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Sample records for central benzodiazepine receptors

  1. Central benzodiazepine receptor imaging and quantitation with single photon emission computerised tomography

    DEFF Research Database (Denmark)

    Okocha, C I; Kapczinski, F; Lassen, N

    1995-01-01

    This review discusses the current use of single photon emission computerised tomography (SPECT) for central benzodiazepine receptor imaging and quantitation. The general principles underlying SPECT imaging and receptor quantitation methods such as the kinetic, pseudo-equilibrium and steady...

  2. Biochemical study of multiple drug recognition sites on central benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Trifiletti, R.R.

    1986-01-01

    The benzodiazepine receptor complex of mammalian brain possesses recognition sites which mediate (at least in part) the pharmacologic actions of the 1,4-benzodiazepines and barbiturates. Evidence is provided suggesting the existence of least seven distinct drug recognition sites on this complex. Interactions between the various recognition sites have been explored using radioligand binding techniques. This information is utilized to provide a comprehensive scheme for characterizing receptor-active drugs on an anxiolytic-anticonvulsant/proconvulsant continuum using radioligand binding techniques, as well as a comprehensive program for identifying potential endogenous receptor-active substances. Further evidence is provided here supporting the notion of benzodiazepine recognition site heterogeneity. Classical 1,4-benzodiazepines do not appear to differentiate two populations of benzodiazepine receptors in an equilibrium sense, but appear to do so in a kinetic sense. An apparent physical separation of the two receptor subtypes can be achieved by differential solubilization. The benzodiazepine binding subunit can be identified by photoaffinity labeling with the benzodiazepine agonist (/sup 3/H)flunitrazepan. Conditions for reproducible partial proteolytic mapping of (/sup 3/H)flunitrazepam photoaffinity labeled receptors are established. From these maps, it is concluded that there are probably no major differences in the primary sequence of the benzodiazepine binding subunit in various regions of the rat central nervous system.

  3. Extraction and purification from Ceratonia siliqua of compounds acting on central and peripheral benzodiazepine receptors.

    Science.gov (United States)

    Avallone, R; Cosenza, F; Farina, F; Baraldi, C; Baraldi, M

    2002-08-01

    The presence of molecules with high affinity for central and peripheral benzodiazepine receptors was determined in the pod and leaves of Ceratonia siliqua (carob). The amount of the substances able to selectively bind the central benzodiazepine receptor recovered from carob pods and leaves was respectively 12.17 and 18.7 ng diazepam equivalent/g. The amount of compounds active on peripheral benzodiazepine receptor in both pods and leaves was higher in comparison with the central one, being 49.83 and 40.00 PK 11195 equivalent/g, respectively. In particular the compounds acting on peripheral benzodiazepine receptors were found to be extremely concentrated in the young leaves (2572.57 ng PK 11195 equivalent/g). The presence of substances with central benzodiazepine activity in carob extracts seems of great importance in view of the possibility to use carob extract as potential natural products with anxiolytic-sedative effects. Moreover, the prevalence in leaves of substances acting on peripheral benzodiazepine receptor suggests the possible utilisation of leave extracts as chemopreventive agents.

  4. Characterization of ( sup 3 H)alprazolam binding to central benzodiazepine receptors

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    McCabe, R.T.; Mahan, D.R.; Smith, R.B.; Wamsley, J.K. (Neuropsychiatric Research Institute, Fargo, ND (USA))

    1990-10-01

    The binding of the triazolobenzodiazepine ({sup 3}H)alprazolam was studied to characterize the in vitro interactions with benzodiazepine receptors in membrane preparations of rat brain. Studies using nonequilibrium and equilibrium binding conditions for ({sup 3}H)alprazolam resulted in high specific to nonspecific (signal to noise) binding ratios. The binding of ({sup 3}H)alprazolam was saturable and specific with a low nanomolar affinity for benzodiazepine receptors in the rat brain. The Kd was 4.6 nM and the Bmax was 2.6 pmol/mg protein. GABA enhanced ({sup 3}H)alprazolam binding while several benzodiazepine receptor ligands were competitive inhibitors of this drug. Compounds that bind to other receptor sites had a very weak or negligible effect on ({sup 3}H)alprazolam binding. Alprazolam, an agent used as an anxiolytic and in the treatment of depression, acts in vitro as a selective and specific ligand for benzodiazepine receptors in the rat brain. The biochemical binding profile does not appear to account for the unique therapeutic properties which distinguish this compound from the other benzodiazepines in its class.

  5. Characterization of astrocytic and neuronal benzodiazepine receptors

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    Bender, A.S.

    1988-01-01

    Primary cultures of astrocytes and neurons express benzodiazepine receptors. Neuronal benzodiazepine receptors were of high-affinity, K{sub D} values were 7.5-43 nM and the densities of receptors (B{sub max}) were 924-4131 fmol/mg protein. Astrocytes posses a high-affinity benzodiazepine receptor, K{sub D} values were 6.6-13 nM. The B{sub max} values were 6,033-12,000 fmol/mg protein. The pharmacological profile of the neuronal benzodiazepine receptor was that of the central-type benzodiazepine receptor, where clonazepam has a high-affinity and Ro 5-4864 (4{prime}-chlorodiazepam) has a low-affinity. Whereas astrocytic benzoidazepine receptor was characteristic of the so called peripheral-type benzodiazepine receptors, which shows a high-affinity towards Ro 5-4863, and a low-affinity towards clonazepam. The astrocytic benzodiazepine receptors was functionally correlated with voltage dependent calcium channels, since dihydropyridines and benzodiazepines interacted with ({sup 3}H) diazepam and ({sup 3}H) nitrendipine receptors with the same rank order of potency, showing a statistically significant correlation. No such correlation was observed in neurons.

  6. Biological properties of 2'-[18F]fluoroflumazenil for central benzodiazepine receptor imaging.

    Science.gov (United States)

    Chang, Young Soo; Jeong, Jae Min; Yoon, Young Hyun; Kang, Won Jun; Lee, Seung Jin; Lee, Dong Soo; Chung, June-Key; Lee, Myung Chul

    2005-04-01

    A novel positron emitting agent, 2'-[18F]fluoroflumazenil (fluoroethyl 8-fluoro-5-methyl-6-oxo-5,6-dihydro-4H-benzo-[f]imidazo[1,5-a][1,4]diazepine-3-carboxylate, FFMZ), has been reported for benzodiazepine imaging. In the present study, biological properties of [18F]FFMZ were investigated. Stability tests of [18F]FFMZ in human and rat sera were performed. Biodistribution was investigated in mice and phosphorimages of brains were obtained from rats. A receptor binding assay was performed using rat brain (mixture of cortex and cerebellum) homogenate. A static positron emission tomography (PET) image was obtained from a normal human volunteer. Although [18F]FFMZ was stable in human serum, it was rapidly hydrolyzed in rat serum. The hydrolysis was 39%, 63% and 92% at 10, 30 and 60 min, respectively. According to the biodistribution study in mice, somewhat even distribution (between 2 approximately 3% ID/g) was observed in most organs. Intestinal uptake increased up to 6% ID/g at 1 h due to biliary excretion. Bone uptake slowly increased from 1.5% to 3.5% ID/g at 1 h. High uptakes in the cortex, thalamus and cerebellum, which could be completely blocked by coinjection of cold FMZ, were observed by phosphorimaging study using rats. Determination of Kd value and Bmax using rat brain tissue was performed by Scatchard plotting and found 1.45+/-0.26 nM and 1.08+/-0.03 pmol/mg protein, respectively. The PET image of the normal human volunteer showed high uptake in the following decreasing order: frontal cortex, temporal cortex, occipital cortex, cerebellum, parietal cortex and thalamus. In conclusion, the new FMZ derivative, [18F]FFMZ appears to be a promising PET agent for central benzodiazepine receptor imaging with a convenient labeling procedure and a specific binding property.

  7. Central and peripheral benzodiazepine receptors in rat brain and platelets: effects of treatment with diazepam and clobazam.

    Science.gov (United States)

    Larkin, J G; Thompson, G G; Scobie, G; Brodie, M J

    1992-09-01

    Tolerance to the effects of benzodiazepines (BZ) may be mediated by changes in benzodiazepine receptors (BZRs). Peripheral BZRs (in brain and platelets) and central BZRs (in brain) were measured in rats following intraperitoneal administration of diazepam and clobazam each for 4 and 12 days. BZRs were measured by binding assays using [3H] PK 11195 (peripheral) and [3H] flunitrazepam (central) as radioligands. Diazepam, but not clobazam, increased peripheral BZR numbers in platelets (both P < 0.005), but not in brain, after 4 and 12 days' treatment compared with appropriate controls. Neither drug altered central BZR affinities or numbers in rat brain. BZ effects on peripheral BZRs in platelets cannot be extrapolated to predict changes in brain receptors, either peripheral or central.

  8. Synthesis and in vivo evaluation of [{sup 11}C]zolpidem, an imidazopyridine with agonist properties at central benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, Filip; Waterhouse, Rikki N. E-mail: rnw7@columbia.edu; Montoya, Julie A.; Mattner, Filomena; Katsifis, Andrew; Kegeles, Lawrence S.; Laruelle, Marc

    2003-05-01

    The synthesis and evaluation of [{sup 11}C]zolpidem, an imidazopyridine with agonist properties at central benzodiazepine receptors, is reported herein. The reaction of desmethylzolpidem with [{sup 11}C] methyl iodide afforded the title compound [{sup 11}C]zolpidem in a yield of 19.19 {+-} 3.23% in 41 {+-} 2 min in specific activities of 0.995-1.19 Ci/{mu}mol (1.115 {+-} 0.105 Ci/{mu}mol) (n = 3; decay corrected, EOB). The amount of radioactivity in the brain after tail vein injection in male Wistar rats was low, and the regional distribution was homogeneous and not consistent with the known distribution of the central benzodiazepine receptors. The frontal cortex/cerebellum ratio was not significantly greater than one (1.007 {+-} 0.266 at 5 min) and did not increase from 5 to 40 min post-injection. A PET brain imaging study in one baboon confirmed the results obtained in rats. Therefore, it can be concluded that [{sup 11}C]zolpidem is not a suitable tracer for in vivo visualization of central benzodiazepine receptors.

  9. Structure-activity relationship of miltirone, an active central benzodiazepine receptor ligand isolated from Salvia miltiorrhiza Bunge (Danshen)

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    Chang, H.M.; Chui, K.Y.; Tan, F.W.; Yang, Y.; Zhong, Z.P.; Lee, C.M.; Sham, H.L.; Wong, H.N. (Chinese Univ. of Hong Kong, Shatin (Hong Kong))

    1991-05-01

    Twenty one o-quinonoid-type compounds and one coumarin-type compound related to miltirone (1) have been synthesized with the aim to identify the key structural elements involved in miltirone's interaction with the central benzodiazepine receptor. On the basis of their inhibition of ({sup 3}H)flunitrazepam binding to bovine cerebral cortex membranes, it is apparent that ring A of miltirone is essential for affinity. Although increasing the size of ring A from six-membered to seven- and eight-membered is well-tolerated, the introduction of polar hydroxyl groups greatly reduces binding affinity. The presence of 1,1-dimethyl groups on ring A is, however, not essential. On the other hand, the isopropyl group on ring C appears to be critical for binding as its removal decreases affinity by more than 30-fold. It can, however, be replaced with a methyl group with minimal reduction in affinity. Finally, linking ring A and B with a -CH{sub 2}CH{sub 2}- bridge results in analogue 89, which is 6 times more potent than miltirone at the central benzodiazepine receptor (IC50 = 0.05 microM).

  10. New insight into the central benzodiazepine receptor-ligand interactions: design, synthesis, biological evaluation, and molecular modeling of 3-substituted 6-phenyl-4H-imidazo[1,5-a][1,4]benzodiazepines and related compounds.

    Science.gov (United States)

    Anzini, Maurizio; Valenti, Salvatore; Braile, Carlo; Cappelli, Andrea; Vomero, Salvatore; Alcaro, Stefano; Ortuso, Francesco; Marinelli, Luciana; Limongelli, Vittorio; Novellino, Ettore; Betti, Laura; Giannaccini, Gino; Lucacchini, Antonio; Daniele, Simona; Martini, Claudia; Ghelardini, Carla; Di Cesare Mannelli, Lorenzo; Giorgi, Gianluca; Mascia, Maria Paola; Biggio, Giovanni

    2011-08-25

    3-Substituted 6-phenyl-4H-imidazo[1,5-a][1,4]benzodiazepines and related compounds were synthesized as central benzodiazepine receptor (CBR) ligands. Most of the compounds showed high affinity for bovine and human CBR, their K(i) values spanning from the low nanomolar to the submicromolar range. In particular, imidazoester 5f was able to promote a massive flow of (36)Cl(-) in rat cerebrocortical synaptoneurosomes overlapping its efficacy profile with that of a typical full agonist. Compound 5f was then examined in mice for its pharmacological effects where it proved to be a safe anxiolytic agent devoid of the unpleasant myorelaxant and amnesic effects of the classical 1,4-benzodiazepines. Moreover, the selectivity of some selected compounds has been assessed in recombinant α(1)β(2)γ(2)L, α(2)β(1)γ(2)L, and α(5)β(2)γ(2)L human GABA(A) receptors. Finally, some compounds were submitted to molecular docking calculations along with molecular dynamics simulations in the Cromer's GABA(A) homology model.

  11. Benzodiazepine receptor antagonists for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Gluud, L L; Gluud, C

    2004-01-01

    Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy....

  12. Imaging of a glioma using peripheral benzodiazepine receptor ligands

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    Starosta-Rubinstein, S.; Ciliax, B.J.; Penney, J.B.; McKeever, P.; Young, A.B.

    1987-02-01

    Two types of benzodiazepine receptors have been demonstrated in mammalian tissues, one which is localized on neuronal elements in brain and the other, on glial cells and in peripheral tissues such as kidney. In vivo administration of /sup 3/H-labeled PK 11195 (1-(2-chlorophenyl-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide) or (/sup 3/H)flunitrazepam with 5 mg of clonazepam per kg to rats with intracranial C6 gliomas resulted in high levels of tritiated-drug binding to the tumor as shown by quantitative autoradiography. Pharmacological studies indicated that the bound drugs labeled the peripheral benzodiazepine binding site. Binding to the peripheral benzodiazepine site was confirmed primarily to malignant cells with little binding to adjacent normal brain tissue or to necrotic tissue. Tumor cell binding was completely inhibited by preadministration of the peripheral benzodiazepine blocking agent PK 11195 at 5 mg/kg. The centrally selective benzodiazepine ligand clonazepam had no effect on PK 11195 binding to the tumor cells. When binding to other tumor cell lines grown in nude mice and nude athymic rats was evaluated, little or no peripheral benzodiazepine binding was detected on human pheochromocytoma (RN1) and neuroblastoma (SK-N-MC, SK-N-SH) tumor cells, respectively. However, high densities of peripheral benzodiazepine binding sites were observed on tumors derived from a human glioma cell line (ATCC HTB 14, U-87 MG). The presence of high concentrations of specific peripheral benzodiazepine receptors on glial tumors suggests that human primary central nervous system tumors could be imaged and diagnosed using peripheral benzodiazepine ligands labeled with positron- or gamma-emitting isotopes.

  13. Mitochondrial benzodiazepine receptors regulate steroid biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Mukhin, A.G.; Papadopoulos, V.; Costa, E.; Krueger, K.E. (Georgetown Univ. School of Medicine, Washington, DC (USA))

    1989-12-01

    Recent observations on the steroid synthetic capability within the brain open the possibility that benzodiazepines may influence steroid synthesis in nervous tissue through interactions with peripheral-type benzodiazepine recognition sites, which are highly expressed in steroidogenic cells and associated with the outer mitochondrial membrane. To examine this possibility nine molecules that exhibit a greater than 10,000-fold difference in their affinities for peripheral-type benzodiazepine binding sites were tested for their effects on a well-established steroidogenic model system, the Y-1 mouse adrenal tumor cell line. 4{prime}-Chlorodiazepam, PK 11195, and PK 14067 stimulated steroid production by 2-fold in Y-1 cells, whereas diazepam, flunitrazepam, zolpidem, and PK 14068 displayed a lower (1.2- to 1.5-fold) maximal stimulation. In contrast, clonazepam and flumazenil did not stimulate steroid synthesis. The potencies of these compounds to inhibit {sup 3}H-labeled PK 11195 binding to peripheral-type benzodiazepine recognition sites correlated with their potencies to stimulate steroid production. Similar findings were observed in bovine and rat adrenocortical cell preparations. These results suggest that ligands of the peripheral-type benzodiazepine recognition site acting on this mitochondrial receptor can enhance steroid production. This action may contribute specificity to the pharmacological profile of drugs preferentially acting on the benzodiazepine recognition site associated with the outer membrane of certain mitochondrial populations.

  14. Autoradiographic localization of benzodiazepine receptor downregulation

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    Tietz, E.I.; Rosenberg, H.C.; Chiu, T.H.

    1986-01-01

    Regional differences in downregulation of brain benzodiazepine receptors were studied using a quantitative autoradiographic method. Rats were given a 4-week flurazepam treatment known to cause tolerance and receptor downregulation. A second group of rats was given a similar treatment, but for only 1 week. A third group was given a single acute dose of diazepam to produce a brain benzodiazepine-like activity equivalent to that found after the chronic treatment. Areas studied included hippocampal formation, cerebral cortex, superior colliculus, substantia nigra, dorsal geniculate nucleus, lateral amygdala and lateral hypothalamus. There was a regional variation in the degree of downregulation after 1 week of flurazepam treatment, ranging from 12% to 25%. Extending the flurazepam treatment to 4 weeks caused little further downregulation in those areas studied, except for the pars reticulata of the substantia nigra, which showed a 13% reduction in (/sup 3/H)flunitrazepam binding after 1 week and a 40% reduction after 4 weeks of treatment. In a few areas, such as the lateral hypothalamus, no significant change in binding was found after 4 weeks. Acute diazepam treatment caused no change in binding. This latter finding as well as results obtained during the development of the methodology show that downregulation was not an artifact due to residual drug content of brain slices. The regional variations in degree and rate of downregulation suggest areas that may be most important for benzodiazepine tolerance and dependence and may be related to the varying time courses for tolerance to different benzodiazepine actions.

  15. The bovine peripheral-type benzodiazepine receptor: A receptor with low affinity for benzodiazepines

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    Parola, A.L.; Laird, H.E. II (Univ. of Arizona, Tucson (USA))

    1991-01-01

    The density of bovine peripheral-type benzodiazepine receptors (PBR) in four tissues was highest in adrenal cortex. The adrenal cortex PBR cofractionated with a mitochondrial membrane marker enzyme and could be solubilized with intact ligand binding properties using digitonin. The membrane bound and soluble mitochondrial receptors were pharmacologically characterized and showed the rank order of potency to inhibit ({sup 3}H)PK 11195 binding was PK 11195 > protoporphyrin IX > benzodiazepines. ({sup 3}H)PK 11195 binding to bovine adrenal mitochondria was unaffected by diethylpyrocarbonate, a histidine residue modifying reagent that decreased binding to rat liver mitochondria by 70%. ({sup 3}H)PK 14105 photolabeled the bovine PBR and the Mr was estimated under nondenaturing and denaturing conditions. These results demonstrate the bovine peripheral-type benzodiazepine receptor is pharmacologically and biochemically distinct from the rat receptor, but the receptor component photolabeled by an isoquinoline ligand has a similar molecular weight.

  16. Purification of high affinity benzodiazepine receptor binding site fragments from rat brain

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    Klotz, K.L.

    1984-01-01

    In central nervous system benzodiazepine recognition sites occur on neuronal cell surfaces as one member of a multireceptor complex, including recognition sites for benzodiazepines, gamma aminobutyric acid (GABA), barbiturates and a chloride ionophore. During photoaffinity labelling, the benzodiazepine agonist, /sup 3/H-flunitrazepam, is irreversibly bound to central benzodiazepine high affinity recognition sites in the presence of ultraviolet light. In these studies a /sup 3/H-flunitrazepam radiolabel was used to track the isolation and purification of high affinity agonist binding site fragments from membrane-bound benzodiazepine receptor in rat brain. The authors present a method for limited proteolysis of /sup 3/H-flunitrazepam photoaffinity labeled rat brain membranes, generating photolabeled benzodiazepine receptor fragments containing the agonist binding site. Using trypsin chymotrypsin A/sub 4/, or a combination of these two proteases, they have demonstrated the extent and time course for partial digestion of benzodiazepine receptor, yielding photolabeled receptor binding site fragments. These photolabeled receptor fragments have been further purified on the basis of size, using ultrafiltration, gel permeation chromatography, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) as well as on the basis of hydrophobicity, using a high performance liquid chromatography (HPLC) precolumn, several HPLC elution schemes, and two different HPLC column types. Using these procedures, they have purified three photolabeled benzodiazepine receptor fragments containing the agonist binding site which appear to have a molecular weight of less than 2000 daltons each.

  17. Midazolam ameliorates the behavior deficits of a rat posttraumatic stress disorder model through dual 18 kDa translocator protein and central benzodiazepine receptor and neurosteroidogenesis.

    Directory of Open Access Journals (Sweden)

    Yu-Liang Miao

    Full Text Available Post-traumatic stress disorder (PTSD is a debilitating anxiety disorder that may develop after an individual has experienced or witnessed a severe traumatic event. It has been shown that the 18 kDa translocator protein (TSPO may be correlated with PTSD and that the TSPO ligand improved the behavioral deficits in a mouse model of PTSD. Midazolam, a ligand for TSPO and central benzodiazepine receptor (CBR, induces anxiolytic- and anti-depressant-like effects in animal models. The present study aimed to determine whether midazolam ameliorates PTSD behavior in rats as assessed by the single prolonged stress (SPS model. The SPS rats received daily Sertraline (Ser (15 mg/kg, i.p. [corrected] and midazolam (0.125, 0.25, 0.5, and 1 mg/kg, i.p. [corrected] during the exposure to SPS and behavioral assessments, which included the open field (OF test, the contextual fear paradigm (CFP, and the elevated plus-maze (EPM. The results showed that, like Ser (15 mg/kg, i.p. [corrected], midazolam (0.25 and 0.5 mg/kg, i.p. [corrected] significantly reversed the behavioral deficiencies of the SPS rats, including PTSD-associated freezing and anxiety-like behavior but not the effects on spontaneous locomotor activity. In addition, the anti-PTSD effects of midazolam (0.5 mg/kg, i.p. [corrected] were antagonized by the TSPO antagonist PK11195 (3 mg/kg, i.p., the CBR antagonist flumazenil (15 mg/kg, i.p. [corrected] and the inhibitor of steroidogenic enzymes finasteride (30 mg/kg, i.p. [corrected], which by themselves had no effect on PTSD-associated freezing and anxiety-like behavior. In summary, this study demonstrated that midazolam improves the behavioral deficits in the SPS model through dual TSPO and CBR and neurosteroidogenesis.

  18. Midazolam Ameliorates the Behavior Deficits of a Rat Posttraumatic Stress Disorder Model through Dual 18 kDa Translocator Protein and Central Benzodiazepine Receptor and Neurosteroidogenesis

    Science.gov (United States)

    Fang, Wei-Wu; Liu, Yan; Liu, Ji; Li, Bao-Wei; Wu, Wei; Li, Yun-Feng

    2014-01-01

    Post-traumatic stress disorder (PTSD) is a debilitating anxiety disorder that may develop after an individual has experienced or witnessed a severe traumatic event. It has been shown that the 18 kDa translocator protein (TSPO) may be correlated with PTSD and that the TSPO ligand improved the behavioral deficits in a mouse model of PTSD. Midazolam, a ligand for TSPO and central benzodiazepine receptor (CBR), induces anxiolytic- and anti-depressant-like effects in animal models. The present study aimed to determine whether midazolam ameliorates PTSD behavior in rats as assessed by the single prolonged stress (SPS) model. The SPS rats received daily Sertraline (Ser) (15 mg/kg, p.o.) and midazolam (0.125, 0.25, 0.5, and 1 mg/kg, p.o.) during the exposure to SPS and behavioral assessments, which included the open field (OF) test, the contextual fear paradigm (CFP), and the elevated plus-maze (EPM). The results showed that, like Ser (15 mg/kg, p.o.), midazolam (0.25 and 0.5 mg/kg, p.o.) significantly reversed the behavioral deficiencies of the SPS rats, including PTSD-associated freezing and anxiety-like behavior but not the effects on spontaneous locomotor activity. In addition, the anti-PTSD effects of midazolam (0.5 mg/kg, p.o.) were antagonized by the TSPO antagonist PK11195 (3 mg/kg, i.p.), the CBR antagonist flumazenil (15 mg/kg, p.o.) and the inhibitor of steroidogenic enzymes finasteride (30 mg/kg, p.o.), which by themselves had no effect on PTSD-associated freezing and anxiety-like behavior. In summary, this study demonstrated that midazolam improves the behavioral deficits in the SPS model through dual TSPO and CBR and neurosteroidogenesis. PMID:24988461

  19. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

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    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-06-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  20. Evaluation of a radiolabelled peripheral benzodiazepine receptor ligand in the central nervous system inflammation of experimental autoimmune encephalomyelitis: a possible probe for imaging multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Mattner, F.; Katsifis, A.; Ballantyne, P. [ANSTO, Radiopharmaceuticals Division, Lucas Heights (Australia); Staykova, M.; Willenborg, D.O. [Australian National University Medical School, The Canberra Hospital, Neurosciences Research Unit, Woden, Canberra (Australia)

    2005-04-01

    Peripheral benzodiazepine receptors (PBRs) are upregulated on macrophages and activated microglia, and radioligands for the PBRs can be used to detect in vivo neuroinflammatory changes in a variety of neurological insults, including multiple sclerosis. Substituted 2-phenyl imidazopyridine-3-acetamides with high affinity and selectivity for PBRs have been prepared that are suitable for radiolabelling with a number of positron emission tomography and single-photon emission computed tomography (SPECT) isotopes. In this investigation, the newly developed high-affinity PBR ligand 6-chloro-2-(4'-iodophenyl)-3-(N,N-diethyl)imidazo[1,2-a]pyridine-3-acetamide, or CLINDE, was radiolabelled with{sup 123}I and its biodistribution in the central nervous system (CNS) of rats with experimental autoimmune encephalomyelitis (EAE) evaluated. EAE was induced in male Lewis rats by injection of an emulsion of myelin basic protein and incomplete Freund's adjuvant containing Mycobacterium butyricum. Biodistribution studies with{sup 123}I-CLINDE were undertaken on EAE rats exhibiting different clinical disease severity and compared with results in controls. Disease severity was confirmed by histopathology in the spinal cord of rats. The relationship between inflammatory lesions and PBR ligand binding was investigated using ex vivo autoradiography and immunohistochemistry on rats with various clinical scores. {sup 123}I-CLINDE uptake was enhanced in the CNS of all rats exhibiting EAE when compared to controls. Binding reflected the ascending nature of EAE inflammation, with lumbar/sacral cord > thoracic cord > cervical cord > medulla. The amount of ligand binding also reflected the clinical severity of disease. Ex vivo autoradiography and immunohistochemistry revealed a good spatial correspondence between radioligand signal and foci of inflammation and in particular ED-1{sup +} cells representing macrophages and microglia. These results demonstrate the ability of {sup 123}I

  1. Hooked on benzodiazepines: GABAA receptor subtypes and addiction

    Science.gov (United States)

    Tan, Kelly R.; Rudolph, Uwe; Lüscher, Christian

    2011-01-01

    Benzodiazepines are widely used clinically to treat anxiety and insomnia. They also induce muscle relaxation, control epileptic seizures, and can provoke amnesia. Moreover, benzodiazepines are often abused after chronic clinical treatment but also for recreational purposes. Within weeks, tolerance to the pharmacological effects can develop, in addition to dependence and even addiction in vulnerable individuals. Here, we review recent observations from animal models regarding the cellular and molecular basis that may underlie the addictive properties of benzodiazepines. These data reveal how benzodiazepines, acting through specific GABAA receptor subtypes, activate midbrain dopamine neurons and how this may hijack the mesolimbic reward system. Such findings have important implications for the future design of benzodiazepines with reduced or even absent addiction liability. PMID:21353710

  2. Daily rhythms of benzodiazepine receptor numbers in frontal lobe and cerebellum of the rat

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    Brennan, M.J.W.; Volicer, L.; Moore-Ede, M.C.; Borsook, D.

    1985-06-17

    Behavioral, biochemical and neurophysiological evidence suggests that gamma-aminobutyric acid (GABA) may play an important role in the neural control of circadian rhythms. Central receptors for benzodiazepines are functionally coupled to GABA receptors and appear to mediate behavioral effects of exogenous benzodiazepines. The binding of /sup 3/H-flunitrazepam to synaptic plasma membranes prepared from various regions of rat brain was examined at 6-hour intervals over a 36-hour period. Prominent daily rhythms in receptor number (Bmax) were observed in the frontal lobe and the cerebellum but not in the temporoparietal regions, hypothalamus or medulla/pons. Binding was highest during periods of sleep/low activity with a significant decrease occurring just prior to waking. These results suggest that daily fluctuations in benzodiazepine receptor numbers may be related to the temporal control of sleep/wake and muscle activity cycles. 23 references, 1 figure, 1 table.

  3. Peripheral-type benzodiazepine receptor: a protein of mitochondrial outer membranes utilizing porphyrins as endogenous ligands

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S.H.; Verma, A.; Trifiletti, R.R.

    1987-10-01

    The peripheral-type benzodiazepine receptor is a site identified by its nanomolar affinity for (/sup 3/H)diazepam, similar to the affinity of diazepam for the central-type benzodiazepine receptor in the brain. The peripheral type benzodiazepine receptor occurs in many peripheral tissues but has discrete localizations as indicated by autoradiographic studies showing uniquely high densities of the receptors in the adrenal cortex and in Leydig cells of the testes. Subcellular localization studies reveal a selective association of the receptors with the outer membrane of mitochondria. Photoaffinity labeling of the mitochondrial receptor with (/sup 3/H)flunitrazepam reveals two discrete labeled protein bands of 30 and 35 kDa, respectively. The 35-kDa band appears to be identical with the voltage-dependent anion channel protein porin. Fractionation of numerous peripheral tissues reveals a single principal endogenous ligand for the receptor, consisting of porphyrins, which display nanomolar affinity. Interactions of porphyrins with the mitochondrial receptor may clarify its physiological role and account for many pharmacological actions of benzodiazepines.

  4. High affinity ligands for 'diazepam-insensitive' benzodiazepine receptors.

    Science.gov (United States)

    Wong, G; Skolnick, P

    1992-01-14

    Structurally diverse compounds have been shown to possess high affinities for benzodiazepine receptors in their 'diazepam-sensitive' (DS) conformations. In contrast, only the imidazobenzodiazepinone Ro 15-4513 has been shown to exhibit a high affinity for the 'diazepam-insensitive' (DI) conformation of benzodiazepine receptors. We examined a series of 1,4-diazepines containing one or more annelated ring systems for their affinities at DI and DS benzodiazepine receptors, several 1,4-diazepinone carboxylates including Ro 19-4603, Ro 16-6028 and Ro 15-3505 were found to possess high affinities (Ki approximately 2.6-20 nM) for DI. Nonetheless, among the ligands examined, Ro 15-4513 was the only substance with a DI/DS potency ratio approximately 1; other substances had ratios ranging from 13 to greater than 1000. Ligands with high to moderate affinities at DI were previously classified as partial agonists, antagonists, or partial inverse agonists at DS benzodiazepine receptors, but behaved as 'GABA neutral' (antagonist) substances at DI. The identification of several additional high affinity ligands at DI benzodiazepine receptors may be helpful in elucidating the pharmacological and physiological importance of these sites.

  5. High-affinity benzodiazepine receptor ligands among benzodiazepines and betacarbolines with different intrinsic activity

    Energy Technology Data Exchange (ETDEWEB)

    Yliniemelae, A.; Gynther, J. (Univ. of Kuopio (Finland)); Konschin, H.; Tylli, H. (Univ. of Helsinki (Finland)); Rouvinen, J. (Univ. of Joensuu (Finland))

    1989-01-01

    Structural and electrostatic features of diazepam, flumazenil, and methyl betacarboline-3-carboxylate (BCCM) have been investigated using the molecular superimposition method. These high-affinity benzodiazepine (BZ) receptor ligands are structurally unrelated and they have different intrinsic activity. These ligands are superimposed in such a way that common structural and electrostatic features essential for the high receptor binding affinity overlap. In addition to this binding pharmacophore, there are roughly three separate binding zones in the BZ receptor, one for each class of ligands. The intrinsic activity of BZ receptor ligands depends on the molecular structures and the way the ligand approaches the receptor.

  6. Benzodiazepine receptor antagonists for acute and chronic hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Kjaergard, L L; Gluud, C

    2001-01-01

    The pathogenesis of hepatic encephalopathy is unknown. It has been suggested that liver failure leads to the accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition which may progress to coma. Several trials have assessed benzodiazepine receptor...

  7. Fluorescent-labeled ligands for the benzodiazepine receptor - Part 1 : Synthesis and characterization of fluorescent-labeled benzodiazepines

    NARCIS (Netherlands)

    Janssen, MJ; Hulst, R; Kellogg, RM; Hendriks, MMWB; Ensing, K; De Zeeuw, RA

    2000-01-01

    Because radioactive labeled ligands in receptor assays have several disadvantages, we synthesized a number of fluorescent-labeled benzodiazepines. Several fluorophores were attached at different positions of 1,4-benzodiazepine molecules in order to assess the impact of the fluorophores and their cou

  8. A fluorescent receptor assay for benzodiazepines using coumarin labeled desethylflumazenil as ligand

    NARCIS (Netherlands)

    Janssen, M.J; Ensing, K; de Zeeuw, R.A

    2001-01-01

    This article describes a novel nonisotopic receptor assay for benzodiazepines with fluorescence detection, As labeled ljgand (coumarin-labeled desethylflumazenil, CLDEF), a metabolite of the benzodiazepine antagonist flumazenil (desetheylflumazenil, Ro15-3890) has been coupled to a coumarin fluoroph

  9. Benzodiazepine receptor-mediated behavioral effects of nitrous oxide in the rat social interaction test.

    Science.gov (United States)

    Quock, R M; Wetzel, P J; Maillefer, R H; Hodges, B L; Curtis, B A; Czech, D A

    1993-09-01

    The present study was conducted to ascertain whether an anxiolytic effect of nitrous oxide was demonstrable in rats using the social interaction test and whether this drug effect might be mediated by benzodiazepine receptors. Compared to behavior of vehicle-pretreated, room air-exposed rats, rat pairs exposed to nitrous oxide showed a generally inverted U-shaped dose-response curve with the maximum increase in social interaction encounters occurring at 25% and significant increase in time of active social interaction at 15-35%; higher concentrations produced a sedative effect that reduced social interaction. Treatment with 5.0 mg/kg of the anxiolytic benzodiazepine chlordiazepoxide also increased social interaction. Pretreatment with 10 mg/kg of the benzodiazepine receptor blocker flumazenil, which alone had no effect, significantly antagonized the social interaction-increasing effects of both nitrous oxide and chlordiazepoxide. In summary, these findings suggest that nitrous oxide produces a flumazenil-sensitive effect comparable to that of chlordiazepoxide and implicate central benzodiazepine mechanisms in mediation of the anxiolytic effect of nitrous oxide.

  10. Effects of peripheral-type benzodiazepine receptor ligands on Ehrlich tumor cell proliferation.

    Science.gov (United States)

    Sakai, Mônica; Fonseca, Evelise Souza Monteiro; Oloris, Silvia Catarina Salgado; Matsuzaki, Patrícia; Otake, Andréia Hanada; Leite, Kátia Ramos Moura; Massoco, Cristina Oliveira; Dagli, Maria Lúcia Zaidan; Palermo-Neto, João

    2006-11-21

    Peripheral-type benzodiazepine receptors have been found throughout the body, and particularly, in high numbers, in neoplastic tissues such as the ovary, liver, colon, breast, prostate and brain cancer. Peripheral-type benzodiazepine receptor expression has been associated with tumor malignity, and its subcellular localization is important to define its function in tumor cells. We investigated the presence of peripheral-type benzodiazepine receptors in Ehrlich tumor cells, and the in vitro effects of peripheral-type benzodiazepine receptors ligands on tumor cell proliferation. Our results demonstrate the presence of peripheral-type benzodiazepine receptor in the nucleus of Ehrlich tumor cells (85.53+/-12.60%). They also show that diazepam and Ro5-4864 (peripheral-type benzodiazepine receptor agonists) but not clonazepam (a molecule with low affinity for the peripheral-type benzodiazepine receptor) decreased the percentage of tumor cells in G0-G1 phases and increased that of cells in S-G2-M phases. The effects of those agonists were prevented by PK11195 (a peripheral-type benzodiazepine receptor antagonist) that did not produce effects by itself. Altogether, these data suggest that the presence of peripheral-type benzodiazepine receptor within the nucleus of Ehrlich tumor cells is associated with tumor malignity and proliferation capacity.

  11. Micromolar-Affinity Benzodiazepine Receptors Regulate Voltage-Sensitive Calcium Channels in Nerve Terminal Preparations

    Science.gov (United States)

    Taft, William C.; Delorenzo, Robert J.

    1984-05-01

    Benzodiazepines in micromolar concentrations significantly inhibit depolarization-sensitive Ca2+ uptake in intact nerve-terminal preparations. Benzodiazepine inhibition of Ca2+ uptake is concentration dependent and stereospecific. Micromolar-affinity benzodiazepine receptors have been identified and characterized in brain membrane and shown to be distinct from nanomolar-affinity benzodiazepine receptors. Evidence is presented that micromolar, and not nanomolar, benzodiazepine binding sites mediate benzodiazepine inhibition of Ca2+ uptake. Irreversible binding to micromolar benzodiazepine binding sites also irreversibly blocked depolarization-dependent Ca2+ uptake in synaptosomes, indicating that these compounds may represent a useful marker for identifying the molecular components of Ca2+ channels in brain. Characterization of benzodiazepine inhibition of Ca2+ uptake demonstrates that these drugs function as Ca2+ channel antagonists, because benzodiazepines effectively blocked voltage-sensitive Ca2+ uptake inhibited by Mn2+, Co2+, verapamil, nitrendipine, and nimodipine. These results indicate that micromolar benzodiazepine binding sites regulate voltage-sensitive Ca2+ channels in brain membrane and suggest that some of the neuronal stabilizing effects of micromolar benzodiazepine receptors may be mediated by the regulation of Ca2+ conductance.

