 patients were enrolled for intermediate dose (median: 3.3 GBq/cycle, range: 2.0-7.4 GBq/cycle and 222 patients were enrolled for high dose (median: 6.7 GBq/cycle, range: 3.7-8.1 GBq/cycle [90Y-DOTA]-TOC treatment. The incidences of hematotoxicities grade 1–4 were 65.0%, 64.9% and 74.8%; the incidences of grade 4/5 kidney toxicities were 8.4%, 6.5% and 14.0%, and the median survival was 39 (range: 1–158 months, 34 (range: 1–118 months and 29 (range: 1–113 months. The high dose protocol was associated with an increased risk of kidney toxicity (Hazard Ratio: 3.12 (1.13-8.59 vs. intermediate dose, p = 0.03 and a shorter overall survival (Hazard Ratio: 2.50 (1.08-5.79 vs. low dose, p = 0.03. Conclusions Increasing [90Y-DOTA]-TOC activities may be associated with increasing hematological toxicities. The dose related hematotoxicity profile of [90Y-DOTA]-TOC could facilitate tailoring [90Y-DOTA]-TOC in patients with preexisting hematotoxicities. The results of the long-term outcome suggest that fractionated [90Y-DOTA]-TOC treatment might allow to reduce renal toxicity and to improve overall survival. (ClinicalTrials.gov number NCT00978211.

  7. Somatostatin-based radiotherapy with [90Y-DOTA]-TOC in neuroendocrine tumors: long-term outcome of a phase I dose escalation study

    Science.gov (United States)

    2013-01-01

    Background We describe the long-term outcome after clinical introduction and dose escalation of somatostatin receptor targeted therapy with [90Y-DOTA]-TOC in patients with metastasized neuroendocrine tumors. Methods In a clinical phase I dose escalation study we treated patients with increasing [90Y-DOTA]-TOC activities. Multivariable Cox regression and competing risk regression were used to compare efficacy and toxicities of the different dosage protocols. Results Overall, 359 patients were recruited; 60 patients were enrolled for low dose (median: 2.4 GBq/cycle, range 0.9-7.8 GBq/cycle), 77 patients were enrolled for intermediate dose (median: 3.3 GBq/cycle, range: 2.0-7.4 GBq/cycle) and 222 patients were enrolled for high dose (median: 6.7 GBq/cycle, range: 3.7-8.1 GBq/cycle) [90Y-DOTA]-TOC treatment. The incidences of hematotoxicities grade 1–4 were 65.0%, 64.9% and 74.8%; the incidences of grade 4/5 kidney toxicities were 8.4%, 6.5% and 14.0%, and the median survival was 39 (range: 1–158) months, 34 (range: 1–118) months and 29 (range: 1–113) months. The high dose protocol was associated with an increased risk of kidney toxicity (Hazard Ratio: 3.12 (1.13-8.59) vs. intermediate dose, p = 0.03) and a shorter overall survival (Hazard Ratio: 2.50 (1.08-5.79) vs. low dose, p = 0.03). Conclusions Increasing [90Y-DOTA]-TOC activities may be associated with increasing hematological toxicities. The dose related hematotoxicity profile of [90Y-DOTA]-TOC could facilitate tailoring [90Y-DOTA]-TOC in patients with preexisting hematotoxicities. The results of the long-term outcome suggest that fractionated [90Y-DOTA]-TOC treatment might allow to reduce renal toxicity and to improve overall survival. Trial registration ClinicalTrials.gov number:NCT00978211 PMID:23320604

  8. Peptide receptor radionuclide therapy with {sup 90}Y-DOTATOC in recurrent meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Bartolomei, Mirco; Bodei, Lisa; De Cicco, Concetta; Grana, Chiara Maria; Baio, Silvia Melania; Arico, Demetrio; Paganelli, Giovanni [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Cremonesi, Marta [European Institute of Oncology, Division of Medical Physics, Milan (Italy); Botteri, Edoardo [European Institute of Oncology, Division of Epidemiology and Biostatistics, Milan (Italy); Sansovini, Maddalena [Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (I.R.S.T.), Radiometabolic Medicine Division, Meldola (Italy)

    2009-09-15

    Meningiomas are generally benign and in most cases surgery is curative. However, for high-grade histotypes or partially resected tumours, recurrence is fairly common. External beam radiation therapy (EBRT) is usually given in such cases but is not always effective. We assessed peptide receptor radionuclide therapy (PRRT) using {sup 90}Y-DOTATOC in a group of patients with meningioma recurring after standard treatments in all of whom somatostatin receptors were strongly expressed on meningioma cell surfaces. Twenty-nine patients with scintigraphically proven somatostatin subtype 2 receptor-positive meningiomas were enrolled: 14 had benign (grade I), 9 had atypical (grade II) and 6 had malignant (grade III) disease. Patients received intravenous {sup 90}Y-DOTATOC for 2-6 cycles for a cumulative dose in the range of 5-15 GBq. Clinical and neuroradiological evaluations were performed at baseline, during and after PRRT. The treatment was well tolerated in all patients. MRI 3 months after treatment completion showed disease stabilization in 19 of 29 patients (66%) and progressive disease in the remaining 10 (34%). Better results were obtained in patients with grade I meningioma than in those with grade II-III, with median time to progression (from beginning PRRT) of 61 months in the low-grade group and 13 months in the high-grade group. PRRT with {sup 90}Y-DOTATOC can interfere with the growth of meningiomas. The adjuvant role of this treatment, soon after surgery, especially in atypical and malignant histotypes, deserves further investigation. (orig.)

  9. Disinhibition in learning and memory circuits: New vistas for somatostatin interneurons and long-term synaptic plasticity.

    Science.gov (United States)

    Artinian, Julien; Lacaille, Jean-Claude

    2017-11-23

    Neural circuit functions involve finely controlled excitation/inhibition interactions that allow complex neuronal computations and support high order brain functions such as learning and memory. Disinhibition, defined as a transient brake on inhibition that favors excitation, recently appeared to be a conserved circuit mechanism implicated in various functions such as sensory processing, learning and memory. Although vasoactive intestinal polypeptide (VIP) interneurons are considered to be the main disinhibitory cells, recent studies highlighted a pivotal role of somatostatin (SOM) interneurons in inhibiting GABAergic interneurons and promoting principal cell activation. Interestingly, long-term potentiation of excitatory input synapses onto hippocampal SOM interneurons is proposed as a lasting mechanism for regulation of disinhibition of principal neurons. Such regulation of network metaplasticity may be important for hippocampal-dependent learning and memory. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Role of high mobility group box-1 and protection of growth hormone and somatostatin in severe acute pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.F. [Department of Surgery, Huashan Hospital, Fudan University, Shanghai (China); Wu, M. [Department of Surgery, Jinshan Pavilion Forest Hospital, Shanghai (China); Ma, B.J.; Cai, D.A.; Yin, B.B. [Department of Surgery, Huashan Hospital, Fudan University, Shanghai (China)

    2014-09-12

    In this study, we investigated the potential role of high-mobility group box 1 (HMGB1) in severe acute pancreatitis (SAP) and the effects of growth hormone (G) and somatostatin (S) in SAP rats. The rats were randomly divided into 6 groups of 20 each: sham-operated, SAP, SAP+saline, SAP+G, SAP+S and SAP+G+S. Ileum and pancreas tissues of rats in each group were evaluated histologically. HMGB1 mRNA expression was measured by reverse transcription-PCR. Levels of circulating TNF-α, IL-1, IL-6, and endotoxin were also measured. In the SAP group, interstitial congestion and edema, inflammatory cell infiltration, and interstitial hemorrhage occurred in ileum and pancreas tissues. The levels of HMGB1, TNF-α, IL-1, IL-6 and endotoxin were significantly up-regulated in the SAP group compared with those in the sham-operated group, and the 7-day survival rate was 0%. In the SAP+G and SAP+S groups, the inflammatory response of the morphological structures was alleviated, the levels of HMGB1, TNF-α, IL-1, IL-6, and endotoxin were significantly decreased compared with those in the SAP group, and the survival rate was increased. Moreover, in the SAP+G+S group, all histological scores were significantly improved and the survival rate was significantly higher compared with the SAP group. In conclusion, HMGB1 might participate in pancreas and ileum injury in SAP. Growth hormone and somatostatin might play a therapeutic role in the inflammatory response of SAP.

  11. Role of high mobility group box-1 and protection of growth hormone and somatostatin in severe acute pancreatitis

    International Nuclear Information System (INIS)

    Wang, Y.F.; Wu, M.; Ma, B.J.; Cai, D.A.; Yin, B.B.

    2014-01-01

    In this study, we investigated the potential role of high-mobility group box 1 (HMGB1) in severe acute pancreatitis (SAP) and the effects of growth hormone (G) and somatostatin (S) in SAP rats. The rats were randomly divided into 6 groups of 20 each: sham-operated, SAP, SAP+saline, SAP+G, SAP+S and SAP+G+S. Ileum and pancreas tissues of rats in each group were evaluated histologically. HMGB1 mRNA expression was measured by reverse transcription-PCR. Levels of circulating TNF-α, IL-1, IL-6, and endotoxin were also measured. In the SAP group, interstitial congestion and edema, inflammatory cell infiltration, and interstitial hemorrhage occurred in ileum and pancreas tissues. The levels of HMGB1, TNF-α, IL-1, IL-6 and endotoxin were significantly up-regulated in the SAP group compared with those in the sham-operated group, and the 7-day survival rate was 0%. In the SAP+G and SAP+S groups, the inflammatory response of the morphological structures was alleviated, the levels of HMGB1, TNF-α, IL-1, IL-6, and endotoxin were significantly decreased compared with those in the SAP group, and the survival rate was increased. Moreover, in the SAP+G+S group, all histological scores were significantly improved and the survival rate was significantly higher compared with the SAP group. In conclusion, HMGB1 might participate in pancreas and ileum injury in SAP. Growth hormone and somatostatin might play a therapeutic role in the inflammatory response of SAP

  12. 125I-[Tyr0,D-Trp8]somatostatin-14 binding sites in the locus coeruleus of the rat are located on both ascending and descending projecting noradrenergic cells

    International Nuclear Information System (INIS)

    Epelbaum, J.; Bluet-Pajot, M.T.; Llorens-Cortes, C.; Kordon, C.; Mounier, F.; Senut, M.C.; Videau, C.

    1990-01-01

    Radioautographic determinations of 125I-[Tyr0,D-Trp8]somatostatin-14 (125I-SRIF) binding sites were performed on frozen serial sections of the locus coeruleus (LC) of control rats and of rats subjected to either bilateral microinjections of 6 hydroxydopamine (6-OHDA) into the LC or unilateral microinjection into the ascending noradrenergic bundles. These experiments were performed in order to determine whether 125I-SRIF binding was localized to noradrenergic-containing cells and in which regions the cells which contain the binding sites are projecting. The extent of the lesions was assessed by measuring norepinephrine (NE) levels in the hippocampus (88% decrease as compared to sham-operated animals) for bilateral LC lesions and in the frontal cortex (87% reduction vs. contralateral side) for unilateral bundle lesions. In control rats, 125I-SRIF binding sites were restricted to the boundaries of the LC and followed closely the distribution of tyrosine hydroxylase-labeled cells. Three weeks after bilateral injections of 6-OHDA, 125I-SRIF binding decreased by 79% in all regions of the LC. In contrast, unilateral destruction of the ascending noradrenergic bundles resulted in a moderate decrease only in the middle part of the LC with a more important effect in the dorsal (55%) than in the ventral (24%) portion of the nucleus. These data demonstrate that: (1) most SRIF receptors in the LC are located in the vicinity of NE-containing cell bodies and (2) NE-containing cells bearing SRIF receptors project to the forebrain as well as to other terminal areas located more caudally in the brain. These data suggest a general role for SRIF in the control of the multiple functions of the LC

  13. Fluorescent ligands for studying neuropeptide receptors by confocal microscopy

    Directory of Open Access Journals (Sweden)

    A. Beaudet

    1998-11-01

    Full Text Available This paper reviews the use of confocal microscopy as it pertains to the identification of G-protein coupled receptors and the study of their dynamic properties in cell cultures and in mammalian brain following their tagging with specific fluorescent ligands. Principles that should guide the choice of suitable ligands and fluorophores are discussed. Examples are provided from the work carried out in the authors' laboratory using custom synthetized fluoresceinylated or BODIPY-tagged bioactive peptides. The results show that confocal microscopic detection of specifically bound fluorescent ligands permits high resolution appraisal of neuropeptide receptor distribution both in cell culture and in brain sections. Within the framework of time course experiments, it also allows for a dynamic assessment of the internalization and subsequent intracellular trafficking of bound fluorescent molecules. Thus, it was found that neurotensin, somatostatin and mu- and delta-selective opioid peptides are internalized in a receptor-dependent fashion and according to receptor-specific patterns into their target cells. In the case of neurotensin, this internalization process was found to be clathrin-mediated, to proceed through classical endosomal pathways and, in neurons, to result in a mobilization of newly formed endosomes from neural processes to nerve cell bodies and from the periphery of cell bodies towards the perinuclear zone. These mechanisms are likely to play an important role for ligand inactivation, receptor regulation and perhaps also transmembrane signaling.

  14. Evaluation of somatostatin and nucleolin receptors for therapeutic delivery in non-small cell lung cancer stem cells applying the somatostatin-analog DOTATATE and the nucleolin-targeting aptamer AS1411

    DEFF Research Database (Denmark)

    Holmboe, Sif; Hansen, Pernille Lund; Thisgaard, Helge

    2017-01-01

    Cancer stem cells represent the putative tumor-driving subpopulation thought to account for drug resistance, relapse, and metastatic spread of epithelial and other cancer types. Accordingly, cell surface markers for therapeutic delivery to cancer stem cells are subject of intense research. Somato...

  15. Receptor assay

    Energy Technology Data Exchange (ETDEWEB)

    Kato, K; Ibayashi, H [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1975-05-01

    This paper summarized present status and problems of analysis of hormone receptor and a few considerations on clinical significance of receptor abnormalities. It was pointed that in future clinical field quantitative and qualitative analysis of receptor did not remain only in the etiological discussion, but that it was an epoch-making field of investigation which contained the possiblity of artificial change of sensitivity of living body on drugs and the development connected directly with treatment of various diseases.

  16. Preliminary study on the inhibition of nuclear internalization of Tat peptides by conjugation with a receptor-specific peptide and fluorescent dyes

    Science.gov (United States)

    Shen, Duanwen; Liang, Kexiang; Ye, Yunpeng; Tetteh, Elizabeth; Achilefu, Samuel

    2006-02-01

    Numerous studies have shown that basic Tat peptide (48-57) internalized non-specifically in cells and localized in the nucleus. However, localization of imaging agents in cellular nucleus is not desirable because of the potential mutagenesis. When conjugated to the peptides that undergo receptor-mediated endocytosis, Tat peptide could target specific cells or pathologic tissue. We tested this hypothesis by incorporating a somatostatin receptor-avid peptide (octreotate, Oct) and two different fluorescent dyes, Cypate 2 (Cy2) and fluorescein 5'-carboxlic acid (5-FAM), into the Tat-peptide sequence. In addition to the Cy2 or 5-FAM-labeled Oct conjugated to Tat peptide (Tat) to produce Tat-Oct-Cypate2 or Tat-Oct-5-FAM, we also labeled the Tat the Tat peptide with these dyes (Tat-Cy2 and Tat-5-FAM) to serve as positive control. A somatostatin receptor-positive pancreatic tumor cell line, AR42J, was used to assess cell internalization. The results show that Tat-5-FAM and Tat-Cypate2 localized in both nucleus and cytoplasm of the cells. In contrast to Tat-Oct-Cypate2, which localized in both the cytoplasm and nucleus, Tat-Oct-5-FAM internalized in the cytoplasm but not in the nucleus of AR42J cells. The internalizations were inhibited by adding non-labeled corresponding peptides, suggesting that the endocytoses of each group of labeled and the corresponding unlabeled compounds occurred through a common pathway. Thus, fluorescent probes and endocytosis complex between octreotate and somatostatin receptors in cytoplasm could control nuclear internalization of Tat peptides.