  12. Synthesis of ethyl 8-fluoro-5,6-dihydro-5-(/sup 11/C)methyl-6-oxo-4H-imidazo(1,5-a)(1,4)benzodiazepine-3-carboxylate (RO 15. 1788-/sup 11/C): a specific radioligand for the in vivo study of central benzodiazepine receptors by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Maziere, M.; Hantraye, P.; Prenant, C.; Sastre, J.; Comar, D. (CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot)

    1984-10-01

    A method of labelling ethyl 8-fluoro-5,6-dihydro-5-(/sup 11/C) methyl-6-oxo-4H-imidazo(1,5-a)(1,4)benzodiazepine-3-carboxylate (RO 15.1788 /sup 11/C), a benzodiazepine antagonist with carbon-11 has been developed. RO 15.1788-/sup 11/C was prepared by methylation of the nor derivative by I/sup 11/CH/sub 3/. About 100 mCi (maximum 153 mCi, 5.66 GBq) of the chemically and radiochemically pure labelled product were obtained within 25 min with a specific activity on average of 1100 mCi/..mu.. mol (maximum 1740 mCi/..mu..mol-64.4 GBq/..mu..mol). Preliminary results obtained after i.v. administration in the baboon have shown RO 15.1788-/sup 11/C to be of interest as a benzodiazepine radioligand for the in vivo study of benzodiazepine receptors by positron emission tomography.

  13. Benzodiazepine receptor ligands: a patent review (2006 -- 2012)

    OpenAIRE

    2013-01-01

    Introduction: Ligands at the benzodiazepine site of the GABAA receptor (GABAA-R) act by modulating the effect of GABAA (g-aminobutyric acid). The selective modulator effects of such ligands are related to the a-subunits type (i.e., a1, a2, a3, and a5), being shown that the a1 subunit is associated with sedative, anticonvulsant and amnesic effects; whereas the a2 and a3 subunits mediate anxiolytic and myorelaxant effects. Recently it was shown the involvement of a5 subunit in...

  14. Flumazenil-sensitive dose-related physical dependence in planarians produced by two benzodiazepine and one non-benzodiazepine benzodiazepine-receptor agonists.

    Science.gov (United States)

    Raffa, Robert B; Cavallo, Federica; Capasso, Anna

    2007-06-14

    Two benzodiazepine (midazolam and clorazepate) and one non-benzodiazepine (zolpidem) benzodiazepine-receptor agonists produced dose-related physical dependence, as evidenced by abstinence-induced decrease in planarian locomotor velocity (pLMV) when drug-exposed planarians were placed into drug-free water, but not when they were placed into drug-containing water (i.e., an abstinence-induced withdrawal, since the effect was only obtained in the removal of drug and not in the continued presence of drug). We have previously shown that the decrease in pLMV is associated with specific and transient withdrawal signs. In the present study, the selective benzodiazepine-receptor antagonist flumazenil significantly antagonized (Pbenzodiazepine-receptor agonists, for two different chemical categories, produce dose-related physical dependence manifested as abstinence-induced withdrawal in this simple and convenient model, and (2) in the absence of cloning or radioligand binding literature, suggest a possible specific interaction site (receptor?) for these compounds in planarians.

  15. Abuse and dependence liability of benzodiazepine-type drugs: GABA(A) receptor modulation and beyond.

    Science.gov (United States)

    Licata, Stephanie C; Rowlett, James K

    2008-07-01

    Over the past several decades, benzodiazepines and the newer non-benzodiazepines have become the anxiolytic/hypnotics of choice over the more readily abused barbiturates. While all drugs from this class act at the GABA(A) receptor, benzodiazepine-type drugs offer the clear advantage of being safer and better tolerated. However, there is still potential for these drugs to be abused, and significant evidence exists to suggest that this is a growing problem. This review examines the behavioral determinants of the abuse and dependence liability of benzodiazepine-type drugs. Moreover, the pharmacological and putative biochemical basis of the abuse-related behavior is discussed.

  16. The benzodiazepine receptor in rat brain and its interaction with ethyl beta-carboline-3-carboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Martin, I.L.; Doble, A.

    1983-06-01

    (3H)Ethyl beta-carboline-3-carboxylate ((3H) beta-CCE) binds to a homogeneous population of recognition sites in rat whole brain membranes with high affinity. The (3H)beta-CCE binding is completely displaceable by low concentrations of a number of benzodiazepines with similar potencies found when using a 3H-benzodiazepine as the ligand. This suggests that the recognition sites for beta-CCE and the benzodiazepines are identical or that they are involved in a close interaction. The binding of (3H)beta-CCE does not obey simple mass-action kinetics. (3H)Flunitrazepam dissociation from its receptor population is biphasic, and different methods of initiation of this dissociation indicate that cooperative interactions take place within the receptor population. We conclude that the benzodiazepine receptor is a single entity that can exist in two conformations, the equilibrium between which may be controlled by some as yet unidentified factor.

  17. Soman- or kainic acid-induced convulsions decrease muscarinic receptors but not benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Churchill, L.; Pazdernik, T.L.; Cross, R.S.; Nelson, S.R.; Samson, F.E. (Univ. of Kansas Medical Center, Kansas City (USA))

    (3H)Quinuclidinyl benzilate (QNB) binding to muscarinic receptors decreased in the rat forebrain after convulsions induced by a single dose of either soman, a potent inhibitor of acetylcholinesterase, or kainic acid, an excitotoxin. A Rosenthal plot revealed that the receptors decreased in number rather than affinity. When the soman-induced convulsions were blocked, the decrease in muscarinic receptors at 3 days was less extensive than when convulsions occurred and at 10 days they approached control levels in most of the brain areas. The most prominent decrements in QNB binding were in the piriform cortex where the decline in QNB binding is probably related to the extensive convulsion-associated neuropathology. The decrements in QNB binding after convulsions suggest that the convulsive state leads to a down-regulation of muscarinic receptors in some brain areas. In contrast to the decrease in QNB binding after convulsions, (3H)flunitrazepam binding to benzodiazepine receptors did not change even in the piriform cortex where the loss in muscarinic receptors was most prominent. Thus, it appears that those neuronal processes that bear muscarinic receptors are more vulnerable to convulsion-induced change than those with benzodiazepine receptors.

  18. Regulation of renal peripheral benzodiazepine receptors by anion transport inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Basile, A.S.; Lueddens, W.M.; Skolnick, P.

    1988-01-01

    The in vitro and in vivo regulation of (/sup 3/H)Ro 5-4864 binding to peripheral benzodiazepine receptors (PBR) by ion transport/exchange inhibitors was studied in the kidney. The potencies of 9-anthroic acid, furosemide, bumetanide, hydrochlorothiazide and SITS as inhibitors of (/sup 3/H)Ro 5-4864 binding to renal membranes were consistent with their actions as anion transport inhibitors (Ki approx. = 30 - 130 ..mu..M). In contrast, spironolactone, amiloride, acetazolamide, and ouabain were less potent (Ki=100-1000 ..mu..M). Administration of furosemide to rats for five days resulted in a profound diuresis accompanied by a significant increase in PBR density (43%) that was apparent by the fifth day of treatment. Administration of hydrochlorothiazide or Ro 5-4864 for five days also caused diuresis and increased renal PBR density. Both the diuresis and increased density of PBR produced by Ro 5-4864 were blocked by coadministration of PK 11195, which alone had no effect on either PBR density or urine volume. The equilibrium binding constants of (/sup 3/H)Ro 5-4864 to cardiac membranes were unaffected by administration of any of these drugs. These findings suggest that renal PBR may be selectively modulated in vivo and in vitro by administration of ion transport/exchange inhibitors. 36 references, 4 tables.

  19. Peripheral-type benzodiazepine receptor in neurosteroid biosynthesis, neuropathology and neurological disorders.

    Science.gov (United States)

    Papadopoulos, V; Lecanu, L; Brown, R C; Han, Z; Yao, Z-X

    2006-01-01

    The peripheral-type benzodiazepine receptor is a mitochondrial protein expressed at high levels in steroid synthesizing tissues, including the glial cells of the brain. Peripheral-type benzodiazepine receptor binds cholesterol with high affinity and is a key element of the cholesterol mitochondrial import machinery responsible for supplying the substrate cholesterol to the first steroidogenic enzyme, thus initiating and maintaining neurosteroid biosynthesis. Neurosteroid formation and metabolism of steroid intermediates are critical components of normal brain function. Peripheral-type benzodiazepine receptor also binds with high affinity various classes of compounds. Upon ligand activation peripheral-type benzodiazepine receptor-dependent cholesterol transport into mitochondria is accelerated leading in increased formation of neuroactive steroids. These steroids, such as allopregnanolone, have been shown to be involved in various neurological disorders, such as anxiety and mood disorders. Thus, peripheral-type benzodiazepine receptor drug ligand-induced neuroactive steroid formation offers a means to regulate brain dysfunction. Peripheral-type benzodiazepine receptor basal expression is upregulated in a number of neuropathologies, including gliomas and neurodegenerative disorders, as well as in various forms of brain injury and inflammation. In Alzheimer's disease pathology neurosteroid biosynthesis is altered and a decrease in the intermediate 22R-hydroxycholesterol levels is observed. This steroid was found to exert neuroprotective properties against beta-amyloid neurotoxicity. Based on this observation, a stable spirostenol derivative showing to display neuroprotective properties was identified, suggesting that compounds developed based on critical intermediates of neurosteroid biosynthesis could offer novel means for neuroprotection. In conclusion, changes in peripheral-type benzodiazepine receptor and neurosteroid levels are part of the phenotype seen in

  20. A Unified Model of the GABA(A) Receptor Comprising Agonist and Benzodiazepine Binding Sites

    DEFF Research Database (Denmark)

    Kongsbak, Kristine Grønning; Bergmann, Rikke; Sørensen, Pernille Louise

    2013-01-01

    We present a full-length a1b2c2 GABA receptor model optimized for agonists and benzodiazepine (BZD) allosteric modulators. We propose binding hypotheses for the agonists GABA, muscimol and THIP and for the allosteric modulator diazepam (DZP). The receptor model is primarily based on the glutamate...

  1. Reduction of group II metabotropic glutamate receptors during development of benzodiazepine dependence.

    Science.gov (United States)

    Okamoto, Ritsuko; Itoh, Yoshinori; Murata, Yusuke; Kobayashi, Daisuke; Hosoi, Masako; Mine, Kazunori

    2013-01-01

    Prolonged use of benzodiazepines often leads to dependence and withdrawal syndrome. However, the cellular mechanisms underlying benzodiazepine dependence have not been fully clarified. Several investigators have shown an involvement of metabotropic glutamate receptors (mGluRs) in the pathophysiology of dependence or withdrawal. This study was performed to elucidate the role of mGluRs in benzodiazepine dependence. Withdrawal signs were precipitated in mice by flumazenil injection (25 mg/kg) after continuous subcutaneous infusion of benzodiazepines for 7 days, and the effects of several Gi-coupled receptor ligands on forskolin-stimulated cyclic AMP accumulation were examined in the cerebral cortex of mice. The mRNA expression for mGluRs was determined by RT-PCR. A single injection of flumazenil precipitated typical withdrawal signs such as tail elevation and tremor in mice treated with diazepam or alprazolam, but not quazepam. The inhibitory effect of nonselective mGluR ligands on adenylate cyclase activity was diminished in mice that showed signs of benzodiazepine withdrawal. The mRNA expression levels of mGluR2 and mGluR3 were lowered in the cerebral cortex of mice pretreated with diazepam or alprazolam. Our findings suggest that the reduction in the expression of group II mGluRs subunits may be involved in the development of benzodiazepine dependence.

  2. Molecular size of benzodiazepine receptor in rat brain in situ: evidence for a functional dimer?

    Science.gov (United States)

    Doble, A.; Iversen, L. L.

    1982-02-01

    Benzodiazepine tranquillizers such as diazepam and chlordiazepoxide interact with high-affinity binding sites in nervous tissue1,2. The correlation between the affinities of various benzodiazepines for these sites with their clinical potencies and activity in behavioural and electrophysiological tests in animals suggests that the sites represent the functional `receptor' whereby benzodiazepines exert their effects3. The intimate involvement of benzodiazepines with γ-aminobutyric acid (GABA) and chloride channels raised the possibility that the benzodiazepine binding site (BDZ-R) may be a protein in the GABA receptor-effector complex4,5. GABA agonists enhance the affinity of BDZ-R for benzodiazepines6, although BDZ-R is distinct from the GABA receptor itself3. However, electrophysiological evidence suggests that the action of benzodiazepines is chloride channel, rather than receptor, directed7-10. Several attempts have been made to measure the molecular weight (Mr) of BDZ-R after solubilization from brain membranes: treatment with 1% Triton X-100 followed by assay of binding activity in solute fractions separated according to molecular weight suggested11 a value of ~200,000, photoaffinity labelling of BDZ-R with 3H-flunitrazepam (3H-FNZ) followed by more rigorous solubilization and gel chromatography indicated12,13 an apparent Mr of ~55,000 and a third approach14 a value of ~100,000. The measured molecular weight seems to depend critically on the solubilization procedure used. Chang et al.15 recently described the use of radiation inactivation to determine the size of BDZ-R in situ in calf brain membranes, and estimated a Mr, of 216,000. We have also used this approach; the results reported here indicate a Mr of between 90,000 and 100,000, but this is reduced to 60,000-63,000 in membranes pretreated with GABA, suggesting the disaggregation of a normally dimeric form.

  3. The active analog approach applied to the pharmacophore identification of benzodiazepine receptor ligands

    Science.gov (United States)

    Tebib, Souhail; Bourguignon, Jean-Jacques; Wermuth, Camille-Georges

    1987-07-01

    Applied to seven potent benzodiazepine-receptor ligands belonging to chemically different classes, the active analog approach allowed the stepwise identification of the pharmacophoric pattern associated with the recognition by the benzodiazepine receptor. A unique pharmacophore model was derived which involves six critical zones: (a) a π-electron rich aromatic (PAR) zone; (b) two electron-rich zones δ1 and δ2 placed at 5.0 and 4.5 Å respectively from the reference centroid in the PAR zone; (c) a freely rotating aromatic ring (FRA) region; (d) an out-of-plane region (OPR), strongly associated with agonist properties; and (e) an additional hydrophobic region (AHR). The model accommodates all presently known ligands of the benzodiazepine receptor, identifies sensitivity to steric hindrance close to the δ1 zone, accounts for R and S differential affinities and distinguishes requirements for agonist versus non-agonist activity profiles.

  4. [Participation of GABA--benzodiazepine receptor complex in the anxiolytic effect of piracetam].

    Science.gov (United States)

    Moldavkin, G M; Voronina, T A; Neznamov, G G; Maletova, O K; Eliava, N V

    2006-01-01

    It is established that bicuculline, picrotoxin, and flumazenil (agents blocking different sites of GABA receptor) decrease the anxiolytic effect of piracetam as manifested in the conflict situation test. The most pronounced interaction was observed between piracetam and flumazenyl. On the background of antagonist action, piracetam inhibited the effects of flumazenil (but not those of bicuculline and picrotoxin). Based on these data, it is assumed that the anxiolytic effect of piracetam is mediated to some extent by benzodiazepine site of the GABA-benzodiazepine receptor complex.

  5. Increased densities of peripheral-type benzodiazepine receptors in brain autopsy samples from cirrhotic patients with hepatic encephalopathy.

    Science.gov (United States)

    Lavoie, J; Layrargues, G P; Butterworth, R F

    1990-05-01

    Peripheral-type benzodiazepine receptors were evaluated using the specific ligand [3H]-PK 11195 in brain homogenates from nine cirrhotic patients who died in hepatic coma and from an equal number of age-matched control subjects. Histopathological studies showed evidence of severe Alzheimer type II astrocytosis in the brains of all cirrhotic patients. Saturation-binding assays revealed a single saturable binding site for [3H]-PK 11195 in brain, with affinities in the 2- to 3-nmol/L range. Diazepam was found to be a relatively potent inhibitor of 3H-PK 11195 binding (IC50 = 253 nmol/L), whereas the central benzodiazepine antagonist Ro 15-1788 displaced 3H-PK 11195 binding with low affinity (IC50 greater than 40 mumols/L). Densities of [3H]-PK 11195 binding sites were found to be increased by 48% (p less than 0.01) and 25% (p less than 0.05) in frontal cortex and caudate nuclei, respectively, from cirrhotic patients. Densities of [3H]-PK 11195 binding sites in frontal cortex from two nonencephalopathic cirrhotic patients were not significantly different from control values. No concomitant changes of affinities of these binding sites were observed. Because it has been suggested that peripheral-type benzodiazepine receptors may be localized on mitochondrial membranes and may therefore be involved in cerebral oxidative metabolism, the alterations observed in this study could be of pathophysiological significance in hepatic encephalopathy.

  6. GABA(A)-benzodiazepine receptor complex sensitivity in 5-HT(1A) receptor knockout mice on a 129/Sv background.

    NARCIS (Netherlands)

    Pattij, T.; Groenink, L.; Oosting, R.S.; Gugten, J. van der; Maes, R.A.A.; Olivier, B.

    2002-01-01

    Previous studies in 5-HT(1A) receptor knockout (1AKO) mice on a mixed Swiss Websterx129/Sv (SWx129/Sv) and a pure 129/Sv genetic background suggest a differential gamma-aminobutyric acid (GABA(A))-benzodiazepine receptor complex sensitivity in both strains, independent from the anxious phenotype. To

  7. Azaflavones compared to flavones as ligands to the benzodiazepine binding site of brain GABAA receptors

    DEFF Research Database (Denmark)

    Nilsson, Jakob; Nielsen, Elsebet Østergaard; Liljefors, Tommy

    2008-01-01

    A series of azaflavone derivatives and analogues were prepared and evaluated for their affinity to the benzodiazepine binding site of the GABA(A) receptor, and compared to their flavone counterparts. Three of the compounds, the azaflavones 9 and 12 as well as the new flavone 13, were also assayed...

  8. Triazoloquinazolinediones as novel high affinity ligands for the benzodiazepine site of GABA(A) receptors

    DEFF Research Database (Denmark)

    Nilsson, Jakob; Gidlöf, Ritha; Nielsen, Elsebet Østergaard

    2011-01-01

    Based on a pharmacophore model of the benzodiazepine-binding site of GABA(A) receptors, a series of 2-aryl-2,6-dihydro[1,2,4]triazolo[4,3-c]quinazoline-3,5-diones (structure type I) were designed, synthesized, and identified as high-affinity ligands of the binding site. For several compounds, K...

  9. Allosteric modulation by benzodiazepine receptor ligands of the GABAA receptor channel expressed in Xenopus oocytes.

    Science.gov (United States)

    Sigel, E; Baur, R

    1988-01-01

    Chick brain mRNA was isolated and injected into Xenopus oocytes. This led to the expression in the surface membrane of functional GABA-activated channels with properties reminiscent of vertebrate GABAA channels. The GABA-induced current was analyzed quantitatively under voltage-clamp conditions. Picrotoxin inhibited this current in a concentration-dependent manner with IC50 = 0.6 microM. The allosteric modulation of GABA currents by a number of drugs acting at the benzodiazepine binding site was characterized quantitatively. In the presence of the benzodiazepine receptor ligands diazepam and clorazepate, GABA responses were enhanced, and in the presence of the convulsant beta-carboline compound methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM), they were depressed. Maximal stimulation of the response elicited by 10 microM GABA was 160% with diazepam and 90% with clorazepate, and maximal inhibition was 42% with DMCM, 30% with methyl beta-carboline-3-carboxylate (beta-CCM), 15% with ethyl-8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo [1,5a][1,4]benzodiazepine-3-carboxylate (Ro 15-1788), and 12% with ethyl beta-carboline-3-carboxylate (beta-CCE). Half-maximal stimulation was observed with 20 nM diazepam and 390 nM clorazepate, respectively, and half-maximal inhibition with 6 nM DMCM. beta-CCM had a similar effect to DMCM, whereas beta-CCE and Ro 15-1788 showed only small inhibition at low concentrations (less than 1 microM). All the tested carboline compounds and Ro 15-1788 showed a biphasic action and stimulated GABA current at concentrations higher than 1 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Behavioural effects of the benzodiazepine receptor partial agonist RO 16-6028 in mice.

    Science.gov (United States)

    Belzung, C; Misslin, R; Vogel, E

    1989-01-01

    The imidazo-diazepinone RO 16-6028 is a benzodiazepine receptor partial agonist which exhibits some anti-conflict effects in the two-chambered light/dark test without significantly affecting the behaviour of mice confronted with the staircase test. In addition, this drug slightly reduced locomotion and more markedly rearing in a free exploration procedure. These results indicate that RO 16-6028 appears to produce some anxiolytic and sedative properties like full agonists, but with weaker magnitude. This could be related to the benzodiazepine partial agonistic profile of the compound.

  11. Affinity of 3-acyl substituted 4-quinolones at the benzodiazepine site of GABAA receptors

    DEFF Research Database (Denmark)

    Lager, Erik; Nilsson, Jakob; Nielsen, Elsebet Østergaard

    2008-01-01

    The finding that alkyl 1,4-dihydro-4-oxoquinoline-3-carboxylate and N-alkyl-1,4-dihydro-4-oxoquinoline-3-carboxamide derivatives may be high-affinity ligands at the benzodiazepine binding site of the GABA(A) receptor, prompted a study of 3-acyl-1,4-dihydro-4-oxoquinoline (3-acyl-4-quinolones......). In general, the affinity of the 3-acyl derivatives was found to be comparable with the 3-carboxylate and the 3-carboxamide derivatives, and certain substituents (e.g., benzyl) in position 6 were again shown to be important. As it is believed that the benzodiazepine binding site is situated between an alpha...

  12. Interactions between modulators of the GABA(A) receptor: Stiripentol and benzodiazepines.

    Science.gov (United States)

    Fisher, Janet L

    2011-03-05

    Many patients with refractory epilepsy are treated with polytherapy, and nearly 15% of epilepsy patients receive two or more anti-convulsant agents. The anti-convulsant stiripentol is used as an add-on treatment for the childhood epilepsy syndrome known as severe myoclonic epilepsy in infancy (Dravet syndrome). Stiripentol has multiple mechanisms of action, both enhancing GABA(A) receptors and reducing activity of metabolic enzymes that break down other drugs. Stiripentol is typically co-administered with other anti-convulsants such as benzodiazepines which also act through GABA(A) receptor modulation. Stiripentol slows the metabolism of some of these drugs through inhibition of a variety of cytochrome P450 enzymes, but could also influence their effects on GABAergic neurotransmission. Is it rational to co-administer drugs which can act through the same target? To examine the potential interaction between these modulators, we transiently transfected HEK-293T cells to produce α3β3γ2L or α3β3δ recombinant GABA(A) receptors. Using whole-cell patch clamp recordings, we measured the response to each benzodiazepine alone and in combination with a maximally effective concentration of stiripentol. We compared the responses to four different benzodiazepines: diazepam, clonazepam, clobazam and norclobazam. In all cases we found that these modulators were equally effective in the presence and absence of stiripentol. The δ-containing receptors were insensitive to modulation by the benzodiazepines, which did not affect potentiation by stiripentol. These data suggest that stiripentol and the benzodiazepines act independently at GABA(A) receptors and that polytherapy could be expected to increase the maximum effect beyond either drug alone, even without consideration of changes in metabolism.

  13. Novel Indications for Benzodiazepine Antagonist Flumazenil in GABA Mediated Pathological Conditions of the Central Nervous System.

    Science.gov (United States)

    Hulse, Gary; Kelty, Erin; Hood, Sean; Norman, Amanda; Basso, Maria Rita; Reece, Albert Stuart

    2015-01-01

    This review paper discusses the central role of gamma-aminobutyric acid (GABA) in diverse physiological systems and functions and the therapeutic potential of the benzodiazepine antagonist flumazenil (Ro 15- 1788) for a wide range of disorders of the central nervous system (CNS). Our group and others have studied the potential of flumazenil as a treatment for benzodiazepine dependence. A small but growing body of research has indicated that flumazenil may also have clinical application in CNS disorders such as Parkinson's disease, idiopathic hypersomnia and amyotrophic lateral sclerosis. Despite this body of research the therapeutic potential of flumazenil remains poorly understood and largely unrealized. The purpose of this paper is not to provide an exhaustive review of all possible therapeutic applications for flumazenil but rather to stimulate research interest, and discussion of the exciting therapeutic potential of this drug for a range of chronic debilitating conditions.

  14. THIP and isoguvacine are partial agonists of GABA-stimulated benzodiazepine receptor binding.

    Science.gov (United States)

    Karobath, M; Lippitsch, M

    1979-10-15

    The effects of THIP and isoguvacine on 3H-flunitrazepam binding to washed membranes prepared from the cerebral cortex of adult rats have been examined. THIP, which has only minimal stimulatory effects on benzodiazepine (BZ) receptor binding, has been found to inhibit the stimulation induced by small concentrations (2 microM) of exogenous GABA. While isoguvacine stimulates BZ receptor binding, although to a smaller extent than GABA, it also antagonizes the stimulation of BZ receptor binding induced by GABA. Thus THIP and isoguvacine exhibit the properties of a partial agonist of GABA-stimulated BZ receptor binding.

  15. Imaging benzodiazepine receptors in man with C-11-suriclone and positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Frost, J.J.; Dannals, R.F.; Ravert, H.T.; Wilson, A.A.; Links, J.M.; Trifiletti, R.; Snyder, S.H.; Wagner, H.N. Jr.

    1985-05-01

    Suriclone is a potent cyclopyrrolone, anti-anxiety drug which binds to the benzodiazepine receptor complex (BZR) with high affinity. Suriclone binds to a site on the BZR distinct from the site where benzodiazepines bind. The K/sub D/ of suriclone at 37oC is 0.03 nM. C-11-suriclone (SUR) was synthesized by reacting C-CH3I with the appropriate amine precursor. SUR (1 ..mu..g/kg) was injected IV into a baboon alone or with 1 mg/kg of Ro-151788, a benzodiazepine antagonist, and serial PET scans of the brain were obtained. High radioactivity concentrations were observed in the cerebral cortex and cerebellum which contain high densities of BZR, intermediate concentrations in thalamus and low concentrations in the striatum. When Ro-151788 was given a uniform distribution of radioactivity was observed; the radioactivity was reduced to ca. 25% of control values in the brain which was contained within the PET slice. SUR (0.2 ..mu..g/kg) was next administered to a human subject. From 30-60 minutes after injection high radioactivity concentrations were observed in the cerebral cortex and cerebellum, intermediate concentrations in the thalamus and a low concentration in the caudate. Radioactivity in the cerebral cortex and cerebellum decreased slowly with time, implying that binding of SUR to a high affinity site had occurred. These results demonstrate utility of SUR for measuring binding to the benzodiazepine receptor complex non-invasively in man.

  16. Abnormal benzodiazepine and zinc modulation of GABAA receptors in an acquired absence epilepsy model.

    Science.gov (United States)

    Wu, Jie; Ellsworth, Kevin; Ellsworth, Marc; Schroeder, Katherine M; Smith, Kris; Fisher, Robert S

    2004-07-01

    Brain cholesterol synthesis inhibition (CSI) at a young age in rats has been shown to be a faithful model of acquired absence epilepsy, a devastating condition for which few therapies or models exist. We employed the CSI model to study cellular mechanisms of acquired absence epilepsy in Long-Evans Hooded rats. Patch-clamp, whole-cell recordings were compared from neurons acutely dissociated from the nucleus reticularis of thalamus (nRt) treated and untreated with a cholesterol synthesis inhibitor, U18666A. In U18666A-treated animals, 91% of rats developed EEG spike-waves (SWs). Patchclamp results revealed that although there was no remarkable change in GABAA receptor affinity, both a loss of ability of benzodiazepines to enhance GABAA-receptor responses and an increase of Zn2+ inhibition of GABAA-receptor responses of nRt neurons occurred in Long-Evans Hooded rats previously administered U18666A. This change was specific, since no significant changes were found in neurons exposed to the GABA allosteric modulator, pentobarbital. Taken collectively, these findings provide evidence for abnormalities in benzodiazepine and Zn2+ modulation of GABAA receptors in the CSI model, and suggest that decreased gamma2 subunit expression may underlie important aspects of generation of thalamocortical SWs in atypical absence seizures. The present results are also consistent with recent findings that mutation of the gamma2 subunit of the GABAA receptor changes benzodiazepine modulation in families with generalized epilepsy syndromes.

  17. Benzodiazepine receptor imaging with iomazenil SPECT in aphasic patients with cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Koshi, Yasuhiko; Kitamura, Shin; Ohyama, Masashi [Nippon Medical School, Tokyo (Japan)] (and others)

    1999-08-01

    To investigate the relationship between prognosis of aphasia and neuronal damage in the cerebral cortex, we evaluated the distribution of central-type benzodiazepine receptor (BZR) binding in post-stroke aphasics with [{sup 123}I]iomazenil and SPECT. We performed iomazenil SPECT in six aphasic patients (aged from 45 to 75 years; all right-handed) with unilateral left cerebral infarction. Three patients showed signs of Broca's aphasia and the other three Wernicke's aphasia. Cerebral blood flow (CBF) imaging was performed with [{sup 123}I]iodoamphetamine (IMP). The regions of interest (ROIs) on both images were set in the cerebral cortex, cerebellar cortex and language relevant area in both hemispheres. Three patients were classified in the mild prognosis group and the other three in the moderate prognosis group. The left language-relevant area was more closely concerned with the difference in aphasic symptoms than the right one in both BZR and CBF distribution, but the ipsilateral to the contralateral ratio (I/C ratio) in the language-relevant areas in the BZR distribution was significantly lower in the moderate prognosis group than in the mild prognosis group, although no difference was seen for these values between the two groups in the CBF distribution. These results suggest that BZR imaging, which makes possible an increase in neuronal cell viability in the cerebral cortex, is useful not only for clarifying the aphasic symptoms but also for evaluating the prognosis of aphasia in patients with cerebral infarction. (author)

  18. Blood flow dependence of the intratumoral distribution of peripheral benzodiazepine receptor binding in intact mouse fibrosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Amitani, Misato [Radiochemistry Section, Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan) and Course of Allied Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871 (Japan)]. E-mail: amitani@sahs.med.osaka-u.ac.jp; Zhang, Ming-Rong [Radiochemistry Section, Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); Noguchi, Junko [Radiochemistry Section, Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); SHI Accelerator Service, Shinagawa-ku, Tokyo 141-8686 (Japan); Kumata, Katsushi [Radiochemistry Section, Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); Ito, Takehito [Radiochemistry Section, Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); SHI Accelerator Service, Shinagawa-ku, Tokyo 141-8686 (Japan); Takai, Nobuhiko [Radiochemistry Section, Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); Suzuki, Kazutoshi [Radiochemistry Section, Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); Hosoi, Rie [Course of Allied Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871 (Japan); Inoue, Osamu [Course of Allied Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871 (Japan)

    2006-11-15

    The intratumoral distribution of [{sup 11}C]AC-5216 binding, a novel peripheral benzodiazepine receptor (PBR) ligand, was examined by autoradiography both in vitro and in vivo using a murine fibrosarcoma model. The regional distribution of [{sup 11}C]AC-5216 in a tumor in vivo was significantly heterogeneous; the uptake of [{sup 11}C]AC-5216 was comparatively higher in the outer rim of the tumor and was lower in the central area. In contrast, the images obtained following the injection of [{sup 11}C]AC-5216 with a large amount of nonlabeled PK11195 showed a relatively homogeneous distribution, suggesting that [{sup 11}C]AC-5216 uptake represented specific binding to PBRs. In vitro autoradiograms of [{sup 11}C]AC-5216 binding were also obtained using the section of the fibrosarcoma that was the same as that used to examine in vivo binding. In vitro autoradiographic binding images showed homogeneous distribution, and significant discrepancies of the intratumoral distribution of [{sup 11}C]AC-5216 were observed between in vivo and in vitro images. The in vivo images of [{sup 11}C]AC-5216 uptake, compared with those of [{sup 14}C]iodoantipyrine uptake, obtained by dual autoradiography to evaluate the influence of blood flow revealed the similar intratumoral distributions of both tracers. These results indicate that the delivery process from the plasma to the tumor might be the rate-limiting step for the intratumoral distribution of PBR binding in vivo in a fibrosarcoma model.

  19. Benzodiazepine/GABA receptor complex during severe ethanol intoxication and withdrawal in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Hemmingsen, R.; Braestrup, C.; Nielsen, M.; Barry, D.I. (Dept. of Psychiatry, Rigshospitalet, Copenhagen, St. Hans Mental Hospital, Roskilde, and Ferrosan Research Laboratory, Soeborg, Denmark)

    1982-01-01

    The benzodiazepine/GABA (gammaaminobutyric acid) receptor complex was investigated during severe ethanol intoxication and withdrawal in the rat. The intragastric intubation technique was used to establish physical ethanol dependence in the animals. Cerebral cortex from male Wistar rats was studied 1) after 31/2 days of severe ethanol intoxication, 2) during the ethanol withdrawal reaction and 3) in a control group. The effect of GABA-ergic activation by muscimol and THIP (4,5,6,7-tetrahydroisoxazole(5,4-c)pyridin-3-01) on /sup 3/H-diazepam binding was unchanged during ethanol intoxication and withdrawal, as was the affinity constant (Ksub(D)) and the maximal number of binding sites (Bsub(max)) for /sup 3/H-flunitrazepam. In conclusion, the benzodiazepine/GABA receptor complex is unlikely to play any causual part in physical ethanol dependence.

  20. Benzodiazepine effect of {sup 125}I-iomazenil-benzodiazepine receptor binding and serum corticosterone level in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Fukumitsu, Nobuyoshi [Proton Medical Research Center, University of Tsukuba, Ibaragi, 305-8575 (Japan)]. E-mail: gzl13162@nifty.ne.jp; Ogi, Shigeyuki [Department of Radiology, Jikei University School of Medicine, Tokyo, 105-8461 (Japan); Uchiyama, Mayuki [Department of Radiology, Jikei University School of Medicine, Tokyo, 105-8461 (Japan); Mori, Yutaka [Department of Radiology, Jikei University School of Medicine, Tokyo, 105-8461 (Japan)

    2005-01-01

    To test the change in free or unoccupied benzodiazepine receptor (BZR) density in response to diazepam, we investigated {sup 125}I-iomazenil ({sup 125}I-IMZ) binding and serum corticosterone levels in a rat model. Wistar male rats, which received psychological stress using a communication box for 5 days, were divided into two groups according to the amount of administered diazepam: no diazepam [D (0)] group and 10 mg/kg per day [D (10)] group of 12 rats each. The standardized uptake value (SUV) of {sup 125}I-IMZ of the D (10) group were significantly lower (P<.05) than those of the D (0) group in the frontal, parietal and temporal cortices, globus pallidus, hippocampus, amygdala and hypothalamus. The serum corticosterone level ratio in the D (10) group was significantly lower than that in the D (0) group (P<.05). From the change in serum corticosterone levels, diazepam attenuated the psychological stress produced by the physical stress to animals in adjacent compartments. From the reduced binding of {sup 125}I-IMZ, it is clear that diazepam competed with endogenous ligand for the free BZR sites, and the frontal, parietal and temporal cortices, globus pallidus, hippocampus, amygdala and hypothalamus are important areas in which {sup 125}I-IMZ binding is strongly affected by administration of diazepam.

  1. Study on measurement of free ligand concentration in blood and quantitative analysis of brain benzodiazepine receptor

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Kenji; Goromaru, Tsuyoshi; Inoue, Osamu; Itoh, Takashi; Yamasaki, Toshiro.

    1988-11-01

    We developed the method to determine rapidly the free ligand concentration in the blood as an input function for the purpose of quantitative analysis of binding potential (B/sub max//K/sub d/) of brain benzodiazepine receptor in vivo. It was found that the unmetabolized radioligand in the blood after intravenous administration of /sup 3/H-Ro 15 - 1788 could be extracted by chloroform, whereas the radioactive metabolites could not be extracted. And the plasma protein binding of /sup 3/H-Ro 15 - 1788 was determined using an ultrafiltration method. The biodistribution of /sup 3/H-Ro 15 - 1788 in the cerebral cortex, cerebellum and pons-medulla after intravenous administration of the radiotracer in the control and forced-swimmed mice was examined. And the time course of the free ligand concentration in the blood was determined as described above. Further, the binding potential of benzodiazepine receptor in the mouse brain was analyzed using a simple mathematical model. It was suggested that the binding potential of benzodiazepine receptor in the mouse brain was significantly decreased by forced-swimming. In conclusion, it was found that these methods would be useful for quantitative analysis of clinical data in the human brain using /sup 11/C-Ro 15 - 1788 and positron emission tomography (PET).

  2. Novel one-pot one-step synthesis of 2'-[{sup 18}F]fluoroflumazenil (FFMZ) for benzodiazepine receptor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Young, Hyun Yoon; Jae, Min Jeong E-mail: jmjng@snu.ac.kr; Hyung, Woo Kim; Sung, Hyun Hong; Lee, Yun-Sang; Hee, Sup Kil; Dae, Yoon Chi; Dong, Soo Lee; Chung, June-Key; Myung, Chul Lee

    2003-05-01

    We describe the synthesis of 2'-[{sup 18}F]fluoroflumazenil (FFMZ), which differs from the typically used [{sup 18}F]fluoroethylflumazenil (FEFMZ) for benzodiazepine receptor imaging. For one-pot one-step labeling, the precursors, 2'-tosyloxyflumazenil (TFMZ) and 2'-mesyloxyflumazenil (MFMZ), were synthesized in three steps. The precursors were successfully labeled with no-carrier-added {sup 18}F-fluoride which was activated by repeated azeotropic distillation with Kryptofix 2.2.2./potassium carbonate in MeCN. An automated system for labeling and purification of [{sup 18}F]FFMZ was developed. Labeling efficiency and radiochemical purity of [{sup 18}F]FFMZ after synthesis by the automated system were 68% and 98%, respectively. Specific binding of [{sup 18}F]FFMZ to central benzodiazepine receptor of rats was demonstrated by phosphoimaging.