  17. Radiopharmaceutical development of a freeze-dried kit formulation for the preparation of [99mTc-EDDA-HYNIC-D-Phe1, Tyr3]-octreotide, a somatostatin analog for tumor diagnosis.

    Science.gov (United States)

    Guggenberg, Elisabeth Von; Mikolajczak, Renata; Janota, Barbara; Riccabona, Georg; Decristoforo, Clemens

    2004-10-01

    [(99m)Tc-EDDA-HYNIC-D-Phe(1),Tyr(3)]-Octreotide ((99m)Tc-EDDA/HYNIC-TOC) is a promising new radiopharmaceutical with the potential to replace [(111)In-DTPA-D-Phe(1)]-Octreotide ((111)In-DTPA-OCT) as the radiopharmaceutical for somatostatin receptor scintigraphy due to the advantage of improved image quality, lower radiation dose for the patient, and daily availability. Here we describe the development of a freeze-dried kit formulation based on the Tricine/EDDA exchange labeling approach for the preparation of this radiopharmaceutical in a clinical setting. Three parameters were of major importance to achieve a suitable formulation with a radiochemical purity (RCP) >90%: addition of bulking agent, the pH of the freeze-drying solution, and the content of stannous chloride. The final formulation consisted of 20 mg Tricine, 10 mg EDDA, 50 mg Mannitol, 20 microg SnCl(2). 2H(2)O, and 20 microg [HYNIC-D-Phe(1), Tyr(3)]-Octreotide (HYNIC-TOC). Radiolabeling was performed by addition of 0.2 M Na(2)HPO(4) to adjust the pH to 6-7, followed by 0.5-2 GBq (99m)Tc sodium pertechnetate, in a total volume of 2 mL and incubation for 10 min in a boiling water bath. Mean RCP values of 10 batches showed values >90% over a storage period of up to 1 year, a high stability up to 24 h of the final preparation, and retained biological activity. The developed kit formulation forms the basis for further clinical evaluation of this promising new radiopharmaceutical. Copyright 2004 Wiley-Liss, Inc. and the American Pharmacists Association

  18. Electrochemical separation of 90-yttrium in the electrochemical 90Sr/90Y generator and its use for radiolabelling of DOTA-conjugated somatostatin analog [DOTA0, Tyr3] octreotate

    Directory of Open Access Journals (Sweden)

    Petrović Đorđe Ž.

    2012-01-01

    Full Text Available Radiopharmaceuticals based on 90Y are widely used in the treatment of malignant deseases. In order to meet the requirements for their future application, a 90Sr/90Y generator was developed and 90Y eluted from this locally produced generator was used for the radiolabelling of the DOTA-conjugated somatostatin analog [DOTA0,Tyr3] octreotate and the preparation of [90Y-DOTA0,Tyr3] octreotate (90Y-DOTATATE for peptide receptore radionuclide therapy. 90Sr/90Y generator was based on the electrochemical separation of 90Y from 90Sr in a two-cycle electrolysis procedure. Three electrode cells were used to perform both electrolyses. In both cycles, working electrodes were kept on constant potential. The pH of the solution was adjusted to 2.7 of the value before the electrolyses. The radionuclidic purity of the 90Y solution was analysed by ITLC and extraction paper chromatography. The labelling of peptide (100 mg DOTATATE with 90YCl3 was performed at 95°C for 30 minutes. Radiochemical purity was determined by HPLC and chromatographic separation, using a solid SepPak C-18 column. Results obtained confirmed the efficiency of our electrochemical separation technique and quality control methods for 90Y. The achieved efficiency of the 90Sr/90Y generator above 96% of the theoretical value represents a good basis for the further development of this generator. The labelling of the DOTATATE with 90Y exhibited a high efficiency, too: there was less than 1% of 90Y3+in the 90Y-DOTATATE.

  19. Outcome of endoscopic transsphenoidal surgery in combination with somatostatin analogues in patients with growth hormone producing pituitary adenoma.

    Science.gov (United States)

    Zhou, Tao; Wang, Fuyu; Meng, Xianghui; Ba, Jianmin; Wei, Shaobo; Xu, Bainan

    2014-11-01

    To determine the efficacy of endoscopic surgery in combination with long-acting somatostatin analogues (SSAs) in treating patients with growth hormone (GH)-secreting pituitary tumor. We performed retrospective analysis of 133 patients with GH producing pituitary adenoma who underwent pure endoscopic transsphenoidal surgery in our center from January 2007 to July 2012. Patients were followed up for a range of 3-48 months. The radiological remission, biochemical remission and complication were evaluated. A total of 110 (82.7%) patients achieved radiological complete resection, 11 (8.2%) subtotal resection, and 12 (9.0%) partial resection. Eighty-eight (66.2%) patients showed nadir GH level less than 1 ng/mL after oral glucose administration. No mortality or severe disability was observed during follow up. Preoperative long-acting SSA successfully improved left ventricle ejection fraction (LVEF) and blood glucose in three patients who subsequently underwent success operation. Long-acting SSA (20 mg every 30 days) achieved biochemical remission in 19 out 23 (82.6%) patients who showed persistent high GH level after surgery. Endoscopic transsphenoidal surgery can biochemically cure the majority of GH producing pituitary adenoma. Post-operative use of SSA can improve biochemical remission.

  20. Somatostatin-positive interneurons in the dentate gyrus of mice provide local- and long-range septal synaptic inhibition.

    Science.gov (United States)

    Yuan, Mei; Meyer, Thomas; Benkowitz, Christoph; Savanthrapadian, Shakuntala; Ansel-Bollepalli, Laura; Foggetti, Angelica; Wulff, Peer; Alcami, Pepe; Elgueta, Claudio; Bartos, Marlene

    2017-04-03

    Somatostatin-expressing-interneurons (SOMIs) in the dentate gyrus (DG) control formation of granule cell (GC) assemblies during memory acquisition. Hilar-perforant-path-associated interneurons (HIPP cells) have been considered to be synonymous for DG-SOMIs. Deviating from this assumption, we show two functionally contrasting DG-SOMI-types. The classical feedback-inhibitory HIPPs distribute axon fibers in the molecular layer. They are engaged by converging GC-inputs and provide dendritic inhibition to the DG circuitry. In contrast, SOMIs with axon in the hilus, termed hilar interneurons (HILs), provide perisomatic inhibition onto GABAergic cells in the DG and project to the medial septum. Repetitive activation of glutamatergic inputs onto HIPP cells induces long-lasting-depression (LTD) of synaptic transmission but long-term-potentiation (LTP) of synaptic signals in HIL cells. Thus, LTD in HIPPs may assist flow of spatial information from the entorhinal cortex to the DG, whereas LTP in HILs may facilitate the temporal coordination of GCs with activity patterns governed by the medial septum.

  1. Amelioration of improper differentiation of somatostatin-positive interneurons by triiodothyronine in a growth-retarded hypothyroid mouse strain.

    Science.gov (United States)

    Uchida, Katsuya; Taguchi, Yusuke; Sato, Chika; Miyazaki, Hidetaka; Kobayashi, Kenichi; Kobayashi, Tetsuya; Itoi, Keiichi

    2014-01-24

    Thyroid hormone (TH) plays an important role in brain development, and TH deficiency during pregnancy or early postnatal periods leads to neurological disorders such as cretinism. Hypothyroidism reduces the number of parvalbumin (PV)-positive interneurons in the neocortex and hippocampus. Here we used a mouse strain (growth-retarded; grt) that shows growth retardation and hypothyroidism to examine whether somatostatin (Sst)-positive interneurons that are generated from the same pool of neural progenitor cells as PV-positive cells are also altered by TH deficiency. The number of PV-positive interneurons was significantly decreased in the neocortex and hippocampus of grt mice as compared with normal control mice. In contrast to the decrease in the number of PV neurons, the number of Sst-positive interneurons in grt mice was increased in the stratum oriens of the hippocampus and the hilus of the dentate gyrus, although their number was unchanged in the neocortex. These changes were reversed by triiodothyronine administration from postnatal day (PD) 0 to 20. TH supplementation that was initiated after PD21 did not, however, affect the number of PV- or Sst-positive cells. These results suggest that during the first three postnatal weeks, TH may be critical for the generation of subpopulations of interneurons. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  2. Synthesis and evaluation of radioiodinated substituted β-naphthylalanine as a potential probe for pancreatic β-cells imaging

    International Nuclear Information System (INIS)

    Amartey, J.K.; Esguerra, C.; Al-Jammaz, I.; Parhar, R.S.; Al-Otaibi, B.

    2006-01-01

    A non-invasive imaging technique capable of relating a signal from the β-cells to their mass will be of immense value in understanding the progression of diabetes. Several molecular markers have indeed been identified and investigations are ongoing aimed at accomplishing the said goal. These include pancreatic islet antigen (IC-2), somatostatin receptors (SSTRs), and sulfonylurea receptors (SURs) on the pancreatic β-cells. Therefore investigations exploiting the potential application of the radiolabeled ligands for these receptors for β-cell imaging are receiving intensive research attention. Radioiodinated peptidomimetic based on β-naphthylalanine and n-hexanediamine has been synthesized. The molecule was subjected to in vitro and in vivo evaluation. Radioligand binding studies on CHO cell line expressing the SSTR2 showed very low affinity. Nonetheless, biodistribution in normal mice showed significant uptake in the pancreas. There was partial blockage of the pancreatic uptake when excess of the peptidomimetic was coinjected. The result implies that the pancreatic uptake was receptor mediated but may not involve the SSTR2 and therefore warrants further investigation

  3. Two peptide receptor ligands (99m)Tc-EDDA/HYNIC-Tyr(3)-octreotide and (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin for scintigraphy of medullary thyroid carcinoma.

    Science.gov (United States)

    Kosowicz, Jerzy; Mikołajczak, Renata; Czepczyński, Rafał; Ziemnicka, Katarzyna; Gryczyńska, Maria; Sowiński, Jerzy

    2007-10-01

    Somatostatin and gastrin receptors are overexpressed in medullary thyroid carcinoma (MTC) cells; hence, both of them are potential targets for peptide receptor scintigraphy and radiotherapy. Therefore, the aim of our study was to assess the clinical value of two technetium-99m-labeled peptides, a new gastrin analog, the EDDA/HYNIC-(D)Glu-octagastrin and a somatostatin analog, EDDA/HYNIC-Tyr(3)-octreotide (EDDA/HYNIC-TOC) for scintigraphy in patients with MTC to detect recurrences and metastases and select patients for peptide receptor radiotherapy. Thirty (30) patients, 20 females and 10 males, 22-83 years of age (mean, 52.7) with the diagnosis of MTC in different stages of the disease (preoperative, postsurgery, remission, recurrence, or metastatic disease) were included in this study. Before surgery, in all patients serum calcitonin concentrations were elevated. The diagnosis of MTC was confirmed in all cases by histopathology of the removed tumor and immunohistochemical staining giving positive reactions for calcitonin and chromogranin A. Imaging studies using (99m)Tc-EDDA/HYNIC-TOC and a new minigastrin analog, (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin, were performed in each patient and the results compared with each other and with other imaging methods. Scans of the whole body, head, neck, and chest were performed 2 and 4 hours after injections of the tracer, 500-600 MBq in each case, using a double-head Varicam (Elscint, Israel) gamma camera. (99m)Tc-EDDA/HYNIC-TOC detected somatostatin receptor-positive lesions in 20 patients with MTC, whereas (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin displayed gastrin receptors in 11 patients. In 9 cases, the scans were positive in both methods, although in 2 cases different pathologic foci were visualized. In 12 cases, only (99m)Tc-EDDA/HYNIC-TOC scintigraphy was positive, whereas in 3 other cases only (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin revealed pathologic lesions. Scintigraphy using (99m)Tc-HYNIC-TOC permits the visualization

  4. Somatostatin-14-like antigenic sites in fixed islet D-cells are unaltered by cysteamine: a quantitative electron microscopic immunocytochemical evaluation

    International Nuclear Information System (INIS)

    Patel, Y.C.; Ravazzola, M.; Amherdt, M.; Orci, L.

    1987-01-01

    Exposure of somatostatin cells to cysteamine (CSH) produces a marked reduction in somatostatin-14-like immunoreactivity (S-14 LI) in cell extracts. In the present study we have evaluated the effects of CSH on S-14-like sites in fixed islet D-cells using immunofluorescence and quantitative electron microscopic immunocytochemistry. Monolayer cultures of rat islet cells exposed to CSH (10 mM) for 1 h and subsequently extracted in 1 M acetic acid exhibited a severe reduction in S-14 LI from 6.6 +/- 0.48 to 0.7 +/- 0.06 ng/dish. CSH-induced reduction in S-14 LI persisted when cells were fixed in Zamboni's solution for 16 h and subsequently extracted and assayed. By immunofluorescence, however, the relative numbers of somatostatin-positive cells as well as the fluorescent intensity were identical in control and CSH-treated cells. CSH did not produce any identifiable abnormality in the ultrastructural appearance of D-cells. Protein A-gold labeling of the islet cells showed a uniform distribution of gold particles in both control and CSH-treated cultures. The density of gold particles over D-cell secretory granules from CSH-exposed cultures (36.6 +/- 3.5 particles/micron2) was not different from that in control D-cell granules (42.2 +/- 5.9 particles/micron2). These data clearly indicate that despite a profound reduction by CSH of S-14 LI in tissue extracts, there is no detectable decrease in the same antigenic sites in tissue sections when assessed immunocytochemically

  5. Somatostatin-based radiopeptide therapy with [177Lu-DOTA]-TOC versus [90Y-DOTA]-TOC in neuroendocrine tumours

    International Nuclear Information System (INIS)

    Romer, A.; Seiler, D.; Brunner, P.; Ng, Q.K.T.; Mueller-Brand, J.; Marincek, N.; Walter, M.A.; Koller, M.T.; Maecke, H.R.; Rochlitz, C.; Briel, M.; Schindler, C.

    2014-01-01

    Somatostatin-based radiopeptide treatment is generally performed using the β-emitting radionuclides 90 Y or 177 Lu. The present study aimed at comparing benefits and harms of both therapeutic approaches. In a comparative cohort study, patients with advanced neuroendocrine tumours underwent repeated cycles of [ 90 Y-DOTA]-TOC or [ 177 Lu-DOTA]-TOC until progression of disease or permanent adverse events. Multivariable Cox regression and competing risks regression were employed to examine predictors of survival and adverse events for both treatment groups. Overall, 910 patients underwent 1,804 cycles of [ 90 Y-DOTA]-TOC and 141 patients underwent 259 cycles of [ 177 Lu-DOTA]-TOC. The median survival after [ 177 Lu-DOTA]-TOC and after [ 90 Y-DOTA]-TOC was comparable (45.5 months versus 35.9 months, hazard ratio 0.91, 95 % confidence interval 0.63-1.30, p = 0.49). Subgroup analyses revealed a significantly longer survival for [ 177 Lu-DOTA]-TOC over [ 90 Y-DOTA]-TOC in patients with low tumour uptake, solitary lesions and extra-hepatic lesions. The rate of severe transient haematotoxicities was lower after [ 177 Lu-DOTA]-TOC treatment (1.4 vs 10.1 %, p = 0.001), while the rate of severe permanent renal toxicities was similar in both treatment groups (9.2 vs 7.8 %, p = 0.32). The present results revealed no difference in median overall survival after [ 177 Lu-DOTA]-TOC and [ 90 Y-DOTA]-TOC. Furthermore, [ 177 Lu-DOTA]-TOC was less haematotoxic than [ 90 Y-DOTA]-TOC. (orig.)

  6. Somatostatin-based radiopeptide therapy with [177Lu-DOTA]-TOC versus [90Y-DOTA]-TOC in neuroendocrine tumours.

    Science.gov (United States)

    Romer, A; Seiler, D; Marincek, N; Brunner, P; Koller, M T; Ng, Q K T; Maecke, H R; Müller-Brand, J; Rochlitz, C; Briel, M; Schindler, C; Walter, M A

    2014-02-01

    Somatostatin-based radiopeptide treatment is generally performed using the β-emitting radionuclides (90)Y or (177)Lu. The present study aimed at comparing benefits and harms of both therapeutic approaches. In a comparative cohort study, patients with advanced neuroendocrine tumours underwent repeated cycles of [(90)Y-DOTA]-TOC or [(177)Lu-DOTA]-TOC until progression of disease or permanent adverse events. Multivariable Cox regression and competing risks regression were employed to examine predictors of survival and adverse events for both treatment groups. Overall, 910 patients underwent 1,804 cycles of [(90)Y-DOTA]-TOC and 141 patients underwent 259 cycles of [(177)Lu-DOTA]-TOC. The median survival after [(177)Lu-DOTA]-TOC and after [(90)Y-DOTA]-TOC was comparable (45.5 months versus 35.9 months, hazard ratio 0.91, 95% confidence interval 0.63-1.30, p = 0.49). Subgroup analyses revealed a significantly longer survival for [(177)Lu-DOTA]-TOC over [(90)Y-DOTA]-TOC in patients with low tumour uptake, solitary lesions and extra-hepatic lesions. The rate of severe transient haematotoxicities was lower after [(177)Lu-DOTA]-TOC treatment (1.4 vs 10.1%, p = 0.001), while the rate of severe permanent renal toxicities was similar in both treatment groups (9.2 vs 7.8%, p = 0.32). The present results revealed no difference in median overall survival after [(177)Lu-DOTA]-TOC and [(90)Y-DOTA]-TOC. Furthermore, [(177)Lu-DOTA]-TOC was less haematotoxic than [(90)Y-DOTA]-TOC.

  7. Renal uptake and retention of radiolabeled somatostatin, bombesin, neurotensin, minigastrin and CCK analogues: species and gender differences

    Energy Technology Data Exchange (ETDEWEB)

    Melis, Marleen [Department of Nuclear Medicine, Erasmus MC Rotterdam, 3015 CE Rotterdam (Netherlands)], E-mail: m.melis@erasmusmc.nl; Krenning, Eric P.; Bernard, Bert F.; Visser, Monique de; Rolleman, Edgar; Jong, Marion de [Department of Nuclear Medicine, Erasmus MC Rotterdam, 3015 CE Rotterdam (Netherlands)

    2007-08-15

    Introduction: During therapy with radiolabeled peptides, the kidney is most often the critical organ. Newly developed peptides are evaluated preclinically in different animal models before their application in humans. In this study, the renal retention of several radiolabeled peptides was compared in male and female rats and mice. Methods: After intravenous injection of radiolabeled peptides [somatostatin, cholecystokinin (CCK), minigastrin, bombesin and neurotensin analogues], renal uptake was determined in both male and female Lewis rats and C57Bl mice. In addition, ex vivo autoradiography of renal sections was performed to localize accumulated radioactivity. Results: An equal distribution pattern of renal radioactivity was found for all peptides: high accumulation in the cortex, lower accumulation in the outer medulla and no radioactivity in the inner medulla of the kidneys. In both male rats and mice, an increasing renal uptake was found: [{sup 111}In-DTPA]CCK8<[{sup 111}In-DTPA-Pro{sup 1},Tyr{sup 4}]bombesin{approx}[{sup 111}In-DTPA] neurotensin<[{sup 111}In-DTPA]octreotide<<[{sup 111}In-DTPA]MG0. Renal uptake of [{sup 111}In-DTPA]octreotide in rats showed no gender difference, and renal radioactivity was about constant over time. In mice, however, renal uptake in females was significantly higher than that in males and decreased rapidly over time in both genders. Moreover, renal radioactivity in female mice injected with [{sup 111}In-DTPA]octreotide showed a different localization pattern. Conclusions: Regarding the renal uptake of different radiolabeled peptides, both species showed the same ranking order. Similar to findings in patients, rats showed comparable and constant renal retention of radioactivity in both genders, in contrast to mice. Therefore, rats appear to be the more favorable species for the study of the renal retention of radioactivity.

  8. The Role of the Neuropeptide Somatostatin on Methamphetamine and Glutamate-Induced Neurotoxicity in the Striatum of Mice

    Science.gov (United States)

    Afanador, Lauriaselle; Mexhitaj, Ina; Diaz, Carolyn; Ordonez, Dalila; Baker, Lisa; Angulo, Jesus A.

    2014-01-01

    A large body of evidence shows that methamphetamine (METH) causes sustained damage to the brain in animal models and human METH users. In chronic users there are indications of cognitive and motor deficits. Striatal neuropeptides are in a position to modulate the neurochemical effects of METH and consequently striatal neural damage. Somatostatin (SST) is an intrinsic striatal neuropeptide that has been shown to inhibit glutamate transmission; glutamate is integral to METH toxicity and contributes to nitric oxide (NO) synthesis. We hypothesize that SST will protect from METH by inhibition of NO synthesis and thus reducing oxidative stress. To this end, the SST analogue octreotide (OCT) was microinjected into the striatum prior to a systemic injection of METH (30 mg/kg). We then assessed 3-nitrotyrosine (3-NT), an indirect index of NO production, tyrosine hydroxylase (TH) protein levels (dopamine terminal marker) and Fluoro-Jade C positive cells (degenerating cells). The SST agonist OCT dose dependently attenuated the METH-induced accumulation of striatal 3-NT. Moreover, pretreatment with OCT effectively mitigated cell death but failed to protect dopamine terminals. Next we co-infused OCT and NMDA and measured 3-NT and Fluoro-Jade C staining. Treatment with OCT had no effect on these parameters. The data demonstrate that SST attenuates the METH-induced production of NO protecting the striatum from the METH-induced cell loss. However, SST failed to prevent the toxicity of the dopamine terminals suggesting that pre- and post-synaptic striatal damage occur via independent mechanisms. PMID:23524190

  9. Renal uptake and retention of radiolabeled somatostatin, bombesin, neurotensin, minigastrin and CCK analogues: species and gender differences

    International Nuclear Information System (INIS)

    Melis, Marleen; Krenning, Eric P.; Bernard, Bert F.; Visser, Monique de; Rolleman, Edgar; Jong, Marion de

    2007-01-01

    Introduction: During therapy with radiolabeled peptides, the kidney is most often the critical organ. Newly developed peptides are evaluated preclinically in different animal models before their application in humans. In this study, the renal retention of several radiolabeled peptides was compared in male and female rats and mice. Methods: After intravenous injection of radiolabeled peptides [somatostatin, cholecystokinin (CCK), minigastrin, bombesin and neurotensin analogues], renal uptake was determined in both male and female Lewis rats and C57Bl mice. In addition, ex vivo autoradiography of renal sections was performed to localize accumulated radioactivity. Results: An equal distribution pattern of renal radioactivity was found for all peptides: high accumulation in the cortex, lower accumulation in the outer medulla and no radioactivity in the inner medulla of the kidneys. In both male rats and mice, an increasing renal uptake was found: [ 111 In-DTPA]CCK8 111 In-DTPA-Pro 1 ,Tyr 4 ]bombesin∼[ 111 In-DTPA] neurotensin 111 In-DTPA]octreotide 111 In-DTPA]MG0. Renal uptake of [ 111 In-DTPA]octreotide in rats showed no gender difference, and renal radioactivity was about constant over time. In mice, however, renal uptake in females was significantly higher than that in males and decreased rapidly over time in both genders. Moreover, renal radioactivity in female mice injected with [ 111 In-DTPA]octreotide showed a different localization pattern. Conclusions: Regarding the renal uptake of different radiolabeled peptides, both species showed the same ranking order. Similar to findings in patients, rats showed comparable and constant renal retention of radioactivity in both genders, in contrast to mice. Therefore, rats appear to be the more favorable species for the study of the renal retention of radioactivity

  10. Prefrontal cortical parvalbumin and somatostatin expression and cell density increase during adolescence and are modified by BDNF and sex.

    Science.gov (United States)

    Du, X; Serena, K; Hwang, W; Grech, A M; Wu, Y W C; Schroeder, A; Hill, R A

    2018-04-01

    Brain-derived neurotrophic factor (BDNF) is known to play a critical role early in the development of cortical GABAergic interneurons. Recently our laboratory and others have shown protracted development of specific subpopulations of GABAergic interneurons extending into adolescence. BDNF expression also changes significantly across adolescent development. However the role of BDNF in regulating GABAergic changes across adolescence remains unclear. Here, we performed a week-by-week analysis of the protein expression and cell density of three major GABAergic interneurons, parvalbumin (PV), somatostatin (SST) and calretinin (Cal) in the medial prefrontal cortex from prepubescence (week 3) to adulthood (week 12). In order to assess how BDNF and sex might influence the adolescent trajectory of GABAergic interneurons we compared WT as well as BDNF heterozygous (+/-) male and female mice. In both males and females PV expression increases during adolescent development in the mPFC. Compared to wild-types, PV expression was reduced in male but not female BDNF+/- mice throughout adolescent development. This reduction in protein expression corresponded with reduced cell density, specifically within the infralimbic prefrontal cortex. SST expression increased in early adolescent WT females and this upregulation was delayed in BDNF+/-. SST cell density also increased in early adolescent mPFC of WT female mice, with BDNF+/- again showing a reduced pattern of expression. Cal protein expression was also sex-dependently altered across adolescence with WT males showing a steady decline but that of BDNF+/- remaining unaltered. Reduced cell density in on the other hand was observed particularly in male BDNF+/- mice. In females, Cal protein expression and cell density remained largely stable. Our results show that PV, SST and calretinin interneurons are indeed still developing into early adolescence in the mPFC and that BDNF plays a critical, sex-specific role in mediating expression and

  11. Place of preoperative treatment of acromegaly with somatostatin analog on surgical outcome: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Francisco Pita-Gutierrez

    Full Text Available CONTEXT: Transsphenoidal neurosurgery is the accepted first-line treatment of acromegaly in the majority of patients. Previous studies addressing preoperative somatostatin analog (SSA treatment and subsequent surgical cure rates are conflicting, reporting either benefits or no significant differences. OBJECTIVE: The aim of this study, based on a meta-analysis of all published reports, was to investigate whether treatment with SSA before surgery improves the surgical outcome of acromegaly. DATA SOURCES: All studies of preoperative treatment of acromegaly with SSA were systematically reviewed up to December 2011. We searched the Medline, Embase, Cochrane and Google Scholar electronic databases. STUDY SELECTION: The primary endpoint was the biochemical postoperative cure rate. We identified 286 studies, out of which 10 studies (3.49% fulfilling the eligibility criteria were selected for analysis; five retrospective studies with a control group, two prospective non-randomized trials, and three prospective controlled trials. The meta-analysis was conducted using the random-effects model. DATA EXTRACTION: Data were extracted from published reports by two independent observers. DATA SYNTHESIS: A borderline effect was detected in the analysis of all of the trials with control groups, with a pooled odds ratio (OR for biochemical cure with SSA treatment of 1.62 (95% CI, 0.93-2.82. In the analysis of the three prospective controlled trials, a statistically significant effect was identified OR: 3.62 (95% CI, 1.88-6.96. CONCLUSIONS: Preoperative treatment with SSA og GH-secreting pituitary adenomas shows a significant improvement on surgical results. This meta-analysis suggests that in centers without optimal results all patients with a GH-secreting pituitary macroadenoma should be treated with a long-acting SSA prior to surgical treatment.

  12. The Zollinger-Ellison syndrome: is there a role for somatostatin analogues in the treatment of the gastrinoma?

    Science.gov (United States)

    Guarnotta, Valentina; Martini, Chiara; Davì, Maria Vittoria; Pizza, Genoveffa; Colao, Annamaria; Faggiano, Antongiulio

    2018-04-01

    Analyze the role of somatostatin analogues (SSAs) in the treatment of sporadic and MEN1-related gastrinomas, trying to define whether recent trials have changed the landscape of gastrinoma therapy. We evaluate the rationale of SSA use in the treatment of gastrinomas, summarize the current literature concerning the effect of SSAs on the control of Zollinger-Ellison syndrome (ZES) and gastrinomas tumor progression and discuss their role in the most recent guidelines. The medical treatment of gastrinoma and related ZES is aimed at controlling acid hypersecretion and tumor progression, in inoperable patients. The use of proton pump inhibitors (PPIs) to control the syndrome is a cornerstone in the ZES therapy. SSAs are not usually indicated for antisecretory purpose, because PPIs are considered the treatment of choice, due to their long lasting high efficacy and oral availability. The antiproliferative effect of SSAs has been established by two placebo-controlled trials that have clearly demonstrated a significant increase in progression free survival in patients affected by non-functioning well-differentiated advanced neuroendocrine tumors (NETs). The recent ENETS guidelines recommend the use of SSAs in advanced well differentiated NETs as antiproliferative agents. The high sstr-expression in gastrinomas make them highly responsive to SSAs and support the use of such drugs to counteract the tumour growth in patients not amenable to surgical cure. Unfortunately, limited data, mainly case reports or small series, support the use of SSAs in advanced gastrinomas, therefore, it is difficult to quantify their ability to control tumour growth and disease progression.