  3. GABA/benzodiazepine receptor complex in long-sleep and short-sleep mice

    Energy Technology Data Exchange (ETDEWEB)

    Marley, R.J.

    1987-01-01

    LS mice are more sensitive to benzodiazepine-induced anesthesia; however, the two lines do not differ in their hypothermic response to flurazepam. SS mice are more resistant to 3-mercaptopropionic acid-induced seizures and more sensitive to the anticonvulsant effects of benzodiazepines. The various correlates of GABA and benzodiazepine actions probably are the results of different mechanisms of action and/or differential regional control. Bicuculline competition for /sup 3/H-GABA binding sites is greater in SS cerebellar tissue and /sup 3/H-flunitrazepam binding is greater in the mid-brain region of LS mice. GABA enhancement of /sup 3/H-flunitrazepma binding is greater in SS mice. Ethanol also enhances /sup 3/H-flunitrazepam binding and increases the levels of /sup 3/H-flunitrazepam binding above those observed for GABA. Using correlational techniques on data from LS and SS mice and several inbred mouse strains, it was demonstrated that a positive relationship exists between the degree of receptor coupling within the GABA receptor complex and the degree of resistance to seizures.

  4. Altered response to benzodiazepine anxiolytics in mice lacking GABA B(1) receptors.

    Science.gov (United States)

    Mombereau, Cedric; Kaupmann, Klemens; van der Putten, Herman; Cryan, John F

    2004-08-16

    Recently, we demonstrated that mice lacking the GABA(B(1)) subunit were more anxious than wild-type animals in several behavioural paradigms, most notably in the light-dark test. In an attempt to assess the effects of classical benzodiazepine anxiolytics on anxiety-like behaviour observed in these mice, animals were administered either chlordiazepoxide (10 mg/kg, p.o.) or diazepam (7.5 mg/kg, p.o.) prior to testing in the light-dark box. Surprisingly, in contrast with the wild-type mice, neither benzodiazepines decreased anxiety-like behaviour in GABA(B(1))(-/-) mice. These data suggest that targeted deletion of GABA(B(1)) subunit alters GABA(A) receptor function in vivo.

  5. Fibrous and protoplasmic astrocytes express GABAA receptors that differ in benzodiazepine pharmacology.

    Science.gov (United States)

    Rosewater, K; Sontheimer, H

    1994-02-04

    Astrocytes cultured from spinal cord contain two morphologically distinguishable types of astrocytes: fibrous and protoplasmic cells. Both astrocyte subtypes, in culture, are able to express GABAA receptors, and their activation results in inward currents at the resting potential. Using patch-clamp electrophysiology we characterized their basic receptor pharmacology and compared it to spinal cord neurons that were also present in small numbers in these cultures. As in neuronal GABAA receptors, the local anesthetic pentobarbital effectively potentiated GABA-induced currents in both astrocyte subtypes. Similarly, the benzodiazepine diazepam, on average doubled GABA-induced currents in both astrocytes subtypes. In contrast to these effects that were similar in both astrocytes types and similar to spinal cord neurons, the response to the convulsant methyl-4-ethyl-6,7-dimethoxy-beta-carboline-3-carboxylate (DMCM), which is an inverse benzodiazepine agonist differs between astrocyte subtypes. DMCM reduced GABA-induced currents by about 50% in fibrous astrocytes as we also observed with spinal cord neurons. In contrast, DMCM increased GABA currents in protoplasmic astrocytes by up to 150%, an effect never observed in neurons. DMCM potentiations of GABA currents have recently been attributed to differences in receptor subunit composition. Our results thus indicate that subtypes of astrocytes express GABAA receptors that differ pharmacologically and likely differ also in subunit composition.

  6. Interactions between modulators of the GABAA receptor: Stiripentol and benzodiazepines

    OpenAIRE

    Fisher, Janet L.

    2011-01-01

    Many patients with refractory epilepsy are treated with polytherapy, and nearly 15% of epilepsy patients receive two or more anti-convulsant agents. The anti-convulsant stiripentol is used as an add-on treatment for the childhood epilepsy syndrome known as severe myoclonic epilepsy in infancy (Dravet Syndrome). Stiripentol has multiple mechanisms of action, both enhancing GABAA receptors and reducing activity of metabolic enzymes that break down other drugs. Stiripentol is typically co-admini...

  7. Multiple benzodiazepine receptors in the ovine brain: ontogenesis, properties, and distribution of /sup 3/H-diazepam binding

    Energy Technology Data Exchange (ETDEWEB)

    Villiger, J.W.; Taylor, K.M.; Gluckman, P.D.

    1982-01-01

    Benzodiazepine receptors in the ovine frontal cortex were present at 56 days gestation and developed slowly until 96 days when the number increased rapidly, reaching adult levels by 120 days gestation. Scatchard analysis of 3H-diazepam specifically bound to cortical membranes suggested high (KD approximately equal to 2.0 nM) and low (KD approximately equal to 20.0 nM) affinity benzodiazepine receptors at all stages of development. Whereas the affinity of these receptors for 3H-diazepam did not alter during development, the number of both high and low affinity receptors increased significantly between 56 and 120 days gestation. The number of low affinity receptors were higher in late gestation and early neonatal life than in adulthood. The functional state of these receptors as determined by sensitivity to GABA did not alter during development. However, in the adult, nitrazepam, flunitrazepam, midazolam, and 1-methylisoguanosine were more potent in displacing 3H-diazepam at the low affinity than the high affinity receptor, whereas chlordiazepoxide and diazepam had greater potency at the high affinity binding site. Development of the benzodiazepine receptor in the majority of other brain regions studied occurred primarily after 68 days gestation, as was the case in frontal cortex. In contrast, hindbrain and midbrain benzodiazepine receptors had reached adult levels by 68 days gestation.

  8. Treatment with dehydroepiandrosterone increases peripheral benzodiazepine receptors of mitochondria from cerebral cortex in D-galactose-induced aged rats.

    Science.gov (United States)

    Chen, Chunfu; Lang, Senyang; Zuo, Pingping; Yang, Nan; Wang, Xiangqing

    2008-12-01

    The aim of this study was to determine whether dehydroepiandrosterone (DHEA) could regulate the expression of peripheral benzodiazepine receptors of mitochondria in cerebral cortex. The rats were divided into five groups. Those, in the vehicle-physiological or senescent group, received physiological or d-galactose (subcutaneously) once a day. Rats, in the vehicle-dimethyl sulfoxide- or DHEA-treated senescent group, received 2% of dimethyl sulfoxide or DHEA (intraperitoneally) every other day besides D-galactose (subcutaneously) once a day. Rats in the DHEA-treated normal group received physiological once a day and DHEA every other day. After 8-week, spatial learning was assessed for 5 days by water maze methods. Following behavioural testing, the cerebral cortex mitochondria were purified for PK11195 binding analysis. When compared to the respective vehicle, D-galactose alone induced a significant impairment in water maze performance accompanied by a reduction (30.7%) in peripheral benzodiazepine receptor density of mitochondria, and DHEA displayed a significant enhancement in learning memory accompanied by the elevation (18.3%) of peripheral benzodiazepine receptor density but not affinity in senescent rats. DHEA showed insignificant effects on both learning/memory ability and peripheral benzodiazepine receptors in normal rats when compared to physiological saline. These results suggest that chronic treatment with DHEA enhance cognitive function and increase peripheral benzodiazepine receptor density in cerebral cortex mitochondria in middle-aged senescent rats.

  9. GABA(A) receptors implicated in REM sleep control express a benzodiazepine binding site.

    Science.gov (United States)

    Nguyen, Tin Quang; Liang, Chang-Lin; Marks, Gerald A

    2013-08-21

    It has been reported that non-subtype-selective GABAA receptor antagonists injected into the nucleus pontis oralis (PnO) of rats induced long-lasting increases in REM sleep. Characteristics of these REM sleep increases were identical to those resulting from injection of muscarinic cholinergic agonists. Both actions were blocked by the muscarinic antagonist, atropine. Microdialysis of GABAA receptor antagonists into the PnO resulted in increased acetylcholine levels. These findings were consistent with GABAA receptor antagonists disinhibiting acetylcholine release in the PnO to result in an acetylcholine-mediated REM sleep induction. Direct evidence has been lacking for localization in the PnO of the specific GABAA receptor-subtypes mediating the REM sleep effects. Here, we demonstrated a dose-related, long-lasting increase in REM sleep following injection (60 nl) in the PnO of the inverse benzodiazepine agonist, methyl-6,7-dimethoxy-4-ethyl-β-carboline (DMCM, 10(-2)M). REM sleep increases were greater and more consistently produced than with the non-selective antagonist gabazine, and both were blocked by atropine. Fluorescence immunohistochemistry and laser scanning confocal microscopy, colocalized in PnO vesicular acetylcholine transporter, a presynaptic marker of cholinergic boutons, with the γ2 subunit of the GABAA receptor. These data provide support for the direct action of GABA on mechanisms of acetylcholine release in the PnO. The presence of the γ2 subunit at this locus and the REM sleep induction by DMCM are consistent with binding of benzodiazepines by a GABAA receptor-subtype in control of REM sleep.

  10. 3-Alkyl- and 3-amido-isothiazoloquinolin-4-ones as ligands for the benzodiazepine site of GABAA receptors

    DEFF Research Database (Denmark)

    Nilsson, Jakob; Nielsen, Elsebet Østergaard; Liljefors, Tommy

    2012-01-01

    Based on a pharmacophore model of the benzodiazepine binding site of the GABA(A) receptors, developed with synthetic flavones and potent 3-carbonylquinolin-4-ones, 3-alkyl- and 3-amido-6-methylisothiazoloquinolin-4-ones were designed, prepared and assayed. The suggestion that the interaction...... interaction with the lipophilic pockets of the pharmacophore model. The most potent 3-alkyl derivative, 3-pentyl-6-methylisothiazoloquinolin-4-one, has an affinity (K(i) value) for the benzodiazepine binding site of the GABA(A) receptors of 13nM. However, by replacing the 3-pentyl with a 3-butyramido group...

  11. Anticonvulsive Activity in Audiogenic DBA/2 Mice of 1,4-Benzodiazepines and 1,5-Benzodiazepines with Different Activities at Cerebellar Granule Cell GABAA Receptors.

    Science.gov (United States)

    Gatta, Elena; Cupello, Aroldo; Di Braccio, Mario; Grossi, Giancarlo; Robello, Mauro; Scicchitano, Francesca; Russo, Emilio; De Sarro, Giovambattista

    2016-12-01

    Herein, we tested in a model of generalized reflex epilepsy in mice different 1,4-benzodiazepines and 1,5-benzodiazepines with agonistic activity at the GABAA receptor population contributing to the peak component of the chloride current elicited by GABA in cerebellar granule cells (CGCs) in culture. The substances have all higher lipophilia than clobazam, an antiepileptic drug well known and used in human therapy. This ensures that they all can pass relatively easily the blood-brain barrier (BBB). The benzodiazepines were administered intraperitoneally (i.p.) and tested for their activity against sound-induced tonic and clonic seizures in a genetic model of experimental epilepsy, the DBA/2 mouse. Our data demonstrates an interesting inverse correlation between the ED50s and the efficacy (E %) of the drugs in increasing the peak chloride current elicited by GABA in cerebellar granule cells in culture. There is indication of the existence of a threshold of E % above which the increase of ED50 with increasing E % becomes linear. This is statistically significant for the clonic phase, whereas it is at the limit of significance for the tonic one. A possible interpretation of these results is that in this epilepsy model, projections from the cerebellum exert a convulsion prevention activity.

  12. Modulation of acetylcholine release from rat striatal slices by the GABA/benzodiazepine receptor complex

    Energy Technology Data Exchange (ETDEWEB)

    Supavilai, P.; Karobath, M.

    1985-02-04

    GABA, THIP and muscimol enhance spontaneous and inhibit electrically induced release of tritium labelled compounds from rat striatal slices which have been pre-labelled with /sup 3/H-choline. Baclofen is inactive in this model. Muscimol can inhibit electrically induced release of tritiated material by approximately 75% with half maximal effects at 2 ..mu..M. The response to muscimol can be blocked by the GABA antagonists bicuculline methobromide, picrotoxin, anisatin, R 5135 and CPTBO (cyclopentylbicyclophosphate). Drugs which act on the benzodiazepine receptor (BR) require the presence of muscimol to be effective and they modulate the effects of muscimol in a bidirectional manner. Thus BR agonists enhance and inverse BR agonists attenuate the inhibitory effects of muscimol on electrically induced release. Ro15-1788, a BR antagonist, does not modulate the inhibitory effects of muscimol but antagonizes the actions of clonazepam, a BR agonist, and of DMCM, an inverse BR agonist. These results demonstrate that a GABA/benzodiazepine receptor complex can modulate acetylcholine release from rat striatal slices in vitro. 24 references, 3 figures, 5 table.

  13. Imidazo-thiazine, -diazinone and -diazepinone derivatives. Synthesis, structure and benzodiazepine receptor binding.

    Science.gov (United States)

    Kieć-Kononowicz, K; Karolak-Wojciechowska, J; Müller, C E; Schumacher, B; Pekala, E; Szymańska, E

    2001-05-01

    In our search for new compounds acting on benzodiazepine receptors among the fused 2-thiohydantoin derivatives, a series of arylidene imidazo[2,1-b]thiazines was synthesized. The 1,2- and 2,3- cyclized derivatives of mono- and di-substituted Z-5-arylidene-2-thiohydantoins were examined (the X-ray crystal structure of Z-2-cinnamylidene-6,7-dihydro-5H-imidazo[2,1-b][1,3]thiazin-3(2H)-one was determined) and compared with the diphenyl derivatives. To investigate the influence of the type of annelated ring on the biological activity, imidazo[2,1-b]pyrimidinone and imidazo[2,1-b]diazepinone derivatives were obtained. The method used in annelation (1,2- and 2,3-cyclized isomers with the exception of fused arylidene imidazothiazines), the substitution pattern (arylidene towards diphenyl) as well as the character of the annelated ring had minor influence on the benzodiazepine receptor affinity of the investigated compounds. It appears that the greatest influence on the biological activity has the character and position of the substituents on the arylidene ring.

  14. Comparison of anticonvulsant tolerance, crosstolerance, and benzodiazepine receptor binding following chronic treatment with diazepam or midazolam.

    Science.gov (United States)

    Ramsey-Williams, V A; Wu, Y; Rosenberg, H C

    1994-07-01

    In a previous study, rats treated chronically with flurazepam were tolerant to the anticonvulsant action of some benzodiazepines (BZs), but not others (34). To determine if this differential crosstolerance was unique to flurazepam, rats were treated chronically with diazepam or midazolam, and tested for tolerance to the anticonvulsant actions of diazepam, midazolam, clonazepam, and clobazam. Regional benzodiazepine receptor binding in brain was also studied. In contrast to previous findings with flurazepam, 1 week treatment with diazepam or with midazolam did not cause tolerance. Rats treated with diazepam for 3 weeks were tolerant to diazepam, clonazepam, clobazam, and midazolam. In contrast, rats treated 3 weeks with midazolam were tolerant to diazepam and midazolam, but not clobazam or clonazepam. Neither diazepam nor midazolam treatment for 3 weeks altered BZ binding in cerebral cortex, cerebellum, or hippocampus. The effects of chronic BZ treatment depended not only on the BZ given chronically, but also on the BZ used to evaluate these effects, suggesting drug-specific interactions of different BZs with their receptors.

  15. Differential expression of the peripheral benzodiazepine receptor and gremlin during adipogenesis.

    Science.gov (United States)

    Wade, F Marlene; Wakade, Chandramohan; Mahesh, Virendra B; Brann, Darrell W

    2005-05-01

    This study used the mRNA differential display technique to identify differentially expressed genes during the process of adipogenesis in the preadipocyte cell line, 3T3-L1. 3T3-L1 cells were treated with dexamethasone, isobutyl-1-methylxanthine, and insulin to induce differentiation into mature adipocytes. Cells were collected at three time-points during differentiation: Day 0 (d0), or nondifferentiated; Day 3 (d3), during differentiation; and Day 10 (d10), >90% of the cells had differentiated into mature adipocytes. Initial studies yielded 18 potentially differentially regulated cDNA candidates (8 down-regulated and 10 up-regulated). Reverse Northern and Northern blots confirmed differential expression of six of the candidates. Four of the candidates up-regulated on d3 and d10 were identified by sequence analysis to be lipoprotein lipase, a well-known marker of adipocyte differentiation. A fifth candidate that was expressed in d0, but not d3 or d10, was identified as DRM/gremlin, a bone morphogenetic protein antagonist. Finally, a sixth candidate that was increased at d3 and d10 was identified as the peripheral benzodiazepine receptor, which has been implicated in proliferation, differentiation, and cholesterol transport in cells. This study is the first to show that peripheral benzodiazepine receptor and DRM/gremlin are expressed in preadipocyte cell lines and that they are differentially regulated during adipogenesis.

  16. Effects of vitamin B-6 nutrition on benzodiazepine (BDZ) receptor binding in the developing rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Borek, J.P.; Guilarte, T.R. (Johns Hopkins Univ., Baltimore, MD (United States))

    1990-02-26

    A dietary deficiency of vitamin B-6 promotes seizure activity in neonatal animals and human infants. Previous studied have shown that neonatal vitamin B-6 deprivation results in reduced levels of brain gamma-aminobutyric acid (GABA) and increased binding at the GABA site of the GABA/BDZ receptor complex. Since the GABA and BDZ receptors are allosterically linked, this study was undertaken to determine if vitamin B-6 deprivation had an effect on BDZ receptor binding. Benzodiazepine receptor binding isotherms using {sup 3}H-flunitrazepam as ligand were performed in the presence and absence of 10 {mu}M GABA. The results indicate a significant increase in the binding affinity (Kd) in the presence of GABA in cerebellar membranes from deficient rat pups at 14 days of age with no effect on receptor number (Bmax). By 28 days of age, the increase in Kd was no longer present. No change in Kd or Bmax was observed in cortical tissue from deficient animals at 14 or 28 days of age. Preliminary studies of GABA-enhancement of {sup 3}H-flunitrazepam binding indicate that vitamin B-6 deficiency also induces alterations in the ability of GABA to enhance BZD receptor binding. In summary, these results indicate that the effects of vitamin B-6 deprivation on BDZ receptor binding are region specific and age related.

  17. Relation of cell proliferation to expression of peripheral benzodiazepine receptors in human breast cancer cell lines.

    Science.gov (United States)

    Beinlich, A; Strohmeier, R; Kaufmann, M; Kuhl, H

    2000-08-01

    Peripheral benzodiazepine receptor (PBR) agonist [(3)H]Ro5-4864 has been shown to bind with high affinity to the human breast cancer cell line BT-20. Therefore, we investigated different human breast cancer cell lines with regard to binding to [(3)H]Ro5-4864 and staining with the PBR-specific monoclonal antibody 8D7. Results were correlated with cell proliferation characteristics. In flow cytometric analysis, the estrogen receptor (ER)-negative breast cancer cell lines BT-20, MDA-MB-435-S, and SK-BR-3 showed significantly higher PBR expression (relative fluorescence intensity) than the ER-positive cells T47-D, MCF-7 and BT-474 (Pdiazepam-binding inhibitor are possibly involved in the regulation of cell proliferation of human breast cancer cell lines.

  18. Souroubea sympetala (Marcgraviaceae): a medicinal plant that exerts anxiolysis through interaction with the GABAA benzodiazepine receptor.

    Science.gov (United States)

    Mullally, Martha; Cayer, Christian; Kramp, Kari; Otárola Rojas, Marco; Sanchez Vindas, Pablo; Garcia, Mario; Poveda Alvarez, Luis; Durst, Tony; Merali, Zul; Trudeau, Vance L; Arnason, John T

    2014-09-01

    The mode of action of the anxiolytic medicinal plant Souroubea sympetala was investigated to test the hypothesis that extracts and the active principle act at the pharmacologically important GABAA-benzodiazepine (GABAA-BZD) receptor. Leaf extracts prepared by ethyl acetate extraction or supercritical extraction, previously determined to have 5.54 mg/g and 6.78 mg/g of the active principle, betulinic acid, respectively, reduced behavioural parameters associated with anxiety in a rat model. When animals were pretreated with the GABAA-BZD receptor antagonist flumazenil, followed by the plant extracts, or a more soluble derivative of the active principle, the methyl ester of betulinic acid (MeBA), flumazenil eliminated the anxiety-reducing effect of plant extracts and MeBA, demonstrating that S. sympetala acts via an agonist action on the GABAA-BZD receptor. An in vitro GABAA-BZD competitive receptor binding assay also demonstrated that S. sympetala extracts have an affinity for the GABAA-BZD receptor, with an EC50 value of 123 μg/mL (EtOAc leaf extract) and 154 μg/mL (supercritical CO2 extract). These experiments indicate that S. sympetala acts at the GABAA-BZD receptor to elicit anxiolysis.

  19. Effects of PhD examination stress on allopregnanolone and cortisol plasma levels and peripheral benzodiazepine receptor density.

    NARCIS (Netherlands)

    Droogleever Fortuyn, H.A.; Broekhoven, F. van; Span, P.N.; Backstrom, T.; Zitman, F.G.; Verkes, R.J.

    2004-01-01

    Peripheral benzodiazepine receptor (PBR) density in blood platelets and plasma allopregnanolone concentration in humans were determined following acute stress as represented by PhD examination. Fifteen healthy PhD students participated. Heart rate, blood pressure, plasma allopregnanolone, plasma cor

  20. Single dose efficacy evaluation of two partial benzodiazepine receptor agonists in photosensitive epilepsy patients : A placebo-controlled pilot study

    NARCIS (Netherlands)

    Kasteleijn-Nolst Trenite, Dorothée G A|info:eu-repo/dai/nl/304819298; Groenwold, Rolf H H|info:eu-repo/dai/nl/30481203X; Schmidt, Bernd; Löscher, Wolfgang

    2016-01-01

    Benzodiazepines (BZDs) are highly effective to suppress various types of seizures; however, their clinical use is limited due to adverse effects and tolerance and dependence liability. Drugs that act only as partial agonists at the BZD recognition site (initially termed "BZD receptor") of the GABAA

  1. Single dose efficacy evaluation of two partial benzodiazepine receptor agonists in photosensitive epilepsy patients : A placebo-controlled pilot study

    NARCIS (Netherlands)

    Kasteleijn-Nolst Trenite, Dorothée G A; Groenwold, Rolf H H; Schmidt, Bernd; Löscher, Wolfgang

    2016-01-01

    Benzodiazepines (BZDs) are highly effective to suppress various types of seizures; however, their clinical use is limited due to adverse effects and tolerance and dependence liability. Drugs that act only as partial agonists at the BZD recognition site (initially termed "BZD receptor") of the GABAA

  2. Synthesis and PET imaging of the benzodiazepine receptor tracer [N-methyl-{sup 11}C]iomazenil

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, Ronald M.; Horti, Andrew G.; Bremner, J. Douglas; Stratton, Morgan D.; Dannals, Robert F.; Ravert, Hayden T.; Zea-Ponce, Yolanda; Ng, Chin K.; Dey, Holley M.; Soufer, Robert; Charney, Dennis S.; Mazza, Samuel M.; Sparks, Richard B.; Stubbs, James B.; Innis, Robert B

    1995-07-01

    The central benzodiazepine receptor tracer [N-methyl-{sup 11}C]iomazenil (Ro 16-0154) was synthesized by alkylation of the desmethyl precursor noriomazenil with [{sup 11}C]methyl iodide. The [{sup 11}C]CH{sub 3}I (prepared by reduction of [{sup 11}C]CO{sub 2} with LiAlH{sub 4} followed by reaction with HI) was reacted with noriomazenil inN,N -dimethylformamide and Bu{sub 4}N{sup +}OH{sup -} for 1 min at 80 deg. C and purified by HPLC (C{sub 18}, 34% CH{sub 3}CN/H{sub 2}O, 7 mL/min). The product was obtained with synthesis time 35 {+-} 5 min (mean {+-} SD, n = 7), radiochemical yield (EOB) 36 {+-} 16%, radiochemical purity 99 {+-} 1%, and specific activity 5100 {+-} 2800 mCi/{mu}mol. Absorbed radiation doses were calculated from previously acquired human biodistribution data. The urinary bladder wall received the highest dose (0.099 mGy/MBq) for 4.8 h voiding interval and the effective dose equivalent was 0.015 mSv/MBq. After i.v. injection of [{sup 11}C]iomazenil in an adult baboon or healthy human volunteer, radioactivity accumulated in the cortex with time-activity curves in agreement with results obtained with [{sup 11}C]flumazenil PET and [{sup 123}I]iomazenil SPECT studies. The count rate was sufficient to obtain quantitative images up to 2 h post-injection with a 14 mCi injection. These results suggest that [{sup 11}C]iomazenil will be a useful agent for measuring benzodiazepine receptorsin vivo by positron emission tomography.

  3. Quantification of human brain benzodiazepine receptors using [{sup 18}F]fluoroethylflumazenil: a first report in volunteers and epileptic patients

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, Philippe [Unite de Tomographie par Positrons, Universite Catholique de Louvain, Louvain-la-Neuve (Belgium); Unite de Chimie Pharmaceutique et de Radiopharmacie, CMFA/REMA, Universite Catholique de Louvain, 73-40 Avenue Mounier, 1200, Bruxelles (Belgium); Sanabria-Bohorquez, Sandra [Imaging Research, Merck Research Laboratories, West Point, Philadelphia (United States); Bol, Anne; Volder, Anne de; Labar, Daniel [Unite de Tomographie par Positrons, Universite Catholique de Louvain, Louvain-la-Neuve (Belgium); Rijckevorsel, K. van [Service de Neurologie, Cliniques Universitaires Saint-Luc, Bruxelles (Belgium); Gallez, Bernard [Unite de Chimie Pharmaceutique et de Radiopharmacie, CMFA/REMA, Universite Catholique de Louvain, 73-40 Avenue Mounier, 1200, Bruxelles (Belgium); Unite de Resonance Magnetique Biomedicale, Universite Catholique de Louvain, Bruxelles (Belgium)

    2003-12-01

    Fluorine-18 fluoroethylflumazenil ([{sup 18}F]FEF) is a tracer for central benzodiazepine (BZ) receptors which is proposed as an alternative to carbon-11 flumazenil for in vivo imaging using positron emission tomography (PET) in humans. In this study, [{sup 18}F]FEF kinetic data were acquired using a 60-min two-injection protocol on three normal subjects and two patients suffering from mesiotemporal epilepsy as demonstrated by abnormal magnetic resonance imaging and [{sup 18}F]fluorodeoxyglucose positron emission tomography. First, a tracer bolus injection was performed and [{sup 18}F]FEF rapidly distributed in the brain according to the known BZ receptor distribution. Thirty minutes later a displacement injection of 0.01 mg/kg of unlabelled flumazenil was performed. Activity was rapidly displaced from all BZ receptor regions demonstrating the specific binding of [{sup 18}F]FEF. No displacement was observed in the pons. Plasma input function was obtained from arterial blood sampling, and metabolite analysis was performed by high-performance liquid chromatography. Metabolite quantification revealed a fast decrease in tracer plasma concentration, such that at 5 min post injection about 70% of the total radioactivity in plasma corresponded to [{sup 18}F]FEF, reaching 24% at 30 min post injection. The interactions between [{sup 18}F]FEF and BZ receptors were described using linear compartmental models with plasma input and reference tissue approaches. Binding potential values were in agreement with the known distribution of BZ receptors in human brain. Finally, in two patients with mesiotemporal sclerosis, reduced uptake of [{sup 18}F]FEF was clearly observed in the implicated left hippocampus. (orig.)

  4. Binding of (/sup 3/H)ethyl-. beta. -carboline-3-carboxylate to brain benzodiazepine receptors. Effect of drugs and anions

    Energy Technology Data Exchange (ETDEWEB)

    Williams, E.F.; Paul, S.M.; Rice, K.C.; Skolnick, P. (National Institutes of Health, Bethesda, MD (USA)); Cain, M. (Wisconsin Univ., Milwaukee (USA). Dept. of Chemistry)

    1981-09-28

    It is reported that in contrast to the changes in affinity of (/sup 3/H)benzodiazepines elicited by halide ions, barbiturates, and pyrazolopyridines, the apparent affinity of ..beta..-(/sup 3/H)CCE (ethyl-..beta..-carboline-3-carboxylate) is unaffected by these agents. Furthermore, Scatchard analysis of ..beta..-(/sup 3/H)CCE binding to cerebral cortical and cerebellar membranes revealed a significantly greater number of binding sites than was observed with either (/sup 3/H)diazepam or (/sup 3/H)flunitazepam, suggesting that at low concentrations benzodiazepines selectively label a subpopulation of the receptors labelled with ..beta..-(/sup 3/H)CCE. Alternatively, ..beta..-(/sup 3/H)CCE may bind to sites that are distinct from those labelled with (/sup 3/H)-benzodiazepines.

  5. Radioreceptor assay to study the affinity of benzodiazepines and their receptor binding activity in human plasma including their active metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Dorow, R.G.; Seidler, J.; Schneider, H.H. (Schering A.G., Berlin (Germany, F.R.))

    1982-04-01

    A radioreceptor assay has been established to measure the receptor affinities of numerous benzodiazepines in clinical use. The time course of receptor binding activity was studied by this method in the plasma of eight healthy subjects randomly treated with 1mg lormetazepam (Noctamid(R)), 2mg flunitrazepam (Rohypnol(R)), and 10mg diazepam (Valium(R)), and placebo on a cross-over basis. Blood samples were collected up to 154h after treatment. Receptor affinities of numerous benzodiazepines in vitro show good correlation with therapeutic human doses (r=0.96) and may be predictive of drug potency in man. Mean peak plasma levels of lormetazepam binding equivalents were 4.8+-1 ng/ml at 2h after lormetazepam, 7.2+-1.8 ng/ml at 8h after flunitrazepam, and 17.9+-2.7 ng/ml at 15h after diazepam. Plasma elimination halflives of benzodiazepine binding equivalents were 9.3, 23 and 63h, respectively. Slow elimination of benzodiazepine binding equivalents following flunitrazepam and diazepam may be due to persistent active metabolites.

  6. Methodology for benzodiazepine receptor binding assays at physiological temperature. Rapid change in equilibrium with falling temperature

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, R.M.

    1986-12-01

    Benzodiazepine receptors of rat cerebellum were assayed with (/sup 3/H)-labeled flunitrazepam at 37/sup 0/C, and assays were terminated by filtration in a cold room according to one of three protocols: keeping each sample at 37 degrees C until ready for filtration, taking the batch of samples (30) into the cold room and filtering sequentially in the order 1-30, and taking the batch of 30 samples into the cold room and filtering sequentially in the order 30-1. the results for each protocol were substantially different from each other, indicating that rapid disruption of equilibrium occurred as the samples cooled in the cold room while waiting to be filtered. Positive or negative cooperativity of binding was apparent, and misleading effects of gamma-aminobutyric acid on the affinity of diazepam were observed, unless each sample was kept at 37/sup 0/C until just prior to filtration.

  7. The role of the peripheral benzodiazepine receptor in the apoptotic response to photodynamic therapy.

    Science.gov (United States)

    Kessel, D; Antolovich, M; Smith, K M

    2001-08-01

    Several previous studies have suggested that the peripheral benzodiazepine receptor (PBR) on the mitochondrial surface was an important target for photodynamic therapy (PDT). In this study we compared PBR affinity vs photodynamic efficacy of protoporphyrin-IX (PP-IX) and two structural analogs, PP-III and PP-XIII, using murine leukemia L1210 cells in culture. The results indicate that the three agents have approximately equal hydrophobicity, affinity for L1210 cells and ability to initiate photodamage leading to an apoptotic response. But only PP-IX had significant affinity for the PBR. These data indicate that the relationship between PDT efficacy and PBR affinity may hold only for sensitizers with the PP-IX configuration.

  8. GABA(A) receptor physiology and its relationship to the mechanism of action of the 1,5-benzodiazepine clobazam.

    Science.gov (United States)

    Sankar, Raman

    2012-03-01

    Clobazam was initially developed in the early 1970s as a nonsedative anxiolytic agent, and is currently available as adjunctive therapy for epilepsy and anxiety disorders in more than 100 countries. In October 2011, clobazam (Onfi™; Lundbeck Inc., Deerfield, IL, USA) was approved by the US FDA for use as adjunctive therapy for the treatment of seizures associated with Lennox-Gastaut syndrome in patients aged 2 years and older. It is a long-acting 1,5-benzodiazepine whose structure distinguishes it from the classic 1,4-benzodiazepines, such as diazepam, lorazepam and clonazepam. Clobazam is well absorbed, with peak concentrations occurring linearly 1-4 hours after administration. Both clobazam and its active metabolite, N-desmethylclobazam, are metabolized in the liver via the cytochrome P450 pathway. The mean half-life of N-desmethylclobazam (67.5 hours) is nearly double the mean half-life of clobazam (37.5 hours). Clobazam was synthesized with the anticipation that its distinct chemical structure would provide greater efficacy with fewer benzodiazepine-associated adverse effects. Frequently reported adverse effects of clobazam therapy include dizziness, sedation, drowsiness and ataxia. Evidence gathered from approximately 50 epilepsy clinical trials in adults and children indicated that the sedative effects observed with clobazam treatment were less severe than those reported with 1,4-benzodiazepines. In several studies of healthy volunteers and patients with anxiety, clobazam appeared to enhance participants' performance in cognitive tests, further distinguishing it from the 1,4-benzodiazepines. The anxiolytic and anticonvulsant effects of clobazam are associated with allosteric activation of the ligand-gated GABA(A) receptor. GABA(A) receptors are found extensively throughout the CNS, occurring synaptically and extrasynaptically. GABA(A) receptors are composed of five protein subunits, two copies of a single type of α subunit, two copies of one type of

  9. A Review of the Updated Pharmacophore for the Alpha 5 GABA(A Benzodiazepine Receptor Model

    Directory of Open Access Journals (Sweden)

    Terry Clayton

    2015-01-01

    Full Text Available An updated model of the GABA(A benzodiazepine receptor pharmacophore of the α5-BzR/GABA(A subtype has been constructed prompted by the synthesis of subtype selective ligands in light of the recent developments in both ligand synthesis, behavioral studies, and molecular modeling studies of the binding site itself. A number of BzR/GABA(A α5 subtype selective compounds were synthesized, notably α5-subtype selective inverse agonist PWZ-029 (1 which is active in enhancing cognition in both rodents and primates. In addition, a chiral positive allosteric modulator (PAM, SH-053-2′F-R-CH3 (2, has been shown to reverse the deleterious effects in the MAM-model of schizophrenia as well as alleviate constriction in airway smooth muscle. Presented here is an updated model of the pharmacophore for α5β2γ2 Bz/GABA(A receptors, including a rendering of PWZ-029 docked within the α5-binding pocket showing specific interactions of the molecule with the receptor. Differences in the included volume as compared to α1β2γ2, α2β2γ2, and α3β2γ2 will be illustrated for clarity. These new models enhance the ability to understand structural characteristics of ligands which act as agonists, antagonists, or inverse agonists at the Bz BS of GABA(A receptors.

  10. Systematic review of modulators of benzodiazepine receptors in irritable bowel syndrome:Is there hope?

    Institute of Scientific and Technical Information of China (English)

    Pooneh Salari; Mohammad Abdollahi

    2011-01-01

    Several drugs are used in the treatment of irritable bowel syndrome (IBS) but all have side effects and variable efficacy.Considering the role of the gut-brain axis,immune,neural,and endocrine pathways in the patho-genesis of IBS and possible beneficial effects of ben-zodiazepines (BZD) in this axis,the present systematic review focuses on the efficacy of BZD receptor modulators in human IBS.For the years 1966 to February 2011,all literature was searched for any articles on the use of BZD receptor modulators and IBS.After thorough evaluation and omission of duplicate data,10 out of 69 articles were included.BZD receptor modulators can be helpful,especially in the diarrhea-dominant form of IBS,by affecting the inflammatory,neural,and psychologic pathways,however,controversies still exist.Recently,a new BZD receptor modulator,dextofisopam was synthesized and studied in human subjects,but the studies are limited to phase II b clinical trials.None of the existing trials considered the neuroimmunomodulatory effectof BZDs in IBS,but bearing in mind the concentration-dependent effect of BZDs on cytokines and cell proliferation,future studies using pharmacodynamic and pharmacokinetic approaches are highly recommended.

  11. Stimulation of Hepatic Apolipoprotein A-I Production by Novel Thieno-Triazolodiazepines: Roles of the Classical Benzodiazepine Receptor, PAF Receptor, and Bromodomain Binding.

    Science.gov (United States)

    Kempen, Herman J; Bellus, Daniel; Fedorov, Oleg; Nicklisch, Silke; Filippakopoulos, Panagis; Picaud, Sarah; Knapp, Stefan

    2013-01-01

    Expression and secretion of apolipoprotein A-I (apoA-I) by cultured liver cells can be markedly stimulated by triazolodiazepines (TZDs). It has been shown previously that the thieno-TZD Ro 11-1464 increases plasma levels of apoA-I and in vivomacrophage reverse cholesterol transport in mice. However, these effects were only seen at high doses, at which the compound could act on central benzodiazepine (BZD) receptors or platelet activating factor (PAF) receptors, interfering with its potential utility. In this work, we describe 2 new thieno-TZDs MDCO-3770 and MDCO-3783, both derived from Ro 11-1464. These compounds display the same high efficacy on apoA-I production, metabolic stability, and lack of cytotoxicity in cultured hepatocytes as Ro 11-1464, but they do not bind to the central BZD receptor and PAF receptor. The quinazoline RVX-208 was less efficacious in stimulating apoA-I production and displayed signs of cytotoxicity. Certain TZDs stimulating apoA-I production are now known to be inhibitors of bromodomain (BRD) extra-terminal (BET) proteins BRDT, BRD2, BRD3, and BRD4, and this inhibition was inferred as a main molecular mechanism for their effect on apoA-I expression. We show here that the thieno-TZD (+)-JQ1, a potent BET inhibitor, strongly stimulated apoA-I production in Hep-G2 cells, but that its enantiomer (-)-JQ1, which has no BET inhibitor activity, also showed considerable effect on apoA-I production. MDCO-3770 and MDCO-3783 also inhibited BRD3 and BRD4 in vitro, with potency somewhat below that of (+)-JQ1. We conclude that the effect of thieno-TZDs on apoA-I expression is not due to inhibition of the BZD or PAF receptors and is not completely explained by transcriptional repression by BET proteins.