  13. Peptide receptor radionuclide therapy (PRRT): clinical significance of re-treatment?

    Energy Technology Data Exchange (ETDEWEB)

    Virgolini, Irene [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Collaboration: The Innsbruck Team

    2015-12-15

    PRRT appears to be the most effective therapeutic option in the management of inoperable or metastasized NET patients with limited side effects if dose limits are respected. In patients with relapse after a first treatment period with {sup 90}Y-DOTATOC, multiple re-treatment cycles with {sup 177}Lu-DOTATATE are feasible, safe and efficacious. Quantitative imaging by dosimetry adds to formulate personalized and evidence-based treatment protocols. However, despite the large body of evidence regarding efficacy and safety of PRRT, the absence of prospective randomized controlled trials questions the utility of PRRT in the community. Furthermore, the growing number of pharmacological or liver-directed therapeutic options competes with the confusion based on the variety of somatostatin analogues to determine the optimal choice and sequencing of PRRT in the individual patient. However, the efficacy of PRRT should not be questioned rather than it should be explored as to when PRRT might be optimally applied in the sequence of available therapy modalities. The results of the present study by the Italian group [5] emphasizes that radiopharmaceuticals are still underused. Despite the huge potential of PRRT the non-availability of PRRT in many countries still limits its widespread use. After acquiring the exclusive rights for {sup 177}Lu-DOTATATE with granted orphan designation, the company Advanced Accelerator Applications (AAA) is currently running a phase III study comparing treatment with {sup 177}Lu-DOTATATE to Octreotide LAR in patients with inoperable, progressive, somatostatin receptor-positive, midgut carcinoid tumours with the aim of registering the radiopharmaceutical under the commercial name of Lutathera. Together with orphan designation also to other somatostatin-based radiopharmaceuticals, such as {sup 90}Y-DOTATOC, {sup 177}Lu-DOTATOC and the {sup 68}Ga-labelled somatostatin antagonist OPS202, these developments promote the advancement of PRRT and PET imaging

  14. Model-Based Discovery of Synthetic Agonists for the Zn2+-Sensing G-Protein-Coupled Receptor 39 (GPR39) Reveals Novel Biological Functions

    DEFF Research Database (Denmark)

    Frimurer, Thomas M.; Mende, Franziska; Graae, Anne-Sofie

    2017-01-01

    binding to other receptors with similar binding pockets to select iterative series of mini-libraries. These libraries were cherry-picked from all com. available synthetic compds. A total of only 520 compds. were tested in vitro, making this method broadly applicable for tool compd. development. The compds....... of the initial library were inactive when tested alone, but lead compds. were identified using Zn2 as an allosteric enhancer. Highly selective, highly potent Zn2-independent GPR39 agonists were found in subsequent mini-libraries. These agonists identified GPR39 as a novel regulator of gastric somatostatin...

  15. Treatment of pituitary gigantism with the growth hormone receptor antagonist pegvisomant.

    Science.gov (United States)

    Goldenberg, Naila; Racine, Michael S; Thomas, Pamela; Degnan, Bernard; Chandler, William; Barkan, Ariel

    2008-08-01

    Treatment of pituitary gigantism is complex and the results are usually unsatisfactory. The objective of the study was to describe the results of therapy of three children with pituitary gigantism by a GH receptor antagonist, pegvisomant. This was a descriptive case series of up to 3.5 yr duration. The study was conducted at a university hospital. Patients included three children (one female, two males) with pituitary gigantism whose GH hypersecretion was incompletely controlled by surgery, somatostatin analog, and dopamine agonist. The intervention was administration of pegvisomant. Plasma IGF-I and growth velocity were measured. In all three children, pegvisomant rapidly decreased plasma IGF-I concentrations. Growth velocity declined to subnormal or normal values. Statural growth fell into lower growth percentiles and acromegalic features resolved. Pituitary tumor size did not change in two children but increased in one boy despite concomitant therapy with a somatostatin analog. Pegvisomant may be an effective modality for the therapy of pituitary gigantism in children. Titration of the dose is necessary for optimal efficacy, and regular surveillance of tumor size is mandatory.

  16. The in vivo disposition and in vitro transmembrane transport of two model radiometabolites of DOTA-conjugated receptor-specific peptides labelled with (177) Lu.

    Science.gov (United States)

    Volková, Marie; Mandíková, Jana; Bárta, Pavel; Navrátilová, Lucie; Lázníčková, Alice; Trejtnar, František

    2015-01-01

    In vivo metabolism of the radiolabelled receptor-specific peptides has been described; however, information regarding the pharmacokinetic behaviour of the degradation products within the body is very scarce. The present study was designed to obtain new knowledge on the disposition and elimination of low-molecular radiometabolites of receptor-specific peptides in the organism and to reveal the potential involvement of selected membrane transport mechanisms in the cellular uptake of radiometabolites, especially in the kidney. The study compared pharmacokinetics of two radiometabolites: a final metabolite of somatostatin analogues, (177)Lu-DOTA-DPhe, and a tripeptide metabolite of (177)Lu-DOTA-minigastrin 11, (177)Lu-DOTA-DGlu-Ala-Tyr. Their pharmacokinetics was compared with that of respective parent (177)Lu-radiopeptide. Both radiometabolites exhibited relative rapid clearing from most body tissues in rats in vivo along with predominant renal excretion. The long-term renal retention of the smaller radiometabolite (177)Lu-DOTA-DPhe was lower than that of (177)Lu-DOTA-DGlu-Ala-Tyr. An uptake of (177)Lu-DOTA-DPhe by human renal influx transporter organic cation transporter 2 was found in vitro in a cellular model. The study brings the first experimental data on the in vivo pharmacokinetics of radiometabolites of receptor-specific somatostatin and gastrin analogues. The found results may indicate a negative correlation between the degree of decomposition of the parent peptide chain and the renal retention of the metabolite. Copyright © 2015 John Wiley & Sons, Ltd.

  17. Dynamic determination of kinetic parameters for the interaction between polypeptide hormones and cell-surface receptors in the perfused rat liver by the multiple-indicator dilution method

    International Nuclear Information System (INIS)

    Sato, H.; Sugiyama, Y.; Sawada, Y.; Iga, T.; Sakamoto, S.; Fuwa, T.; Hanano, M.

    1988-01-01

    Hepatic elimination of epidermal growth factor (EGF) via receptor-mediated endocytosis was studied by a multiple-indicator dilution method in the isolated perfused rat liver, in which cell polarity and spatial organization are maintained. In this method EGF was given with inulin, an extracellular reference, as a bolus into the portal vein, and dilution curves of both compounds in the hepatic vein effluent were analyzed. Analysis of the dilution curve for EGF, compared with that for somatostatin, which showed no specific binding to isolated liver plasma membranes, resulted as follows: (i) both extraction ratio and distribution volume of 125 I-labeled EGF decreased as the injected amount of unlabeled EGF increased; (ii) the ratio plot of the dilution curve for EGF exhibited an upward straight line initially for a short period of time, whereas the ratio plot of somatostatin gradually decreased. The multiple-indicator dilution method was used for other peptides also. Insulin and glucagon, known to have hepatocyte receptors, behaved similarly to EGF in shape of their ratio plots. The kinetic parameters calculated by this analysis were comparable with reported values obtained by in vitro direct binding measurements at equilibrium using liver homogenates. They conclude that the multiple-indicator dilution method is a good tool for analyzing the dynamics of peptide hormones-cell-surface receptor interaction under a condition in which spatial architecture of the liver is maintained

  18. Favorable Response of Metastatic Merkel Cell Carcinoma to Targeted 177Lu-DOTATATE Therapy: Will PRRT Evolve to Become an Important Approach in Receptor-Positive Cases?

    Science.gov (United States)

    Basu, Sandip; Ranade, Rohit

    2016-06-01

    This report illustrates an excellent partial response of Merkel cell carcinoma with multiple bilobar hepatic metastases to a single cycle of peptide receptor radionuclide therapy (PRRT) with (177)Lu-DOTATATE. This response, coupled with minimal side effects, warrants consideration of this therapy early in the disease course (rather than at an advanced stage after failure of other therapies) if the metastatic lesions exhibit adequate tracer avidity on somatostatin receptor-based imaging. Our patient showed progression of systemic disease after having undergone a second surgery and adjuvant radiotherapy to the head and neck, as well as chemotherapy, and hence was considered a candidate for PRRT. In a pretreatment study, the metastatic lesions demonstrated avidity to both somatostatin receptors and (18)F-FDG. Three months after the first cycle of treatment, when the patient was being evaluated for a second cycle, both imaging parameters showed evidence of a partial response that included nearly complete resolution of the two previously seen lesions. In view of the relatively good tolerability, minimal side effects, and targeted nature of the treatment, PRRT may evolve to become the first-line therapy for metastatic Merkel cell carcinoma and should be examined further in a larger number of patients. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  19. Radio-peptides targeting g-protein coupled receptors in cancer: from bench to bed

    International Nuclear Information System (INIS)

    Maecke, H.R.

    2015-01-01

    Full text of publication follows. In the development of targeted imaging and therapy agents the most important challenge and prerequisite is to identify and validate the molecular targets of any disease. The targets should be specific, relevant, easily accessible and highly expressed. In addition they should have no or at least very low expression in normal tissue. Among the many drug targets is the large family of G-protein coupled receptors (GPCRs). It is the most important family of marketed drugs and the basic accomplishments in the field were recognised by the award of the recent Nobel price in chemistry. GPCRs also play a role in cancer. Several of these receptors are massively over-expressed in different human tumors such as neuroendocrine tumors (over-expression of the somatostatin receptor family), prostate and breast tumors (bombesin receptor family), brain tumors (NK1 receptor) etc.. This allows to develop (nuclear, MRI, optical) probes for imaging and potentially targeted therapy (theragnostics). Natural ligands targeting GPCRs are often peptides. They need to be modified for metabolic stability, modified for labeling with radio-metals (conjugation of bifunctional chelators) or radio-halogens (prosthetic groups). Preserved biological integrity after modification and labeling needs to be assured, long retention times in the tumor is important, conferred by internalisation. Radio-metal labeling in particular needs to be reasonably fast and the radio metal complexes have to show high stability with regard to radio-metal release. These prerequisites will be discussed for somatostatin receptor based radio-peptides in particular. For a successful clinical application preclinical imaging and biodistribution in adequate animal models are mandatory. New tracers for positron emission tomography (PET) and single photon emission computed tomography (SPECT) will be presented for neuroendocrine tumors and prostate cancer. In particular radiolabeled antagonists will

  20. Plasma growth hormone response to human growth hormone releasing factor in rats administered with chlorpromazine and antiserum against somatostatin. Effects of hypo- and hyperthyroidism.

    Science.gov (United States)

    Wakabayashi, I; Tonegawa, Y; Ihara, T; Hattori, M; Shibasaki, T; Ling, N

    1985-10-01

    The effect of hypo- and hyperthyroidism on the plasma growth hormone (GH) response to synthetic human growth hormone releasing factor (GRF) was determined in conscious, freely moving rats pretreated with chlorpromazine and antiserum against somatostatin. Chlorpromazine plus somatostatin antiserum pretreated rats gave consistent response to GRF which was not observed in untreated rats. Chlorpromazine alone has no effect on GH secretion induced by GRF in rat pituitary monolayer culture. In rats made hypothyroid by thyroidectomy, both basal and peak plasma GH responses to a small (0.25 microgram/kg bw) and a moderate dose of GRF (1 microgram/kg bw) were significantly reduced as compared to controls. In rats made hyperthyroid by the administration of thyroxine, basal and peak plasma GH responses to a small but not to a moderate dose of GRF were significantly reduced as compared to controls. A reduced plasma GH response to a small dose of GRF was observed 8 days after the cessation of thyroxine administration. The pituitary GH reserve was markedly reduced in hypothyroid but not in hyperthyroid rats as compared to their respective controls. These results indicate that plasma GH response to GRF is reduced both in hypo- and hyperthyroidism. The mechanism involved in the phenomenon appears to be different between the two conditions.

  1. A 12-month phase 3 study of pasireotide in Cushing's disease

    DEFF Research Database (Denmark)

    Colao, Annamaria; Petersenn, Stephan; Newell-Price, John

    2012-01-01

    Cushing's disease is associated with high morbidity and mortality. Pasireotide, a potential therapy, has a unique, broad somatostatin-receptor-binding profile, with high binding affinity for somatostatin-receptor subtype 5.......Cushing's disease is associated with high morbidity and mortality. Pasireotide, a potential therapy, has a unique, broad somatostatin-receptor-binding profile, with high binding affinity for somatostatin-receptor subtype 5....

  2. The components of somatostatin and ghrelin systems are altered in neuroendocrine lung carcinoids and associated to clinical-histological features.

    Science.gov (United States)

    Herrera-Martínez, Aura D; Gahete, Manuel D; Sánchez-Sánchez, Rafael; Salas, Rosa Ortega; Serrano-Blanch, Raquel; Salvatierra, Ángel; Hofland, Leo J; Luque, Raúl M; Gálvez-Moreno, María A; Castaño, Justo P

    2017-07-01

    Lung carcinoids (LCs) are rare tumors that comprise 1-5% of lung malignancies but represent 20-30% of neuroendocrine tumors. Their incidence is progressively increasing and a better characterization of these tumors is required. Alterations in somatostatin (SST)/cortistatin (CORT) and ghrelin systems have been associated to development/progression of various endocrine-related cancers, wherein they may become useful diagnostic, prognostic and therapeutic biomarkers. We aimed to evaluate the expression levels of ghrelin and SST/CORT system components in LCs, as well as to explore their putative relationship with histological/clinical characteristics. An observational retrospective study was performed; 75 LC patients with clinical/histological characteristics were included. Samples from 46 patients were processed to isolate mRNA from tumor and adjacent non-tumor region, and the expression levels of SST/CORT and ghrelin systems components, determined by quantitative-PCR, were compared to those of 7 normal lung tissues. Patient cohort was characterized by mean age 53±15 years, 48% males, 34% with tobacco exposure; 71.4/28.6% typical/atypical carcinoids, 21.7% incidental tumors, 4.3% functioning tumors, 17.7% with metastasis. SST/CORT and ghrelin system components were expressed at variable levels in a high proportion of tumors, as well as in adjacent non-tumor tissues, while a lower proportion of normal lung samples also expressed these molecules. A gradation was observed from normal non-neoplastic lung tissues, non-tumor adjacent tissue and LCs, being SST, sst4, sst5, GHS-R1a and GHS-R1b overexpressed in tumor tissue compared to normal tissue. Importantly, several SST/CORT and ghrelin system components displayed significant correlations with relevant clinical parameters, such as necrosis, peritumoral and vascular invasion, or metastasis. Altogether, these data reveal a prominent, widespread expression of key SST/CORT/ghrelin system components in LCs, where they display

  3. Treatment adherence and persistence with long-acting somatostatin analog therapy for the treatment of acromegaly: a retrospective analysis.

    Science.gov (United States)

    Gurel, Michelle H; Han, Yi; Stevens, Andrea L; Furtado, Aaron; Cox, David

    2017-04-04

    Many patients with acromegaly require medical treatment that includes somatostatin analogs (SSAs). Long-acting SSA formulations are widely used, due in part to increased patient convenience and increased treatment adherence vs daily medications. Although medication compliance can be poor in patients with chronic conditions, adherence and persistence with these SSAs in patients with acromegaly has not been evaluated. This analysis utilized claims data to estimate treatment adherence and persistence for lanreotide depot and long-acting octreotide in this population. This retrospective analysis used the MarketScan® database (~100 payors, 500 million claims in the US), which was searched between January 2007 and June 2012 to identify patients with acromegaly taking either lanreotide depot or long-acting octreotide. Patients switching treatments were excluded. Treatment adherence was assessed using medication possession ratio (MPR; number of doses dispensed in relation to dispensing period; ≥80% is considered adherent), injection count, and treatment time. Persistence was estimated by Kaplan-Meier analyses and Cox proportional hazards modeling. A washout period, defined as no acromegaly-related prescription activity 180 days prior to the index date, was employed to minimize effects of prior therapy and focus on patients more likely to be treatment-naïve. Altogether 1308 patients with acromegaly receiving a single SSA for treatment (1127 octreotide, 181 lanreotide) who had not switched treatments were identified. Mean MPR in patients with a 180-day washout (n = 663) was 89% for those receiving octreotide (n = 545) and 87% for those receiving lanreotide (n = 118). Median number of days on therapy was 169 (95% CI 135-232) for octreotide patients and 400 (95% CI 232-532) for lanreotide patients. The point estimate of the Cox proportional hazard ratio for stopping treatment was 1.385 for octreotide vs lanreotide (95% CI 1.079-1.777), suggesting a 38

  4. Effects of +G_z exposure on gallbladder emptying function,cholecystokinin,and somatostatin in rabbits with high cholesterol diets

    Directory of Open Access Journals (Sweden)

    Guo-feng XIAO

    2011-12-01

    Full Text Available Objective The present study explores the effects of +Gz exposure on the gallbladder emptying function,cholecystokinin(CCK,and somatostatin(SS in rabbits with high cholesterol diets and investigates its mechanism in the occurrence of cholecystolithiasis.Methods Twenty-four male New Zealand rabbits were randomly divided into the high cholesterol diet(control group,n=8 and high cholesterol diet plus +Gz exposure groups.The latter was divided into the four-and six-week +Gz exposure groups(n=8 based on the exposure time.Radioimmunoassay was used to determine the CCK and SS contents of the gallbladder at the end of the experiment in the fourth and sixth weeks and to calculate the gallbladder volume and maximum emptying ratio.A microcomputer biodynamic pressure monitor was used to record the hydrostatic pressure in the gallbladder to measure its capacity.Moreover,the bile properties and formation of concretion were observed with the naked eye,and polarized light microscopy was used to observe cholesterin crystallization on the gallbladder wall.Results The gallbladder capacity increased upon +Gz exposure for four and six weeks,indicating that the maximum emptying ratio(E% decreased,the empty and residual volumes improved,and the pressure increased(P < 0.05.After +Gz exposure for four and six weeks,the CCK contents in the experimental groups were evidently lower than that in the control group and gradually decreased(P < 0.05 as the +Gz exposure time increased.On the other hand,after +Gz exposure for four and six weeks,the SS contents in the experimental groups were higher than that in the control group and gradually improved(P < 0.05 as the +Gz exposure time increased.After +Gz exposure for four and six weeks,bile was turbid and sticky with cholesterol crystals and without visible concretion.Conclusions Therefore,+Gz exposure may cause abnormal gallbladder emptying functions,decrease CCK content,increase SS content,and thus cause bile stasis

  5. 99mTc-HYNIC-TOC increased uptake can mimic malignancy in the pancreas uncinate process at somatostatin receptor SPECT/CT.

    Science.gov (United States)

    Yamaga, Lilian Yuri Itaya; Neto, Guilherme Campos Carvalho; da Cunha, Marcelo Livorsi; Osawa, Akemi; Oliveira, Julio Cesar Silveira; Fonseca, Ricardo Quartim; Nogueira, Solange Amorim; Wagner, Jairo; Funari, Marcelo Gusmão

    2016-03-01

    The aim of this study was to assess the occurrence and frequency of increased physiologic uptake of 99mTc-HYNIC-TOC by the uncinate process of the pancreas in SPECT/CT images. Forty-six scans of 41 patients were evaluated retrospectively. The uptake of 99mTc-HYNIC-TOC was considered to be physiologic in patients with normal findings at dedicated abdominal CT or MR and lack of neoplastic lesions in clinical follow-ups. The intensity of uncinate process uptake was compared to the uptake of the normal liver. Focal uptake was attributed to the presence of pancreatic NET in 5 patients. Among the 36 patients without any evidence of malignancy in CT, MR and follow-up, 7 (19.4 %) showed increased uptake in the uncinate process. The intensity of uptake was lesser in 3 (8.3 %), similar in 3 and greater than the normal liver in 1 (2.8 %) case. Increased 99mTc-HYNIC-TOC uptake occurred in 19.4 % of those subjects without any evidence of neuroendocrine tumor in the uncinate process.

  6. Clinical indications to the use of Tc-99m-EDDA/HYNIC-TOC to detect somatostatin receptor-positive neuroendocrine tumors

    NARCIS (Netherlands)

    Parisella, M. G.; Chianelli, M.; D'Alessandria, C.; Todino, V.; Mikolajczak, R.; Papini, E.; Dierckx, R. A.; Scopinaro, F.; Signore, A.

    The aim of this study was to define, retrospectively, the utility to perform Tc-99m-EDDA/HYNIC-Tyr3-octreotide (Tc-99m-EDDA/HYNIC-TOC) scan in patients with NET. We studied 50 consecutive patients affected by different types of NET and divided in two groups. Group 1: 34 patients with known lesions

  7. Clinical indications to the use of (99m)Tc-EDDA/HYNIC-TOC to detect somatostatin receptor-positive neuroendocrine tumors.

    Science.gov (United States)

    Parisella, M G; Chianelli, M; D'Alessandria, C; Todino, V; Mikolajczak, R; Papini, E; Dierckx, R A; Scopinaro, F; Signore, A

    2012-02-01

    The aim of this study was to define, retrospectively, the utility to perform (99m)Tc-EDDA/HYNIC-Tyr3-octreotide ((99m)Tc-EDDA/HYNIC-TOC) scan in patients with NET. We studied 50 consecutive patients affected by different types of NET and divided in two groups. Group 1: 34 patients with known lesions in which (99m)Tc-EDDA/HYNIC-TOC was performed for staging, characterisation or to choose the appropriate treatment. Group 2: 16 patients suspected of having NET or in follow up after surgery. Patients were injected with 370 MBq of (99m)Tc-EDDA/HYNIC-Tyr3-octreotide and whole-body and SPET images acquired 2-3 hours after injection. Overall, 29 patients (58%) had a positive scan, with a sensitivity, specificity and accuracy of 70.3%, 76.9% and 72%, respectively (78.1%, 50% and 76.5%, in group 1 and 20%, 81.2%, 62.5% in group 2). In patients from group 1 (99m)Tc-HYNIC-TOC scintigraphy showed a concordance of 68% with another imaging procedure and in 9 patients revealed a greater number of lesions. In the second group, false negative results were especially found in patients with medullary thyroid cancer with negative radiological findings and elevated calcitonin. In conclusion, (99m)Tc-EDDA/HYNIC-TOC is highly indicated for in vivo histological characterization of known NET lesions, previously identified by other imaging modalities or biopsy, to plan appropriate therapy especially for patients with inoperable disease. In patients with only biochemical suspicion of NET and in those with negative markers, this scintigraphy does not significantly modify the clinical management.

  8. Relative potencies of the somatostatin analogs octreotide, BIM-23014, and RC-160 on the inhibition of hormone release by cultured human endocrine tumor cells and normal rat anterior pituitary cells

    NARCIS (Netherlands)

    L.J. Hofland (Leo); P.M. van Koetsveld (Peter); M. Waaijers (Marlijn); J. Zuyderwijk; S.W.J. Lamberts (Steven)

    1994-01-01

    textabstractIn the present study we investigated the effects of the somatostatin (SS) analogs octreotide, RC-160, and BIM-23014 on GH release by cultured cells of human GH-secreting pituitary tumors, in normal rat anterior pituitary cells, and on gastrin release by

  9. The development of radioimmunoassay for somatostatin, its use in the measurement of this peptide in tissues and biological fluids, and an assessment of its physiological role in health and disease

    International Nuclear Information System (INIS)

    Pimstone, B.; Sheppard, M.

    1979-06-01

    Somatostatin peptide initially isolated from ovine hypothalamus has inhibitory effect on secretion growth hormone and on other pituitary hormones like TSH, ACTH. The assay sensitivity sensitivity was approximately 6 pg/tube. The authors did not observe any significant crossreactivity with 19 different hormones and biological substances. High concentration of somatostatin was found in central nervous system, but not only in median eminence of hypothalamus but also in other areas including spine cord. High level of somatostatin was also observed in pancreas, gastric antrum and distal colon. The determinations of somatostatin-like in sera of 22 men and 26 women allowed to establish the normal values which are 0.274+-0.009 ng/ml. MCR in normal subjects was 1949+-250 ml/min, in cases with chronic liver disease the values were similar, and in subjects with chronic renal failure highly significant lowering of MCR equal 501+-32.7 ml/min was observed. Tsub(1/2) varied from 1.1 to 3.0 min in normal subjects, in patients with liver diseases was in ranges 1.2 - 4.8 min and in chronic renal failure from 2.6 - 4.9 min

  10. Hepatic Cyst Infection During Use of the Somatostatin Analog Lanreotide in Autosomal Dominant Polycystic Kidney Disease: An Interim Analysis of the Randomized Open-Label Multicenter DIPAK-1 Study

    NARCIS (Netherlands)

    Lantinga, M.A. (Marten A.); D’Agnolo, H.M.A. (Hedwig M. A.); E. Casteleijn (Eric); de Fijter, J.W. (Johan W.); E. Meijer (Esther); A.L. Messchendorp (A. Lianne); D. Peters (Dorien); M. Salih (Mahdi); E.M. Spithoven (Edwin); D. Soonawala (Darius); F.W. Visser (Folkert); Wetzels, J.F.M. (Jack F. M.); R. Zietse (Bob); J.P.H. Drenth (Joost); R.T. Gansevoort (Ron); Drenth, J.P.H.; J.W. de Fijter (Johan); Gansevoort, R.T.; D.J.M. Peters (Dorien J.M.); J.F.M. Wetzels (Jack); Zietse, R.

    2017-01-01

    textabstractIntroduction and Aims: The DIPAK-1 Study investigates the reno- and hepatoprotective efficacy of the somatostatin analog lanreotide compared with standard care in patients with later stage autosomal dominant polycystic kidney disease (ADPKD). During this trial, we witnessed several

  11. The long-acting somatostatin analogue octreotide alleviates symptoms by reducing posttranslational conversion of prepro-glucagon to glucagon in a patient with malignant glucagonoma, but does not prevent tumor growth

    NARCIS (Netherlands)

    F. Jockenhövel (F.); S. Lederbogen (S.); T. Olbricht (T.); H. Schmidt-Gayk (H.); E.P. Krenning (Eric); S.W.J. Lamberts (Steven); D. Reinwein (D.)

    1994-01-01

    textabstractA 52-year-old female with metastatic glucagonoma secreting glucagon and chromogranin A was treated with the somatostatin analogue octreotide for 2 years without any additional tumor-reducing interventions. Before therapy plasma glucagon was above 8 μg/l (normal <0.2) and within 2 days 3

  12. Structure and function of the amygdaloid NPY system: NPY Y2 receptors regulate excitatory and inhibitory synaptic transmission in the centromedial amygdala.

    Science.gov (United States)

    Wood, J; Verma, D; Lach, G; Bonaventure, P; Herzog, H; Sperk, G; Tasan, R O

    2016-09-01

    The amygdala is essential for generating emotional-affective behaviors. It consists of several nuclei with highly selective, elaborate functions. In particular, the central extended amygdala, consisting of the central amygdala (CEA) and the bed nucleus of the stria terminalis (BNST) is an essential component actively controlling efferent connections to downstream effectors like hypothalamus and brain stem. Both, CEA and BNST contain high amounts of different neuropeptides that significantly contribute to synaptic transmission. Among these, neuropeptide Y (NPY) has emerged as an important anxiolytic and fear-reducing neuromodulator. Here, we characterized the expression, connectivity and electrophysiological function of NPY and Y2 receptors within the CEA. We identified several NPY-expressing neuronal populations, including somatostatin- and calretinin-expressing neurons. Furthermore, in the main intercalated nucleus, NPY is expressed primarily in dopamine D1 receptor-expressing neurons but also in interspersed somatostatin-expressing neurons. Interestingly, NPY neurons did not co-localize with the Y2 receptor. Retrograde tract tracing experiments revealed that NPY neurons reciprocally connect the CEA and BNST. Functionally, the Y2 receptor agonist PYY3-36, reduced both, inhibitory as well as excitatory synaptic transmission in the centromedial amygdala (CEm). However, we also provide evidence that lack of NPY or Y2 receptors results in increased GABA release specifically at inhibitory synapses in the CEm. Taken together, our findings suggest that NPY expressed by distinct populations of neurons can modulate afferent and efferent projections of the CEA via presynaptic Y2 receptors located at inhibitory and excitatory synapses.

  13. Comparison between non-dedicated positron emission tomography (NPET) with [F18] Fluor Deoxi glucose (FDG)and Radionuclide-labeled somatostatin analogues for the diagnostic purposes in the Differential Thyroid Cancer

    International Nuclear Information System (INIS)

    Escobar, E.I.; Giammarile, G.F.; Borson-Chazot, B.F.; Hasdi, H.Z.; Sassolas, S.G.

    2002-01-01

    . There is a important number of false positive which makes the sensibility to come down and the most likely reason for that is the small lesion size that could not been detected, and perhaps for the somatostatin analogue the explanation is that there is not enough receptors for achieve a good image

  14. Safety, Pharmacokinetics and Dosimetry of a Long-Acting Radiolabeled Somatostatin Analogue 177Lu-DOTA-EB-TATE in Patients with Advanced Metastatic Neuroendocrine Tumors.

    Science.gov (United States)

    Zhang, Jingjing; Wang, Hao; Jacobson Weiss, Orit; Cheng, Yuejuan; Niu, Gang; Li, Fang; Bai, Chunmei; Zhu, Zhaohui; Chen, Xiaoyuan

    2018-04-13

    Radiolabeled somatostatin analogue therapy has become an established treatment method for patients with well to moderately differentiated unresectable or metastatic neuroendocrine tumors (NETs). The most frequently used somatostatin analogues in clinical practice are octreotide and octreotate. However, both peptides showed suboptimal retention within tumors. The aim of this first-in-human study is to explore the safety and dosimetry of a long-acting radiolabeled somatostatin analogue, lutetium-177-1, 4, 7, 10-tetra-azacyclododecane-1, 4, 7, 10-tetraacetic acid-Evans blue-octreotate ( 177 Lu-DOTA-EB-TATE). Methods: Eight patients (6 males and 2 females; age range, 27-61 y) with advanced metastatic neuroendocrine tumors were recruited. Five patients received a single dose 0.35-0.70 GBq (9.5-18.9 mCi) of 177 Lu-DOTA-EB-TATE and underwent serial whole body planar and single-photon emission computed tomography-computed tomography (SPECT-CT) scans at 2, 24, 72, 120 and 168 h after injection. The other 3 patients received intravenous injection of 0.28-0.41 GBq (7.5-11.1 mCi) of 177 Lu-DOTATATE for the same imaging acquisition procedures at 1, 3, 4, 24 and 72 h after injection. The dosimetry was calculated using the OLINDA/EXM 1.1 software. Results: Administration of 177 Lu-DOTA-EB-TATE was well tolerated, with no adverse symptoms being noticed or reported in any of the patients. Compared with 177 Lu-DOTATATE, 177 Lu-DOTA-EB-TATE showed extended circulation in the blood and achieved 7.9-fold increase of tumor dose delivery. The total body effective doses were 0.205 ± 0.161 mSv/MBq for 177 Lu-DOTA-EB-TATE and 0.174 ± 0.072 mSv/MBq for 177 Lu-DOTATATE. Significant dose delivery increases to the kidneys and bone marrow were also observed in patients receiving 177 Lu-DOTA-EB-TATE than those receiving 177 Lu-DOTATATE (3.2 and 18.2-fold, respectively). Conclusion: By introducing an albumin binding moiety, 177 Lu-DOTA-EB-TATE showed remarkably higher uptake and retention in NET

  15. DOTATOC: a powerful new tool for receptor-mediated radionuclide therapy

    International Nuclear Information System (INIS)

    Otte, A.; Jermann, E.; Behe, M.; Goetze, M.; Bucher, H.C.; Roser, H.W.; Heppeler, A.; Mueller-Brand, J.; Maecke, H.R.