  12. GABA systems, benzodiazepines, and substance dependence.

    Science.gov (United States)

    Malcolm, Robert J

    2003-01-01

    Alterations in the gamma-aminobutyric acid (GABA) receptor complex and GABA neurotransmission influence the reinforcing and intoxicating effects of alcohol and benzodiazepines. Chronic modulation of the GABA(A)-benzodiazepine receptor complex plays a major role in central nervous system dysregulation during alcohol abstinence. Withdrawal symptoms stem in part from a decreased GABAergic inhibitory function and an increase in glutamatergic excitatory function. GABA(A) receptors play a role in both reward and withdrawal phenomena from alcohol and sedative-hypnotics. Although less well understood, GABA(B) receptor complexes appear to play a role in inhibition of motivation and diminish relapse potential to reinforcing drugs. Evidence suggests that long-term alcohol use and concomitant serial withdrawals permanently alter GABAergic function, down-regulate benzodiazepine binding sites, and in preclinical models lead to cell death. Benzodiazepines have substantial drawbacks in the treatment of substance use-related disorders that include interactions with alcohol, rebound effects, alcohol priming, and the risk of supplanting alcohol dependency with addiction to both alcohol and benzodiazepines. Polysubstance-dependent individuals frequently self-medicate with benzodiazepines. Selective GABA agents with novel mechanisms of action have anxiolytic, anticonvulsant, and reward inhibition profiles that have potential in treating substance use and withdrawal and enhancing relapse prevention with less liability than benzodiazepines. The GABA(B) receptor agonist baclofen has promise in relapse prevention in a number of substance dependence disorders. The GABA(A) and GABA(B) pump reuptake inhibitor tiagabine has potential for managing alcohol and sedative-hypnotic withdrawal and also possibly a role in relapse prevention.

  13. Effects of hippocampal injections of a novel ligand selective for the alpha 5 beta 2 gamma 2 subunits of the GABA/benzodiazepine receptor on Pavlovian conditioning.

    Science.gov (United States)

    Bailey, David J; Tetzlaff, Julie E; Cook, James M; He, Xiaohui; Helmstetter, Fred J

    2002-07-01

    Benzodiazepine pharmacology has led to greater insight into the neural mechanisms underlying learning and anxiety. The synthesis of new compounds capable of modulating responses produced by these receptors has been made possible by the development of an isoform model of the GABA(A)/benzodiazepine receptor complex. In the current experiment, rats were pretreated with several concentrations of the novel ligand RY024 (an alpha 5 beta 2 gamma 2 -selective benzodiazepine receptor inverse agonist) in the hippocampus and were trained in a Pavlovian fear conditioning paradigm. RY024 independently produced fear-related behavior prior to training and, at the highest concentration, decreased the strength of conditioning observed 24 h after training. These data provide further evidence for the involvement of hippocampal GABA(A)/benzodiazepine receptors in learning and anxiety.

  14. Alterations of benzodiazepine receptor binding potential in anxiety and somatoform disorders measured by {sup 123}I-iomazenil SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Tokunaga, Mari; Ida, Ituro; Mikuni, Masahiko [Gunma Univ., Maebashi (Japan). School of Medicine; Higuchi, Teruhiko

    1997-05-01

    {sup 123}I-iomazenil (IMZ), a newly developed radioligand which acts on benzodiazepine receptors (BZR) as a partial inverse agonist, made it possible to evaluate the function of central BZR by single photon emission tomography (SPECT). To examine the alterations of the binding potential (BP) in the anxiety state, {sup 123}I-IMZ SPECT was performed in five patients with anxiety and somatoform disorders, and five epileptic patients without anxiety symptoms served as a reference. The BP of BZR was determined by using a table look-up procedure based on a three-compartment, two-parameter model in the bilateral superior frontal, inferior frontal, temporal, parietal, occipital, and cerebellar cortex. The mean BP of patients with anxiety and somatoform disorders was significantly decreased in the superior frontal, temporal, and parietal cortex, in comparison with that of epileptic patients. A significant correlation was observed between the anxiety levels scored on the Hamilton anxiety scale and BP in the right temporal cortex and left superior frontal cortex. These changes in BZR revealed by SPECT suggest the usefulness of {sup 123}I-IMZ SPECT to objectively evaluate anxiety levels in patients with anxiety symptoms. (author)

  15. Opioid receptors are involved in the sedative and antinociceptive effects of hesperidin as well as in its potentiation with benzodiazepines.

    Science.gov (United States)

    Loscalzo, Leonardo M; Wasowski, Cristina; Paladini, Alejandro C; Marder, Mariel

    2008-02-12

    Previous reports from our laboratory described the sedative activity of hesperidin (hesperetin-7-rhamnoglucoside). This property is greatly increased when the glycoside is injected jointly with diazepam and this interaction has been shown to be synergistic. In the present work the generality of the synergistic phenomenon is proved, since potentiation also occurs with several other benzodiazepines, namely alprazolam, bromazepam, midazolam and flunitrazepam. In order to advance in the study of the mechanism of action of hesperidin, the possible participation of several brain receptors, which are implicated in the control of numerous behavioral and physiological functions, was explored by investigating the effects of a variety of their antagonists on hesperidin actions. The results showed that the 5-HT2 receptor and the alpha1-adrenoceptor seem unlikely to be involved in the behavioral effects of hesperidin. Naltrexone, a nonselective antagonist of opioid receptors, totally blocked hesperidin effects on locomotion, and partially antagonized hesperidin-induced decreased exploration in the hole board test. Nor-binaltorphimine, a selective kappa opioid receptor antagonist, was able to partially block hesperidin effects on locomotor activity. Furthermore, hesperidin-induced antinociception was partially blocked by naltrexone, and potentiated by co-administration with alprazolam. Hence, the participation of the opioid system in the sedative, antinociceptive and potentianting effects of hesperidin with benzodiazepines in mice is highly probable. Our results suggest a possible beneficial use of the association of hesperidin with benzodiazepines, not only to improve human sedative therapy, but also in the management of pain.

  16. Subchronic treatment with antiepileptic drugs modifies pentylenetetrazol-induced seizures in mice: Its correlation with benzodiazepine receptor binding

    Directory of Open Access Journals (Sweden)

    Luisa Rocha

    2008-06-01

    Full Text Available Luisa RochaPharmacobiology Department, Center for Research and Advanced Studies, Calz, Tenorios, MéxicoAbstract: Experiments using male CD1 mice were carried out to investigate the effects of subchronic (daily administration for 8 days pretreatments with drugs enhancing GABAergic transmission (diazepam, 10 mg/kg, ip; gabapentin, 100 mg/kg, po; or vigabatrin, 500 mg/kg, po on pentylenetetrazol (PTZ-induced seizures, 24 h after the last injection. Subchronic administration of diazepam reduced latencies to clonus, tonic extension and death induced by PTZ. Subchronic vigabatrin produced enhanced latency to the first clonus but faster occurrence of tonic extension and death induced by PTZ. Subchronic gabapentin did not modify PTZ-induced seizures. Autoradiography experiments revealed reduced benzodiazepine receptor binding in several brain areas after subchronic treatment with diazepam or gabapentin, whereas subchronic vigabatrin did not induce significant receptor changes. The present results indicate differential effects induced by the subchronic administration of diazepam, vigabatrin, and gabapentin on the susceptibility to PTZ-induced seizures, benzodiazepine receptor binding, or both.Keywords: diazepam, gabapentin, vigabatrin, pentylenetetrazol, benzodiazepine receptors

  17. In vivo molecular imaging of the GABA/benzodiazepine receptor complex in the aged rat brain.

    Science.gov (United States)

    Hoekzema, Elseline; Rojas, Santiago; Herance, Raúl; Pareto, Deborah; Abad, Sergio; Jiménez, Xavier; Figueiras, Francisca P; Popota, Foteini; Ruiz, Alba; Flotats, Núria; Fernández, Francisco J; Rocha, Milagros; Rovira, Mariana; Víctor, Víctor M; Gispert, Juan D

    2012-07-01

    The GABA-ergic system, known to regulate neural tissue genesis during cortical development, has been postulated to play a role in cerebral aging processes. Using in vivo molecular imaging and voxel-wise quantification, we aimed to assess the effects of aging on the benzodiazepine (BDZ) recognition site of the GABA(A) receptor. To visualize BDZ site availability, [(11)C]-flumazenil microPET acquisitions were conducted in young and old rats. The data were analyzed and region of interest analyses were applied to validate the voxel-wise approach. We observed decreased [(11)C]-flumazenil binding in the aged rat brains in comparison with the young control group. More specifically, clusters of reduced radioligand uptake were detected in the bilateral hippocampus, cerebellum, midbrain, and bilateral frontal and parieto-occipital cortex. Our results support the pertinence of voxel-wise quantification in the analysis of microPET data. Moreover, these findings indicate that the aging process involves declines in neural BDZ recognition site availability, proposed to reflect alterations in GABA(A) receptor subunit polypeptide expression.

  18. The "peripheral-type" benzodiazepine (omega 3) receptor in hyperammonemic disorders.

    Science.gov (United States)

    Desjardins, Paul; Butterworth, Roger F

    2002-01-01

    Increased levels of brain ammonia occur in both congenital and acquired hyperammonemic syndromes including hepatic encephalopathy, fulminant hepatic failure, Reye's syndrome and congenital urea cycle disorders. In addition to its effect on neurotransmission and energy metabolism, ammonia modulates the expression of various genes including the astrocytic "peripheral-type" benzodiazepine (or omega 3) receptor (PTBR). Increased expression of the isoquinoline carboxamide binding protein (IBP), one of the components of the PTBR complex, is observed in brain and peripheral tissues following chronic liver failure as well as in cultured astrocytes exposed to ammonia. Increased densities of binding sites for the PTBR ligand [3H]-PK11195 are also observed in these conditions as well as in brains of animals with acute liver failure, congenital urea cycle disorders and in patients who died in hepatic coma. The precise role of PTBR in brain function has not yet fully elucidated, but among other functions, PTBR mediates the transport of cholesterol across the mitochondrial membrane and thus plays a key role in the biosynthesis of neurosteroids some of which modulate major neurotransmitter systems such as the gamma-aminobutyric acid (GABA(A)) and glutamate (N-methyl-D-aspartate (NMDA)) receptors. Activation of PTBR in chronic and acute hyperammonemia results in increased synthesis of neurosteroids which could lead to an imbalance between excitatory and inhibitory neurotransmission in the CNS. Preliminary reports suggest that positron emission tomography (PET) studies using [11C]-PK11195 may be useful for the assessment of the neurological consequences of chronic liver failure.

  19. Development of a unique 3D interaction model of endogenous and synthetic peripheral benzodiazepine receptor ligands

    Science.gov (United States)

    Cinone, Nunzia; Höltje, Hans-Dieter; Carotti, Angelo

    2000-11-01

    Different classes of Peripheral-type Benzodiazepine Receptor (PBR) ligands were examined and common structural elements were detected and used to develop a rational binding model based on energetically allowed ligand conformations. Two lipophilic regions and one electrostatic interaction site are essential features for high affinity ligand binding, while a further lipophilic region plays an important modulator role. A comparative molecular field analysis, performed over 130 PBR ligands by means of the GRID/GOLPE methodology, led to a PLS model with both high fitting and predictive values (r2 = 0.898, Q2 = 0.761). The outcome from the 3D QSAR model and the GRID interaction fields computed on the putative endogenous PBR ligands DBI (Diazepam Binding Inhibitor) and TTN (Tetracontatetraneuropeptide) was used to identify the amino acids most probably involved in PBR binding. Three amino acids, bearing lipophilic side chains, were detected in DBI (Phe49, Leu47 and Met46) and in TTN (Phe33, Leu31 and Met30) as likely residues underlying receptor binding. Moreover, a qualitative comparison of the molecular electrostatic potentials of DBI, TTN and selected synthetic ligands indicated also similar electronic properties. Convergent results from the modeling studies of synthetic and endogenous ligands suggest a common binding mode to PBRs. This may help the rational design of new high affinity PBR ligands.

  20. Decreased benzodiazepine receptor binding in epileptic El mice: A quantitative autoradiographic study

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    Shirasaka, Y.; Ito, M.; Tsuda, H.; Shiraishi, H.; Oguro, K.; Mutoh, K.; Mikawa, H. (Kyoto Univ. (Japan))

    1990-09-01

    Benzodiazepine receptors and subtypes were examined in El mice and normal ddY mice with a quantitative autoradiographic technique. Specific (3H)flunitrazepam binding in stimulated El mice, which had experienced repeated convulsions, was significantly lower in the cortex and hippocampus than in ddY mice and unstimulated El mice. In the amygdala, specific ({sup 3}H)flunitrazepam binding in stimulated El mice was lower than in ddY mice. There was a tendency for the ({sup 3}H)flunitrazepam binding in these regions in unstimulated El mice to be intermediate between that in stimulated El mice and that in ddY mice, but there was no significant difference between unstimulated El mice and ddY mice. ({sup 3}H)Flunitrazepam binding displaced by CL218,872 was significantly lower in the cortex of stimulated El mice than in that of the other two groups, and in the hippocampus of stimulated than of unstimulated El mice. These data suggest that the decrease in ({sup 3}H)flunitrazepam binding in stimulated El mice may be due mainly to that of type 1 receptor and may be the result of repeated convulsions.

  1. Inhibitory effects of benzodiazepines on the adenosine A(2B) receptor mediated secretion of interleukin-8 in human mast cells.

    Science.gov (United States)

    Hoffmann, Kristina; Xifró, Rosa Altarcheh; Hartweg, Julia Lisa; Spitzlei, Petra; Meis, Kirsten; Molderings, Gerhard J; von Kügelgen, Ivar

    2013-01-30

    The activation of adenosine A(2B) receptors in human mast cells causes pro-inflammatory responses such as the secretion of interleukin-8. There is evidence for an inhibitory effect of benzodiazepines on mast cell mediated symptoms in patients with systemic mast cell activation disease. Therefore, we investigated the effects of benzodiazepines on adenosine A(2B) receptor mediated interleukin-8 production in human mast cell leukaemia (HMC1) cells by an enzyme linked immunosorbent assay. The adenosine analogue N-ethylcarboxamidoadenosine (NECA, 0.3-3 μM) increased interleukin-8 production about 5-fold above baseline. This effect was attenuated by the adenosine A(2B) receptor antagonist MRS1754 (N-(4-cyanophenyl)-2-{4-(2,3,6,7-tetrahydro-2,6-dioxo-1,3-dipropyl-1H-purin-8-yl)phenoxy}-acetamide) 1 μM. In addition, diazepam, 4'-chlorodiazepam and flunitrazepam (1-30 μM) markedly reduced NECA-induced interleukin-8 production in that order of potency, whereas clonazepam showed only a modest inhibition. The inhibitory effect of diazepam was not altered by flumazenil 10 μM or PK11195 (1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide) 10 μM. Diazepam attenuated the NECA-induced expression of mRNA encoding for interleukin-8. Moreover, diazepam and flunitrazepam reduced the increasing effects of NECA on cAMP-response element- and nuclear factor of activated t-cells-driven luciferase reporter gene activities in HMC1 cells. Neither diazepam nor flunitrazepam affected NECA-induced increases in cellular cAMP levels in CHO Flp-In cells stably expressing recombinant human adenosine A(2B) receptors, excluding a direct action of benzodiazepines on human adenosine A(2B) receptors. In conclusion, this is the first study showing an inhibitory action of benzodiazepines on adenosine A(2B) receptor mediated interleukin-8 production in human mast (HMC1) cells. The rank order of potency indicates the involvement of an atypical benzodiazepine binding site.

  2. Peripheral-type benzodiazepine receptors in bronchoalveolar lavage cells of patients with interstitial lung disease

    Energy Technology Data Exchange (ETDEWEB)

    Branley, Howard M. [Imperial College London, Hammersmith Campus, W12 OHS London (United Kingdom)]. E-mail: howard.branley@whittington.nhs.uk; Bois, Roland M. du [Royal Brompton Hospital, SW3 6NP London (United Kingdom); Wells, Athol U. [Royal Brompton Hospital, SW3 6NP London (United Kingdom); Jones, Hazel A. [Imperial College London, Hammersmith Campus, W12 OHS London (United Kingdom)

    2007-07-15

    Introduction: PK11195 is a ligand with high affinity for peripheral benzodiazepine receptors (PBRs), which are present in large numbers in macrophages. PBRs play a role in antioxidant pathways and apoptosis, key factors in control of lung health. Intrapulmonary PBRs, assessed in vivo by positron emission tomography (PET), are decreased in interstitial lung disease (ILD) despite increased macrophage numbers. We wished to ascertain whether the observed decrease in in vivo expression of PBRs in the PET scans could be accounted for by a reduction in PBRs per cell by saturation-binding assays of R-PK11195 in cells obtained by bronchoalveolar lavage (BAL). Methods: We performed receptor saturation-binding assays with [{sup 3}H]-R-PK11195 on a mixed population of cells recovered by BAL to quantify the number of R-PK11195 binding sites per macrophage in 10 subjects with ILD and 10 normal subjects. Results: Receptor affinity [dissociation constant (Kd)] was similar in ILD patients and controls. However, R-PK11195 binding sites per cell [(maximal binding sites available (B {sub max})] were decreased in macrophages obtained by BAL from subjects with ILD compared to normal (P<.0005). Microautoradiography confirmed localization of R-PK11195 to macrophages in a mixed inflammatory cell population obtained by BAL. Conclusion: These results demonstrate that in vitro PBR expression per cell on macrophages obtained by BAL is reduced in patients with ILD indicating a potentially functionally different macrophage phenotype. As PBRs are involved in the orchestration of lung inflammatory responses, this finding offers further insight into the role of macrophages in the pathogenesis of ILDs and offers a potential avenue for pharmacological strategy.

  3. Interactions of pyrethroid insecticides with GABA sub A and peripheral-type benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Devaud, L.L.

    1988-01-01

    Pyrethroid insecticides are potent proconvulsants in the rat. All pyrethroids evincing proconvulsant activity elicited a similar 25-30% maximal reduction of seizure threshold. The Type II pyrethroids were the most potent proconvulsants with 1R{alpha}S, cis cypermethrin having an ED{sub 50} value of 6.3 nmol/kg. The proconvulsant activity of both Type I and Type II pyrenthroids was blocked by pretreatment with PK 11195, the peripheral-type benzodiazepine receptor (PTBR) antagonist. In contrast, phenytoin did not antagonize the proconvulsant activity of either deltamethrin or permethrin. Pyrethroids displaced the specific binding of ({sup 3}H)Ro5-4864 to rat brain membranes with a significant correlation between the log EC{sub 50} values for their activities as proconvulsants and the log IC{sub 50} values for their inhibition of ({sup 3}H)Ro5-4864 binding. Both Ro5-4864 and pyrethroid insecticides were found to influence specific ({sup 35}S)TBPS binding in a GABA-dependent manner. PK 11195 and the Type II pyrethroid, deltamethrin antagonized the Ro5-4864-induced modulation of ({sup 35}S)TBPS binding. Pyrethroid insecticides, Ro5-4864 and veratridine influenced GABA-gated {sup 36}Chloride influx. Moreover, the Type II pyrethroids elicited an increase in {sup 36}chloride influx in the absence of GABA-stimulation. Both of these actions were antagonized by PK 11195 and tetrodotoxin.

  4. In Vivo Imaging of Peripheral Benzodiazepine Receptors in Mouse Lungs: A Biomarker of Inflammation

    Directory of Open Access Journals (Sweden)

    Matthew J. Hardwick

    2005-10-01

    Full Text Available The ability to visualize the immune response with radioligands targeted to immune cells will enhance our understanding of cellular responses in inflammatory diseases. Peripheral benzodiazepine receptors (PBR are present in monocytes and neutrophils as well as in lung tissue. We used lipopolysaccharide (LPS as a model of inflammation to assess whether the PBR could be used as a noninvasive marker of inflammation in the lungs. Planar imaging of mice administrated 10 or 30 mg/kg LPS showed increased [123I]-(R-PK11195 radioactivity in the thorax 2 days after LPS treatment relative to control. Following imaging, lungs from control and LPS-treated mice were harvested for ex vivo gamma counting and showed significantly increased radioactivity above control levels. The specificity of the PBR response was determined using a blocking dose of nonradioactive PK11195 given 30 min prior to radiotracer injection. Static planar images of the thorax of nonradioactive PK11195 pretreated animals showed a significantly lower level of radiotracer accumulation in control and in LPS-treated animals (p < .05. These data show that LPS induces specific increases in PBR ligand binding in the lungs. We also used in vivo small-animal PET studies to demonstrate increased [11C]-(R-PK11195 accumulation in the lungs of LPS-treated mice. This study suggests that measuring PBR expression using in vivo imaging techniques may be a useful biomarker to image lung inflammation.

  5. Maternal Characteristics of Women Exposed to Hypnotic Benzodiazepine Receptor Agonist during Pregnancy

    Directory of Open Access Journals (Sweden)

    Bjarke Askaa

    2014-01-01

    Full Text Available Background. There is little knowledge regarding the characteristics of women treated with hypnotic benzodiazepine receptor agonists (HBRAs during pregnancy. In this large Danish cohort study, we characterize women exposed to HBRA during pregnancy. We determined changes in prevalence of HBRA use from 1997 to 2010 and exposure to HBRAs in relation to pregnancy. Methods. We performed a retrospective cohort study including 911,017 pregnant women in the period from 1997 to 2010. Information was retrieved from The Danish Birth Registry and The Registry of Medicinal Product Statistics to identify pregnant women redeeming a prescription of HBRAs. Results. We identified 2,552 women exposed to HBRAs during pregnancy, increasing from 0.18% in 1997 to 0.23% in 2010. Compared to unexposed women, exposed women were characterized by being older, with higher BMI, in their third or fourth parity, of lower income and education level, more frequently smokers, and more likely to be comedicated with antipsychotic, anxiolytic, or antidepressant drugs (P<0.0001. Conclusion. Women using HBRAs during their pregnancy differ from unexposed women in socioeconomic factors and were more likely to receive comedication. The consumption of HBRAs was reduced during pregnancy compared to before conception.

  6. Effects of peripheral benzodiazepine receptor ligands on proliferation and differentiation of human mesenchymal stem cells.

    Science.gov (United States)

    Lee, D H; Kang, S K; Lee, R H; Ryu, J M; Park, H Y; Choi, H S; Bae, Y C; Suh, K T; Kim, Y K; Jung, Jin Sup

    2004-01-01

    The peripheral benzodiazepine receptor (PBR) has been known to have many functions such as a role in cell proliferation, cell differentiation, steroidogenesis, calcium flow, cellular respiration, cellular immunity, malignancy, and apoptosis. However, the presence of PBR has not been examined in mesenchymal stem cells. In this study, we demonstrated the expression of PBR in human bone marrow stromal cells (hBMSCs) and human adipose stromal cells (hATSCs) by RT-PCR and immunocytochemistry. To determine the roles of PBR in cellular functions of human mesenchymal stem cells (hMSCs), effects of diazepam, PK11195, and Ro5-4864 were examined. Adipose differentiation of hMSCs was decreased by high concentration of PBR ligands (50 microM), whereas it was increased by low concentrations of PBR ligands (<10 microM). PBR ligands showed a biphasic effect on glycerol-3-phosphate dehydrogenase (GPDH) activity. High concentration of PBR ligands (from 25 to 75 microM) inhibited proliferation of hMSCs. However, clonazepam, which does not have an affinity to PBR, did not affect adipose differentiation and proliferation of hMSCs. The PBR ligands did not induce cell death in hMSCs. PK11195 (50 microM) and Ro5-5864 (50 microM) induced cell cycle arrest in the G(2)/M phase. These results indicate that PBR ligands play roles in adipose differentiation and proliferation of hMSCs.

  7. Convulsions induced by centrally administered NMDA in mice: effects of NMDA antagonists, benzodiazepines, minor tranquilizers and anticonvulsants.

    Science.gov (United States)

    Moreau, J. L.; Pieri, L.; Prud'hon, B.

    1989-01-01

    1. Convulsions were induced reproducibly by intracerebroventricular injection of N-methyl-D-aspartic acid (NMDA) to conscious mice. 2. Competitive (carboxypiperazine-propylphosphonic acid, CPP; 2-amino-7-phosphonoheptanoic acid, AP7) and non-competitive (MK801; phencyclidine, PCP; thienylcyclohexylpiperidine, TCP; dextrorphan; dextromethorphan) NMDA antagonists prevented NMDA-induced convulsions. 3. Benzodiazepine receptor agonists and partial agonists (triazolam, diazepam, clonazepam, Ro 16-6028), classical anticonvulsants (diphenylhydantoin, phenobarbitone, sodium valproate) and meprobamate were also found to prevent NMDA-induced convulsions. 4. Flumazenil (a benzodiazepine receptor antagonist) and the GABA agonists THIP and muscimol (up to subtoxic doses) were without effect. 5. Flumazenil reversed the anticonvulsant action of diazepam, but not that of MK801. 6. Results obtained in this model differ somewhat from those described in a seizure model with systemic administration of NMDA. An explanation for this discrepancy is offered. 7. This model is a simple test for assessing the in vivo activity of NMDA antagonists and also expands the battery of chemically-induced seizure models for characterizing anticonvulsants not acting at NMDA receptors. PMID:2574061

  8. Potential role of cortical 5-HT(2A) receptors in the anxiolytic action of cyamemazine in benzodiazepine withdrawal.

    Science.gov (United States)

    Benyamina, Amine; Naassila, Mickaël; Bourin, Michel

    2012-07-30

    The antipsychotic cyamemazine is a potent serotonin 5-HT(2A) receptor (5-HT(2AR)) antagonist. A positron emission tomography (PET) study in human patients showed that therapeutic doses of cyamemazine produced near saturation of 5-HT(2AR) occupancy in the frontal cortex, whereas dopamine D(2) occupancy remained below the level for motor side effects observed with typical antipsychotics. Recently, numerous studies have revealed the involvement of 5-HT(2AR) in the pathophysiology of anxiety and a double-blind, randomized clinical trial showed similar efficacy of cyamemazine and bromazepam in reducing the anxiety associated with benzodiazepine withdrawal. Therefore, we reviewed the above articles about 5-HT(2AR) and anxiety in order to understand better the anxiolytic mechanisms of cyamemazine in benzodiazepine withdrawal. The 5-HT(2AR) is the most abundant serotonin receptor subtype in the cortex. Non-pharmacological studies with antisense oligodeoxynucleotides and genetically modified mice clearly showed that cortical 5-HT(2AR) signaling positively modulates anxiety-like behavior. With a few exceptions, most other studies reviewed here further support this view. Therefore, the anxiolytic efficacy of cyamemazine in benzodiazepine withdrawal can be due to a 5-HT(2AR) antagonistic activity at the cortical level. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Discriminative stimulus effects of benzodiazepine (BZ)(1) receptor-selective ligands in rhesus monkeys.

    Science.gov (United States)

    McMahon, Lance R; Gerak, Lisa R; Carter, Lawrence; Ma, Chunrong; Cook, James M; France, Charles P

    2002-02-01

    Drug discrimination was used to examine the effects of benzodiazepine (BZ)(1) receptor-selective ligands in rhesus monkeys. In diazepam-treated (5.6 mg/kg, p.o.) monkeys discriminating the nonselective BZ antagonist flumazenil (0.32 mg/kg, s.c.), the BZ(1)-selective antagonist beta-carboline-3-carboxylate-t-butyl ester (beta-CCt) substituted for flumazenil. The onset of action of beta-CCt was delayed with a dose of 5.6 mg/kg beta-CCt substituting for flumazenil 2 h after injection. In monkeys discriminating the nonselective BZ agonist midazolam (0.56 mg/kg, s.c.), the BZ(1)-selective agonists zaleplon (ED(50) = 0.78 mg/kg) and zolpidem (ED(50) = 1.73 mg/kg) substituted for midazolam. The discriminative stimulus effects of midazolam, zaleplon, and zolpidem were antagonized by beta-CCt (1.0-5.6 mg/kg, s.c.), and the effects of zaleplon and zolpidem were also antagonized by flumazenil (0.01-0.32 mg/kg, s.c.). Schild analyses supported the notion of a simple, competitive interaction between beta-CCt and midazolam (slope = -1.08; apparent pA(2) = 5.41) or zaleplon (slope = -1.57; apparent pA(2) = 5.49) and not between beta-CCt and zolpidem. Schild analyses also were consistent with a simple, competitive interaction between flumazenil and zaleplon (slope = -1.03; apparent pA(2) = 7.45) or zolpidem (slope = -1.11; apparent pA(2) = 7.63). These results suggest that the same BZ receptor subtype(s) mediate(s) the effects of midazolam, zolpidem, and zaleplon under these conditions and that selective binding of BZ ligands does not necessarily confer selective effects in vivo.

  10. Pharmacological properties of AC-3933, a novel benzodiazepine receptor partial inverse agonist.

    Science.gov (United States)

    Hashimoto, T; Kiyoshi, T; Kohayakawa, H; Iwamura, Y; Yoshida, N

    2014-01-01

    We investigated in this study the pharmacological properties of AC-3933 (5-(3-methoxyphenyl)-3-(5-methyl-1,2,4-oxadiazol-3-yl)-1,6-naphthyridin-2(1H)-one), a novel benzodiazepine receptor (BzR) partial inverse agonist. AC-3933 potently inhibited [3H]-flumazenil binding to rat whole brain membrane with a Ki value of 5.15 ± 0.39 nM and a GABA ratio of 0.84 ± 0.03. AC-3933 exhibited almost no affinity for the other receptors, transporters and ion channels used in this study. In addition, AC-3933, in the presence of GABA (1 μM), gradually but significantly increased [³⁵S] tert-butylbicyclophosphorothionate binding to rat cortical membrane to 117.1% of the control (maximum increase ratio) at 3000 nM. However, this increase reached a plateau at 30 nM with hardly any change at a concentration range of 100-3000 nM (from 115.2% to 117.1%). AC-3933 (0.1-10 μM) significantly enhanced KCl-evoked acetylcholine (ACh) release from rat hippocampal slices in a concentration-dependent manner. Moreover, in vivo brain microdialysis showed that intragastric administration of AC-3933 at the dose of 10 mg/kg significantly increased extracellular ACh levels in the hippocampus of freely moving rats (area under the curve (AUC₀₋₂ h) of ACh level; 288.3% of baseline). These results indicate that AC-3933, a potent and selective BzR inverse agonist with low intrinsic activity, might be useful in the treatment of cognitive disorders associated with degeneration of the cholinergic system.

  11. Evidence for involvement of the astrocytic benzodiazepine receptor in the mechanism of action of convulsant and anticonvulsant drugs

    Energy Technology Data Exchange (ETDEWEB)

    Bender, A.S.; Hertz, L.

    1988-01-01

    The anticonvulsant drugs carbamazepine, phenobarbital, trimethadione, valproic acid and ethosuximide at pharmacologically relevant concentrations inhibit (/sup 3/H)diazepam binding to astrocytes in primary cultures but have much less effect on a corresponding preparation of neurons. Phenytoin as well as pentobarbital (which is not used chronically as an anticonvulsant) are equipotent in the two cell types. The convulsants picrotoxinin and pentylenetetrazol, the convulsant benzodiazepine RO 5-3663 and the two convulsant barbiturates DMBB and CHEB similarly inhibit diazepam binding to astrocytes but have little effect on neurons. On the basis of these findings it is suggested that these convulsants and anticonvulsants owe at least part of their effect to an interaction with the astrocytic benzodiazepine receptor, perhaps by interference with a calcium channel.

  12. Synthesis of [{sup 123}I]iodine labelled imidazo[1,2-b] pyridazines as potential probes for the study of peripheral benzodiazepine receptors using SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Katsifis, A.; Mattner, F.; Dikic, B. [Radiopharmaceuticals Div. ANSTO, Menai, NSW (Australia); Barlin, G. [Div. of Neurosciences, John Curtin School of Medical Research, Australian National Univ., Canberra (Australia)

    2004-07-01

    The pyridazines 3-acetamidomethyl-6-chloro-2-(4'-iodophenyl)imidazo[1,2-b]pyridazine 1 (IC{sub 50} = 1.6 nM) and 3-benzamidomethyl-6-iodo-2-(4'-t-butylphenyl)imidazo[1,2-b] pyridazine 2 (IC{sub 50} = 4.2 nM), are high affinity and selective ligands for the peripheral benzodiazepine receptors (PBR) compared to the central benzodiazepine counterparts. The [{sup 123}I]1 and [{sup 123}I]2 labelled analogues of these compounds were subsequently synthesised for the potential study of the PBR in vivo using SPECT. Radioiodination of [{sup 123}I]1 was achieved by iododestannylation of the corresponding tributyl tin precursor with Na[{sup 123}I] in the presence of peracetic acid or chloramine-T and the product isolated by C-18 RP HPLC. Radioiodination of [{sup 123}I]2 was achieved by copper assisted bromine [{sup 123}I]iodine exchange of the corresponding bromo precursor in the presence of acetic acid and sodium bisulfate as reducing agent at 200 C. Purification of the crude products were achieved by semi-preparative C-18 RP HPLC to give the products in radiochemical yields > 90%. The products were obtained in > 97% chemical and radiochemical purity and with specific activities > 180 GBq/{mu}mol. (orig.)

  13. Decrease in benzodiazepine receptor binding in a patient with Angelman syndrome detected by iodine-123 iomazenil and single-photon emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Odano, Ikuo [Dept. of Radiology, Niigata Univ. School of Medicine, Niigata (Japan); Anezaki, Toshiharu [Dept. of Neurology, Brain Research Inst., Niigata Univ., Niigata (Japan); Ohkubo, Masaki [Dept. of Radiology, Niigata Univ. School of Medicine, Niigata (Japan); Yonekura, Yoshiharu [Nihon Medi-Physics Co. Ltd., Hyogo (Japan); Onishi, Yoshihiro [Biomedical Imaging Research Center, Fukui Medical School, Fukui (Japan); Inuzuka, Takashi [Dept. of Neurology, Brain Research Inst., Niigata Univ., Niigata (Japan); Takahashi, Makoto [Dept. of Radiology, Niigata Univ. School of Medicine, Niigata (Japan); Tsuji, Shoji [Dept. of Neurology, Brain Research Inst., Niigata Univ., Niigata (Japan)

    1996-05-01

    A receptor mapping technique using iodine-123 iomazenil and single-photon emission tomography (SPET) was employed to examine benzodiazepine receptor binding in a patient with Angelman syndrome (AS). AS is characterized by developmental delay, seizures, inappropriate laughter and ataxic movement. In this entity there is a cytogenic deletion of the proximal long arm of chromosome 15q11-q13, where the gene encoding the GABA{sub A} receptor {beta}3 subunit (GABRB3) is located. Since the benzodiazepine receptor is constructed as a receptor-ionophore complex that contains the GABA{sub A} receptor, it is a suitable marker for GABA-ergic synapsis. To determine whether benzodiazepine receptor density, which indirectly indicates changes in GABA{sub A} receptor density, is altered in the brain in patients with AS, we investigated a 27-year-old woman with AS using {sup 123}I-iomazenil and SPET. Receptor density was quantitatively assessed by measuring the binding potential using a simplified method. Regional cerebral blood flow was also measured with N-isopropyl-p-[{sup 123}]iodoamphetamine. We demonstrated that benzodiazepine receptor density is severely decreased in the cerebellum, and mildly decreased in the frontal and temporal cortices and basal ganglia, a result which is considered to indicate decreased GABA{sub A} receptor density in these regions. Although the deletion of GABRB3 was not observed in the present study, we indirectly demonstrated the disturbance of inhibitory neurotransmission mediated by the GABA{sub A} receptor in the investigated patient. {sup 123}I-iomazenil with SPET was useful to map benzodiazepine receptors, which indicate GABA{sub A} receptor distribution and their density. (orig.)

  14. Alterations in in-vivo benzodiazepine-receptor binding of C-11-Ro15-1788 (flumazepil)

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, T.; Inoue, O.; Shinoto, H.; Ito, T.; Hashimoto, K.; Suzuki, K.; Tateno, Y.

    1985-05-01

    Alterations of the central benzodiazepine - receptor function caused by the change of physiological or psychological conditions, were recognized in both animal and human studies. Before the human study, animal experiments using tritiated Ro15-1788 were carried out. The stress was produced by forcing the mice to swim in a water-basin at 16/sup 0/C for 5 min. Within 3 min after the forced swimming, the tracer was injected. Brain radioactivities in stress-loaded mice increased over a period of 15 min after the intra-venous injection of tracers, while brain activities of carrier-added tracer decreased. In human study, approximately 5 mCi of C-11-Ro15-1788, which specific activity is 0.3-1.0 Ci/..mu..mol, were intravenously injected to each case. Measurements of the brain activity were performed using positron-CT, with blood sample collection. 31 human studies were performed on. Cerebral cortex time activity curves in several volunteers in nervous and stressful state, showed the same pattern to that in the stress-loaded animal experiment. It is important that the significant different time course of cerebral activity after the injection of labelled Ro15-1788, was observed in stressful state, compared with control, in both human and animal study. From these results, it will be concluded the positron CT study using /sup 11/C-Ro15-1788 will become a new technic to detect the change of psychological conditions in human brain and to diagnose some kind of neuropsychiatric disease.

  15. Peripheral benzodiazepine receptors and cerebral ischemia%外周型苯二氮革受体与脑缺血

    Institute of Scientific and Technical Information of China (English)

    程超; 陈春富

    2009-01-01

    1he increased peripheral benzodiazepine receptors are more significant than normal ones after cerebral ischemia. Its main reactions are the multiple pathological changes,including microglial activation, participating in neuroinflammation response, and regulation of mitochondrial function. Using radionuclide-laheled specific ligands of the peripheral benzodiaz-epine receptor (such as PK11195) for in vivo imaging contribute to the location and quantitative detection for brain injury and the study of the pathophysiological changes after cerebral ischemi-a. In addition, this receptor is promising to become a new target of neuroprotective treatment.This article reviews the recent progress in research on peripheral benzodiazepine receptors and cerebral ischemia.%脑缺血后,外周型苯二氮革受体较正常时有明显增加,主要反应为小胶质细胞的活化、参与神经炎症反应以及线粒体功能调节等多途径病理学变化.应用放射性核素标记的特异性外周型苯二氮革受体配体(如PK11195)进行体内成像,有助于对脑损伤进行定位和定量检测以及研究脑缺血后病理生理学改变.另外,该受体还有望成为神经保护治疗的新靶点.文章就外周型苯二氮革受体与脑缺血的研究进展做一综述.

  16. Delayed image of iodine-123 iomazenil as a relative map of benzodiazepine receptor binding: the optimal scan time

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yoshihiro [Nihon Medi-Physics Co. Ltd., Nishinomiya (Japan); Yonekura, Yoshiharu [Fukui Medical School, Fukui (Japan); Tanaka, Fumiko [Kyoto University School of Medicine, Kyoto (Japan); Nishizawa, Sadahiko [Kyoto University School of Medicine, Kyoto (Japan); Okazawa, Hidehiko [Kyoto University School of Medicine, Kyoto (Japan); Ishizu, Koichi [Kyoto University School of Medicine, Kyoto (Japan); Fujita, Toru [Kyoto University School of Medicine, Kyoto (Japan); Konishi, Junji [Kyoto University School of Medicine, Kyoto (Japan); Mukai, Takao [Kyoto College of Medical Technology, Kyoto (Japan)

    1996-11-01

    ``Delayed`` single-photon emission tomograpic (SPET) images after an intravenous bolus injection of iodine-123 iomazenil have been used as a relative map of benzodiazepine receptor binding. We determined the optimal scan time for obtaining such a map and assessed the errors of the map. SPET and blood data from six healthy volunteers and five patients were used. A three-compartment kinetic model was employed in simulation studies and analyses of actual data. The simulation studies suggested that, in the normal brain, the scan time at which a single SPET image best represented the relative receptor binding was 3.0-3.5 h post-injection. This finding was supported by actual data from the volunteers. The simulation studies also suggested that the optimal scan time was not greatly changed by the variability of the input functions, and that the error in the SPET image contrast in the vicinity of the optimal scan time was not increased by changes in the tracer kinetics in the entire brain. The SPET image contrast in the patients at 3.0 h post-injection agreed well with the reference receptor binding estimated by kinetic analysis, with a mean error of 3.6%. These findings support the use of a single SPET image after bolus injection of [{sup 123}I]iomazenil as a relative map of benzodiazepine receptor binding. For this purpose, a SPET scan time of 3.0-3.5 h post-injection is recommended. (orig.). With 5 figs., 1 tab.

  17. Benzodiazepine receptor equilibrium constants for flumazenil and midazolam determined in humans with the single photon emission computer tomography tracer [123I]iomazenil

    DEFF Research Database (Denmark)

    Videbaek, C; Friberg, L; Holm, S

    1993-01-01

    twice, once without receptor blockade and once with a constant degree of partial blockade of the benzodiazepine receptors by infusion of nonradioactive flumazenil (Lanexat) or midazolam (Dormicum). Single photon emission computer tomography and blood sampling were performed intermittently for 6 h after...

  18. Antiplasmodial and GABA(A)-benzodiazepine receptor binding activities of five plants used in traditional medicine in Mali, West Africa.

    Science.gov (United States)

    Bah, Sekou; Jäger, Anna K; Adsersen, Anne; Diallo, Drissa; Paulsen, Berit Smestad

    2007-04-04

    Extracts of five medicinal plants: Boscia angustifolia, Cissus quadrangularis, Securidaca longipedunculata, Stylosanthes erecta and Trichilia emetica, used traditionally in Malian traditional medicine were screened for in vitro antiplasmodial activity and GABA(A)-benzodiazepine receptor binding activity. Four extracts showed significant antiplasmodial activities, with the dichloromethane extract of leaf of Securidaca longipedunculata being the most active (IC(50) of 7 microg/ml [95% CI: 5-9]). The dichloromethane extract of leaf of Trichilia emetica, in addition to its antiplasmodial activity (IC(50): 12 microg/ml [95% CI: 12-14]), exhibited a good binding activity to the GABA(A)-benzodiazepine receptor, while water and methanol extracts of the same plant did not show any activity. A strong GABA(A)-receptor complex binding activity was observed in the methanol extract of aerial part of Stylosanthes erecta. The results in this study justify some of the traditional indications of the plants investigated and may thus be candidates for Improved Traditional Medicines in Mali.

  19. Increased expression of mitochondrial benzodiazepine receptors following low-level light treatment facilitates enhanced protoporphyrin IX production in glioma-derived cells in vitro

    Science.gov (United States)

    Bisland, S. K.; Hassanali, N. S.; Johnson, C.; Wilson, B. C.

    2007-02-01

    This study investigates whether low level light treatment (LLLT) can enhance the expression of Peripheral-type mitochondrial benzodiazepine receptors (PBRs) on the glioma-derived tumour cell line, CNS-1, and by doing so promote the synthesis of protoporphyrin IX (PpIX) and increase the photodynamic therapy (PDT)-induced cell kill using 5-aminolevulinic acid (ALA). The endogenous photosensitizer, (PpIX) and related metabolites including coproporphyrin III are known to traffic via the PBRs on the outer mitochondrial membrane on their passage into or out of the mitochondria. Astrocyte-derived cells within the brain express PBRs, while neurons express the central-type of benzodiazepine receptor. CNS-1 cells were exposed to a range of differing low-level light protocols immediately prior to PDT. LLLT involved using broad-spectrum light or monochromatic laser light specific to 635 or 905 nm wavelength. Cells (5μ10 5) were exposed to a range of LLLT doses (0, 1 or 5 J/cm2) using a fixed intensity of 10 mW/cm2 and subsequently harvested for cell viability, immunofluorescence or western blot analysis of PBR expression. The amount of PpIX within the cells was determined using chemical extraction techniques. Results confirm the induction of PBR following LLLT is dependent on the dose and wavelength of light used. Broadspectrum light provided the greatest cell kill following PDT, although LLLT with 635 nm or 905 nm also increased cell kill as compared to PDT alone. All LLLT regimens increased PBR expression compared to controls with corresponding increases in PpIX production. These data suggest that by selectively increasing PBR expression in tumour cells, LLLT may facilitate enhanced cell kill using ALA-PDT without damaging surrounding normal brain.

  20. GABAA-benzodiazepine receptor availability in smokers and nonsmokers: relationship to subsyndromal anxiety and depression.

    Science.gov (United States)

    Esterlis, Irina; Cosgrove, Kelly P; Batis, Jeffery C; Bois, Frederic; Kloczynski, Tracy A; Stiklus, Stephanie M; Perry, Edward; Tamagnan, Gilles D; Seibyl, John P; Makuch, Robert; Krishnan-Sarin, Suchitra; O'Malley, Stephanie; Staley, Julie K

    2009-12-01

    Many smokers experience subsyndromal anxiety symptoms while smoking and during acute abstinence, which may contribute to relapse. We hypothesized that cortical gamma aminobutyric acid(A)-benzodiazepine receptor (GABA(A)-BZR) availability in smokers and nonsmokers might be related to the expression of subsyndromal anxiety, depressive, and pain symptoms. Cortical GABA(A)-BZRs were imaged in 15 smokers (8 men and 7 women), and 15 healthy age and sex-matched nonsmokers, and 4 abstinent tobacco smokers (3 men; 1 woman) using [(123)I]iomazenil and single photon emission computed tomography (SPECT). Anxiety and depressive symptoms were measured using the Spielberger's State-Trait Anxiety Index (STAI) and the Center for Epidemiology Scale for Depressive Symptoms (CES-D). The cold pressor task was administered to assess pain tolerance and sensitivity. The relationship between cortical GABA(A)-BZR availability, smoking status, and subsyndromal depression and anxiety symptoms, as well as pain tolerance and sensitivity, were evaluated. Surprisingly, there were no statistically significant differences in overall GABA(A)-BZR availability between smokers and nonsmokers or between active and abstinent smokers; however, cortical GABA(A)-BZR availability negatively correlated with subsyndromal state anxiety symptoms in nonsmokers but not in smokers. In nonsmokers, the correlation was seen across many brain areas with state anxiety [parietal (r = -0.47, P = 0.03), frontal (r = -0.46, P = 0.03), anterior cingulate (r = -0.47, P = 0.04), temporal (r = -0.47, P = 0.03), occipital (r = -0.43, P = 0.05) cortices, and cerebellum (r = -0.46, P = 0.04)], trait anxiety [parietal (r = -0.72, P = 0.02), frontal (r = -0.72, P = 0.02), and occipital (r = -0.65, P = 0.04) cortices] and depressive symptoms [parietal (r = -0.68; P = 0.02), frontal (r = -0.65; P = 0.03), anterior cingulate (r = -0.61; P = 0.04), and temporal (r = -0.66; P = 0.02) cortices]. The finding that a similar relationship

  1. Peripheral benzodiazepine receptors in the brain of cirrhosis patients with manifest hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Iversen, Peter; Bender, Dirk; Munk, Ole L.; Cumming, Paul [Aarhus University Hospital, PET Centre, Aarhus (Denmark); Aagaard Hansen, Dorthe; Keiding, Susanne [Aarhus University Hospital, PET Centre, Aarhus (Denmark); Aarhus University Hospital, Department of Medicine V (Hepatology), Aarhus (Denmark); Rodell, Anders [Aarhus University Hospital, Centre of Functionally Integrative Neuroscience (CFIN), Aarhus (Denmark)

    2006-07-15

    It has been suggested that ammonia-induced enhancement of peripheral benzodiazepine receptors (PBRs) in the brain is involved in the development of hepatic encephalopathy (HE). This hypothesis is based on animal experiments and studies of post-mortem human brains using radiolabelled PK11195, a specific ligand for PBR, but to our knowledge has not been tested in living patients. The aim of the present study was to test this hypothesis by measuring the number of cerebral PBRs in specific brain regions in cirrhotic patients with an acute episode of clinically manifest HE and healthy subjects using dynamic {sup 11}C-PK11195 brain PET. Eight cirrhotic patients with an acute episode of clinically manifest HE (mean arterial ammonia 81 {mu}mol/l) and five healthy subjects (22 {mu}mol/l) underwent dynamic {sup 11}C-PK11195 and {sup 15}O-H{sub 2}O PET, co-registered with MR images. Brain regions (putamen, cerebellum, cortex and thalamus) were delineated on co-registered {sup 15}O-H{sub 2} {sup 15}O and MR images and copied to the dynamic {sup 15}O-H{sub 2}O and {sup 11}C-PK11195 images. Regional cerebral blood flow (CBF) ({sup 15}O-H{sub 2}O scan) and the volume of distribution of PK11195 ({sup 11}C-PK11195 scan) were calculated by kinetic analysis. There were regional differences in the CBF, with lowest values in the cortex and highest values in the putamen in both groups of subjects (p<0.05), but no significant differences between the groups. There were no significant differences in the volume of distribution of PK11195 (V{sub d}) between regions or between the two groups of subjects. Mean values of V{sub d} ranged from 1.0 to 1.1 in both groups of subjects. The results do not confirm the hypothesis of an increased number of PBRs in patients with HE. (orig.)

  2. {sup 125}I-iomazenil - benzodiazepine receptor binding and serum corticosterone level during psychological stress in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Fukumitsu, Nobuyoshi E-mail: GZL13162@nifty.ne.jp; Ogi, Shigeyuki; Uchiyama, Mayuki; Mori, Yutaka

    2004-02-01

    To test the hypothesis that benzodiazepine receptor density decreases in response to stress, we correlated {sup 125}I-iomazenil ({sup 125}I-IMZ) binding with serum corticosterone levels in a rat model. Wistar male rats were divided into four groups; control group (CON, 10 rats), no physical or psychological stress; and one-, three-, and five-day stress groups of 12 rats each (1-DAY, 3-DAY, and 5-DAY, respectively), receiving psychological stress for the given number of days. Psychological stress were given to rats with a communication box. The standardized uptake value (SUV) of {sup 125}I-iomazenil of the 3-DAY and 5-DAY showed that {sup 125}I-iomazenil - benzodiazepine receptor binding was significantly reduced in the cortices, accumbens nuclei, amygdala and caudate putamen (p<0.05). Serum corticosterone level ratio appeared to be slightly elevated in 3-DAY and 5-DAY, although this elevation was not significant. These data suggest that {sup 125}I-IMZ is a useful radioligand to reflect received stress and its binding in the cortices, accumbens nuclei, amygdala and caudate putamen is strongly affected by psychological stress.

  3. GABAA receptor γ2 subunit knockdown mice have enhanced anxiety-like behavior but unaltered hypnotic response to benzodiazepines

    Directory of Open Access Journals (Sweden)

    De Blas Angel L

    2005-04-01

    Full Text Available Abstract Background Gamma-aminobutyric acid type A receptors (GABAA-Rs are the major inhibitory receptors in the mammalian brain and are modulated by a number of sedative/hypnotic drugs including benzodiazepines and anesthetics. The significance of specific GABAA-Rs subunits with respect to behavior and in vivo drug responses is incompletely understood. The γ2 subunit is highly expressed throughout the brain. Global γ2 knockout mice are insensitive to the hypnotic effects of diazepam and die perinatally. Heterozygous γ2 global knockout mice are viable and have increased anxiety-like behaviors. To further investigate the role of the γ2 subunit in behavior and whole animal drug action, we used gene targeting to create a novel mouse line with attenuated γ2 expression, i.e., γ2 knockdown mice. Results Knockdown mice were created by inserting a neomycin resistance cassette into intron 8 of the γ2 gene. Knockdown mice, on average, showed a 65% reduction of γ2 subunit mRNA compared to controls; however γ2 gene expression was highly variable in these mice, ranging from 10–95% of normal. Immunohistochemical studies demonstrated that γ2 protein levels were also variably reduced. Pharmacological studies using autoradiography on frozen brain sections demonstrated that binding of the benzodiazepine site ligand Ro15-4513 was decreased in mutant mice compared to controls. Behaviorally, knockdown mice displayed enhanced anxiety-like behaviors on the elevated plus maze and forced novelty exploration tests. Surprisingly, mutant mice had an unaltered response to hypnotic doses of the benzodiazepine site ligands diazepam, midazolam and zolpidem as well as ethanol and pentobarbital. Lastly, we demonstrated that the γ2 knockdown mouse line can be used to create γ2 global knockout mice by crossing to a general deleter cre-expressing mouse line. Conclusion We conclude that: 1 insertion of a neomycin resistance gene into intron 8 of the γ2 gene variably

  4. [Benzodiazepine and nonbenzodiazepine hypnotics].

    Science.gov (United States)

    Nakamura, Masaki; Inoue, Yuichi

    2015-06-01

    The prevalence of insomnia shows an age-associated increase. Especially, persons with age over 60 years frequently suffer from arousal during sleep and early-morning awakening. The reason of this phenomenon can be explained by age-related change in sleepwake regulation, comorbid diseases and psycho-social status. Benzodiazepine derivatives and benzodiazepine agonists have been widely used for treatment of insomnia. These GABA-A receptor agonist hypnotics have sedative effect, possibly causing various adverse events, i.e. falls and hip fracture, anterograde amnesia, next morning hangover especially in the elderly. When making a choice of treatment drugs for the elderly, low dose benzodiazepine hypnotics with relatively high Ω1-selectivity, and newer hypnotics including melatonic receptor agonist or orexin receptor antagonist can become important candidates considering their comorbid diseases or drug interaction with other medications.

  5. Human studies on the benzodiazepine receptor antagonist beta-carboline ZK 93 426: antagonism of lormetazepam's psychotropic effects.

    Science.gov (United States)

    Duka, T; Goerke, D; Dorow, R; Höller, L; Fichte, K

    1988-01-01

    The effects of lormetazepam (0.03 mg/kg IV) a benzodiazepine (BZ) derivative in combination with ZK 93 426 (0.04 mg/kg IV) a beta-carboline, benzodiazepine receptor antagonist were evaluated in humans. Independently, the effects of ZK 93 426 on its own were investigated. A psychometric test battery to evaluate sedation (visual analog scales (VAS), anxiolysis (state-trait-anxiety inventory scale (STAIG X1) and cognitive functions [logical reasoning test (LR), letter detection test (LD)] was applied before and several hours after initiation of treatment. Multiple sleep latency test (MSLT), which measures day time sleepiness, was also applied. Vigilosomnograms analysed from standard EEG recordings were evaluated shortly before and for 1 h after treatment. Treatment started with an intravenous injection of either lormetazepam (LMZ) or placebo (PLA), which was followed 30 min later by administration of either ZK 93 426 or placebo; thus four treatment groups were created (PLA + PLA, LMZ + PLA, LMZ + ZK 93 426 and PLA + ZK 93 426). ZK 93 426 antagonized the sedative and hypnotic effect of LMZ as estimated by MSLT and vigilosomnograms, respectively. Impairment of cognitive functions (LR and LD) induced by LMZ was also antagonized by ZK 93 426. ZK 93 426 had no effect on the changes in the time estimation seen in the LMZ group. Furthermore, ZK 93 426 on its own increased vigilance (alertness) as measured by the vigilosomnogram. A competitive antagonism at the benzodiazepine binding site between ZK 93 426 and LMZ is suggested by their combination effects; the intrinsic activity of ZK 93 426 seems to be due to its weak partial inverse agonist component.

  6. A simple method for the quantification of benzodiazepine receptors using iodine-123 iomazenil and single-photon emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi [Dept. of Nuclear Medicine and Radiology, Div. of Brain Sciences, Inst. of Development, Aging and Cancer, Tohoku Univ. Sendai (Japan); Goto, Ryoui [Dept. of Nuclear Medicine and Radiology, Div. of Brain Sciences, Inst. of Development, Aging and Cancer, Tohoku Univ. Sendai (Japan); Koyama, Masamichi [Dept. of Nuclear Medicine and Radiology, Div. of Brain Sciences, Inst. of Development, Aging and Cancer, Tohoku Univ. Sendai (Japan); Kawashima, Ryuta [Dept. of Nuclear Medicine and Radiology, Div. of Brain Sciences, Inst. of Development, Aging and Cancer, Tohoku Univ. Sendai (Japan); Ono, Shuichi [Dept. of Nuclear Medicine and Radiology, Div. of Brain Sciences, Inst. of Development, Aging and Cancer, Tohoku Univ. Sendai (Japan); Sato, Kazunori [Dept. of Nuclear Medicine and Radiology, Div. of Brain Sciences, Inst. of Development, Aging and Cancer, Tohoku Univ. Sendai (Japan); Fukuda, Hiroshi [Dept. of Nuclear Medicine and Radiology, Div. of Brain Sciences, Inst. of Development, Aging and Cancer, Tohoku Univ. Sendai (Japan)

    1996-07-01

    Iodine-123 iomazenil (Iomazenil) is a ligand for central type benzodiazepine receptors that is suitable for single-photon emission tomography (SPET). The purpose of this study was to develop a simple method for the quantification of its binding potential (BP). The method is based on a two-compartment model (K{sub 1}, influx rate constant; k{sub 2}`, efflux rate constant; V{sub T}`(=K{sub 1}/k{sub 2}`), the total distribution volumes relative to the total arterial tracer concentration), and requires two SPET scans and one blood sampling. For a given input function, the radioactivity ratio of the early to delayed scans can be considered to tabulate as a function of k{sub 2}`, and a table lookup procedure provides the corresponding k{sub 2}` value, from which K{sub 1} and V{sub t}` values are then calculated. The arterial input function is obtained by calibration of the standard input function by the single blood sampling. SPET studies were performed on 14 patients with cerebrovascular diseases, dementia or brain tumours (mean age {+-}SD, 56.0{+-}12.2). None of the patients had any heart, renal or liver disease. A dynamic SPET scan was performed following intravenous bolus injection of Iomazenil. A static SPET scan was performed at 180 min after injection. Frequent blood sampling from the brachial artery was performed on all subjects for determination of the arterial input function. Two-compartment model analysis was validated for calculation of the V{sub T}` value of Iomazenil. Good correlations were observed between V{sub T}` values calculated by three-compartment model analysis and those calculated by the present method, in which the scan time combinations (early scan/delayed scan) used were 15/180 min, 30/180 min or 45/180 min (all combinations: r=0.92), supporting the validity of this method. The present method is simple and applicable for clinical use. (orig.)

  7. Influences of housing conditions and ethanol intake on binding characteristics of D2, 5-HT1A, and benzodiazepine receptors of rats.

    Science.gov (United States)

    Rilke, O; May, T; Oehler, J; Wolffgramm, J

    1995-09-01

    The effects of different housing conditions and ethanol treatment (6 vol % in the drinking water) on the in vitro binding characteristics of striatal dopaminergic D2 ([3H]spiperone), hippocampal serotonergic 5-HT1A ([3H]8-OH-DPAT), and cortical benzodiazepine ([3H]flunitrazepam) receptors have been examined. Social deprivation due to contact caging, short- (1 day) and long-term isolation (5 weeks) yielded a significant decrease of striatal D2 receptor density with the greatest decrease after long-term isolation (-21% Bmax) without changes of Kd in comparison to group animals. The effect of ethanol on striatal D2 receptor density depended on the housing conditions. Whereas ethanol treatment reduced receptor density of group animals (down to 88%), chronic exposure to ethanol under long-term isolation elicited no significant alteration of D2 receptor density compared with group animals. Different housing and ethanol treatment had no effect on 5-HT1A receptor affinity and density. Alterations of benzodiazepine receptor density were not found, but social deprivation as well as ethanol treatment of group animals caused an increased affinity of [3H]flunitrazepam (reduced Kd value). These results indicate that different housing conditions of adult rats evoked significant alterations in D2 and benzodiazepine receptor binding assays, which were modified by ethanol treatment in the case of striatal D2 receptor density.

  8. A Quantum of Solace: molecular electronics of benzodiazepines

    Science.gov (United States)

    Turin, Luca; Horsfield, Andrew; Stoneham, Marshall

    2011-03-01

    Benzodiazepines and related drugs modulate the activity of GABA-A receptors, the main inhibitory receptor of the central nervous system. The prevailing view is that these drugs bind at the interface between two receptor subunits and allosterically modulate the response to GABA. In this talk I shall present evidence that benzodiazepines work instead by facilitating electron transport from the cytoplasm to a crucial redox-sensitive group in the gamma subunit. If this idea is correct, benzodiazepines should not only be regarded as keys fitting into a lock, but also as one-electron chemical field-effect transistors fitting into an electronic circuit. Supported by DARPA Grant N66001-10-1-4062.

  9. PK11195 binding to the peripheral benzodiazepine receptor as a marker of microglia activation in multiple sclerosis and experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Vowinckel, E; Reutens, D; Becher, B

    1997-01-01

    Activated glial cells are implicated in regulating and effecting the immune response that occurs within the CNS as part of multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). The peripheral benzodiazepine receptor (PBR) is expressed in glial cells. We...

  10. Comparison of blood flow and distribution of benzodiazepine receptors in focal epilepsy: Preliminary results of a SPECT study. Vergleich von Blutfluss und Benzodiazepin-Rezeptorverteilung bei fokaler Epilepsie: Vorlaeufige Ergebnisse einer SPECT-Studie

    Energy Technology Data Exchange (ETDEWEB)

    Bartenstein, P.; Schober, O.; Lottes, G.; Boettger, I. (Muenster Univ. (Germany, F.R.). Klinik und Poliklinik fuer Nuklearmedizin); Ludolph, A. (Muenster Univ. (Germany, F.R.). Klinik und Poliklinik fuer Neurologie); Beer, H.F. (Paul Scherrer Inst., Wuerenlingen (Switzerland))

    1989-10-01

    {sup 99m}Tc-HMPAO-SPECT and SPECT with the {sup 123}I-labelled benzodiazepine (Bz) receptor ligand Ro 16-0154 were performed in 10 patients suffering from partial epilepsy, without cerebral lesion in MRT or CT.2 h p.i. of Ro 16-0154 the distribution of activity correlated with the known distribution of Bz-receptors in the human brain. Perfusion and receptor-binding were found decreased in 7 patients of each study in the suspicious brain-area. {sup 123}I-labelled Ro 16-0154 is suitable for Bz-receptor mapping by SPECT. The decrease of Bz-receptor binding in epileptic foci, as described in PET-studies, was also detected by SPECT in 7 of 10 patients. (orig.).

  11. Structure-activity relationship of benzodiazepine derivatives as LXXLL peptide mimetics that inhibit the interaction of vitamin D receptor with coactivators.

    Science.gov (United States)

    Mita, Yusuke; Dodo, Kosuke; Noguchi-Yachide, Tomomi; Hashimoto, Yuichi; Ishikawa, Minoru

    2013-02-15

    Suppression of vitamin D receptor (VDR)-mediated transcription is expected to be of therapeutic value in Paget's disease of bone. It is known that interaction between VDR and coactivators is necessary for VDR transactivation, and the interaction occurs when VDR recognizes an LXXLL peptide motif of coactivators. We previously reported that benzodiazepine derivatives designed as LXXLL peptide mimetics inhibited the interaction of VDR and coactivators, and reduced VDR transcription. Here, we investigated the structure-activity relationship of 7- and 8-substituted benzodiazepine derivatives, and established that the amino group at the 8-position is critical for the inhibitory activity.

  12. Receptor binding characterization of the benzodiazepine radioligand sup 125 I-Ro16-0154: Potential probe for SPECT (Single Photon Emission Computed Tomography) brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, E.W.; Woods, S.W.; Zoghbi, S.; Baldwin, R.M.; Innis, R.B. (Yale Univ., West Haven, CT (USA)); McBride, B.J. (Medi-Physics, Inc., Emeryville, CA (USA))

    1990-01-01

    The binding of an iodinated benzodiazepine (BZ) radioligand has been characterized, particularly in regard to its potential use as a neuroreceptor brain imaging agent with SPECT (Single Photon Emission Computed Tomography). Ro16-0154 is an iodine-containing BZ antagonist and a close analog of Ro15-1788. In tissue homogenates prepared from human and monkey brain, the binding of {sup 125}I-labeled Ro16-0154 was saturable, of high affinity, and had high ratios of specific to non-specific binding. Physiological concentrations of NaCl enhanced specific binding approximately 15% compared to buffer without this salt. Kinetic studies of association and dissociation demonstrated a temperature dependent decrease in affinity with increasing temperature. Drug displacement studies confirmed that {sup 125}I-Ro16-0154 binds to the central type BZ receptor: binding is virtually identical to that of {sup 3}H-Ro15-1788 except that {sup 125}I-Ro16-0154 shows an almost 10 fold higher affinity at 37{degree}C. These in vitro results suggest that {sup 123}I-labeled Ro16-0154 shows promise as a selective, high affinity SPECT probe of the brain's BZ receptor.

  13. Expression of peripheral benzodiazepine receptor (PBR) in human tumors: relationship to breast, colorectal, and prostate tumor progression.

    Science.gov (United States)

    Han, Zeqiu; Slack, Rebecca S; Li, Wenping; Papadopoulos, Vassilios

    2003-01-01

    High levels of peripheral-type benzodiazepine receptor (PBR), the alternative-binding site for diazepam, are part of the aggressive human breast cancer cell phenotype in vitro. We examined PBR levels and distribution in normal tissue and tumors from multiple cancer types by immunohistochemistry. Among normal breast tissues, fibroadenomas, primary and metastatic adenocarcinomas, there is a progressive increase in PBR levels parallel to the invasive and metastatic ability of the tumor (p cancers, such as those of breast, colon-rectum and prostate tissues, where elevated PBR expression is associated with tumor progression. Thus, we propose that PBR overexpression could serve as a novel prognostic indicator of an aggressive phenotype in breast, colorectal and prostate cancers.

  14. HZ166, a novel GABAA receptor subtype-selective benzodiazepine site ligand, is antihyperalgesic in mouse models of inflammatory and neuropathic pain

    OpenAIRE

    2011-01-01

    Diminished GABAergic and glycinergic inhibition in the spinal dorsal horn contributes significantly to chronic pain of different origins. Accordingly, pharmacological facilitation of GABAergic inhibition by spinal benzodiazepines (BDZs) has been shown to reverse pathological pain in animals as well as in human patients. Previous studies in GABA(A) receptor point-mutated mice have demonstrated that the spinal anti-hyperalgesic effect of classical BDZs is mainly mediated by GABA(A) receptors co...

  15. Transcranial Random Noise Stimulation-induced plasticity is NMDA-receptor independent but sodium-channel blocker and benzodiazepines sensitive

    Directory of Open Access Journals (Sweden)

    Leila eChaieb

    2015-04-01

    Full Text Available Background: Application of transcranial random noise stimulation (tRNS between 0.1 and 640 Hz of the primary motor cortex (M1 for 10 minutes induces a persistent excitability increase lasting for at least 60 minutes. However, the mechanism of tRNS-induced cortical excitability alterations is not yet fully understood. Objective: The main aim of this study was to get first efficacy data with regard to the possible neuronal effect of tRNS. Methods: Single-pulse transcranial magnetic stimulation (TMS was used to measure levels of cortical excitability before and after combined application of tRNS at an intensity of 1mA for 10mins stimulation duration and a pharmacological agent (or sham on 8 healthy male participants. Results: The sodium channel blocker carbamazepine showed a tendency towards inhibiting MEPs 5-60 mins poststimulation. The GABAA agonist lorazepam suppressed tRNS-induced cortical excitability increases at 0-20 and 60 min time points. The partial NMDA receptor agonist D-cycloserine, the NMDA receptor antagonist dextromethorphan and the D2/D3 receptor agonist ropinirole had no significant effects on the excitability increases seen with tRNS.Conclusions: In contrast to transcranial direct current stimulation (tDCS, aftereffects of tRNS are seem to be not NMDA receptor dependent and can be suppressed by benzodiazepines suggesting that tDCS and tRNS depend upon different mechanisms.

  16. Benzodiazepine-induced anxiolysis and reduction of conditioned fear are mediated by distinct GABAA receptor subtypes in mice.

    Science.gov (United States)

    Smith, Kiersten S; Engin, Elif; Meloni, Edward G; Rudolph, Uwe

    2012-08-01

    GABA(A) receptor modulating drugs such as benzodiazepines (BZs) have been used to treat anxiety disorders for over five decades. In order to determine whether the same or different GABA(A) receptor subtypes are necessary for the anxiolytic-like action of BZs in unconditioned anxiety and conditioned fear models, we investigated the role of different GABA(A) receptor subtypes by challenging wild type, α1(H101R), α2(H101R) and α3(H126R) mice bred on the C57BL/6J background with diazepam or chlordiazepoxide in the elevated plus maze and the fear-potentiated startle paradigms. Both drugs significantly increased open arm exploration in the elevated plus maze in wild type, α1(H101R) and α3(H126R), but this effect was abolished in α2(H101R) mice; these were expected results based on previous published results. In contrast, while administration of diazepam and chlordiazepoxide significantly attenuated fear-potentiated startle (FPS) in wild type mice and α3(H126R) mice, the fear-reducing effects of these drugs were absent in both α1(H101R) and α2(H101R) point mutants, indicating that both α1- and α2-containing GABA(A) receptors are necessary for BZs to exert their effects on conditioned fear responses. Our findings illustrate both an overlap and a divergence between the GABA(A) receptor subtype requirements for the impact of BZs, specifically that both α1- and α2-containing GABA(A) receptors are necessary for BZs to reduce conditioned fear whereas only α2-containing GABA(A) receptors are needed for BZ-induced anxiolysis in unconditioned tests of anxiety. This raises the possibility that GABAergic pharmacological interventions for specific anxiety disorders can be differentially tailored.

  17. Functional modulation of cerebral gamma-aminobutyric acidA receptor/benzodiazepine receptor/chloride ion channel complex with ethyl beta-carboline-3-carboxylate: Presence of independent binding site for ethyl beta-carboline-3-carboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, J.; Kuriyama, K. (Kyoto Prefectural Univ. of Medicine (Japan))

    1990-05-01

    Effect of ethyl beta-carboline-3-carboxylate (beta-CCE) on the function of gamma-aminobutyric acid (GABA)A receptor/benzodiazepine receptor/chloride ion channel complex was studied. Beta-CCE noncompetitively and competitively inhibited (3H)flunitrazepam binding to benzodiazepine receptor, but not (3H)muscimol binding to GABAA receptor as well as t-(3H)butylbicycloorthobenzoate (( 3H) TBOB) binding to chloride ion channel, in particulate fraction of the mouse brain. Ro15-1788 also inhibited competitively (3H) flunitrazepam binding. On the other hand, the binding of beta-(3H)CCE was inhibited noncompetitively and competitively by clonazepam and competitively by Ro15-1788. In agreement with these results, benzodiazepines-stimulated (3H)muscimol binding was antagonized by beta-CCE and Ro15-1788. Gel column chromatography for the solubilized fraction from cerebral particulate fraction by 0.2% sodium deoxycholate (DOC-Na) in the presence of 1 M KCl indicated that beta-(3H)CCE binding site was eluted in the same fraction (molecular weight, 250,000) as the binding sites for (3H)flunitrazepam, (3H)muscimol and (3H)TBOB. GABA-stimulated 36Cl- influx into membrane vesicles prepared from the bovine cerebral cortex was stimulated and attenuated by flunitrazepam and beta-CCE, respectively. These effects of flunitrazepam and beta-CCE on the GABA-stimulated 36Cl- influx were antagonized by Ro15-1788. The present results suggest that the binding site for beta-CCE, which resides on GABAA receptor/benzodiazepine receptor/chloride ion channel complex, may be different from that for benzodiazepine. Possible roles of beta-CCE binding site in the allosteric inhibitions on benzodiazepine binding site as well as on the functional coupling between chloride ion channel and GABAA receptor are also suggested.

  18. Functional characterization of the 1,5-benzodiazepine clobazam and its major active metabolite N-desmethylclobazam at human GABA(A) receptors expressed in Xenopus laevis oocytes.

    Science.gov (United States)

    Hammer, Harriet; Ebert, Bjarke; Jensen, Henrik Sindal; Jensen, Anders A

    2015-01-01

    The 1,5-benzodiazepine clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome in patients 2 years of age or older in the United States, and for treatment of anxiety and various forms of epilepsy elsewhere. Clobazam has been reported to exhibit different in vivo adverse effects and addiction liability profile than the classic 1,4-benzodiazepines. In this study, it was investigated whether the in vitro pharmacological properties of clobazam and its major active metabolite N-desmethylclobazam could explain some of these clinical differences. The functional properties of the two 1,5-benzodiazepines were characterized at the human γ-aminobutyric acid type A receptor (GABA(A)R) subtypes α1β2γ(2S), α2β2γ(2S), α3β2γ(2S), α5β2γ(2S) and α6β2δ expressed in Xenopus laevis oocytes by use of two-electrode voltage-clamp electrophysiology and compared to those exhibited by the 1,4-benzodiazepine clonazepam. All three compounds potentiated GABA EC20-evoked responses through the α(1,2,3,5)β2γ(2S) GABA(A)Rs in a reversible and concentration-dependent manner, with each displaying similar EC50 values at the four subtypes. Furthermore, the degrees of potentiation of the GABA EC20 currents through the four receptors mediated by saturating modulator concentrations did not differ substantially for any of the three benzodiazepines. The three compounds were substantially less potent (200-3900 fold) as positive allosteric modulators at the α6β2δ GABA(A)R than at the α(1,2,3,5)β2γ(2S) receptors. Interestingly, however, clobazam and especially N-desmethylclobazam were highly efficacious potentiators of α6β2δ receptor signaling. Although this activity component is unlikely to contribute to the in vivo effects of clobazam/N-desmethylclobazam, the 1,5-benzodiazepine could constitute an interesting lead for novel modulators targeting this low-affinity binding site in GABAARs. In conclusion, the non-selective modulation

  19. Functional characterization of the 1,5-benzodiazepine clobazam and its major active metabolite N-desmethylclobazam at human GABA(A receptors expressed in Xenopus laevis oocytes.

    Directory of Open Access Journals (Sweden)

    Harriet Hammer

    Full Text Available The 1,5-benzodiazepine clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome in patients 2 years of age or older in the United States, and for treatment of anxiety and various forms of epilepsy elsewhere. Clobazam has been reported to exhibit different in vivo adverse effects and addiction liability profile than the classic 1,4-benzodiazepines. In this study, it was investigated whether the in vitro pharmacological properties of clobazam and its major active metabolite N-desmethylclobazam could explain some of these clinical differences. The functional properties of the two 1,5-benzodiazepines were characterized at the human γ-aminobutyric acid type A receptor (GABA(AR subtypes α1β2γ(2S, α2β2γ(2S, α3β2γ(2S, α5β2γ(2S and α6β2δ expressed in Xenopus laevis oocytes by use of two-electrode voltage-clamp electrophysiology and compared to those exhibited by the 1,4-benzodiazepine clonazepam. All three compounds potentiated GABA EC20-evoked responses through the α(1,2,3,5β2γ(2S GABA(ARs in a reversible and concentration-dependent manner, with each displaying similar EC50 values at the four subtypes. Furthermore, the degrees of potentiation of the GABA EC20 currents through the four receptors mediated by saturating modulator concentrations did not differ substantially for any of the three benzodiazepines. The three compounds were substantially less potent (200-3900 fold as positive allosteric modulators at the α6β2δ GABA(AR than at the α(1,2,3,5β2γ(2S receptors. Interestingly, however, clobazam and especially N-desmethylclobazam were highly efficacious potentiators of α6β2δ receptor signaling. Although this activity component is unlikely to contribute to the in vivo effects of clobazam/N-desmethylclobazam, the 1,5-benzodiazepine could constitute an interesting lead for novel modulators targeting this low-affinity binding site in GABAARs. In conclusion, the non

  20. SPECT imaging of GABA{sub A}/benzodiazepine receptors and cerebral perfusion in mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Pappata, Sabina; Varrone, Andrea; Vicidomini, Caterina; Sansone, Valeria; Comerci, Marco; Panico, Maria Rosaria; Quarantelli, Mario [CNR, Institute of Biostructure and Bioimaging, Naples (Italy); Milan, Graziella; De Falco, Caterina; Lore, Elisa; Postiglione, Alfredo [University ' ' Federico II' ' , Department of Clinical and Experimental Medicine, Naples (Italy); Iavarone, Alessandro [Neurologic and Stroke Unit, CTO Hospital, Naples (Italy); Salvatore, Marco [CNR, Institute of Biostructure and Bioimaging, Naples (Italy); University ' ' Federico II' ' , Department of Biomorphological and Functional Sciences, Naples (Italy)

    2010-06-15

    The involvement of neocortical and limbic GABA{sub A}/benzodiazepine (BZD) receptors in Alzheimer's disease (AD) is controversial and mainly reported in advanced stages. The status of these receptors in the very early stages of AD is unclear and has not been explored in vivo. Our aims were to investigate in vivo the integrity of cerebral cortical GABA{sub A}/BZD receptors in subjects with amnestic mild cognitive impairment (MCI) and to compare possible receptor changes to those in cerebral perfusion. [{sup 123}I]Iomazenil and [{sup 99m}Tc]HMPAO SPECT images were acquired in 16 patients with amnestic MCI and in 14 normal elderly control subjects (only [{sup 123}I]iomazenil imaging in 5, only [{sup 99m}Tc]HMPAO imaging in 4, and both [{sup 123}I]iomazenil and [{sup 99m}Tc]HMPAO imaging in 5). Region of interest (ROI) analysis and voxel-based analysis were performed with cerebellar normalization. Neither ROI analysis nor voxel-based analysis showed significant [{sup 123}I]iomazenil binding changes in MCI patients compared to control subjects, either as a whole group or when considering only those patients with MCI that converted to AD within 2 years of clinical follow-up. In contrast, the ROI analysis revealed significant hypoperfusion of the precuneus and posterior cingulate cortex in the whole group of MCI patients and in MCI converters as compared to control subjects. Voxel-based analysis showed similar results. These results indicate that in the very early stages of AD, neocortical and limbic neurons/synapses expressing GABA{sub A}/BZD receptors are essentially preserved. They suggest that in MCI patients functional changes precede neuronal/synaptic loss in neocortical posterior regions and that [{sup 99m}Tc]HMPAO rCBF imaging is more sensitive than [{sup 123}I]iomazenil GABA{sub A}/BZD receptor imaging in detecting prodromal AD. (orig.)