    1997-01-01

    This study presents the first successful use of a peptidic vector, DOTATOC, labelled with the β-emitting radioisotope yttrium-90, for the treatment of a patient with somatostatin receptor-positive abdominal metastases of a neuroendocrine carcinoma of unknown localization. Tumour response and symptomatic relief were achieved. In addition, the new substance DOTATOC was labelled with the diagnostic chemical analogue indium-111 and studied in three patients with histopathologically verified neuroendocrine abdominal tumours for its diagnostic sensitivity and compared with the commercially available OctreoScan. In all patients the kidney-to-tumour uptake ratio (in counts per pixel) was on average 1.9-fold lower with 111 In-DOTATOC than with OctreoScan. DOTATOC could be a potential new diagnostic and therapeutic agent in the management of neuroendocrine tumours. (orig.). With 4 figs., 1 tab

  16. PET SUV correlates with radionuclide uptake in peptide receptor therapy in meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Haenscheid, Heribert; Buck, Andreas K.; Samnick, Samuel; Kreissl, Michael [University Hospital Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Sweeney, Reinhart A.; Flentje, Michael [University Hospital Wuerzburg, Department of Radiation Oncology, Wuerzburg (Germany); Loehr, Mario [University Hospital Wuerzburg, Department of Neurosurgery, Wuerzburg (Germany); Verburg, Frederik A. [University Hospital Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); RWTH University Hospital Aachen, Department of Nuclear Medicine, Aachen (Germany)

    2012-08-15

    To investigate whether the tumour uptake of radionuclide in peptide receptor radionuclide therapy (PRRT) of meningioma can be predicted by a PET scan with {sup 68}Ga-labelled somatostatin analogue. In this pilot trial, 11 meningioma patients with a PET scan indicating somatostatin receptor expression received PRRT with 7.4 GBq {sup 177}Lu-DOTATOC or {sup 177}Lu-DOTATATE, followed by external beam radiotherapy. A second PET scan was scheduled for 3 months after therapy. During PRRT, multiple whole-body scans and a SPECT/CT scan of the head and neck region were acquired and used to determine the kinetics and dose in the voxel with the highest radionuclide uptake within the tumour. Maximum voxel dose and retention of activity 1 h after administration in PRRT were compared to the maximum standardized uptake values (SUV{sub max}) in the meningiomas from the PET scans before and after therapy. The median SUV{sub max} in the meningiomas was 13.7 (range 4.3 to 68.7), and the maximum fractional radionuclide uptake in voxels of size 0.11 cm{sup 3} was a median of 23.4 x 10{sup -6} (range 0.4 x 10{sup -6} to 68.3 x 10{sup -6}). A strong correlation was observed between SUV{sub max} and the PRRT radionuclide tumour retention in the voxels with the highest uptake (Spearman's rank test, P < 0.01). Excluding one patient who showed large differences in biokinetics between PET and PRRT and another patient with incomplete data, linear regression analysis indicated significant correlations between SUV{sub max} and the therapeutic uptake (r = 0.95) and between SUV{sub max} and the maximum voxel dose from PRRT (r = 0.76). Observed absolute deviations from the values expected from regression were a median of 5.6 x 10{sup -6} (maximum 9.3 x 10{sup -6}) for the voxel fractional radionuclide uptake and 0.40 Gy per GBq (maximum 0.85 Gy per GBq) {sup 177}Lu for the voxel dose from PRRT. PET with {sup 68}Ga-labelled somatostatin analogues allows the pretherapeutic assessment of tumour

  17. PET SUV correlates with radionuclide uptake in peptide receptor therapy in meningioma

    International Nuclear Information System (INIS)

    Haenscheid, Heribert; Buck, Andreas K.; Samnick, Samuel; Kreissl, Michael; Sweeney, Reinhart A.; Flentje, Michael; Loehr, Mario; Verburg, Frederik A.

    2012-01-01

    To investigate whether the tumour uptake of radionuclide in peptide receptor radionuclide therapy (PRRT) of meningioma can be predicted by a PET scan with 68 Ga-labelled somatostatin analogue. In this pilot trial, 11 meningioma patients with a PET scan indicating somatostatin receptor expression received PRRT with 7.4 GBq 177 Lu-DOTATOC or 177 Lu-DOTATATE, followed by external beam radiotherapy. A second PET scan was scheduled for 3 months after therapy. During PRRT, multiple whole-body scans and a SPECT/CT scan of the head and neck region were acquired and used to determine the kinetics and dose in the voxel with the highest radionuclide uptake within the tumour. Maximum voxel dose and retention of activity 1 h after administration in PRRT were compared to the maximum standardized uptake values (SUV max ) in the meningiomas from the PET scans before and after therapy. The median SUV max in the meningiomas was 13.7 (range 4.3 to 68.7), and the maximum fractional radionuclide uptake in voxels of size 0.11 cm 3 was a median of 23.4 x 10 -6 (range 0.4 x 10 -6 to 68.3 x 10 -6 ). A strong correlation was observed between SUV max and the PRRT radionuclide tumour retention in the voxels with the highest uptake (Spearman's rank test, P max and the therapeutic uptake (r = 0.95) and between SUV max and the maximum voxel dose from PRRT (r = 0.76). Observed absolute deviations from the values expected from regression were a median of 5.6 x 10 -6 (maximum 9.3 x 10 -6 ) for the voxel fractional radionuclide uptake and 0.40 Gy per GBq (maximum 0.85 Gy per GBq) 177 Lu for the voxel dose from PRRT. PET with 68 Ga-labelled somatostatin analogues allows the pretherapeutic assessment of tumour radionuclide uptake in PRRT of meningioma and an estimate of the achievable dose. (orig.)

  18. Interim report on intrathoracic radiotherapy of human small-cell lung carcinoma in nude mice with Re-188-RC-160, a radiolabeled somatostatin analogue

    International Nuclear Information System (INIS)

    Zamora, P.O.; Bender, H.; Biersack, H.J.; Knapp, F.F. Jr.

    1995-01-01

    The purpose of this study was to evaluate the therapeutic efficacy of Re-188-RC-160 in experimental models of human small cell lung carcinomas which mimic the clinical presentation. In the experimental model, cells from the human small cell lung carcinoma cell line NCI-H69 cells were inoculated into the thoracic cavity of athymic mice and rats. Subsequently, the biodistribution of Re-188-RC-160 after injection into the pleural cavity, a radiolabeled somatostatin analogue, was monitored as was the effect on the subsequent growth of tumors. The results presented here, and which are a part of a larger series of studies, suggest that Re-188-RC-160 can be effectively used in this animal model to restrict the growth of small cell lung carcinoma in the thoracic cavity

  19. Sazan (Cyprinus carpio Balığı Gastrointestinal Kanal Mukozasındaki CCK-8, Gastrin 1, VIP, Sekretin, Somatostatin-14, Bombesin ve Histamin Peptidlerinin Lokalizasyonu.

    Directory of Open Access Journals (Sweden)

    Nurgül Şenol

    2015-12-01

    Full Text Available Bu çalışmada; Cyprinus carpio (sazan gastrointestinal kanal mukozasının kolesistokinin-8, gastrin 1, vasoaktif intesinal polypeptid, sekretin, somatostatin-14, bombesin ve histamin peptidlerinin lokalizasyon ve dağılımlarının belirlenmesi amaçlanmıştır. Yapılan immunohistokimyasal çalışmalar sonucunda sazan (Cyprinus carpio’ın mide (sazanda genişlemiş ön bağırsak bölgesi ve bağırsak bölümlerinde (ilk, orta ve son bağırsak genel olarak çalışılan tüm peptidlerin farklı yoğunlukta lokalize oldukları tespit edildi

  20. NMDA Receptors Regulate the Structural Plasticity of Spines and Axonal Boutons in Hippocampal Interneurons

    Directory of Open Access Journals (Sweden)

    Marta Perez-Rando

    2017-06-01

    Full Text Available N-methyl-D-aspartate receptors (NMDARs are present in both pyramidal neurons and interneurons of the hippocampus. These receptors play an important role in the adult structural plasticity of excitatory neurons, but their impact on the remodeling of interneurons is unknown. Among hippocampal interneurons, somatostatin-expressing cells located in the stratum oriens are of special interest because of their functional importance and structural characteristics: they display dendritic spines, which change density in response to different stimuli. In order to understand the role of NMDARs on the structural plasticity of these interneurons, we have injected acutely MK-801, an NMDAR antagonist, to adult mice which constitutively express enhanced green fluorescent protein (EGFP in these cells. We have behaviorally tested the animals, confirming effects of the drug on locomotion and anxiety-related behaviors. NMDARs were expressed in the somata and dendritic spines of somatostatin-expressing interneurons. Twenty-four hours after the injection, the density of spines did not vary, but we found a significant increase in the density of their en passant boutons (EPB. We have also used entorhino-hippocampal organotypic cultures to study these interneurons in real-time. There was a rapid decrease in the apparition rate of spines after MK-801 administration, which persisted for 24 h and returned to basal levels afterwards. A similar reversible decrease was detected in spine density. Our results show that both spines and axons of interneurons can undergo remodeling and highlight NMDARs as regulators of this plasticity. These results are specially relevant given the importance of all these players on hippocampal physiology and the etiopathology of certain psychiatric disorders.

  1. A clinical and radiological objective tumor response with somatostatin analogs (SSA in well-differentiated neuroendocrine metastatic tumor of the ileum: a case report

    Directory of Open Access Journals (Sweden)

    De Divitiis C

    2015-03-01

    Full Text Available Chiara De Divitiis,1 Claudia von Arx,2 Roberto Carbone,3 Fabiana Tatangelo,4 Elena di Girolamo,5 Giovanni Maria Romano,1 Alessandro Ottaiano,1 Elisabetta de Lutio di Castelguidone,3 Rosario Vincenzo Iaffaioli,1 Salvatore Tafuto1 On behalf of the European Neuroendocrine Tumor Society (ENETS Center of Excellence Multidisciplinary Group for Neuroendocrine Tumors in Naples (Italy 1Department of Abdominal Oncology, National Cancer Institute “Fondazione G. Pascale”, Naples, Italy; 2Department of Clinical Medicine and Surgery, “Federico II” University, Naples, Italy; 3Department of Radiology, 4Department of Pathology, 5Department of Endoscopy, National Cancer Institute “Fondazione G Pascale”, Naples, Italy Abstract: Somatostatin analogs (SSAs are typically used to treat the symptoms caused by neuroendocrine tumors (NETs, but they are not used as the primary treatment to induce tumor shrinkage. We report a case of a 63-year-old woman with a symptomatic metastatic NET of the ileum. Complete symptomatic response was achieved after 1 month of treatment with SSAs. In addition, there was an objective response in the liver, with the disappearance of secondary lesions noted on computed tomography scan after 3 months of octreotide treatment. Our experience suggests that SSAs could be useful for downstaging and/or downsizing well-differentiated NETs, and they could allow surgery to be performed. Such presurgery therapy could be a promising tool in the management of patients with initially inoperable NETs. Keywords: neuroendocrine tumor, somatostatin analogs, octreotide, metastatic tumor of the ileum, radiological tumor response

  2. Glucagon-like peptide-1 receptor overexpression in cancer and its impact on clinical applications

    Directory of Open Access Journals (Sweden)

    Meike eKörner

    2012-12-01

    Full Text Available Peptide hormones of the glucagon-like peptide (GLP family play an increasing clinical role, such as GLP-1 in diabetes therapy. Moreover, GLP receptors are over-expressed in various human tumor types and therefore represent molecular targets for important clinical applications. In particular, virtually all benign insulinomas highly over-express GLP-1 receptors (GLP-1R. Targeting GLP-1R with the stable GLP-1 analogs 111In-DOTA/ DPTA-exendin-4 offers a new approach to successfully localize these small tumors. This non-invasive technique has the potential to replace the invasive localization of insulinomas by selective arterial stimulation and venous sampling. Malignant insulinomas, in contrast to their benign counterparts, express GLP-1R in only one third of the cases, while they more often express the somatostatin type 2 receptors. Importantly, one of the two receptors appears to be always expressed in malignant insulinomas. The GLP-1R overexpression in selected cancers is worth to be kept in mind with regard to the increasing use of GLP-1 analogs for diabetes therapy. While the functional role of GLP-1R in neoplasia is not known yet, it may be safe to monitore patients undergoing GLP-1 therapy carefully.

  3. Human Anti-Oxidation Protein A1M—A Potential Kidney Protection Agent in Peptide Receptor Radionuclide Therapy

    Directory of Open Access Journals (Sweden)

    Jonas Ahlstedt

    2015-12-01

    Full Text Available Peptide receptor radionuclide therapy (PRRT has been in clinical use for 15 years to treat metastatic neuroendocrine tumors. PRRT is limited by reabsorption and retention of the administered radiolabeled somatostatin analogues in the proximal tubule. Consequently, it is essential to develop and employ methods to protect the kidneys during PRRT. Today, infusion of positively charged amino acids is the standard method of kidney protection. Other methods, such as administration of amifostine, are still under evaluation and show promising results. α1-microglobulin (A1M is a reductase and radical scavenging protein ubiquitously present in plasma and extravascular tissue. Human A1M has antioxidation properties and has been shown to prevent radiation-induced in vitro cell damage and protect non-irradiated surrounding cells. It has recently been shown in mice that exogenously infused A1M and the somatostatin analogue octreotide are co-localized in proximal tubules of the kidney after intravenous infusion. In this review we describe the current situation of kidney protection during PRRT, discuss the necessity and implications of more precise dosimetry and present A1M as a new, potential candidate for renal protection during PRRT and related targeted radionuclide therapies.

  4. New radiopharmaecuticals for receptor scintigraphy and radionuclide therapy

    International Nuclear Information System (INIS)

    Virgolini, I.; Traub, T.; Leimer, M.; Novotny, C.; Pangerl, T.; Ofluoglu, S.; Halvadjieva, E.; Smith-Jones, P.; Flores, J.; Li, S.R.; Angelberger, P.; Havlik, E.; Andreae, F.; Raderer, M.; Kurtaran, A.; Niederle, B.; Dudczak, R.