  1. Bromine-76 and carbon-11 labelled NNC 13-8199, metabolically stable benzodiazepine receptor agonists as radioligands for positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Foged, C. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, Stockholm (Sweden)]|[Novo Nordisk A/S, Health Care Discovery and Development, Maaloev (Denmark); Halldin, C.; Pauli, S.; Suhara, T.; Swahn, C.G.; Karlsson, P.; Farde, L. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, Stockholm (Sweden); Loc`h, C.; Maziere, B.; Maziere, M. [Service Hospitalier Frederic Joliot, CEA, Orsay (France); Hansen, H.C. [Novo Nordisk A/S, Health Care Discovery and Development, Maaloev (Denmark)

    1997-10-01

    NNC 13-8241 has recently been labelled with iodine-123 and developed as a metabolically stable benzodiazepine receptor ligand for single-photon emission computed tomography (SPECT) in monkeys and man. NNC 13-8199 is a bromo-analogue of NNC 13-8241. This partial agonist binds selectively and with subnanomolar affinity to the benzodiazepine receptors. We prepared {sup 76}Br labelled NNC 13-8199 from the trimethyltin precursor by the chloramine-T method. Carbon-11 labelled NNC 13-8199 was synthesised by N-alkylation of the nitrogen of the amide group with [{sup 11}C]methyl iodide. Positron emission tomography (PET) examination with the two radioligands in monkeys demonstrated a high uptake of radioactivity in the occipital, temporal and frontal cortex. In the study with [{sup 76}Br]NNC 13-8199, the monkey brain uptake continued to increase until the time of displacement with flumazenil at 215 min after injection. For both radioligands the radioactivity in the cortical brain regions was markedly reduced after displacement with flumazenil. More than 98% of the radioactivity in monkey plasma represented unchanged radioligand 40 min after injection. The low degree of metabolism indicates that NNC 13-8199 is metabolically much more stable than hitherto developed PET radioligands for imaging of benzodiazepine receptors in the primate brain. [{sup 76}Br]NNC 13-8199 has potential as a radioligand in human PET studies using models where a slow metabolism is an advantage. (orig.) With 8 figs., 28 refs.

  2. Wavelet denoising for voxel-based compartmental analysis of peripheral benzodiazepine receptors with {sup 18}F-FEDAA1106

    Energy Technology Data Exchange (ETDEWEB)

    Shidahara, Miho; Ikoma, Yoko; Seki, Chie; Kanno, Iwao; Kimura, Yuichi [National Institute of Radiological Sciences, Biophysics Group, Molecular Imaging Center, Chiba (Japan); Fujimura, Yota; Ito, Hiroshi; Suhara, Tetsuya [National Institute of Radiological Sciences, Molecular Neuroimaging Group, Molecular Imaging Center, Chiba (Japan); Naganawa, Mika [National Institute of Radiological Sciences, Biophysics Group, Molecular Imaging Center, Chiba (Japan); Japan Society for the Promotion of Science, Tokyo (Japan)

    2008-02-15

    We evaluated the noise reduction capability of wavelet denoising for estimated binding potential (BP) images (k{sub 3}/k{sub 4}) of the peripheral benzodiazepine receptor using {sup 18}F-FEDAA1106 and nonlinear least-square fitting. Wavelet denoising within a three-dimensional discrete dual-tree complex wavelet transform was applied to simulate data and clinical dynamic positron emission tomography images of {sup 18}F-FEDAA1106. To eliminate noise components in wavelet coefficients, real and imaginary coefficients for each subband were thresholded individually using NormalShrink. A simulated dynamic brain image of {sup 18}F-FEDAA1106 was generated and Gaussian noise was added to mimic PET dynamic scan. The derived BP images were compared with true images using 156 rectangular regions of interest. Wavelet denoising was also applied to data derived from seven young normal volunteers. In the simulations, estimated BP by denoised image showed better correlation with the true BP values (Y = 0.83X + 0.94, r = 0.80), although no correlation was observed in the estimates between noise-added and true images (Y = 1.2X + 0.78, r = 0.49). For clinical data, there were visual improvements in the signal-to-noise ratio for estimated BP images. Wavelet denoising improved the bias and reduced the variation of pharmacokinetic parameters for BP. (orig.)

  3. [{sup 11}C]DAA1106: radiosynthesis and in vivo binding to peripheral benzodiazepine receptors in mouse brain

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Mingrong E-mail: zhang@nirs.go.jp; Kida, Takayo; Noguchi, Junko; Furutsuka, Kenji; Maeda, Jun; Suhara, Tetsuya; Suzuki, Kazutoshi

    2003-05-01

    DAA1106 (N-(2,5-Dimethoxybenzyl)-N-(5-fluoro-2-phenoxyphenyl)acetamide), is a potent and selective ligand for peripheral benzodiazepine receptors (PBR) in mitochondrial fractions of rat (K{sub i}=0.043 nM) and monkey (K{sub i}=0.188 nM) brains. This compound was labeled by [{sup 11}C]methylation of a corresponding desmethyl precursor (DAA1123) with [{sup 11}C]CH{sub 3}I in the presence of NaH, with a 72{+-}16% (corrected for decay) incorporation yield of radioactivity. After HPLC purification, [{sup 11}C]DAA1106 was obtained with {>=}98% radiochemical purity and specific activity of 90-156 GBq/{mu}mol at the end of synthesis. After iv injection of [{sup 11}C]DAA1106 into mice, high accumulations of radioactivity were found in the olfactory bulb and cerebellum, the high PBR density regions in the brain. Coinjection of [{sup 11}C]DAA1106 with unlabeled DAA1106 and PBR-selective PK11195 displayed a significant reduction of radioactivity, suggesting a high specific binding of [{sup 11}C]DAA1106 to PBR. Although this tracer was rapidly metabolized in the plasma, only [{sup 11}C]DAA1106 was detected in the brain tissues, suggesting the specific binding in the brain due to the tracer itself. These findings revealed that [{sup 11}C]DAA1106 is a potential and selective positron emitting radioligand for PBR.

  4. Anxiolytic-like effects of standardized extract of Justicia pectoralis (SEJP) in mice: Involvement of GABA/benzodiazepine in receptor.

    Science.gov (United States)

    Venâncio, E T; Rocha, N F M; Rios, E R V; Feitosa, M L; Linhares, M I; Melo, F H C; Matias, M S; Fonseca, F N; Sousa, F C F; Leal, L K A M; Fonteles, M M F

    2011-03-01

    Justicia pectoralis (Acanthaceae) is used as an antiinflammatory, antimicrobial and bronchodilator, and its extract exerts an anxiolytic-like effect profile in animal models. This work presents the behavioral effects of an aqueous standardized extract of Justicia pectoralis (SEJP) in animal models, such as the elevated plus maze (EPM), light/dark, open field, rota rod and pentobarbital sleep time. The extract was administered intragastrically to male mice at single doses of 50, 100 and 200 mg/kg, while diazepam 1 or 2 mg/kg was used as a standard drug and flumazenil 2.5 mg/kg was used to evaluate the participation of benzodiazepinic receptors. The results showed that, similar to diazepam (1 mg/kg), SEJP significantly modified all the observed parameters in the EPM test, without altering the general motor activity in the open field, rota rod and pentobarbital sleep time tests. Flumazenil reversed not only the diazepam effect but also the SEJP effect. In the same way, all doses of SEJP increased the time of permanence in the light box in the light/dark test. The results showed that SEJP presented an anxiolytic-like effect, disproving sedative effects.

  5. In vivo pharmacological characterization of AC-3933, a benzodiazepine receptor partial inverse agonist for the treatment of Alzheimer's disease.

    Science.gov (United States)

    Hatayama, Y; Hashimoto, T; Kohayakawa, H; Kiyoshi, T; Nakamichi, K; Kinoshita, T; Yoshida, N

    2014-04-18

    GABAergic neurons are known to inhibit neural transduction and therefore negatively affect excitatory neural circuits in the brain. We have previously reported that 5-(3-methoxyphenyl)-3-(5-methyl-1,2,4-oxadiazol-3-yl)-1,6-naphthyridin-2(1H)-one (AC-3933), a partial inverse agonist for the benzodiazepine receptor (BzR), reverses GABAergic inhibitory effect on cholinergic neurons, and thus enhances acetylcholine release from these neurons in rat hippocampal slices. In this study, we evaluated AC-3933 potential for the treatment of Alzheimer's disease, a disorder characterized by progressive decline mainly in cholinergic function. Oral administration of AC-3933 (0.01-0.03mg/kg) resulted in the amelioration of scopolamine-induced amnesia, as well as a shift in electroencephalogram (EEG) relative power characteristic of pro-cognitive cholinergic activators, such as donepezil. In addition, treatment with AC-3933 even at the high dose of 100mg/kg p.o. produced no seizure or anxiety, two major adverse effects of BzR inverse agonists developed in the past. These findings indicate that AC-3933 with its low risk for side effects may be useful in the treatment of Alzheimer's disease.

  6. Reducing Prescriptions of Long-acting Benzodiazepine Drugs in Denmark

    DEFF Research Database (Denmark)

    Eriksen, Sophie Isabel; Bjerrum, Lars

    2015-01-01

    Prolonged consumption of benzodiazepine drugs (BZD) and benzodiazepine receptor agonists (zolpidem, zaleplon, zopiclone; altogether Z drugs) is related to potential physiological and psychological dependence along with other adverse effects. This study aimed to analyse the prescribing of long...

  7. Experiment K-6-18. Study of muscarinic and gaba (benzodiazepine) receptors in the sensory-motor cortex, hippcampus and spinal code

    Science.gov (United States)

    Daunton, N.; Damelio, F.; Krasnov, I.

    1990-01-01

    Frontal lobe samples of rat brains flown aboard Cosmos 1887 were processed for the study of muscarinic (cholinergic) and GABA (benzodiazepine) receptors and for immunocytochemical localization of the neurotransmitter gamma-aminobutyric acid (GABA) and glial fibrillary acidic protein (GFAP). Although radioactive labeling of both muscarinic cholinergic and GABA (benzodiazepine) receptors proved to be successful with the techniques employed, distinct receptor localization of individual laminae of the frontal neocortex was not possible since the sampling of the area was different in the various groups of animals. In spite of efforts made for proper orientation and regional identification of laminae, it was found that a densitometric (quantitation of autoradiograms) analysis of the tissue did not contribute to the final interpretation of the effects of weightlessness on these receptors. As to the immunocytochemical studies the use of both markers, GFAP and GABA antiserum, confirmed the suitability of the techniques for use in frozen material. However, similar problems to those encountered in the receptor studies prevented an adequate interpretation of the effects of micro-G exposure on the localization and distribution of GABA and GFAP. This study did, however, confirm the feasibility of investigating neurotransmitters and their receptors in future space flight experiments.

  8. GABAA Receptors Implicated in REM Sleep Control Express a Benzodiazepine Binding Site

    OpenAIRE

    Nguyen, Tin Quang; Liang, Chang-Lin; Marks, Gerald A.

    2013-01-01

    It has been reported that non-subtype-selective GABAA receptor antagonists injected into the nucleus pontis oralis (PnO) of rats induced long-lasting increases in REM sleep. Characteristics of these REM sleep increases were identical to those resulting from injection of muscarinic cholinergic agonists. Both actions were blocked by the muscarinic antagonist, atropine. Microdialysis of GABAA receptor antagonists into the PnO resulted in increased acetylcholine levels. These findings were consis...

  9. Study of the Interaction of 1,4- and 1,5-Benzodiazepines with GABAA Receptors of Rat Cerebellum Granule Cells in Culture.

    Science.gov (United States)

    Nikas, Periklis; Gatta, Elena; Cupello, Aroldo; Di Braccio, Mario; Grossi, Giancarlo; Pellistri, Francesca; Robello, Mauro

    2015-08-01

    The effects of a classical 1,4-benzodiazepine agonist, such as diazepam, its catabolite N-desmethyl-diazepam (nordiazepam), and 1,5-benzodiazepines such as clobazam and RL 214 (a triazolobenzodiazepine previously synthesized in our labs) were evaluated on native GABAA receptors of cerebellar granule cells in culture. The parameter studied was the increase of GABA-activated chloride currents caused by these substances. The contributions of α6 β2/3 γ2 and α1 α6 β2/3 γ2 receptor subtypes to the increase of GABA-activated chloride current were investigated by comparing the effects of such substances in the presence vs. the absence of furosemide. Furosemide is in fact able to block such receptors. It was found that the percent enhancement of peak GABA-activated current doubled for diazepam, clobazam, and RL 214. However, it did not change for N-desmethyl-diazepam. These results indicate that diazepam, clobazam, and RL 214 interact exclusively with α1 β2/3 γ2 receptors, while N-desmethyl-diazepam seems to interact with not only α1- but also α6-containing receptors.

  10. GABA receptors and benzodiazepine binding sites modulate hippocampal acetylcholine release in vivo

    NARCIS (Netherlands)

    Moor, E; de Boer, P; Westerink, B.H.C.

    1998-01-01

    In the present study, the regulation of acetylcholine release from the ventral hippocampus by gamma-aminobutyric acid (GABA) was investigated in vivo. GABA receptor agonists and antagonists were administered locally in the medial septum and the adjacent vertical limb of the diagonal band of Broca, o

  11. Radiosynthesis and initial evaluation of [{sup 18}F]-FEPPA for PET imaging of peripheral benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Alan A. [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8 (Canada)], E-mail: alan.wilson@camhpet.ca; Garcia, Armando; Parkes, Jun [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); McCormick, Patrick [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Stephenson, Karin A. [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Houle, Sylvain; Vasdev, Neil [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8 (Canada)

    2008-04-15

    Introduction: A novel [{sup 18}F]-radiolabelled phenoxyanilide, [{sup 18}F]-FEPPA, has been synthesized and evaluated, in vitro and ex vivo, as a potential positron emission tomography imaging agent for the peripheral benzodiazepine receptor (PBR). Methods: [{sup 18}F]-FEPPA and two other radiotracers for imaging PBR, namely [{sup 11}C]-PBR28 and [{sup 11}C]-PBR28-d3, were synthesised and evaluated in vitro and ex vivo as potential PBR imaging agents. Results: [{sup 18}F]-FEPPA is efficiently prepared in one step from its tosylate precursor and [{sup 18}F]-fluoride in high radiochemical yields and at high specific activity. FEPPA displayed a K{sub i} of 0.07 nM for PBR in rat mitochondrial membrane preparations and a suitable lipophilicity for brain penetration (log P of 2.99 at pH 7.4). Upon intravenous injection into rats, [{sup 18}F]-FEPPA showed moderate brain uptake [standard uptake value (SUV) of 0.6 at 5 min] and a slow washout (SUV of 0.35 after 60 min). Highest uptake of radioactivity was seen in the hypothalamus and olfactory bulb, regions previously reported to be enriched in PBR in rat brain. Analysis of plasma and brain extracts demonstrated that [{sup 18}F]-FEPPA was rapidly metabolized, but no lipophilic metabolites were observed in either preparation and only 5% radioactive metabolites were present in brain tissue extracts. Blocking studies to determine the extent of specific binding of [{sup 18}F]-FEPPA in rat brain were problematic due to large perturbations in circulating radiotracer and the lack of a reference region. Conclusions: Further evaluation of the potential of [{sup 18}F]-FEPPA will require the employment of rigorous kinetic models and/or appropriate animal models.

  12. Functional characterization of the 1,5-benzodiazepine clobazam and its major active metabolite N-desmethylclobazam at human GABAA receptors expressed in Xenopus laevis oocytes

    DEFF Research Database (Denmark)

    Hammer, Harriet; Ebert, Bjarke; Jensen, Henrik S.

    2015-01-01

    The 1,5-benzodiazepine clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome in patients 2 years of age or older in the United States, and for treatment of anxiety and various forms of epilepsy elsewhere. Clobazam has been reported to exhibit...... different in vivo adverse effects and addiction liability profile than the classic 1,4-benzodiazepines. In this study, it was investigated whether the in vitro pharmacological properties of clobazam and its major active metabolite N-desmethylclobazam could explain some of these clinical differences....... The functional properties of the two 1,5-benzodiazepines were characterized at the human γ-aminobutyric acid type A receptor (GABAAR) subtypes α1β2γ2S, α2β2γ2S, α3β2γ2S, α5β2γ2S and α6β2δ expressed in Xenopus laevis oocytes by use of two-electrode voltage-clamp electrophysiology and compared to those exhibited...

  13. Interaction of pyracetam with specific /sup 3/H-imipramine binding sites and GABA-benzodiazepine receptor complex of brain membranes

    Energy Technology Data Exchange (ETDEWEB)

    Rozhanets, V.V.; Chakhbra, K.K.; Danchev, N.D.; Malin, K.M.; Rusakov, D.Yu.; Val' dman, A.V.

    1986-06-01

    This paper studies the effect of pyracetam on parameters of specific binding of tritium-imipramine and GABA-activated binding of tritium-flunitrazepam with rat brain membranes. The experimental method is described and it is shown that pyracetam and mebicar in experiments in vivo on normal animals can exert their anxiolytic action without the participation of bensodiazepine receptors. Either the interaction of pyracetam and mebicar with benzodiazeprine receptors has a different interpretation than competition of these compounds with specific binding sites of tritium-flunitrazepam, or in experiments on normal animals in vivo GABA-benzodiazepine receptor complex does not accept pyracetam and mebicar, for it contains endogenous inhibitors of GABA-modulating action.

  14. A comparison of the effects of a subtype selective and non-selective benzodiazepine receptor agonist in two CO(2) models of experimental human anxiety.

    Science.gov (United States)

    Bailey, J E; Papadopoulos, A; Seddon, K; Nutt, D J

    2009-03-01

    Studies in human volunteers that can demonstrate proof of concept are attractive in that possible mechanisms and potential new drug treatments can be examined. We have been developing models of anxiety disorders using the inhalation of 7.5% CO(2) for 20 min to model generalised anxiety disorder, as well as using the previously reported 35% CO(2) as a model for panic anxiety. In a double-blind, placebo-controlled, three-way crossover study in 12 healthy volunteer subjects, we compared a full agonist at the benzodiazepine receptor that binds to four alpha-subtypes of the receptor (alpha-1,-2,-3,-5) (alprazolam 1 mg), with zolpidem (5 mg), an agonist selective for the alpha-1 subtype of the gamma amino butyric acid-receptor subtype A (GABA-A) receptor, which is a widely used hypnotic drug. Compared with placebo, both drugs significantly attenuated peak CO(2)-induced changes in subjective feelings after the inhalation of 7.5% CO(2) for 20 min. However, there were fewer significant differences after a single vital capacity inhalation of 35% CO(2), where zolpidem was less efficacious than alprazolam at reducing CO(2)-induced symptoms. In conclusion, our results show that zolpidem shows some anxiolytic efficacy in the 7.5% CO(2) model, similar to alprazolam, and this is the first report of such an effect of zolpidem in a model of anxiety. These and other studies of benzodiazepines in clinical and volunteer studies suggest a definite role of the GABA-A receptor in CO(2)-induced anxiety, and it would be of interest to examine other GABA-A receptor subtype selective drugs, which are now in early phase clinical studies and are showing selective efficacy in pharmacodynamic studies.

  15. The human peripheral benzodiazepine receptor gene: cloning and characterization of alternative splicing in normal tissues and in a patient with congenital lipoid adrenal hyperplasia.

    Science.gov (United States)

    Lin, D; Chang, Y J; Strauss, J F; Miller, W L

    1993-12-01

    The mitochondrial benzodiazepine receptor (mBzR) appears to be a key factor in the flow of cholesterol into mitochondria to permit the initiation of steroid hormone synthesis. The mBzR consists of three components; the 18-kDa component on the outer mitochondrial membrane appears to contain the benzodiazepine binding site, and is hence often termed the peripheral benzodiazepine receptor (PBR). Using a cloned human PBR cDNA as probe, we have cloned the human PBR gene. The 13-kb gene is divided into four exons, with exon 1 encoding only a short 5' untranslated segment. The 5' flanking DNA lacks TATA and CAAT boxes but contains a cluster of SP-1 binding sites, typical of "house-keeping" genes. The encoded PBR mRNA is alternately spliced into two forms: "authentic" PBR mRNA retains all four exons, while a short form termed PBR-S lacks exon 2. While PBR-S contains a 102-codon open reading frame with a typical initiator sequence, the reading frame differs from that of PBR, so that the encoded protein is unrelated to PBR. RT-PCR and RNase protection experiments confirm that both PBR and PBR-S are expressed in all tissues examined and that expression PBR-S is about 10 times the level of PBR. Expression of PBR cDNA in pCMV5 vectors transfected into COS-1 cells resulted in increased binding of [3H]PK11195, but expression of PBR-S did not. It has been speculated that patients with congenital lipoid adrenal hyperplasia, who cannot make any steroids, might have a genetic lesion in mBzR. RT-PCR analysis of testicular RNA from such a patient, sequencing of the cDNA, and blotting analysis of genomic DNA all indicate that the gene and mRNA for the PBR component of mBzR are normal in this disease.

  16. Region-selective effects of neuroinflammation and antioxidant treatment on peripheral benzodiazepine receptors and NMDA receptors in the rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Biegon, A.; Alvarado, M.; Budinger, T.F.; Grossman, R.; Hensley, K.; West, M.S.; Kotake, Y.; Ono, M.; Floyd, R.A.

    2001-12-10

    Following induction of acute neuroinflammation by intracisternal injection of endotoxin (lipopolysaccharide) in rats, quantitative autoradiography was used to assess the regional level of microglial activation and glutamate (NMDA) receptor binding. The possible protective action of the antioxidant phenyl-tert-butyl nitrone in this model was tested by administering the drug in the drinking water for 6 days starting 24 hours after endotoxin injection. Animals were killed 7 days post-injection and consecutive cryostat brain sections labeled with [3H]PK11195 as a marker of activated microglia and [125I]iodoMK801 as a marker of the open-channel, activated state of NMDA receptors. Lipopolysaccharide increased [3H]PK11195 binding in the brain, with the largest increases (2-3 fold) in temporal and entorhinal cortex, hippocampus, and substantia innominata. A significant (>50 percent) decrease in [125I]iodoMK801 binding was found in the same brain regions. Phenyl-tert-butyl nitrone treatment resulted in a partial inhibition ({approx}25 percent decrease) of the lipopolysaccharide-induced increase in [3H]PK11195 binding but completely reversed the lipopolysaccharide-induced decrease in [125I]iodoMK80 binding in the entorhinal cortex, hippocampus, and substantia innominata. Loss of NMDA receptor function in cortical and hippocampal regions may contribute to the cognitive deficits observed in diseases with a neuroinflammatory component, such as meningitis or Alzheimer's disease.

  17. A [11C]Ro15 4513 PET study suggests that alcohol dependence in man is associated with reduced α5 benzodiazepine receptors in limbic regions.

    Science.gov (United States)

    Lingford-Hughes, Anne; Reid, Alastair G; Myers, James; Feeney, Adrian; Hammers, Alexander; Taylor, Lindsay G; Rosso, Lula; Turkheimer, Federico; Brooks, David J; Grasby, Paul; Nutt, David J

    2012-02-01

    Preclinical evidence suggests the α5 subtype of the GABA-benzodiazepine receptor is involved in some of the actions of alcohol and in memory. The positron emission tomography (PET) tracer, [(11)C]Ro15 4513 shows relative selectivity in labelling the α5 subtype over the other GABA-benzodiazepine receptor subtypes in limbic regions of the brain. We used this tracer to investigate the distribution of α5 subtype availability in human alcohol dependence and its relationship to clinical variables. Abstinent (>6 weeks) alcohol-dependent men and healthy male controls underwent an [(11)C]Ro15 4513 PET scan. We report [(11)C]Ro15 4513 brain uptake for 8 alcohol-dependent men and 11 healthy controls. We found a significant reduction in [(11)C]Ro15 4513 binding in the nucleus accumbens, parahippocampal gyri, right hippocampus and amygdala in the alcohol-dependent compared with the healthy control group. Levels of [(11)C]Ro15 4513 binding in both hippocampi were significantly and positively associated with performance on a delayed verbal memory task in the alcohol-dependent but not the control group. We speculate that the reduced limbic [(11)C]Ro15 4513 binding seen here results from the effects of alcohol, though we cannot currently distinguish whether they are compensatory in nature or evidence of brain toxicity.

  18. 2-Phenyl-imidazo[1,2-a]pyridine compounds containing hydrophilic groups as potent and selective ligands for peripheral benzodiazepine receptors: synthesis, binding affinity and electrophysiological studies.

    Science.gov (United States)

    Denora, Nunzio; Laquintana, Valentino; Pisu, Maria Giuseppina; Dore, Riccardo; Murru, Luca; Latrofa, Andrea; Trapani, Giuseppe; Sanna, Enrico

    2008-11-13

    A series of imidazopyridine acetamides were synthesized to evaluate the effects of structural changes at both central (CBRs) and peripheral benzodiazepine receptors (PBRs). These changes include the introduction of polar substituents or ionizable functional groups at the 2- and 8-position of the imidazopyridine skeleton. The results suggest that substituents endowed with hydrogen bonding acceptor and/or donor properties in the para position of the phenyl ring lead to high affinity for PBR. In electrophysiological studies, it was found that compounds 9, 12, 13, and 28 markedly enhanced GABA-evoked Cl (-) currents in Xenopus oocytes expressing alpha 1beta 2gamma 2 GABA A receptors. The capability of flumazenil to reduce the stimulatory effect exerted by compound 9 supports the conclusion that the modulatory effects of the examined compounds occur involving the CBR. The ability of compound 16 to increase GABA A receptor-mediated miniature inhibitory postsynaptic currents in CA1 pyramidal neurons is indicative of its ability to stimulate the local synthesis and secretion of neurosteroids.

  19. Is there a way to curb benzodiazepine addiction?

    Science.gov (United States)

    Lalive, Arnaud L; Rudolph, Uwe; Lüscher, Christian; Tan, Kelly R

    2011-10-19

    Benzodiazepines are widely prescribed drugs used to treat anxiety and insomnia, induce muscle relaxation, control epileptic seizures, promote anaesthesia or produce amnesia. Benzodiazepines are also abused for recreational purposes and the number of benzodiazepine abusers is unfortunately increasing. Within weeks of chronic use, tolerance to the pharmacological effects can develop and withdrawal becomes apparent once the drug is no longer available, which are both conditions indicative of benzodiazepine dependence. Diagnosis of addiction (i.e. compulsive use despite negative consequences) may follow in vulnerable individuals. Here, we review the historical and current use of benzodiazepines from their original synthesis, discovery and commercialisation to the recent identification of the molecular mechanism by which benzodiazepines induce addiction. These results have identified the mechanisms underlying the activation of midbrain dopamine neurons by benzodiazepines, and how these drugs can hijack the mesocorticolimbic reward system. Such knowledge calls for future developments of new receptor subtype specific benzodiazepines with a reduced addiction liability.

  20. Research Progress in Physical Dependence of Benzodiazepine-type Drugs and Receptor Mechanism%苯二氮(艹卓)类药物的躯体依赖及受体机制研究进展

    Institute of Scientific and Technical Information of China (English)

    王丽华

    2011-01-01

    Prolonged use of benzodiazepines can lead to physical dependence. The diverse behavioral effects of benzodiazepines may reflect the actions on different subtypes of GABAA receptors. Benzodiazepine action appears to be determined by the presence of particular ct subunits. But a complex picture is emerging with respect to abuse of benzodiazepines and the roles of different GABAA receptor subtypes. Recent researches suggest an interaction with all GABAA receptor subtypes is required for physical dependence of benzodiazepines. This article reviews physical dependence of benzodiazepine and mediating GABAA receptor subunits.%苯二氮(艹卓)类药物的长期使用会使患者产生躯体依赖.不同的苯二氮(艹卓)类药物的行为效应可能由不同的GABAA受体亚单位介导.苯二氮(艹卓)类药物主要作用于特定的α亚单位.然而,苯二氮艹 卓类药物的滥用和不同的GABAA受体亚单位所起的作用之间却是复杂的.研究表明,苯二氮(艹卓)类药物躯体依赖的发生需要所有GABAA受体亚单位的相互作用.现重点介绍国内外有关苯二氮(艹卓)类药物的躯体依赖的产生,GABAA受体亚单位介导的苯二氮(艹卓)类药物的躯体依赖等研究情况.

  1. Synthesis and evaluation of sup 11 C-PK 11195 for in vivo study of peripheral-type benzodiazepine receptors using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Kenji (Fukuyama Univ., Hiroshima (Japan). Faculty of Pharmacy and Pharmaceutical Sciences); Inoue, Osamu; Suzuki, Kazutoshi; Yamasaki, Toshiro; Kojima, Masaharu

    1989-07-01

    The biodistribution of {sup 3}H-PK 11195, an antagonist of the peripheral-type benzodiazepine receptors, was studied in mice. High accumulations of radioactivity in the heart, lung, spleen, kidney and adrenal were observed after intravenous injection of tracer amounts of {sup 3}H-PK 11195 into the mice. The radioactivity in the heart, lung, spleen, kidney and adrenal was significantly decreased by the coadministration of carrier PK 11195, which indicated that PK 11195 specifically binds to the receptors. No radioactive metabolites were observed in the heart, lung and brain 20 min after intravenous administration of {sup 3}H-PK 11195. The accumulation of {sup 3}H-PK 11195 in the lung was not affected by pretreatment with either {alpha}-methyl benzylamine or imipramine, suggesting that {sup 3}H-PK 11195 specifically binds to the receptors. The ratios of radioactivity of the kidney, adrenal and spleen to blood increased as a function of time, whereas that of the lung and heart rapidly reached to a steady state. {sup 11}C-PK 11195 was synthesized by the N-methylation of desmethyl precursor yielding more than 100 mCi with high specific activity (more than 1.4 Ci/{mu}mol). The lebeling and purification procedure was completed within 23 min after the end of bombardment (EOB). The {sup 11}C-PK 11195 solution for injection seems to have a high potential for the in vivo study of the peripheral-type benzodiazepine receptors in the living human by means of positron emission tomography (PET). (author).

  2. Effects of ZK 93,426, a beta-carboline benzodiazepine receptor antagonist on night sleep pattern in healthy male volunteers.

    Science.gov (United States)

    Duka, T; Goerke, D; Fichte, K

    1995-01-01

    The beta-carboline ZK 93,426, a benzodiazepine-antagonist with weak inverse agonist activity, was administered intravenously to human volunteers at a dose of 0.04 mg/kg when they initially reached slow-wave sleep during their night's sleep. Eight subjects, subjected to half a night of sleep withdrawal, took part in the study, which was performed according to a double-blind, placebo-controlled, cross-over design. Sleep parameters as determined by electroencephalography, actometry (wrist actometer) and temperature (rectal thermometer) were monitored for the whole night. Vital functions (blood pressure and heart rate) as well as subjectively experienced effects via visual analogue scales were evaluated and blood samples for hormone plasma level estimation were taken before and after sleep. ZK 93,426 was well tolerated. Sleep parameters were reduced under the influence of the drug indicating a stimulant effect. Slow wave sleep (sleep stages 3 and 4) was significantly reduced in favour of light sleep stages 1 and 2 during the first 30 min after the administration of ZK 93,426 (P = 0.02). In keeping with these findings subjects exhibited a significantly (P < 0.02) elevated number and intensity of movements during the first 90 min after the beta-carboline injection. Effects on self-ratings, in body temperature and on hormonal changes were not found. It is assumed that the benzodiazepine-antagonist ZK 93,426 is able to induce activation and disturb sleep via modulation of GABAergic transmission mainly by benzodiazepine receptor blocking properties.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. PET and SPECT in medically non-refractory complex partial seizures. Temporal asymmetries of glucose consumption, Benzodiazepine receptor density

    Energy Technology Data Exchange (ETDEWEB)

    Matheja, P.; Kuwert, T.; Wolf, K.; Schober, O. [Muenster Univ. (Germany). Kliniken und Polikliniken fuer Nuklearmedizin; Stodieck, S.R.G.; Diehl, B.; Ringelstein, E.B. [Muenster Univ. (Germany). Klinik fuer Neurologie; Schuierer, G. [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie

    1998-12-31

    Aim: In contrast to medically refractory complex partial seizures (CPS), only limited knowledge exists on cerebral perfusion and metabolism in medically non-refractory CPS. The aim of this study was to investigate the frequency of temporal asymmetries in regional cerebral glucose consumption (rCMRGlc), regional cerebral blood flow (rCBF), and regional cerebral benzodiazepine receptor density (BRD) in this group of patients. Methods: The study included 49 patients with medically non-refractory cryptogenic CPS (age: 36.0{+-}16.1 years). rCMRGlc was studied with F-18-FDG-PET (FDG), rCBF with Tc-99m-ECD-SPECT (ECD), and BRD with I-123-iomazenil-SPECT (IMZ). All studies were performed interictally and within four weeks in each patient. Duration of epilepsy ranged from 0.1 to 42 years (median 4.0 years). SPECT was performed with the triple-headed SPECT camera Multispect 3, PET with the PET camera ECAT EXACT 47. Using linear profiles, glucose consumption, as well as uptake of ECD and IMZ, were measured in four temporal regions of interest (ROIs), and asymmetry indices were calculated (ASY). The results were compared to 95% confidence intervals determined in control subjects. Results: Thirty-five of the 49 (71%) patients had at least one significantly elevated ASY; temporal rCMRGlc was asymmetrical in 41% of the patients, temporal BRD in 29%, and temporal rCBF in 24%. One patient had an asymmetry of all three variables, two of temporal rCMRGlc and BRD, three of temporal rCMRGlc and rCBF, and another four of rCBF and BRD. Fourteen patients had an isolated temporal asymmetry in rCMRGlc, seven in BRD, and four in rCBF. A discrepancy in lateralization between the three modalities was not observed. Conclusion: The majority of patients with medically non-refractory CPS have focal abnormalities of blood flow and metabolism in their temporal lobe. In this group of patients, FDG-PET demonstrates abnormalities with the highest frequency of the three modalities studied, followed by

  4. Anxiolytic-like profiles of histamine H3 receptor agonists in animal models of anxiety: a comparative study with antidepressants and benzodiazepine anxiolytic.

    Science.gov (United States)

    Yokoyama, Fumikazu; Yamauchi, Miki; Oyama, Masayo; Okuma, Kunihiro; Onozawa, Kaname; Nagayama, Takako; Shinei, Rie; Ishikawa, Makoto; Sato, Yasuo; Kakui, Nobukazu

    2009-08-01

    Histamine H3 receptor functions as a presynaptic auto- and hetero-receptor on histaminergic and non-histaminergic neurons in the brain regulating the synaptic release of numerous neurotransmitters. Therefore, the ligands for this receptor have been proposed to be of therapeutic interest for the treatment of various neuropsychiatric disorders. At present, however, the psychopharmacological profiles of H3 ligands, particularly H3 agonists, have not been extensively studied. The present study investigated the anxiolytic-like profiles of H3-selective agonists in a variety of classical (benzodiazepine-sensitive) and atypical (antidepressant-effective) animal models of anxiety. Comparator drugs used were diazepam and both fluvoxamine and desipramine in the former and latter models, respectively. H3 agonist R-alpha-methylhistamine and immepip were inactive in rat elevated plus maze test and Vogel type conflict test where diazepam (5 mg/kg) produced significant anxiolytic-like effects. Meanwhile, these H3 agonists (10-30 mg/kg) significantly reduced isolation-induced vocalizations in guinea pig pups and isolation-induced aggressive behavior in mouse resident-intruder test. Moreover, in rat conditioned fear stress test, R-alpha-methylhistamine (30 mg/kg) and immepip (10 mg/kg) significantly decreased freezing time, which were completely reversed by concomitant treatment with H3 antagonist, thioperamide (10 mg/kg). In contrast to the limited efficacy obtained with desipramine (30 mg/kg), fluvoxamine (20-60 mg/kg) exhibited anxiolytic-like effects in all the latter three atypical models. These data suggest that the H3 agonists may have anxiolytic-like effects similar to those of selective serotonin reuptake inhibitors but not benzodiazepine anxiolytics and represent a novel strategy for the treatment of some anxiety disorders in which selective serotonin reuptake inhibitors are prescribed.

  5. Intracerebroventricular administration of inosine is anticonvulsant against quinolinic acid-induced seizures in mice: an effect independent of benzodiazepine and adenosine receptors.

    Science.gov (United States)

    Ganzella, Marcelo; Faraco, Rafael Berger; Almeida, Roberto Farina; Fernandes, Vinícius Fornari; Souza, Diogo Onofre

    2011-12-01

    Inosine (INO) has an anticonvulsant effect against seizures induced by antagonists of GABAergic system. Quinolinic acid (QA) is an agonist NMDA receptors implicated in the neurobiology of seizures. In the present study, we investigated the anticonvulsant effect of intracerebroventricular (i.c.v.) INO administration against QA-induced seizures in adult mice. We also investigated whether the benzodiazepines (BZ) or adenosine (ADO) receptors were involved in the INO effects. Animals were pretreated with an i.c.v. injection of either vehicle or INO before an i.c.v. administration of 4 μl QA (36.8 nmol). All animals pretreated with vehicle followed by QA presented seizures. INO protected against QA-induced seizures in a time and dose dependent manner (up to 60% at 400 nmol, 5 min before QA injection). Diazepam (DZ) and ADO (i.c.v.) also exhibited anticonvulsant effect against QA induced seizures. Additionally, i.p. administration of either flumazenil, a BZ receptor antagonist, or caffeine, an ADO receptor antagonist, did not change the anticonvulsant potency of INO i.c.v. injection, but completely abolished the DZ and ADO anticonvulsant effects, respectively. In conclusion, this study demonstrated that INO exert anticonvulsant effect against hyperactivity of the glutamatergic system independently of BZ or ADO receptors activation.

  6. The mouse defense test battery: evaluation of the effects of non-selective and BZ-1 (omega1) selective, benzodiazepine receptor ligands.

    Science.gov (United States)

    Griebel, G.; Sanger, D.J.; Perrault, G.

    1996-11-01

    The behavioral effects of several benzodiazepine (BZ) (omega) receptor ligands were compared using the Mouse Defense Test Battery which has been designed to assess defensive reactions of Swiss mice confronted with a natural threat (a rat) and situations associated with this threat. Primary measures taken before, during and after rat confrontation were escape attempts, flight, risk assessment and defensive threat and attack. The drugs used included non-selective BZ (omega) full (clonazepam, clorazepate, chlordiazepoxide and diazepam) and partial (bretazenil and imidazenil) agonists, and BZ-1 (omega1) selective (abecarnil, CL 218,872 and zolpidem) receptor ligands. With the exception of clonazepam, non-selective BZ (omega) receptor compounds only partially affected flight behaviors. The drugs reduced some but not all flight measures in response to the approaching rat, whereas clonazepam attenuated all flight reactions. In contrast to their mild and inconsistent actions on flight, the non-selective BZ (omega) receptor agonists displayed clear effects on risk assessment when subjects were chased by the rat. When contact was forced between the subject and the rat, the non-selective BZ (omega) receptor full agonists reduced defensive threat and attack reactions, while the partial agonists imidazenil and bretazenil only weakly attenuated defensive attack behavior. Similarly, after the rat had been removed from the test area, the non-selective BZ (omega) receptor full agonists displayed greater efficacy than the partial agonists in reducing escape attempts. Overall, results obtained with the selective BZ-1 (omega1) receptor ligands demonstrated either no clear effects or no specific action on defensive reactions. Taken together, these data demonstrate that: (1) non-selective BZ (omega) agonists displaying high intrinsic activity affect a wider range of defensive behaviors than non-selective BZ (omega) receptor partial agonists; (2) the defense system does not involve

  7. Central cholinergic regulation of respiration: nicotinic receptors

    Institute of Scientific and Technical Information of China (English)

    Xuesi M SHAO; Jack L FELDMAN

    2009-01-01

    Nicotinic acetylcholine receptors (nAChRs) are expressed in brainstem and spinal cord regions involved in the control of breathing. These receptors mediate central cholinergic regulation of respiration and effects of the exogenous ligand nicotine on respiratory pattern. Activation of a4* nAChRs in the preBotzinger Complex (preBotC), an essential site for normal respiratory rhythm generation in mammals, modulates excitatory glutamatergic neurotransmission and depolarizes preBotC inspiratory neurons, leading to increases in respiratory frequency. nAChRs are also present in motor nuclei innervating respiratory muscles. Activation of post- and/or extra-synaptic a4* nAChRs on hypoglossal (XII) motoneurons depolarizes these neurons, potentiating tonic and respiratory-related rhythmic activity. As perinatal nicotine exposure may contribute to the pathogenesis of sudden infant death syndrome (SIDS), we discuss the effects of perinatal nicotine exposure on development of the cholinergic and other neurotransmitter systems involved in control of breathing. Advances in understanding of the mechanisms underlying central cholinergic/nicotinic modulation of respiration provide a pharmacological basis for exploiting nAChRs as therapeutic targets for neurological disorders related to neural control of breathing such as sleep apnea and SIDS.

  8. Increased densities of binding sites for the peripheral-type benzodiazepine receptor ligand [3H]PK 11195 in congenital ornithine transcarbamylase-deficient sparse fur mouse.

    Science.gov (United States)

    Rao, V L; Qureshi, I A; Butterworth, R F

    1993-12-01

    Peripheral-type (mitochondrial) benzodiazepine receptors (PTBR) were studied in the brain and peripheral organs (kidney, liver, and testis) of normal male mice (CD-1/Y) and the congenitally hyperammonemic sparse fur (spf/Y) mouse. Radioligand binding assays were performed with [3H]PK 11195, a ligand with high selectivity and affinity for PTBR. Densities (maximal number of binding sites) of [3H]PK 11195 binding sites were greatest in kidney, followed by liver, testis, and brain. Densities of [3H]PK 11195 binding sites were significantly increased in all tissues of spf mice compared with control animals. In view of the localization of PTBR on the outer mitochondrial membrane, changes in PTBR in spf mouse tissues may modulate the altered mitochondrial function and oxidative metabolism, in brain and peripheral tissues, in congenital OTC deficiency. The positron emission tomography ligand 11C-PK 11195 could find an application in the assessment of end organ dysfunction in this disorder.

  9. Peripheral-type benzodiazepine receptor levels correlate with the ability of human breast cancer MDA-MB-231 cell line to grow in SCID mice.

    Science.gov (United States)

    Hardwick, M; Rone, J; Han, Z; Haddad, B; Papadopoulos, V

    2001-11-01

    MDA-MB-231 (MDA-231) human breast cancer cells have a high proliferation rate, lack the estrogen receptor, express the intermediate filament vimentin, the hyaluronan receptor CD44, and are able to form tumors in nude mice. The MDA-231 cell line has been used in our laboratory to examine the role of the peripheral-type benzodiazepine receptor (PBR) in the progression of cancer. During these studies 2 populations of MDA-231 cells were subcloned based on the levels of PBR. The subclones proliferated at approximately the same rate, lacked the estrogen receptor, expressed vimentin and CD44, and had the same in vitro chemoinvasive and chemotactic potential. Both restriction fragment length polymorphism and comparative genomic hybridization analyses of genomic DNA from these cells indicated that both subclones are of the same genetic lineage. Only the subclone with high PBR levels, however, was able to form tumors when injected in SCID mice. These data suggest that the ability of MDA-231 cells to form tumors in vivo may depend on the amount of PBR present in the cells.

  10. The human peripheral benzodiazepine receptor gene: Cloning and characterization of alternative splicing in normal tissues and in a patient with congenital lipoid adrenal hyperplasia

    Energy Technology Data Exchange (ETDEWEB)

    Lin, D.; Miller, W.L. (Univ. of California, San Francisco, CA (United States)); Chang, Y.J.; Strauss, J.F. III (Univ. of Pennsylvania School of Medicine, Philadelphia, PA (United States))

    1993-12-01

    The mitochondrial benzodiazepine receptor (mBzR) appears to be a key factor in the flow of cholesterol into mitochondia to permit the initiation of steroid hormone synthesis. The mBzR consists of three components; the 18-kDa component on the outer mitochondrial membrane appears to contain the benzodiazepine binding site, and is hence often termed the peripheral benzodiazepine receptor (PBR). Using a cloned human PBR cDNA as probe, the authors have cloned the human PBR gene. The 13-kb gene is divided into four exons, with exon 1 encoding only a short 5[prime] untranslated segment. The 5[prime] flanking DNA lacks TATA and CAAT boxes but contains a cluster of SP-1 binding sites, typical of [open quotes]housekeeping[close quotes] genes. The encoded PBR mRNA is alternately spliced into two forms: [open quotes]authentic[close quotes] PBR mRNA retains all four exons, while a short form termed PBR-S lacks exon 2. While PBR-S contains a 102-codon open reading frame with a typical initiator sequence, the reading frame differs from that of PBR, so that the encoded protein is unrelated to PBR. RT-PCR and RNase protection experiments confirm that both PBR and PBR-S are expressed in all tissues examined and that expression of PBR-S is about 10 times the level of PBR. Expression of PBR cDNA in pCMV5 vectors transfected into COS-1 cells resulted in increased binding of [[sup 3]H]PK11195, but expression of PBR-S did not. It has been speculated that patients with congenital lipoid adrenal hyperplasia, who cannot make any steroids, might have a genetic lesion in mBzR. RT-PCR analysis of testicular RNA from such a patient, sequencing of the cDNA, and blotting analysis of genomic DNA all indicate that the gene and mRNA for the PBR component of mBzR are normal in this disease. 36 refs., 6 figs.

  11. GABA receptor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Doo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    GABA is primary an inhibitory neurotransmitter that is localized in inhibitory interneurons. GABA is released from presynaptic terminals and functions by binding to GABA receptors. There are two types of GABA receptors, GABA{sub A}-receptor that allows chloride to pass through a ligand gated ion channel and GABA{sub B}-receptor that uses G-proteins for signaling. The GABA{sub A}-receptor has a GABA binding site as well as a benzodiazepine binding sites, which modulate GABA{sub A}-receptor function. Benzodiazepine GABAA receptor imaging can be accomplished by radiolabeling derivates that activates benzodiazepine binding sites. There has been much research on flumazenil (FMZ) labeled with {sup 11}C-FMZ, a benzodiazepine derivate that is a selective, reversible antagonist to GABAA receptors. Recently, {sup 18}F-fluoroflumazenil (FFMZ) has been developed to overcome {sup 11}C's short half-life. {sup 18}F-FFMZ shows high selective affinity and good pharmacodynamics, and is a promising PET agent with better central benzodiazepine receptor imaging capabilities. In an epileptic focus, because the GABA/benzodiazepine receptor amount is decreased, using '1{sup 1}C-FMZ PET instead of {sup 18}F-FDG, PET, restrict the foci better and may also help find lesions better than high resolution MR. GABA{sub A} receptors are widely distributed in the cerebral cortex, and can be used as an viable neuronal marker. Therefore it can be used as a neuronal cell viability marker in cerebral ischemia. Also, GABA-receptors decrease in areas where neuronal plasticity develops, therefore, GABA imaging can be used to evaluate plasticity. Besides these usages, GABA receptors are related with psychological diseases, especially depression and schizophrenia as well as cerebral palsy, a motor-related disorder, so further in-depth studies are needed for these areas.

  12. Using [(11)C]Ro15 4513 PET to characterise GABA-benzodiazepine receptors in opiate addiction: Similarities and differences with alcoholism.

    Science.gov (United States)

    Lingford-Hughes, Anne; Myers, James; Watson, Ben; Reid, Alastair G; Kalk, Nicola; Feeney, Adrian; Hammers, Alexander; Riaño-Barros, Daniela A; McGinnity, Colm J; Taylor, Lindsay G; Rosso, Lula; Brooks, David J; Turkheimer, Federico; Nutt, David J

    2016-05-15

    The importance of the GABA-benzodiazepine receptor complex and its subtypes are increasingly recognised in addiction. Using the α1/α5 benzodiazepine receptor PET radioligand [(11)C]Ro15 4513, we previously showed reduced binding in the nucleus accumbens and hippocampus in abstinent alcohol dependence. We proposed that reduced [(11)C]Ro15 4513 binding in the nucleus accumbens was a marker of addiction whilst the reduction in hippocampus and positive relationship with memory was a consequence of chronic alcohol abuse. To examine this further we assessed [(11)C]Ro15 4513 binding in another addiction, opiate dependence, and used spectral analysis to estimate contributions of α1 and α5 subtypes to [(11)C]Ro15 4513 binding in opiate and previously acquired alcohol-dependent groups. Opiate substitute maintained opiate-dependent men (n=12) underwent an [(11)C]Ro15 4513 PET scan and compared with matched healthy controls (n=13). We found a significant reduction in [(11)C]Ro15 4513 binding in the nucleus accumbens in the opiate-dependent compared with the healthy control group. There was no relationship between [(11)C]Ro15 4513 binding in the hippocampus with memory. We found that reduced [(11)C]Ro15 4513 binding was associated with reduced α5 but not α1 subtypes in the opiate-dependent group. This was also seen in an alcohol-dependent group where an association between memory performance and [(11)C]Ro15 4513 binding was primarily driven by α5 and not α1 subtype. We suggest that reduced α5 levels in the nucleus accumbens are associated with addiction since we have now shown this in dependence to two pharmacologically different substances, alcohol and opiates.

  13. Imaging brain inflammation with [(11)C]PK11195 by PET and induction of the peripheral-type benzodiazepine receptor after transient focal ischemia in rats.

    Science.gov (United States)

    Rojas, Santiago; Martín, Abraham; Arranz, Maria J; Pareto, Deborah; Purroy, Jesús; Verdaguer, Esther; Llop, Jordi; Gómez, Vanessa; Gispert, Joan D; Millán, Olga; Chamorro, Angel; Planas, Anna M

    2007-12-01

    [(11)C]PK11195 is used in positron emission tomography (PET) studies for imaging brain inflammation in vivo as it binds to the peripheral-type benzodiazepine receptor (PBR) expressed by reactive glia and macrophages. However, features of the cellular reaction required to induce a positive [(11)C]PK11195 signal are not well characterized. We performed [(11)C]PK11195 PET and autoradiography in rats after transient focal cerebral ischemia. We determined [(3)H]PK11195 binding and PBR expression in brain tissue and examined the lesion with several markers. [(11)C]PK11195 standard uptake value increased at day 4 and grew further at day 7 within the ischemic core. Accordingly, ex vivo [(3)H]PK11195 binding increased at day 4, and increases further at day 7. The PET signal also augmented in peripheral regions, but to a lesser extent than in the core. Binding in the region surrounding infarction was supported by [(11)C]PK11195 autoradiography at day 7 showing that the radioactive signal extended beyond the infarcted core. Enhanced binding was preceded by increases in PBR mRNA expression in the ipsilateral hemisphere, and a 18-kDa band corresponding to PBR protein was detected. Peripheral-type benzodiazepine receptor immunohistochemistry showed subsets of ameboid microglia/macrophages within the infarcted core showing a distinctive strong PBR expression from day 4. These cells were often located surrounding microhemorrhages. Reactive astrocytes forming a rim surrounding infarction at day 7 also showed some PBR immunostaining. These results show cellular heterogeneity in the level of PBR expression, supporting that PBR is not a simple marker of inflammation, and that the extent of [(11)C]PK11195 binding depends on intrinsic features of the inflammatory cells.

  14. Detection of viable cortical neurons using benzodiazepine receptor imaging after reversible focal ischaemia in rats: comparison with regional cerebral blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshiyuki [Dept. of Radiology, Osaka National Hospital (Japan); Nakano, Takayuki; Yutani, Kenji; Nishimura, Hiroshi; Nishimura, Tsunehiko [Div. of Tracer Kinetics, Osaka University Medical School (Japan); Kusuoka, Hideo [Clinical Research Institute, Osaka National Hospital (Japan); Nakamura, Hironobu [Dept. of Radiology, Osaka University Medical School (Japan)

    2000-03-01

    To elucidate the utility of benzodiazepine receptor imaging for the detection of viable cortical neurons, dual-tracer autoradiography using iodine-125 iomazenil (IMZ) and iodine-123 N-isopropyl-4-iodoamphetamine (IMP) was performed in a model of reversible focal ischaemia during the acute and subacute phases. The right middle cerebral artery of anaesthetized rats was occluded for 60 min using an intraluminal filament and reperfused. In the acute phase study, {sup 125}I-IMZ (370 kBq) was injected via the femoral vein at 2 h after reperfusion, and {sup 123}I-IMP (37 MBq) was injected at 50 min post-injection. Rats were sacrificed 10 min after the injection of {sup 123}I-IMP. In the subacute phase study, the same procedure was performed at 5 days after reperfusion. In the acute phase, the IMP uptake was significantly decreased in almost all areas of the lesioned hemisphere, an exception being the cerebellum; however, the IMZ uptake was significantly decreased only in ischaemic cores. The discrepancy between IMZ and IMP uptake was observed in the lateral neocortex and the lateral caudate putamen (CPu), which were most frequently damaged in this ischaemic model. In the subacute phase, the IMZ uptake in lesioned rats was significantly decreased only in the parietal lobe and hippocampus, though the IMP uptake was decreased in many regions of lesioned hemispheres (the frontal, parietal cortex, CPu, hippocampus and thalamus). Histopathological findings indicated that both the IMP and the IMZ uptake was markedly decreased in necrotic areas. Although the IMP uptake was significantly decreased in the ischaemic areas, the IMZ uptake was maintained in these areas. These results suggest that benzodiazepine receptor imaging is superior to regional cerebral blood flow imaging for the detection of viable cortical neurons in both the acute and subacute phases of ischaemia. (orig.)

  15. Experiment K-7-18: Effects of Spaceflight in the Muscle Adductor Longus of Rats Flown in the Soviet Biosatellite Cosmos 2044. Part 2; Quantitative Autoradiographic Analysis of Gaba (Benzodiazepine) and Muscarinic (Cholinergic) Receptors in the Forebrain of Rats Flown on Cosmos 2044

    Science.gov (United States)

    Wu, L.; Daunton, N. G.; Krasnov, I. B.; DAmelio, F.; Hyde, T. M.; Sigworth, S. K.

    1994-01-01

    Quantitative autoradiographic analysis of receptors for GABA and acetylcholine in the forebrain of rats flown on COSMOS 2044 was undertaken as part of a joint US-Soviet study to determine the effects of microgravity on the central nervous system, and in particular on the sensory and motor portions of the forebrain. Changes in binding of these receptors in tissue from animals exposed to microgravity would provide evidence for possible changes in neural processing as a result of exposure to microgravity. Tritium-labelled diazepam and Quinuclidinyl-benzilate (QNB) were used to visualize GABA (benzodiazepine) and muscarinic (cholinergic) receptors, respectively. The density of tritium-labelled radioligands bound to various regions in the forebrain of both flight and control animals were measured from autoradiograms. Data from rats flown in space and from ground-based control animals that were not exposed to microgravity were compared.

  16. Benzodiazepines and Pregnancy

    Science.gov (United States)

    Benzodiazepines and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of having ... risk. This sheet talks about whether exposure to benzodiazepines may increase the risk for birth defects over ...

  17. Flumazenil, a Benzodiazepine Receptor Anatagonist, in the Reversal of Conscious Sedation following Gastroscopy. A Placebo Controlled, Dose Finding Study

    Directory of Open Access Journals (Sweden)

    Lloyd Sutherland

    1991-01-01

    Full Text Available Tim double-blind, placebo controlled, study assessed the efficacy and safety of flumazenil, a benzodiazepine antagonist, in reversing diazepam-induced sedation in 60 patients undergoing endoscopy. Patients were randomly assigned to one of six treatment groups (placebo, 5, 10, 15, 20 or 25 μg/kg flumazenil. Patient psychomotor function was determined using four standard assessments – Trieger, digit substitution, track tracing and cancellation tests. Flumazenil was well tolerated by all patients. All doses of Flumazenil were superior to placebo in reversing sedation. No significant differences were detected between the various treatment groups. Forty-five minutes after the flumazenil infusion, there were no differences between flumazenil- and placebo-treated patients in psychomotor function. Flumazenil is a safe, effective medication which reverses diazepam-induced conscious sedation. For most patients 0.5 mg given intravenously will reverse sedation.

  18. [Suicidal poisoning with benzodiazepines].

    Science.gov (United States)

    Chodorowski, Z; Sein Anand, J

    1997-01-01

    In the period from 1987 to 1996, 103 patients with suicidal benzodiazepines poisoning were treated, including 62 women and 41 men from 16 to 79 (mean 34) years old. 23 persons were poisoned only by benzodiazepines, in 80 remaining cases intoxications were mixed eg. including benzodiazepines and alcohol, tricyclic antidepressants, barbiturates, opioids, phenothiazines. The main causes of suicides were mainly depression, drug addiction and alcoholism. Nobody died in the benzodiazepines group, while mortality rate in the group of mixed poisoning was 4%. Prescribing benzodiazepines by physicians was quite often not justified and facilitated, among others, accumulation of the dose sufficient for suicide attempt. Flumazenil was efficient for leading out from coma in 86% of cases with poisoning only by benzodiazepines and 13% of cases with mixed intoxications mainly containing benzodiazepines and alcohol or carbamazepine.

  19. Further evidence for differences between non-selective and BZ-1 (omega 1) selective, benzodiazepine receptor ligands in murine models of "state" and "trait" anxiety.

    Science.gov (United States)

    Griebel, G; Sanger, D J; Perrault, G

    1996-01-01

    -1 (omega 1) receptor subtype cannot be considered as the primary target mediating the anxiolytic action of drugs interacting with the GABAA benzodiazepine receptor complex.

  20. Benzodiazepines do not potentiate GABA responses in neonatal hippocampal neurons.

    Science.gov (United States)

    Rovira, C; Ben-Ari, Y

    1991-09-16

    Benzodiazepines (midazolam; flunitrazepam) and pentobarbital increase the response to exogenous gamma-aminobutyric acid (GABA) in adult hippocampal cells. We report in this paper that in contrast pentobarbital but not benzodiazepine potentiate the effects of exogenous (GABA) in neurons recorded from slices of less than two weeks old. This finding suggests that the functional association of benzodiazepine and GABAA receptors is changed during early postnatal life.

  1. Tissue-specific alterations of binding sites for peripheral-type benzodiazepine receptor ligand [3H]PK11195 in rats following portacaval anastomosis.

    Science.gov (United States)

    Rao, V L; Audet, R; Therrien, G; Butterworth, R F

    1994-05-01

    Kinetics of binding of [3H]PK11195, an antagonist ligand with high selectivity for the peripheral-type (mitochondrial) benzodiazepine receptor (PTBR), was studied in homogenates of cerebral cortex, kidney, heart, and testis of portacaval shunted rats and sham-operated controls. Portacaval anastomosis resulted in a significant two- to threefold increase in the number of [3H]PK11195 binding sites in cerebral cortex and kidney. A reduction in the number of [3H]PK11195 binding sites was observed in testis preparations, while the number of binding sites in the heart remained unaltered. These differences in the response of PTBRs to portacaval anastomosis, in different organs suggest that the physiological function of these receptors and the factors regulating them are modulated by distinct mechanisms. The finding of increased densities of [3H]PK11195 binding sites in brain and kidney following portacaval anastomosis parallels the cellular hypertrophy in these tissues and, together with previous observations of similar increases of these binding sites in brain and kidney in congenital hyperammonemia, suggest a pathophysiologic role for ammonia in these changes. In contrast, the significant loss of [3H]PK11195 binding sites in testicular preparations following portacaval anastomosis together with the known effects of steroid hormones on these sites suggests a role for PTBRs in the pathogenesis of testicular atrophy in chronic liver disease.

  2. The Anticonvulsant Activity of a Flavonoid-Rich Extract from Orange Juice Involves both NMDA and GABA-Benzodiazepine Receptor Complexes

    Directory of Open Access Journals (Sweden)

    Rita Citraro

    2016-09-01

    Full Text Available The usage of dietary supplements and other natural products to treat neurological diseases has been growing over time, and accumulating evidence suggests that flavonoids possess anticonvulsant properties. The aim of this study was to examine the effects of a flavonoid-rich extract from orange juice (OJe in some rodent models of epilepsy and to explore its possible mechanism of action. The genetically audiogenic seizures (AGS-susceptible DBA/2 mouse, the pentylenetetrazole (PTZ-induced seizures in ICR-CD1 mice and the WAG/Rij rat as a genetic model of absence epilepsy with comorbidity of depression were used. Our results demonstrate that OJe was able to exert anticonvulsant effects on AGS-sensible DBA/2 mice and to inhibit PTZ-induced tonic seizures, increasing their latency. Conversely, it did not have anti-absence effects on WAG/Rij rats. Our experimental findings suggest that the anti-convulsant effects of OJe are likely mediated by both an inhibition of NMDA receptors at the glycine-binding site and an agonistic activity on benzodiazepine-binding site at GABAA receptors. This study provides evidences for the antiepileptic activity of OJe, and its results could be used as scientific basis for further researches aimed to develop novel complementary therapy for the treatment of epilepsy in a context of a multitarget pharmacological strategy.

  3. 5-HT1A and benzodiazepine receptors in the basolateral amygdala modulate anxiety in the social interaction test, but not in the elevated plus-maze.

    Science.gov (United States)

    Gonzalez, L E; Andrews, N; File, S E

    1996-09-01

    In order to investigate the role of the 5-HT1A receptors of the amygdala in modulating anxiety, rats were implanted with bilateral cannulae aimed at the basolateral nucleus of the amygdala complex and infused with either artificial cerebrospinal fluid (aCSF) or the selective 5-HT1A receptor agonist 8-OH-DPAT (50-200 ng) and tested in two animal models of anxiety. In the elevated plus-maze test, no significant effects were detected in this dose range. In contrast, 8-OH-DPAT caused an overall reduction in levels of social investigation, thus indicating anxiogenic actions in the social interaction test. At 50 ng, 8-OH-DPAT had a selective action on anxiety, while at 200 ng there was a concomitant reduction in locomotor activity and, in some animals, signs of the 5-HT1A syndrome. Evidence that the anxiogenic effect of 8-OH-DPAT (50 ng) was due to activation of 5-HT1A receptors came from the finding that (-)-tertatolol, a 5-HT1A receptor antagonist, reversed this effect at a dose (1.5 micrograms) which was silent when given alone. The benzodiazepine receptor agonist, midazolam (1 and 2 micrograms) was bilaterally administered into the basolateral nucleus of the amygdala and evoked clear-cut anxiolytic effects in the social interaction test. These data indicate that the agonist activation of post-synaptic 5-HT1A receptors in the basolateral nucleus of the amygdala may produce anxiogenic effects, while agonist activation of BDZ receptors in the same areas evokes anxiolytic effects. Our results from the social interaction test are similar to those previously reported from tests of anxiety using punished paradigms, but contrast with those found in the elevated plus-maze. Thus, it is concluded that either the two tests have different sensitivities to midazolam and 8-OH-DPAT or more intriguingly, the tests are evoking fundamentally different states of anxiety, with that evoked by the plus-maze being mediated via brain areas or receptors different from those studied here.

  4. The history of benzodiazepines.

    Science.gov (United States)

    Wick, Jeannette Y

    2013-09-01

    After more than 50 years of experience with benzodiazepines, the American health care system has a love-hate relationship with them. In 1955, Hoffmann-La Roche chemist Leo Sternbach serendipitously identified the first benzodiazepine, chlordiazepoxide (Librium). By 1960, Hoffmann-La Roche marketed it as Librium, and it pursued molecular modifications for enhanced activity. Valium (diazepam) followed in 1963. Hoffmann-La Roche's competitors also began looking for analogues. Initially, benzodiazepines appeared to be less toxic and less likely to cause dependence than older drugs. A specific improvement was their lack of respiratory depression, a safety concern with barbiturates. Medical professionals greeted benzodiazepines enthusiastically at first, skyrocketing their popularity and patient demand. In the mid-to-late 1970s, benzodiazepines topped all "most frequently prescribed" lists. It took 15 years for researchers to associate benzodiazepines and their effect on gamma-aminobutyric acid as a mechanism of action. By the 1980s, clinicians' earlier enthusiasm and propensity to prescribe created a new concern: the specter of abuse and dependence. As information about benzodiazepines, both raising and damning, accumulated, medical leaders and legislators began to take action. The result: individual benzodiazepines and the entire class began to appear on guidelines and in legislation giving guidance on their use. Concurrently, clinicians began to raise concerns about benzodiazepine use by elderly patients, indicating that elders'lesser therapeutic response and heightened sensitivity to side effects demanded prescriber caution. The benzodiazepine story continues to evolve and includes modern-day issues and concerns beyond those ever anticipated.

  5. Development of a multiplex non-radioactive receptor assay : the benzodiazepine receptor, the serotonin transporter and the beta-adrenergic receptor

    NARCIS (Netherlands)

    de Jong, Lutea A. A.; Jeronimus-Stratingh, C. Margot; Cremers, Thomas I. F. H.

    2007-01-01

    Binding assays still form a fundamental part of modem drug development. Receptor binding assays are mostly based on radioactivity because of their speed, ease of use and reproducibility. Disadvantages, such as health hazards and production of radioactive waste, have prompted the development of non-r

  6. Neural bases for addictive properties of benzodiazepines.

    Science.gov (United States)

    Tan, Kelly R; Brown, Matthew; Labouèbe, Gwenaël; Yvon, Cédric; Creton, Cyril; Fritschy, Jean-Marc; Rudolph, Uwe; Lüscher, Christian

    2010-02-11

    Benzodiazepines are widely used in clinics and for recreational purposes, but will lead to addiction in vulnerable individuals. Addictive drugs increase the levels of dopamine and also trigger long-lasting synaptic adaptations in the mesolimbic reward system that ultimately may induce the pathological behaviour. The neural basis for the addictive nature of benzodiazepines, however, remains elusive. Here we show that benzodiazepines increase firing of dopamine neurons of the ventral tegmental area through the positive modulation of GABA(A) (gamma-aminobutyric acid type A) receptors in nearby interneurons. Such disinhibition, which relies on alpha1-containing GABA(A) receptors expressed in these cells, triggers drug-evoked synaptic plasticity in excitatory afferents onto dopamine neurons and underlies drug reinforcement. Taken together, our data provide evidence that benzodiazepines share defining pharmacological features of addictive drugs through cell-type-specific expression of alpha1-containing GABA(A) receptors in the ventral tegmental area. The data also indicate that subunit-selective benzodiazepines sparing alpha1 may be devoid of addiction liability.

  7. Radiosynthesis and in vivo evaluation of N-[{sup 11}C]methylated imidazopyridineacetamides as PET tracers for peripheral benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Sekimata, Katsuhiko [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan); Hatano, Kentaro [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan)], E-mail: hatanok@nils.go.jp; Ogawa, Mikako [Photon Medical Research Center, Hamamatsu University School of Medicine, Shizuoka 431-3192 Japan (Japan); Abe, Junichiro [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan); Magata, Yasuhiro [Photon Medical Research Center, Hamamatsu University School of Medicine, Shizuoka 431-3192 Japan (Japan); Biggio, Giovanni; Serra, Mariangela [Department of Experimental Biology, University of Cagliari, Cagliari 09100 (Italy); Laquintana, Valentino; Denora, Nunzio; Latrofa, Andrea; Trapani, Giuseppe; Liso, Gaetano [Pharmaco-Chemistry Department, University of Bari, Bari 70125 (Italy); Ito, Kengo [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan)

    2008-04-15

    Imidazopyridineacetoamide 5-8, a series of novel and potentially selective peripheral benzodiazepine receptor (PBR) ligands with affinities comparable to those of known PBR ligands, was investigated. Radiosyntheses of [{sup 11}C]5, 6, 7 or 8 was accomplished by N-methylation of the corresponding desmethyl precursors with [{sup 11}C]methyl iodide in the presence of NaH in dimethylformamide (DMF), resulting in 25% to 77% radiochemical yield and specific activitiy of 20 to 150 MBq/nmol. Each of the labeled compounds was injected in ddY mice, and the radioactivity and weight of dissected peripheral organs and brain regions were measured. Organ distribution of [{sup 11}C]7 was consistent with the known PBR distribution. Moreover, [{sup 11}C]7 showed the best combination of brain uptake and PBR binding, leading to its high retention in the olfactory bulb and cerebellum, areas where PBR density is high in mouse brain. Coinjection of PK11195 or unlabeled 7 significantly reduced the brain uptake of [{sup 11}C]7. These results suggest that [{sup 11}C]7 could be a useful radioligand for positron emission tomography imaging of PBRs.

  8. Different sensitivities to competitive inhibition of benzodiazepine receptor binding of {sup 11}C-iomazenil and {sup 11}C-flumazenil in rhesus monkey brain

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Osamu; Hosoi, Rie; Kobayashi, Kaoru [Osaka Univ., Suita (Japan). Medical School; Itoh, Takashi; Gee, A.; Suzuki, Kazutoshi

    2001-04-01

    The in vivo binding kinetics of {sup 11}C-iomazenil were compared with those of {sup 11}C-flumazenil binding in rhesus monkey brain. The monkey was anesthetized with ketamine and intravenously injected with either {sup 11}C-iomazenil or {sup 11}C-flumazenil in combination with the coadministration of different doses of non-radioactive flumazenil (0, 5 and 20 {mu}g/kg). The regional distribution of {sup 11}C-iomazenil in the brain was similar to that of {sup 11}C-flumazenil, but the sensitivity of {sup 11}C-iomazenil binding to competitive inhibition by non-radioactive flumazenil was much less than that of {sup 11}C-flumazenil binding. A significant reduction in {sup 11}C-flumazenil binding in the cerebral cortex was observed with 20 {mu}g/kg of flumazenil, whereas a relatively smaller inhibition of {sup 11}C-iomazenil binding in the same region was observed with the same dose of flumazenil. These results suggest that {sup 11}C-flumazenil may be a superior radiotracer for estimating benzodiazepine receptor occupancy in the intact brain. (author)

  9. Improved synthesis of the peripheral benzodiazepine receptor ligand [{sup 11}C]DPA-713 using [{sup 11}C]methyl triflate

    Energy Technology Data Exchange (ETDEWEB)

    Thominiaux, C. [Service Hospitalier Frederic Joliot, Departement de Recherche Medicale, CEA/DSV, 4 place du General Leclerc, F-91401 Orsay (France); Dolle, F. [Service Hospitalier Frederic Joliot, Departement de Recherche Medicale, CEA/DSV, 4 place du General Leclerc, F-91401 Orsay (France); James, M.L. [Department of Pharmacology, University of Sydney, NSW 2006 (Australia)] (and others)

    2006-05-15

    Recently, the pyrazolopyrimidine, [{sup 11}C] N,N-Diethyl-2-[2-(4-methoxyphenyl)-5,7-dimethylpyrazolo [1,5-a]pyrimidin-3-yl]acetamide (DPA-713) has been reported as a new promising marker for the study of peripheral benzodiazepine receptors with positron emission tomography. In the present study, DPA-713 has been labelled from the corresponding nor-analogue using [{sup 11}C]methyl triflate (CH{sub 3}OTf). Conditions for HPLC were also modified to include physiological saline (aq. 0.9% NaCl)/ethanol:60/40 as mobile phase making it suitable for injection. The total time of radiosynthesis, including HPLC purification, was 18-20 min. This reported synthesis of [{sup 11}C]DPA-713, using [{sup 11}C]CH{sub 3}OTf, resulted in an improved radiochemical yield (30-38%) compared to [{sup 11}C]methyl iodide (CH{sub 3}I) (9) with a simpler purification method. This ultimately enhances the potential of [{sup 11}C]DPA-713 for further pharmacological and clinical evaluation. These improvements make this radioligand more suitable for automated synthesis which is of benefit where multi-dose preparations and repeated syntheses of radioligand are required.

  10. Rapid and efficient radiosynthesis of [{sup 123}I]I-PK11195, a single photon emission computed tomography tracer for peripheral benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Pimlott, Sally L. [Department of Clinical Physics, West of Scotland Radionuclide Dispensary, Western Infirmary, G11 6NT Glasgow (United Kingdom)], E-mail: s.pimlott@clinmed.gla.ac.uk; Stevenson, Louise [Department of Chemistry, WestCHEM, University of Glasgow, G12 8QQ Glasgow (United Kingdom); Wyper, David J. [Institute of Neurological Sciences, Southern General Hospital, G51 4TF Glasgow (United Kingdom); Sutherland, Andrew [Department of Chemistry, WestCHEM, University of Glasgow, G12 8QQ Glasgow (United Kingdom)

    2008-07-15

    Introduction: [{sup 123}I]I-PK11195 is a high-affinity single photon emission computed tomography radiotracer for peripheral benzodiazepine receptors that has previously been used to measure activated microglia and to assess neuroinflammation in the living human brain. This study investigates the radiosynthesis of [{sup 123}I]I-PK11195 in order to develop a rapid and efficient method that obtains [{sup 123}I]I-PK11195 with a high specific activity for in vivo animal and human imaging studies. Methods: The synthesis of [{sup 123}I]I-PK11195 was evaluated using a solid-state interhalogen exchange method and an electrophilic iododestannylation method, where bromine and trimethylstannyl derivatives were used as precursors, respectively. In the electrophilic iododestannylation method, the oxidants peracetic acid and chloramine-T were both investigated. Results: Electrophilic iododestannylation produced [{sup 123}I]I-PK11195 with a higher isolated radiochemical yield and a higher specific activity than achievable using the halogen exchange method investigated. Using chloramine-T as oxidant provided a rapid and efficient method of choice for the synthesis of [{sup 123}I]I-PK11195. Conclusions: [{sup 123}I]I-PK11195 has been successfully synthesized via a rapid and efficient electrophilic iododestannylation method, producing [{sup 123}I]I-PK11195 with a higher isolated radiochemical yield and a higher specific activity than previously achieved.

  11. Increased binding of peripheral benzodiazepine receptor in mild cognitive impairment-dementia converters measured by positron emission tomography with [¹¹C]DAA1106.