    2000-01-01

    In vitro data have demonstrated a high amount of receptors for various hormones and peptides on malignant cells of neuroendocrine origin. Among these, binding sites for member of the SST-family (hSSTR1-5) are frequently found, and their expression has led to therapeutic and diagnostic attempts to specifically target these receptors. Receptor scintigraphy using radiolabeled peptide ligands has proved its effectiveness in clinical practice. In addition, initial results have indicated a clinical potential for receptor-targeted radiotherapy. Based on somatostatin (SST) receptor (R) recognition, the novel radiopharmaceuticals 111 In/ 9 0Y-DOTA-lanreotide developed at the University of Vienna as well as 111 In/ 9 0Y-DOTA-DPhe 1 -Tyr 3 -octreotide (NOVARTIS) both have provided promising data for diagnosis and treatment of hSSTR-positive tumors. SSTR scintigraphy using 111 In-DTPA-DPhe 1 -octreotide has a high positive predictive value for the vast majority of neuroendocrine tumors and has gained its place in the diagnostic work-up as well as follow-up of patients. Here it was used 111 In-DOTA-lanreotide scintigraphy in 166 patients since 1997 and have seen positive results in 93% of patients. In 42 patients with neuroendocrine tumors comparative data were obtained. As opposed to 111 In-DTPA-DPhe 1 -octreotide and 111 In-DOTA-DPhe 1 -Tyr 3 -octreotide, discrepancies in the scintigraphic results were seen in about one third of patients concerning both the tumor uptake as well as tumor lesion detection. Initial results both with 9 0Y-DOTA-lanreotide as well as 9 0Y-DOTA-DPhe 1 -Tyr 3 -octreotide has pointed out the clinical potential of radionuclide receptor-targeted radiotherapy. This new therapy could offer palliation and disease control at a reduced cost. The final peptide therapy strategy is most probably cheaper than conventional radio therapies or prolonged chemo therapies. Overall, receptor-mediated radiotherapy with 9 0Y-DOTA-lanreotide/ 9 0Y-DOTA-DPhe 1 -Tyr 3

  5. New radiopharmaceuticals for receptor scintigraphy and radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Virgolini, I.; Traub, T.; Leimer, M.; Novotny, C.; Pangerl, T.; Ofluoglu, S.; Halvadjieva, E.; Smith-Jones, P.; Flores, J.; Li, S.R.; Angelberger, P.; Havlik, E.; Andreae, F.; Raderer, M.; Kurtaran, A.; Niederle, B.; Dudczak, R. [Vienna Univ., Vienna (Austria). Dept. of Nuclear Medicine

    2000-03-01

    In vitro data have demonstrated a high amount of receptors for various hormones and peptides on malignant cells of neuroendocrine origin. Among these, binding sites for member of the SST-family (hSSTR1-5) are frequently found, and their expression has led to therapeutic and diagnostic attempts to specifically target these receptors. Receptor scintigraphy using radiolabeled peptide ligands has proved its effectiveness in clinical practice. In addition, initial results have indicated a clinical potential for receptor-targeted radiotherapy. Based on somatostatin (SST) receptor (R) recognition, the novel radiopharmaceuticals {sup 111}In/{sup 9}0Y-DOTA-lanreotide developed at the University of Vienna as well as {sup 111}In/{sup 9}0Y-DOTA-DPhe{sup 1}-Tyr{sup 3}-octreotide (NOVARTIS) both have provided promising data for diagnosis and treatment of hSSTR-positive tumors. SSTR scintigraphy using {sup 111}In-DTPA-DPhe{sup 1}-octreotide has a high positive predictive value for the vast majority of neuroendocrine tumors and has gained its place in the diagnostic work-up as well as follow-up of patients. Here it was used {sup 111}In-DOTA-lanreotide scintigraphy in 166 patients since 1997 and have seen positive results in 93% of patients. In 42 patients with neuroendocrine tumors comparative data were obtained. As opposed to {sup 111}In-DTPA-DPhe{sup 1}-octreotide and {sup 111}In-DOTA-DPhe{sup 1}-Tyr{sup 3}-octreotide, discrepancies in the scintigraphic results were seen in about one third of patients concerning both the tumor uptake as well as tumor lesion detection. Initial results both with {sup 9}0Y-DOTA-lanreotide as well as {sup 9}0Y-DOTA-DPhe{sup 1}-Tyr{sup 3}-octreotide has pointed out the clinical potential of radionuclide receptor-targeted radiotherapy. This new therapy could offer palliation and disease control at a reduced cost. The final peptide therapy strategy is most probably cheaper than conventional radio therapies or prolonged chemo therapies. Overall

  6. Aberrant expression of glucagon receptors in adrenal glands of a patient with Cushing's syndrome and ACTH-independent macronodular adrenal hyperplasia

    Directory of Open Access Journals (Sweden)

    Valeria de Miguel

    2010-06-01

    Full Text Available Adrenocorticotropin (ACTH independent bilateral macronodular adrenal hyperplasia (AIMAH is a rare cause of Cushing´s syndrome, characterized by bilateral adrenal lesions and excess cortisol production despite ACTH suppression. Cortisol synthesis is produced in response to abnormal activation of G-protein- coupled receptors, such as gastric inhibitory peptide, vasopressin, beta adrenergic agonists, LH/hCG and serotonin receptors. The aim of this study was to analyze the expression of glucagon receptors in adrenal glands from an AIMAH patient. A patient with ACTH-independent Cushing´s syndrome and bilateral macronodular adrenal hyperplasia was screened for altered activation of adrenal receptors by physiological (mixed meal and pharmacological (gonadotrophin releasing hormone, ACTH and glucagon tests. The results showed abnormally high levels of serum cortisol after stimulation with glucagon. Hypercortisolism was successfully managed with ketoconazole treatment. Interestingly, a 4-month treatment with a somatostatin analogue (octreotide was also able to reduce cortisol secretion. Finally, Cushing's syndrome was cured after bilateral adrenalectomy. Abnormal mRNA expression for glucagon receptor in the patient´s adrenal glands was observed by Real-Time PCR procedure. These results strongly suggest that the mechanism of AIMAH causing Cushing´s syndrome in this case involves the illicit activation of adrenal glucagon receptors. This is the first case reported of AIMAH associated with ectopic glucagon receptors.

  7. (68)Ga-DOTATATE PET in juvenile angiofibroma.

    Science.gov (United States)

    Gronkiewicz, Zuzanna; Kukwa, Wojciech; Krolicki, Leszek; Cyran-Chlebicka, Agata; Pawlak, Dariusz; Stankiewicz, Czeslaw; Krzeski, Antoni; Górnicka, Barbara; Wolosz, Dominika; Kunikowska, Jolanta

    2016-06-01

    As somatostatin receptors (SSTRs) may be overexpressed in rapidly growing vessels, the aim of this study was the analysis of in vivo and in vitro SSTR2A expression in juvenile angiofibroma (JA). A group of six male adolescents with a diagnosis of primary, recurrent/residual JA was enrolled in the study. All patients underwent (68)Ga-DOTATATE PET/computed tomography (CT) followed by immunohistochemical staining for SSTR expression. (68)Ga-DOTATATE PET/CT showed accumulation in areas matching the pathologic tissue in the nasopharynx of all patients studied with SUVmax of 5.1 ± 0.9 (ranging from 3.6 to 6.4). In all cases, the immunohistochemical examination showed a presence of SSTR2A with a high staining index. In vitro SSTR2A cytoplasm expression was found to be high in all tumor specimens. However, the uptake of (68)Ga-DOTATATE was weak in the PET/CT studies. We postulate that the intracellular localization of the SSTR2A in JA may cause this discrepancy.

  8. The LDL receptor.

    Science.gov (United States)

    Goldstein, Joseph L; Brown, Michael S

    2009-04-01

    In this article, the history of the LDL receptor is recounted by its codiscoverers. Their early work on the LDL receptor explained a genetic cause of heart attacks and led to new ways of thinking about cholesterol metabolism. The LDL receptor discovery also introduced three general concepts to cell biology: receptor-mediated endocytosis, receptor recycling, and feedback regulation of receptors. The latter concept provides the mechanism by which statins selectively lower plasma LDL, reducing heart attacks and prolonging life.

  9. G protein-coupled receptor transmembrane binding pockets and their applications in GPCR research and drug discovery: a survey.

    Science.gov (United States)

    Kratochwil, Nicole A; Gatti-McArthur, Silvia; Hoener, Marius C; Lindemann, Lothar; Christ, Andreas D; Green, Luke G; Guba, Wolfgang; Martin, Rainer E; Malherbe, Pari; Porter, Richard H P; Slack, Jay P; Winnig, Marcel; Dehmlow, Henrietta; Grether, Uwe; Hertel, Cornelia; Narquizian, Robert; Panousis, Constantinos G; Kolczewski, Sabine; Steward, Lucinda

    2011-01-01

    G protein-coupled receptors (GPCRs) share a common architecture consisting of seven transmembrane (TM) domains. Various lines of evidence suggest that this fold provides a generic binding pocket within the TM region for hosting agonists, antagonists, and allosteric modulators. Hence, an automated method was developed that allows a fast analysis and comparison of these generic ligand binding pockets across the entire GPCR family by providing the relevant information for all GPCRs in the same format. This methodology compiles amino acids lining the TM binding pocket including parts of the ECL2 loop in a so-called 1D ligand binding pocket vector and translates these 1D vectors in a second step into 3D receptor pharmacophore models. It aims to support various aspects of GPCR drug discovery in the pharmaceutical industry. Applications of pharmacophore similarity analysis of these 1D LPVs include definition of receptor subfamilies, prediction of species differences within subfamilies in regard to in vitro pharmacology and identification of nearest neighbors for GPCRs of interest to generate starting points for GPCR lead identification programs. These aspects of GPCR research are exemplified in the field of melanopsins, trace amine-associated receptors and somatostatin receptor subtype 5. In addition, it is demonstrated how 3D pharmacophore models of the LPVs can support the prediction of amino acids involved in ligand recognition, the understanding of mutational data in a 3D context and the elucidation of binding modes for GPCR ligands and their evaluation. Furthermore, guidance through 3D receptor pharmacophore modeling for the synthesis of subtype-specific GPCR ligands will be reported. Illustrative examples are taken from the GPCR family class C, metabotropic glutamate receptors 1 and 5 and sweet taste receptors, and from the GPCR class A, e.g. nicotinic acid and 5-hydroxytryptamine 5A receptor. © 2011 Bentham Science Publishers

  10. Utility of 99mTc-Hynic-TOC in 131I Whole-Body Scan Negative Thyroid Cancer Patients with Elevated Serum Thyroglobulin Levels

    Science.gov (United States)

    Shinto, Ajit S.; Kamaleshwaran, K. K.; Mallia, Madhav; Korde, Aruna; Samuel, Grace; Banerjee, Sharmila; Velayutham, Pavanasam; Damodharan, Suresh; Sairam, Madhu

    2015-01-01

    Several studies have reported on the expression of somatostatin receptors (SSTRs) in patients with differentiated thyroid cancer (DTC). The aim of this study was to evaluate the imaging abilities of a recently developed Technetium-99m labeled somatostatin analog, 99mTc-Hynic-TOC, in terms of precise localization of the disease. The study population consisted of 28 patients (16 men, 12 women; age range: 39-72 years) with histologically confirmed DTC, who presented with recurrent or persistent disease as indicated by elevated serum thyroglobulin (Tg) levels after initial treatment (serum Tg > 10 ng/ml off T4 suppression for 4-6 weeks). All patients were negative on the Iodine-131 posttherapy whole-body scans. Fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) was performed in all patients. SSTR scintigraphy was true positive in 23 cases (82.1%), true negative in two cases (7.1%) and false negative in three cases (10.7%) which resulted in a sensitivity of 88.46%, specificity of 100% and an accuracy of 89.2%. Sensitivity of 99mTc-Hynic-TOC scan was higher (93.7%) for patients with advanced stages, that is stages III and IV. 18F-FDG showed a sensitivity of 93.7%, a specificity of 50% and an accuracy of 89.3%. 18F-FDG PET was found to be more sensitive, with lower specificity due to false positive results in 2 patients. Analysis on a lesion basis demonstrated substantial agreement between the two imaging techniques with a Cohen's kappa of 0.66. Scintigraphy with 99mTc-Hynic-TOC might be a promising tool for treatment planning; it is easy to perform and showed sufficient accuracy for localization diagnostics in thyroid cancer patients with recurrent or metastatic disease. PMID:26097420

  11. Utility of (99m)Tc-Hynic-TOC in 131I Whole-Body Scan Negative Thyroid Cancer Patients with Elevated Serum Thyroglobulin Levels.

    Science.gov (United States)

    Shinto, Ajit S; Kamaleshwaran, K K; Mallia, Madhav; Korde, Aruna; Samuel, Grace; Banerjee, Sharmila; Velayutham, Pavanasam; Damodharan, Suresh; Sairam, Madhu

    2015-01-01

    Several studies have reported on the expression of somatostatin receptors (SSTRs) in patients with differentiated thyroid cancer (DTC). The aim of this study was to evaluate the imaging abilities of a recently developed Technetium-99m labeled somatostatin analog, (99m)Tc-Hynic-TOC, in terms of precise localization of the disease. The study population consisted of 28 patients (16 men, 12 women; age range: 39-72 years) with histologically confirmed DTC, who presented with recurrent or persistent disease as indicated by elevated serum thyroglobulin (Tg) levels after initial treatment (serum Tg > 10 ng/ml off T4 suppression for 4-6 weeks). All patients were negative on the Iodine-131 posttherapy whole-body scans. Fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) was performed in all patients. SSTR scintigraphy was true positive in 23 cases (82.1%), true negative in two cases (7.1%) and false negative in three cases (10.7%) which resulted in a sensitivity of 88.46%, specificity of 100% and an accuracy of 89.2%. Sensitivity of (99m)Tc-Hynic-TOC scan was higher (93.7%) for patients with advanced stages, that is stages III and IV. (18)F-FDG showed a sensitivity of 93.7%, a specificity of 50% and an accuracy of 89.3%. (18)F-FDG PET was found to be more sensitive, with lower specificity due to false positive results in 2 patients. Analysis on a lesion basis demonstrated substantial agreement between the two imaging techniques with a Cohen's kappa of 0.66. Scintigraphy with (99m)Tc-Hynic-TOC might be a promising tool for treatment planning; it is easy to perform and showed sufficient accuracy for localization diagnostics in thyroid cancer patients with recurrent or metastatic disease.

  12. Utility of 99mTc-Hynic-TOC in 131I Whole-Body Scan Negative Thyroid Cancer Patients with Elevated Serum Thyroglobulin Levels

    International Nuclear Information System (INIS)

    Shinto, Ajit S.; Kamaleshwaran, K. K.; Mallia, Madhav; Korde, Aruna; Samuel, Grace; Banerjee, Sharmila; Velayutham, Pavanasam; Damodharan, Suresh; Sairam, Madhu

    2015-01-01

    Several studies have reported on the expression of somatostatin receptors (SSTRs) in patients with differentiated thyroid cancer (DTC). The aim of this study was to evaluate the imaging abilities of a recently developed Technetium-99m labeled somatostatin analog, 99m Tc-Hynic-TOC, in terms of precise localization of the disease. The study population consisted of 28 patients (16 men, 12 women; age range: 39-72 years) with histologically confirmed DTC, who presented with recurrent or persistent disease as indicated by elevated serum thyroglobulin (Tg) levels after initial treatment (serum Tg > 10 ng/ml off T4 suppression for 4-6 weeks). All patients were negative on the Iodine-131 posttherapy whole-body scans. Fluorine-18 fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET) was performed in all patients. SSTR scintigraphy was true positive in 23 cases (82.1%), true negative in two cases (7.1%) and false negative in three cases (10.7%) which resulted in a sensitivity of 88.46%, specificity of 100% and an accuracy of 89.2%. Sensitivity of 99m Tc-Hynic-TOC scan was higher (93.7%) for patients with advanced stages, that is stages III and IV. 18 F-FDG showed a sensitivity of 93.7%, a specificity of 50% and an accuracy of 89.3%. 18 F-FDG PET was found to be more sensitive, with lower specificity due to false positive results in 2 patients. Analysis on a lesion basis demonstrated substantial agreement between the two imaging techniques with a Cohen's kappa of 0.66. Scintigraphy with 99m Tc-Hynic-TOC might be a promising tool for treatment planning; it is easy to perform and showed sufficient accuracy for localization diagnostics in thyroid cancer patients with recurrent or metastatic disease

  13. Peptide receptor chemoradionuclide therapy in small cell carcinoma: from bench to bedside

    International Nuclear Information System (INIS)

    Lewin, Jeremy; Rao, Aparna; Mileshkin, Linda; Cullinane, Carleen; Akhurst, Tim; Eu, Peter; Waldeck, Kelly; Watkins, D.N.; Hicks, Rodney J.

    2015-01-01

    Small cell cancers (SmCC), whether pulmonary (SCLC) or extrapulmonary, have a poor prognosis unless localised at diagnosis. Given a proportion of these cancers express somatostatin receptor subtype 2 (SSTR2), we aimed to investigate the efficacy of targeted peptide receptor chemoradionuclide therapy (PRCRT). In this preclinical study, we used a SCLC xenograft mouse model with high expression of SSTR2 to investigate the effect of peptide receptor radionuclide therapy (PRRT) with chemotherapy compared to either alone. We subsequently explored the clinical utility in a patient with SmCC with high SSTR expression treated with PRCRT. Robust expression of SSTR2 in NCI-H69 SCLC xenografts was documented by 68 Ga-DOTA-octreotate (GaTate) (tumour to background uptake ratio = 35). The combination of PRRT using 177 Lu-DOTA-octreotate (LuTate) with carboplatin/etoposide (C/E) chemotherapy was more effective than either LuTate or C/E alone for regression of the NCI-H69 model (p value < 0.05). PRCRT was associated with significantly prolonged survival versus PRRT (p value = 0.0001) or chemotherapy alone (p value = 0.0058). In the subsequent case study, a patient with relapsed SmCC with high SSTR2 expression on GaTate PET underwent PRCRT with radiosensitising etoposide with evidence of a complete metabolic response for 4 months. Given the limited treatment options in this setting, PRCRT is a promising therapeutic option for SSTR2-expressing SmCC. (orig.)

  14. Neurotransmitters activate T-cells and elicit crucial functions via neurotransmitter receptors.

    Science.gov (United States)

    Levite, Mia

    2008-08-01

    Neurotransmitters are traditionally viewed as nerve-secreted molecules that trigger or inhibit neuronal functions. Yet, neurotransmitters bind also their neurotransmitter receptors in T-cells and directly activate or suppress T-cell functions. This review focuses only on the activating effects of neurotransmitters on T-cells, primarily naïve/resting cells, and covers dopamine, glutamate, serotonin, and few neuropeptides: GnRH-I, GnRH-II, substance P, somatostatin, CGRP, and neuropeptide Y. T-cells express many neurotransmitter receptors. These are regulated by TCR-activation, cytokines, or the neurotransmitters themselves, and are upregulated/downregulated in some human diseases. The context - whether the T-cells are naïve/resting or antigen/mitogen/cytokine-activated, the T-cell subset (CD4/CD8/Th1/Th2/Teff/Treg), neurotransmitter dose (low/optimal or high/excess), exact neurotransmitter receptors expressed, and the cytokine milieu - is crucial, and can determine either activation or suppression of T-cells by the same neurotransmitter. T-cells also produce many neurotransmitters. In summary, neurotransmitters activate vital T-cell functions in a direct, potent and specific manner, and may serve for communicating between the brain and the immune system to elicit an effective and orchestrated immune function, and for new therapeutic avenues, to improve T-cell eradication of cancer and infectious organisms.

  15. Análogos de la somatostatina en el tratamiento de la retinopatía diabética Somatostatin analogues in the treatment of diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Juana Elvira Maciques Rodríguez

    2012-04-01

    Full Text Available La retinopatía diabética constituye un importante problema de salud por la discapacidad visual que provoca. El tratamiento de elección continúa siendo la fotocoagulación láser, pero en ocasiones hay formas avanzadas en que la respuesta es pobre y la evolución tórpida. Se continúan buscando otras alternativas de tratamiento que puedan mejorar la evolución, como son los esteroides y antiangiogénicos. Con el objetivo de reagrupar información actual sobre este grupo de medicamentos (análogos de la somatostatina, los cuales tienen efectos antiangiogénicos y han sido usados en el tratamiento de la retinopatía diabética proliferativa y el edema macular diabético, se realizó esta revisión. Los análogos de la somatostatina han mostrado ser eficaces, fundamentalmente, en el control de los fenómenos hemorrágicos y proliferativos en la retinopatía diabética proliferativa, y al mejorar también la integridad de la barrera hematoretiniana, ofrecen una alternativa de tratamiento para el edema macular diabético, fundamentalmente, cuando la respuesta al láser no resulta favorable.The diabetic retinopathy is an important health problem due to visual disability provoked. The choice treatment still remains the laser photocoagulation, but sometimes there is advanced ways in which the response is poor and the course is torpid. Other alternatives of treatment are look for to improve the course including the steroids and anti-angiogenic. The aim of present review was to regroup the current information on this group of drugs (somatostatin analogues, which has a anti-angiogenic effect and used in the treatment of proliferative diabetic retinopathy and the diabetic macular edema. The somatostatin analogues have shown to be effective, mainly in the control of hemorrhagic and proliferative phenomena and to also improve the integrity of the hematoretinal barrier, offer an alternative of treatment for diabetic macular edema, mainly when the response

  16. Large variability in synaptic N-methyl-D-aspartate receptor density on interneurons and a comparison with pyramidal-cell spines in the rat hippocampus.

    Science.gov (United States)

    Nyíri, G; Stephenson, F A; Freund, T F; Somogyi, P

    2003-01-01

    Pyramidal cells receive input from several types of GABA-releasing interneurons and innervate them reciprocally. Glutamatergic activation of interneurons involves both alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) type glutamate receptors expressed in type I synapses, mostly on their dendritic shafts. On average, the synaptic AMPA receptor content is several times higher on interneurons than in the spines of pyramidal cells. To compare the NMDA receptor content of synapses, we used a quantitative postembedding immunogold technique on serial electron microscopic sections, and analysed the synapses on interneuron dendrites and pyramidal cell spines in the CA1 area. Because all NMDA receptors contain the obligatory NR1 subunit, receptor localisation was carried out using antibodies recognising all splice variants of the NR1 subunit. Four populations of synapse were examined: i). on spines of pyramidal cells in stratum (str.) radiatum and str. oriens; ii). on parvalbumin-positive interneuronal dendritic shafts in str. radiatum; iii). on randomly found dendritic shafts in str. oriens and iv). on somatostatin-positive interneuronal dendritic shafts and somata in str. oriens. On average, the size of the synapses on spines was about half of those on interneurons. The four populations of synapse significantly differed in labelling for the NR1 subunit. The median density of NR1 subunit labelling was highest on pyramidal cell spines. It was lowest in the synapses on parvalbumin-positive dendrites in str. radiatum, where more than half of these synapses were immunonegative. In str. oriens, synapses on interneurons had a high variability of receptor content; some dendrites were similar to those in str. radiatum, including the proximal synapses of somatostatin-positive cells, whereas others had immunoreactivity for the NR1 subunit similar to or higher than synapses on pyramidal cell spines. These results show that synaptic NMDA

  17. In-vivo-receptor scintigraphy with [sup 111]In-octreotid in patients with breast tumors. In-vivo-Rezeptorszintigraphie mit [sup 111]In-Octreotid bei Patientinnen mit palpablen Mammatumoren

    Energy Technology Data Exchange (ETDEWEB)

    Goehring, U.J. (Frauenklinik, Koeln Univ. (Germany)); Scheidhauer, K. (Klinik fuer Nuklearmedizin, Koeln Univ. (Germany)); Schomaecker, K. (Klinik fuer Nuklearmedizin, Koeln Univ. (Germany)); Scharl, A. (Frauenklinik, Koeln Univ. (Germany))

    1993-12-01

    Somatostatin is a ligand for a transmembrane peptid receptor protein, which is frequently expressed in breast cancer. We injected the radiolabeled somatostatin analogon In-111-pentatreotid in 19 patients suspicious for breast carcinoma. Planar imaging of the thorax was performed up to 15 minutes p.i. and 3-5 hours p.i. Single photon emission computed tomography (SPECT) was additionaly performed 3-5 hours p.i. Radioactivity was rapidly cleared from blood; concentration in serum decreased by 75% within 1 h. 78% of activity was excreted in urine within 8 h. Positive imaging was seen in 2 of 5 patients with benign breast tumors (fibroadenoma). 11 of 14 carcinomas yielded concentration of 111-In-pentatreotid. 4 of 8 patients with axillary node metastases displayed axillar activity, which was not seen in any patient without node involvement (n=6). These date demonstrate, that radiolabeled pentatreotide binds to certain breast tumors. There is evidence, that in-vivo-imaging of peptid receptors in breast carcinomas is feasible. (orig.)

  18. Distribution of peptidergic populations in the human dentate gyrus (somatostatin [SOM-28, SOM-12] and neuropeptide Y [NPY]) during postnatal development.

    Science.gov (United States)

    Cebada-Sánchez, S; Insausti, R; González-Fuentes, J; Arroyo-Jiménez, M M; Rivas-Infante, E; Lagartos, M J; Martínez-Ruiz, J; Lozano, G; Marcos, P

    2014-10-01

    The postnatal development of the human hippocampal formation establishes the time and place at which we start autobiographical memories. However, data concerning the maturation of the neurochemical phenotypes characteristic of interneurons in the human hippocampus are scarce. We have studied the perinatal and postnatal changes of the dentate gyrus (DG) interneuron populations at three rostrocaudal levels. Immunohistochemically identified neurons and fibers for somatostatin (SOM-12 and SOM-28) and neuropeptide Y (NPY) and the co-localization of SOM-28 and NPY were analyzed. In total, 13 cases were investigated from late pregnancy (1 case), perinatal period (6 cases), first year (1 case), early infancy (3 cases), and late infancy (2 cases). Overall, the pattern of distribution of these peptides in the DG was similar to that of the adult. The distribution of cells was charted, and the cell density (number of positive cells/mm(2)) was calculated. The highest density corresponded to the polymorphic cell layer and was higher at pre- and perinatal periods. At increasing ages, neuron density modifications revealed a decrease from 5 postnatal months onward. In contrast, by late infancy, two immunoreactive bands for SOM-28 and NPY in the molecular layer were much better defined. Double-immunohistochemistry showed that NPY-positive neurons co-localized with SOM-28, whereas some fibers contained only one or other of the neuropeptides. Thus, this peptidergic population, presumably inhibitory, probably has a role in DG maturation and its subsequent functional activity in memory processing.

  19. Somatostatin reduces 3H-thymidine incorporation and c-myc, but not thyroglobulin ribonucleic acid levels in human thyroid follicular cells in vitro

    International Nuclear Information System (INIS)

    degli Uberti, E.C.; Hanau, S.; Rossi, R.; Piva, R.; Margutti, A.; Trasforini, G.; Pansini, G.; del Senno, L.

    1991-01-01

    The action of somatostatin (SRIH) on 3 H-thymidine (thy) incorporation and on c-myc and thyroglobulin RNA levels in a suspension of follicles from normal and goitrous human thyroid was examined. SRIH, at 10 - 7 M concentration, inhibited basal thy incorporation (maximally by 4 h lasting for up 24 h), which effect was greater in goiter than in normal thyroid and was also detected in growing adherent epithelial cells. Moreover, in a follicle suspension SRIH prevented TSH-stimulated thy incorporation, both in normal and in goitrous thyroid. Basal expression of c-myc RNA was not affected by SRIH in either tissue, whereas the TSH-stimulated c-myc RNA level was significantly reduced in goiter. No effect of SRIH was observed on basal or TSH-stimulated thyroglobulin RNA levels. SRIH did not alter basal cAMP concentrations in normal or goitrous follicles, but it significantly reduced TSH-stimulated cAMP accumulation both in normal thyroid and in goiter. Overall, our data indicate a direct inhibitory action of SRIH on growth, but not on differentiation, of human thyroid, probably by a mechanism not entirely cAMP dependent

  20. Parvalbumin-expressing interneurons can act solo while somatostatin-expressing interneurons act in chorus in most cases on cortical pyramidal cells.

    Science.gov (United States)

    Safari, Mir-Shahram; Mirnajafi-Zadeh, Javad; Hioki, Hiroyuki; Tsumoto, Tadaharu

    2017-10-06

    Neural circuits in the cerebral cortex consist primarily of excitatory pyramidal (Pyr) cells and inhibitory interneurons. Interneurons are divided into several subtypes, in which the two major groups are those expressing parvalbumin (PV) or somatostatin (SOM). These subtypes of interneurons are reported to play distinct roles in tuning and/or gain of visual response of pyramidal cells in the visual cortex. It remains unclear whether there is any quantitative and functional difference between the PV → Pyr and SOM → Pyr connections. We compared unitary inhibitory postsynaptic currents (uIPSCs) evoked by electrophysiological activation of single presynaptic interneurons with population IPSCs evoked by photo-activation of a mass of interneurons in vivo and in vitro in transgenic mice in which PV or SOM neurons expressed channelrhodopsin-2, and found that at least about 14 PV neurons made strong connections with a postsynaptic Pyr cell while a much larger number of SOM neurons made weak connections. Activation or suppression of single PV neurons modified visual responses of postsynaptic Pyr cells in 6 of 7 pairs whereas that of single SOM neurons showed no significant modification in 8 of 11 pairs, suggesting that PV neurons can act solo whereas most of SOM neurons may act in chorus on Pyr cells.

  1. Effect of subcutaneous injection of a long-acting analogue of somatostatin (SMS 201-995) on plasma thyroid-stimulating hormone in normal human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, S.; Tanaka, K.; Kumagae, M.; Takeda, F.; Morio, K.; Kogure, M.; Hasegawa, M.; Horiuchi, T.; Watabe, T.; Miyabe, S.

    1988-01-01

    SMS 201-995 (SMS), a synthetic analogue of somatostatin (SRIF) has been shown to be effective in the treatment of the hypersecretion of hormones such as in acromegaly. However, little is known about the effects of SMS on the secretion of thyroid-stimulating hormone (TSH) in normal subjects. In this study, plasma TSH was determined with a highly sensitive immunoradiometric assay, in addition to the concentration of SMS in plasma and urine with a radioimmunoassay, following subcutaneous injection of 25, 50, 100 ..mu..g of SMS or a placebo to normal male subjects, at 0900 h after an overnight fast. The plasma concentrations of SMS were dose-responsive and the peak levels were 1.61 +/- 0.09, 4.91 +/- 0.30 and 8.52 +/- 1.18 ng/ml, which were observed at 30, 15 and 45 min after the injection of 25, 50, and 100 ..mu..g of SMS, respectively. Mean plasma disappearance half-time of SMS was estimated to be 110 +/- 3 min. Plasma TSH was suppressed in a dose dependent manner and the suppression lasted for at least 8 hours. At 8 hours after the injection of 25, 50, and 100 ..mu..g of SMS, the plasma TSH levels were 43.8 +/- 19.4, 33.9 +/- 9.4 and 24.9 +/- 3.2%, respectively, of the basal values.