    Science.gov (United States)

    Yasuno, Fumihiko; Kosaka, Jun; Ota, Miho; Higuchi, Makoto; Ito, Hiroshi; Fujimura, Yota; Nozaki, Shoko; Takahashi, Sho; Mizukami, Katsuyoshi; Asada, Takashi; Suhara, Tetsuya

    2012-07-30

    Subjects with mild cognitive impairment (MCI) have "prodromal or incipient" dementia with neuropathological changes. Peripheral benzodiazepine receptor (PBR) binding was shown to reflect activated microglia, one of the predictive biomarkers of conversion to dementia. We sought to evaluate PBR binding in MCI subjects using positron emission tomography (PET). PET scans with [¹¹C]DAA1106, a potent and selective ligand for PBR, were performed on seven MCI subjects, 10 patients with Alzheimer's disease (AD) and 10 age-matched control subjects. PBR binding in the regions of interest was quantified by binding potential (BP). Five MCI subjects were clinically followed for 5 years after their initial PET scans. [¹¹C]DAA1106 binding to PBR was significantly increased in widespread areas in MCI subjects when compared to healthy controls. We found no significant difference in BP between MCI and AD patients. MCI subjects with [¹¹C]DAA1106 binding values higher than the control mean +0.5 standard deviation (S.D.) developed dementia within 5 years. Our finding of higher DAA binding in MCI subjects indicated that microglial activation may occur before the onset of dementia. In vivo detection of microglial activation may provide useful prognostic information with respect to stratifying MCI subjects at increased risk of dementia.

  12. Imaging of peripheral-type benzodiazepine receptor in tumor: carbon ion irradiation reduced the uptake of a positron emission tomography ligand [11C]DAC in tumor.

    Science.gov (United States)

    Yamasaki, Tomoteru; Koike, Sachiko; Hatori, Akiko; Yanamoto, Kazuhiko; Kawamura, Kazunori; Yui, Joji; Kumata, Katsushi; Ando, Koichi; Zhang, Ming-Rong

    2010-01-01

    We aimed to determine the effect of carbon ion irradiation on the uptake of N-benzyl-N-11C-methyl-2-(7-methyl-8-oxo-2-phenyl-7,8-dihydro-9H-purin-9-yl)acetamide ([(11)C]DAC), a positron emission tomography (PET) ligand for the peripheral-type benzodiazepine receptor (PBR), in tumor cells and tumor-bearing mice. Spontaneous murine fibrosarcoma (NFSa) cells were implanted into the right hind legs of syngeneic C3H male mice. Conditioning irradiation with 290 MeV/u carbon ions was delivered to the 7- to 8-mm tumors In vitro uptake of [(11)C]DAC was measured in single NFSa cells isolated from NFSa-bearing mice after irradiation. In vivo biodistribution of [(11)C]DAC in NFSa-bearing mice was determined by small animal PET scanning and dissection. In vitro autoradiography was performed using tumor sections prepared from mice after PET scanning. In vitro and in vivo uptake of [(11)C]DAC in single NFSa cells and NFSa-bearing mice was significantly reduced by carbon ion irradiation. The decrease in [(11)C]DAC uptake in the tumor sections was mainly due to the change in PBR expression. In conclusion, [(11)C]DAC PET responded to the change in PBR expression in tumors caused by carbon ion irradiation in this study. Thus, [(11)C]DAC is a promising predictor for evaluating the effect of carbon ion radiotherapy.

  13. Contextual fear conditioning and baseline startle responses in the rat fear-potentiated startle test: a comparison of benzodiazepine/gamma-aminobutyric acid-A receptor agonists.

    Science.gov (United States)

    Guscott, M R; Cook, G P; Bristow, L J

    2000-09-01

    In the rat, fear-potentiated startle (FPS) test animals are first trained to associate brief light presentations with a mild electric footshock and then tested for startle responses to acoustic stimuli, delivered either in darkness (i.e. baseline startle) or after the conditioning stimulus. Following light presentation the magnitude of the startle response is markedly increased, and the test is commonly used to distinguish anxiolytic drug effects (i.e. a reduction in FPS) from non-specific effects such as sedation/muscle relaxation. However, recent studies suggest that the environment in which the animal is trained may also contribute towards the acquisition of a conditioned fear response (i.e. contextual fear conditioning) and that this may elevate startle responses recorded in the dark. In the present study, therefore, we have compared the benzodiazepine/gamma-aminobutyric acid-A receptor agonist chlordiazepoxide with the partial agonists FG 8205 and bretazenil, which are known to have a reduced propensity to produce sedation/myorelaxation, using two different FPS procedures: (i) conditioning and testing in stabilimeter chambers, and (ii) conditioning and testing in different environments. The results show that FPS can be demonstrated in both procedures and that treatment with chlordiazepoxide, FG 8205 or bretazenil dose-dependently attenuates the response. However, animals conditioned and tested in stabilimeter chambers also showed a significant increase in dark-startle amplitudes compared with non-shocked rats, suggesting that this response was elevated by contextual fear conditioning. Furthermore, despite clear differences in side-effect liabilities, FG 8205 and bretazenil significantly reduced dark-startle responses, suggesting that this measure is also sensitive to the anxiolytic effects of benzodiazepines. In contrast, when animals were conditioned and tested in different environments, dark-startle responses were not significantly different from those

  14. Long-term studies on anticonvulsant tolerance and withdrawal characteristics of benzodiazepine receptor ligands in different seizure models in mice. I. Comparison of diazepam, clonazepam, clobazam and abecarnil.

    Science.gov (United States)

    Löscher, W; Rundfeldt, C; Hönack, D; Ebert, U

    1996-11-01

    We have reported recently that the seizure model and experimental protocol may markedly influence anticonvulsant tolerance and withdrawal characteristics of benzodiazepine (BDZ) receptor ligands so that predictions on tolerance and dependence liability of novel drugs should be based on a battery of chronic experiments. In the present study, we compared BDZ receptor ligands with different intrinsic efficacy and/or gamma-aminobutyric acidA/BDZ receptor subtype selectivity in two seizure models, by using different experimental approaches to assess the tolerance and dependence liability. In one approach, mice were chronically treated with either diazepam, clonazepam, clobazam or the novel anxiolytic and anticonvulsant beta-carboline derivative abecarnil for 4 weeks, at doses which were about equipotent to increase the threshold for myoclonic seizures induced by pentylenetetrazole. Anticonvulsant activity was determined several times during the period of chronic treatment as well as up to 2 weeks after termination of treatment in the same group of animals per drug. The threshold for electroshock-induced tonic seizures was used as a second seizure model in separate groups of mice. In another approach, drug treatment protocols were the same but the seizures were induced only twice during the 4-week period of treatment to reduce the number of trials which could lead to "learned" tolerance. In additional groups of mice, the seizure thresholds were only determined before and after the period of treatment to assess whether repeated seizure induction during the chronic treatment affects the development of dependence. All four drugs lost anticonvulsant activity during the chronic treatment in the different models and experimental approaches, without indication for a significant involvement of learned tolerance. However, marked protocol-related differences were seen with respect to withdrawal symptoms, i.e., measures of physical dependence-inducing properties of the different

  15. The 18 kDa translocator protein (peripheral benzodiazepine receptor) expression in the bone of normal, osteoprotegerin or low calcium diet treated mice.

    Science.gov (United States)

    Kam, Winnie Wai-Ying; Meikle, Steven R; Zhou, Hong; Zheng, Yu; Blair, Julie M; Seibel, Marcus; Dunstan, Colin R; Banati, Richard B

    2012-01-01

    The presence of the translocator protein (TSPO), previously named as the mitochondrial or peripheral benzodiazepine receptor, in bone cells was studied in vitro and in situ using RT-qPCR, and receptor autoradiography using the selective TSPO ligand PK11195.In vitro, the TSPO is highly expressed in osteoblastic and osteoclastic cells.In situ, constitutive expression of TSPO is found in bone marrow and trabecular bone, e.g., spongiosa. Mice with a reduction of bone turnover induced by a 4-day treatment of osteoprotegerin reduces [(3)H]PK11195 binding in the spongiosa (320±128 Bq x mg(-1), 499±106 Bq x mg(-1) in saline-treated controls). In contrast, mice with an increase in bone turnover caused by a 4-day low calcium diet increases [(3)H]PK11195 binding in the spongiosa (615±90 Bq x mg(-1)). Further, our study includes technical feasibility data on [(18)F]fluoride microPET imaging of rodent bone with altered turnover. Despite [(18)F]fluoride having high uptake, the in vivo signal differences were small. Using a phantom model, we describe the spillover effect and partial volume loss that affect the quantitative microPET imaging of the small bone structures in experimental mouse models. In summary, we demonstrate the expression of TSPO in small rodent bone tissues, including osteoblasts and osteoclasts. A trend increase in TSPO expression was observed in the spongiosa from low to high bone turnover conditions. However, despite the potential utility of TSPO expression as an in vivo biomarker of bone turnover in experimental rodent models, our small animal PET imaging data using [(18)F]fluoride show that even under the condition of a good biological signal-to-noise ratio and high tracer uptake, the currently achievable instrument sensitivity and spatial resolution is unlikely to be sufficient to detect subtle differences in small structures, such as mouse bone.

  16. The 18 kDa translocator protein (peripheral benzodiazepine receptor expression in the bone of normal, osteoprotegerin or low calcium diet treated mice.

    Directory of Open Access Journals (Sweden)

    Winnie Wai-Ying Kam

    Full Text Available The presence of the translocator protein (TSPO, previously named as the mitochondrial or peripheral benzodiazepine receptor, in bone cells was studied in vitro and in situ using RT-qPCR, and receptor autoradiography using the selective TSPO ligand PK11195.In vitro, the TSPO is highly expressed in osteoblastic and osteoclastic cells.In situ, constitutive expression of TSPO is found in bone marrow and trabecular bone, e.g., spongiosa. Mice with a reduction of bone turnover induced by a 4-day treatment of osteoprotegerin reduces [(3H]PK11195 binding in the spongiosa (320±128 Bq x mg(-1, 499±106 Bq x mg(-1 in saline-treated controls. In contrast, mice with an increase in bone turnover caused by a 4-day low calcium diet increases [(3H]PK11195 binding in the spongiosa (615±90 Bq x mg(-1. Further, our study includes technical feasibility data on [(18F]fluoride microPET imaging of rodent bone with altered turnover. Despite [(18F]fluoride having high uptake, the in vivo signal differences were small. Using a phantom model, we describe the spillover effect and partial volume loss that affect the quantitative microPET imaging of the small bone structures in experimental mouse models. In summary, we demonstrate the expression of TSPO in small rodent bone tissues, including osteoblasts and osteoclasts. A trend increase in TSPO expression was observed in the spongiosa from low to high bone turnover conditions. However, despite the potential utility of TSPO expression as an in vivo biomarker of bone turnover in experimental rodent models, our small animal PET imaging data using [(18F]fluoride show that even under the condition of a good biological signal-to-noise ratio and high tracer uptake, the currently achievable instrument sensitivity and spatial resolution is unlikely to be sufficient to detect subtle differences in small structures, such as mouse bone.

  17. Benzodiazepine poisoning in elderly.

    Science.gov (United States)

    Vukcević, Natasa Perković; Ercegović, Gordana Vuković; Segrt, Zoran; Djordjević, Snezana; Stosić, Jasmina Jović

    2016-03-01

    Benzodiazepines are among the most frequently ingested drugs in self-poisonings. Elderly may be at greater risk compared with younger individuals due to impaired metabolism and increased sensitivity to benzodiazepines. The aim of this study was to assess toxicity of benzodiazepines in elderly attempted suicide. A retrospective study of consecutive presentations to hospital after self-poisoning with benzodiazepines was done. Collected data consisted of patient's characteristics (age, gender), benzodiazepine ingested with its blood concentrations at admission, clinical findings including vital signs and Glasgow coma score, routine blood chemistry, complications of poisoning, details of management, length of hospital stay and outcome. According the age, patients are classified as young (15-40-year old), middle aged (41-65-year old) and elderly (older than 65). During a 2-year observational period 387 patients were admitted because of pure benzodiazepine poisoning. The most frequently ingested drug was bromazepam, the second was diazepam. The incidence of coma was significantly higher, and the length of hospital stay significantly longer in elderly. Respiratory failure and aspiration pneumonia occurred more frequently in old age. Also, flumazenil was more frequently required in the group of elderly patients. Massive benzodiazepines overdose in elderly may be associated with a significant morbidity, including deep coma with aspiration pneumonia, respiratory failure, and even death. Flumazenil is indicated more often to reduce CNS depression and prevent complications of prolonged unconsciousness, but supportive treatment and proper airway management of comatose patients is the mainstay of the treatment of acute benzodiazepine poisoning.

  18. Effects of 2,3-benzodiazepine AMPA receptor antagonists on dopamine turnover in the striatum of rats with experimental parkinsonism.

    Science.gov (United States)

    Megyeri, Katalin; Marko, Bernadett; Sziray, Nora; Gacsalyi, Istvan; Juranyi, Zsolt; Levay, Gyorgy; Harsing, Laszlo G

    2007-03-15

    Although levodopa is the current "gold standard" for treatment of Parkinson's disease, there has been disputation on whether AMPA receptor antagonists can be used as adjuvant therapy to improve the effects of levodopa. Systemic administration of levodopa, the precursor of dopamine, increases brain dopamine turnover rate and this elevated turnover is believed to be essential for successful treatment of Parkinson's disease. However, long-term treatment of patients with levodopa often leads to development of dyskinesia. Therefore, drugs that feature potentiation of dopamine turnover rate and are able to reduce daily levodopa dosages might be used as adjuvant in the treatment of patients suffering from Parkinson's disease. To investigate such combined treatment, we have examined the effects of two non-competitive AMPA receptor antagonists, GYKI-52466 and GYKI-53405, alone or in combination with levodopa on dopamine turnover rate in 6-hydroxydopamine-lesioned striatum of the rat. We found here that repeated administration of levodopa, added with the peripheral DOPA decarboxylase inhibitor carbidopa, increased dopamine turnover rate after lesioning the striatum with 6-hydroxydopamine. Moreover, combination of levodopa with GYKI-52466 or GYKI-53405 further increased dopamine turnover enhanced by levodopa administration while the AMPA receptor antagonists by themselves failed to influence striatal dopamine turnover. We concluded from the present data that potentiation observed between levodopa and AMPA receptor antagonists may reflect levodopa-sparing effects in clinical treatment indicating the therapeutic potential of such combination in the management of Parkinson's disease.

  19. Triton X-100 inhibits agonist-induced currents and suppresses benzodiazepine modulation of GABA(A) receptors in Xenopus oocytes

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Ebert, Bjarke; Klaerke, Dan

    2009-01-01

    Changes in lipid bilayer elastic properties have been proposed to underlie the modulation of voltage-gated Na(+) and L-type Ca(2+) channels and GABA(A) receptors by amphiphiles. The amphiphile Triton X-100 increases the elasticity of lipid bilayers at micromolar concentrations, assessed from its ...

  20. Benzodiazepine dependence and its treatment with low dose flumazenil.

    Science.gov (United States)

    Hood, Sean David; Norman, Amanda; Hince, Dana Adelle; Melichar, Jan Krzysztof; Hulse, Gary Kenneth

    2014-02-01

    Globally benzodiazepines remain one of the most prescribed medication groups, especially in the primary care setting. With such high levels of prescribing it is not surprising that benzodiazepine dependence is common, cutting across all socioeconomic levels. Despite recognition of the potential for the development of iatrogenic dependence and the lack of any effective treatment, benzodiazepines continue to be widely prescribed in general practice. Conventional dependence management, benzodiazepine tapering, is commonly a protracted process over several weeks or months. It is often associated with significant withdrawal symptoms and craving leading to patient drop out and return to use. Accordingly, there is a worldwide need to find effective pharmacotherapeutic interventions for benzodiazepine dependence. One drug of increasing interest is the GABAA benzodiazepine receptor antagonist/partial agonist, flumazenil. Multiple bolus intravenous infusions of low dose flumazenil used either with or without benzodiazepine tapering can reduce withdrawal sequelae, and/or longer term symptoms in the months following withdrawal. Preliminary data suggest that continuous intravenous or subcutaneous flumazenil infusion for 4 days significantly reduces acute benzodiazepine withdrawal sequelae. The subcutaneous infusion was shown to be tissue compatible so the development of a longer acting (i.e. several weeks) depot flumazenil formulation has been explored. This could be capable of managing both acute and longer term benzodiazepine withdrawal sequelae. Preliminary in vitro water bath and in vivo biocompatibility data in sheep show that such an implant is feasible and so is likely to be used in clinical trials in the near future.

  1. Mechanism and site of inhibition of AMPA receptors: substitution of one and two methyl groups at the 4-aminophenyl ring of 2,3-benzodiazepine and implications in the "E" site.

    Science.gov (United States)

    Wang, Congzhou; Wu, Andrew; Shen, Yu-Chuan; Ettari, Roberta; Grasso, Silvana; Niu, Li

    2015-08-19

    2,3-Benzodiazepines are a well-known group of compounds for their potential antagonism against AMPA receptors. It has been previously reported that the inhibitory effect of 2,3-benzodiazepine derivatives with a 7,8-ethylenedioxy moiety can be enhanced by simply adding a chlorine atom at position 3 of the 4-aminophenyl ring. Here we report that adding a methyl group at position 3 on the 4-aminophenyl ring, termed as BDZ-11-7, can similarly enhance the inhibitory activity, as compared with the unsubstituted one or BDZ-11-2. Our kinetic studies have shown that BDZ-11-7 is a noncompetitive antagonist of GluA2Q homomeric receptors and prefers to inhibit the closed-channel state. However, adding another methyl group at position 5 on the 4-aminophenyl ring, termed as BDZ-11-6, fails to yield extra inhibition on GluA2Q receptors. Instead, BDZ-11-6 exhibits a diminished inhibition of GluA2Q. Site interaction test indicates the two compounds, BDZ-11-6 and BDZ-11-7, bind to the same site on GluA2Q, which is also the binding site for their prototype, BDZ-11-2. Based on the results from this and our earlier studies, we propose that the binding site that accommodates the 4-aminophenyl ring must contain two interactive points, with one preferring polar groups like chlorine and the other preferring nonpolar groups such as a methyl group. Either adding a chlorine or a methyl group may enhance the inhibitory activity of 2,3-benzodiazepine derivatives with a 7,8-ethylenedioxy moiety. Adding any two of the same group on positions 3 and 5 of the 4-aminophenyl ring, however, significantly reduces the interaction between these 2,3-benzodiazepines and their binding site, because one group is always repelled by one interactive point. We predict therefore that adding a chlorine atom at position 3 and a methyl group at position 5 of the 4-aminophenyl ring of 2,3-benzodiazepine derivatives with a 7,8-ethylenedioxy moiety may produce a new compound that is more potent.

  2. Central projections of auditory receptor neurons of crickets.

    Science.gov (United States)

    Imaizumi, Kazuo; Pollack, Gerald S

    2005-12-19

    We describe the central projections of physiologically characterized auditory receptor neurons of crickets as revealed by confocal microscopy. Receptors tuned to ultrasonic frequencies (similar to those produced by echolocating, insectivorous bats), to a mid-range of frequencies, and a subset of those tuned to low, cricket-like frequencies have similar projections, terminating medially within the auditory neuropile. Quantitative analysis shows that despite the general similarity of these projections they are tonotopic, with receptors tuned to lower frequencies terminating more medially. Another subset of cricket-song-tuned receptors projects more laterally and posteriorly than the other types. Double-fills of receptors and identified interneurons show that the three medially projecting receptor types are anatomically well positioned to provide monosynaptic input to interneurons that relay auditory information to the brain and to interneurons that modify this ascending information. The more laterally and posteriorly branching receptor type may not interact directly with this ascending pathway, but is well positioned to provide direct input to an interneuron that carries auditory information to more posterior ganglia. These results suggest that information about cricket song is segregated into functionally different pathways as early as the level of receptor neurons. Ultrasound-tuned and mid-frequency tuned receptors have approximately twice as many varicosities, which are sites of transmitter release, per receptor as either anatomical type of cricket-song-tuned receptor. This may compensate in part for the numerical under-representation of these receptor types.

  3. Biodistribution and dosimetry of [{sup 123}I]iodo-Pk 11195: a potential agent for SPET imaging of the peripheral benzodiazepine receptor

    Energy Technology Data Exchange (ETDEWEB)

    Versijpt, J. [Groningen Univ. Hospital (Netherlands). Dept. of Biological Psychiatry; Div. of Nuclear Medicine, Ghent Univ. Hospital (Belgium); Dumont, F.; Vos, F. de; Slegers, G. [Dept. of Radiopharmacy, Ghent Univ. (Belgium); Thierens, H. [Dept. of Biomedical Physics and Radiation Protection, Ghent Univ. (Belgium); Jansen, H.; Dierckx, R.A. [Div. of Nuclear Medicine, Ghent Univ. Hospital (Belgium); Santens, P. [Dept. of Neurology, Ghent Univ. Hospital (Belgium); Korf, J. [Groningen Univ. Hospital (Netherlands). Dept. of Biological Psychiatry

    2000-09-01

    The highest concentrations of the peripheral benzodiazepine receptor (PBR) are found in the kidneys and heart. In addition, the PBR has been reported to reflect neuro-inflammatory damage by co-localisation with activated microglia. PK 11195 is a high-affinity ligand for the PBR. The aim of this study was to investigate in humans the biodistribution and dosimetry of [{sup 123}I]iodo-PK 11195, a potential single-photon emission tomography tracer for the PBR. Five healthy volunteers were injected with 112 MBq of [{sup 123}I]iodo-PK 11195. Sequential whole-body scans were performed up to 72 h post injection. Multiple blood samples were taken, and urine was collected to measure the fraction voided by the renal system. Decay-corrected regions of interest of the whole-body images were analysed, and geometric mean count rates were used to determine organ activity. Organ absorbed doses and effective dose were calculated using the MIRD method. [{sup 123}I]iodo-PK 11195 was rapidly cleared from the blood, mainly by the hepatobiliary system. Approximately 22% was voided in urine after 48 h. Average organ residence times were 0.74, 0.44 and 0.29 h for the liver, upper large intestine and lower large intestine, respectively. The testes received the highest dose, 109.4 {mu}Gy/MBq. All other organs investigated received doses of less than 50 {mu}Gy/MBq. The effective dose was 40.3 {mu}Sv/MBq. In conclusion, [{sup 123}I]iodo-PK 11195 is a suitable agent for the visualisation of the PBR and indirectly for the imaging of neuro-inflammatory lesions. Taking into account the radiation burden of 7.46 mSv following an administration of 185 MBq, a [{sup 123}I]iodo-PK 11195 investigation has to be considered an ICRP risk category IIb investigation. (orig.)

  4. Imaging of peripheral benzodiazepine receptor expression as biomarkers of detrimental versus beneficial glial responses in mouse models of Alzheimer's and other CNS pathologies.

    Science.gov (United States)

    Ji, Bin; Maeda, Jun; Sawada, Makoto; Ono, Maiko; Okauchi, Takashi; Inaji, Motoki; Zhang, Ming-Rong; Suzuki, Kazutoshi; Ando, Kiyoshi; Staufenbiel, Matthias; Trojanowski, John Q; Lee, Virginia M Y; Higuchi, Makoto; Suhara, Tetsuya

    2008-11-19

    We demonstrate the significance of peripheral benzodiazepine receptor (PBR) imaging in living mouse models of Alzheimer's disease (AD) as biomarkers and functional signatures of glial activation. By radiochemically and immunohistochemically analyzing murine models of the two pathological hallmarks of AD, we found that AD-like Abeta deposition is concurrent with astrocyte-dominant PBR expression, in striking contrast with nonastroglial PBR upregulation in accumulations of AD-like phosphorylated tau. Because tau-induced massive neuronal loss was distinct from the marginal neurodegeneration associated with Abeta plaques in these models, cellular localization of PBR reflected deleterious and beneficial glial reactions to tau versus Abeta pathologies, respectively. This notion was subsequently examined in models of various non-AD neuropathologies, revealing the following reactive glial dynamics underlying differential PBR upregulation: (1) PBR(-) astrogliosis uncoupled with microgliosis or coupled with PBR(+) microgliosis associated with irreversible neuronal insults; and (2) PBR(+) astrogliosis coupled with PBR(- or +/-) microgliosis associated with minimal or reversible neuronal toxicity. Intracranial transplantation of microglia also indicated that nontoxic microglia drives astroglial PBR expression. Moreover, levels of glial cell line-derived neurotrophic factor (GDNF) in astrocytes were correlated with astroglial PBR, except for increased GDNF in PBR(-) astrocytes in the model of AD-like tau pathology, thereby suggesting that PBR upregulation in astrocytes is an indicator of neurotrophic support. Together, PBR expressions in astrocytes and microglia reflect beneficial and deleterious glial reactions, respectively, in diverse neurodegenerative disorders including AD, pointing to new applications of PBR imaging for monitoring the impact of gliosis on the pathogenesis and treatment of AD.

  5. Comparison of benzodiazepine receptor and regional cerebral blood flow imagings of epileptiform foci in hippocampal kindled rabbits; A study with a double tracer autoradiography using [sup 125]I-Ro 16-0154 and [sup 99m]Tc-HMPAO

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, Kenzo (Kanazawa Univ. (Japan). School of Medicine)

    1993-10-01

    To compare the benzodiazepine (Bz) receptor imaging and regional cerebral blood flow (rCBF) imaging in the detection of epileptic foci, the distribution pattern of the Bz receptor and rCBF in hippocampal kindled rabbits was examined by a double tracer autoradiography using ethyl 7-[[sup 125]I]-5,6-dihydro-5-methyl-6-oxo-4H-imidazo [1, 5-a][1,4] benzodiazepine-3-carboxylate ([sup 125]I-Ro 16-0154) and [sup 99m]Tc-hexamethyl-propyleneamine oxime ([sup 99m]Tc-HMPAO). In visual and quantitative analyses, [sup 125]I-Ro 16-0154 accumulation in brain slices extracted after the completion of the kindling was markedly and extensively decreased in the kindled CA1 region mimicking a primary epileptic focus. [sup 125]I-Ro 16-0154 accumulation was moderately decreased in the ipsilateral temporal lobe, dentate gyrus, CA2, CA4, and bilateral CA3 regions, regarded as the propagated sites of seizure discharges. [sup 99m]Tc-HMPAO accumulation was found to be decreased in the ipsilateral CA1, frontal, temporal and dentate gyri. However, the decrease was much more slight and less extensive than that in [sup 125]I-Ro 16-0154 accumulation. These results suggest that Bz receptor imaging is much more sensitive in the detection of epileptic foci than rCBF imaging, and therefore that Bz receptor imaging is useful in clinical epilepsy. (author).

  6. [Benzodiazepines in geriatrics].

    Science.gov (United States)

    Hofmann, W

    2013-12-01

    About 10 % of community dwelling elderly people are chronically consuming benzodiazepines. This proportion rises to 30 % in nursing homes or hospitals. Particularly in older patients, this usage leads to a higher risk of adverse drug reactions. Exposure contributes to delirium and falls with subsequent femoral neck fractures. The WHO has classified the risk potential of the new z-drugs to be the same as that associated with benzodiazepines. It is recommended that benzodiazepines should be discontinued step by step under supervision of a doctor or the dosage should be reduced.

  7. Benzodiazepines: Sedation and Agitation.

    Science.gov (United States)

    Gallagher, Catherine

    2016-01-01

    Dental anxiety is common and frequently poses a barrier to necessary dental treatment. The increasing availability of conscious sedation in dental practice has made treatment much more accessible for anxious patients. At present, benzodiazepines are the most commonly used drugs in sedation practice and provide a pleasant experience for most, but not all, patients. An understanding of the mechanism of action of benzodiazepines should inform our practice and deepen our understanding of why and how sedation may fail. CPD/CLINICAL RELEVANCE: As an increasing number of dentists provide sedation for their patients an update on benzodiazepines is timely.

  8. Application of gamma-aminobutyric acid type A-benzodiazepine receptor imaging for study of neuropsychiatric disorders%γ-氨基丁酸A型-苯二氮革受体显像剂在神经系统疾病中的应用

    Institute of Scientific and Technical Information of China (English)

    鲍伟奇; 邱春; 管一晖

    2012-01-01

    γ-氨基丁酸A型-苯二氮革(GABAA-BZ)受体广泛分布于中枢神经系统,是嵌于神经细胞膜上的异质性多肽五聚体,不同的亚单位组合发挥不同的神经抑制性药理作用,如镇静催眠、抗惊厥、抗焦虑等.PET可用于活体内受体结合的研究.GABAA-BZ受体PET显像剂分为拮抗剂、激动剂、反向激动剂3类,其中以拮抗剂显像剂11C-氟马西尼最为成熟,在癫癎、焦虑症、抑郁症、植物状态、成瘾等神经精神疾病中广泛应用.%Gamma-aminobutyric acid type A-benzodiazepine receptors are heterogeneous polypeptide pentamers widely spread in the central nervous system on the neuron membrane.Different subunit combinations educe various neuro-inhibitory pharmacological effects such as sedative,hypnosis,anticonvulsion and anxiolysis.PET can be utilized to study the binding of the receptors in vivo.PET radioligands of gammaaminobutyric acid type A-benzodiazepine receptors can be classified into 3 types:antagonists,agonists and reverse agonists,of which antagonist radiotracer 11C-flumazenil is the most commonly applied in epilepsy,anxiety disorders,depression,vegetative state,addiction and other neuro-psychiatric disorders.

  9. sup 123 I-iomazenil: A quantitative study of the central benzodoazepine receptor distribution

    Energy Technology Data Exchange (ETDEWEB)

    Haldemann, R.C.; Bicik, I.; Pfeiffer, A.; Schulthess, G.K. von (Div. of Nuclear Medicine, Dept. of Medical Radiology, Univ. Hospital Zurich (Switzerland)); Wieser, H.G. (Clinic and Policlinic of Neurology, Univ. Hospital Zurich (Switzerland)); Hasler, P.H.; Schubiger, P. (Paul Scherrer Inst., Villigen (Switzerland))

    1992-06-01

    Fourteen patients with temporal lobe epilepsy, 9 patients after amygdalohippocampectomy and 3 healthy volunteers were examined with the new benzodiazepine receptor marker {sup 123}I-Iomazenil and SPECT. For comparison perfusion SPECT studies with {sup 99m}Tc-HMPAO were done and a quantitative ROI analysis of the date performed. This quantitative analysis consisted of calculation of right-to-left ratios for {sup 123}I{sup I}omazenil SPECTs, whereby values of 1 were obtained with narrow standard deviations. ROI measurements of the medial occipital, frontal and parietal cortex, the cerebellum and white matter showed a pattern of benzodiazepine receptor concentration in concordance with that previously found in PET and autoradiographic studies, if {sup 123}I-Iomazenil ROIs were normalized to the corresponding {sup 99m}Tc-HMPAO ROIs. The abnormal distribution in the temporal lobes will not be discussed in this paper. (orig.).

  10. Benzodiazepine poisoning in elderly

    Directory of Open Access Journals (Sweden)

    Perković-Vukčević Nataša

    2016-01-01

    Full Text Available Background/Aim. Benzodiazepines are among the most frequently ingested drugs in self-poisonings. Elderly may be at greater risk compared with younger individuals due to impaired metabolism and increased sensitivity to benzodiazepines. The aim of this study was to assess toxicity of benzodiazepines in elderly attempted suicide. Methods. A retrospective study of consecutive presentations to hospital after self-poisoning with benzodiazepines was done. Collected data consisted of patient's characteristics (age, gender, benzodiazepine ingested with its blood concentrations at admission, clinical findings including vital signs and Glasgow coma score, routine blood chemistry, complications of poisoning, details of management, length of hospital stay and outcome. According the age, patients are classified as young (15-40-year old, middle aged (41-65-year old and elderly (older than 65. Results. During a 2-year observational period 387 patients were admitted because of pure benzodiazepine poisoning. The most frequently ingested drug was bromazepam, the second was diazepam. The incidence of coma was significantly higher, and the length of hospital stay significantly longer in elderly. Respiratory failure and aspiration pneumonia occurred more frequently in old age. Also, flumazenil was more frequently required in the group of elderly patients. Conclusion. Massive benzodiazepines overdose in elderly may be associated with a significant morbidity, including deep coma with aspiration pneumonia, respiratory failure, and even death. Flumazenil is indicated more often to reduce CNS depression and prevent complications of prolonged unconsciousness, but supportive treatment and proper airway management of comatose patients is the mainstay of the treatment of acute benzodiazepine poisoning.

  11. Central Leptin Receptor Action and Resistance in Obesity

    OpenAIRE

    Bjørbæk, Christian

    2009-01-01

    The discovery of leptin in 1994 has lead to remarkable advances in obesity research. We now know that leptin is a cytokine-like hormone that is produced in adipose tissue and plays a pivotal role in regulation of energy balance and in a variety of additional processes via actions in the central nervous system. This symposium review covers current understandings of neuronal leptin receptor signaling, mechanisms of obesity-related leptin resistance in the central nervous system, and provides re...

  12. Orexin, orexin receptor antagonists and central cardiovascular control

    OpenAIRE

    Carrive, Pascal

    2013-01-01

    Orexin makes an important contribution to the regulation of cardiovascular function. When injected centrally under anesthesia, orexin increases blood pressure, heart rate and sympathetic nerve activity. This is consistent with the location of orexin neurons in the hypothalamus and the distribution of orexin terminals in the central autonomic network. Thus, the two orexin receptors, Ox1R and Ox2R, which have partly overlapping distributions in the brain, are expressed in the sympathetic pregan...

  13. Enhancement of peripheral benzodiazepine receptor ligand-induced apoptosis and cell cycle arrest of esophageal cancer cells by simultaneous inhibition of MAPK/ERK kinase.

    Science.gov (United States)

    Sutter, Andreas P; Maaser, Kerstin; Gerst, Bastian; Krahn, Antje; Zeitz, Martin; Scherübl, Hans

    2004-05-01

    Specific ligands of the peripheral benzodiazepine receptor (PBR) activate pro-apoptotic and anti-proliferative signaling pathways. Previously, we found that PBR ligands activated the p38 mitogen-activated protein kinase (MAPK) pathway in esophageal cancer cells, and that the activation of p38MAPK contributed to tumor cell apoptosis and cell cycle arrest. Here, we report that PBR ligands also activate the pro-survival MAPK/ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway in esophageal cancer cells, which might compromise the efficacy of PBR ligands. Hence, a combination treatment of PBR ligands and MEK inhibitors, which are emerging as promising anticancer agents, was pursued to determine whether this treatment could lead to enhanced apoptosis and cell cycle arrest. Using Western blotting we demonstrated a time- and dose-dependent phosphorylation of ERK1/2 in response to PBR ligands. Apoptosis was investigated by assessment of mitochondrial alterations and caspase-3 activity. Cell cycle arrest was measured by flow cytometric analysis of stained isolated nuclei. The inhibition of MEK/ERK with a pharmacologic inhibitor, 2'-amino-3'-methoxyflavone (PD 98059), resulted in a synergistic enhancement of PBR-ligand-induced growth inhibition, apoptosis and cell cycle arrest. Specifity of the pharmacologic inhibitor was confirmed by the use of 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene (U 0126), a second MEK/ERK inhibitor, and 1,4-diamino-2,3-dicyano-1,4-bis(methylthio)butadiene (U 0124), a structural analogue of it which does not display any affinity to MEK. Enhanced pro-apoptotic and anti-proliferative effects were observed both in KYSE-140 esophageal squamous cancer and OE-33 adenocarcinoma cells, suggesting that this effect was not cell-type specific. In addition, the PBR-mediated overexpression of the stress response gene (growth arrest and DNA-damage-inducible gene gadd153) was synergistically enhanced by MEK inhibition. This is the

  14. Evaluation of C.L.I.N.D.E. as potent peripheral-type benzodiazepine receptor tracer in a rat model of micro-glial activation

    Energy Technology Data Exchange (ETDEWEB)

    Arlicot, N.; Guilloteau, D.; Chalon, S. [Institut National de la Sante et de la Recherche Medicale (INSERM), U619, 37 - Tours (France); Universite Francois Rabelais de Tours, 37 (France); Katsifis, A.; Mattner, F. [ANSTO, Sydney (Australia)

    2008-02-15

    The peripheral-type benzodiazepine receptors (P.B.R.) are localized in mitochondria of glial cells and are very low expressed in normal brain. Their expression rises after micro-glial activation consecutive to brain injury. Accordingly, P.B.R. are potential targets to evaluate neuro inflammatory changes in a variety of C.N.S. disorders. To date no effective tool is available to explore P.B.R. by SPECT. We characterized here 6-chloro-2-(4 iodophenyl)-3-(N,N-diethyl)-imidazo[1,2-a]pyridine- 3-acetamide, C.L.I.N.D.E., in a rat model of excitotoxic lesion. Excitotoxicity was induced in male Wistar rats by unilateral intra striatal injection of different amounts of quinolinic acid (Q.A.: 75, 150 or 300 nmol). One week later, 2 groups of rats (n = 5-6/group) were i.v. injected with [{sup 125}I]-C.L.I.N.D.E. (0.4 MBq), one group being pre-injected with P.K.11195 (5 mg/kg). Brains were removed 30 min after tracer injection and the radioactivity of cerebral areas measured. Complementary ex vivo autoradiography and immunohistochemical studies using O.X.-42 were performed on brain sections In the control group, [{sup 125}I]-C.L.I.N.D.E. binding was significantly higher ( p < 0.001) in lesioned than that in intact side (striatum: 0.552 {+-} 0.109 vs. 0.123 {+-} 0.012% I.D./g tissue; cortex: 0.385 {+-} 0.126 vs. 0.131 {+-} 0.007% with 300 nmol Q.A.). This binding disappeared in rats pretreated with P.K.11195 ( p < 0.001), showing specific binding of C.L.I.N.D.E. to P.B.R.. Ex vivo autoradiography and immunohistochemistry were consistent with this, revealing a spatial correspondence between radioactivity signal and activated micro-glia. Regression analysis yielded a significant correlation ( p < 0.001) between the ligand binding and the dose of Q.A.. These results demonstrate that C.L.I.N.D.E. is suitable for P.B.R. in vivo SPECT imaging to explore their involvement in neuro degenerative disorders associated with micro-glial activation. (authors)

  15. Ethanol-related changes in benzodiazepine receptor ligand modulation of GABA[sub A] receptor-operated chloride channels: Relevance to ethanol tolerance and dependence

    Energy Technology Data Exchange (ETDEWEB)

    Buck, K.J.

    1990-01-01

    This study focuses on how ethanol exposure affects biochemical processes associated with the GABA[sub A] complex in the mammalian CNS, and examines the role of these changes in the development of alcohol tolerance and withdrawal. In vitro studies of control mice and those acutely or chronically exposed to alcohol were conducted. Radioligand binding using the low-affinity GABA[sub A] receptor-selective antagonist [[sup 3]H]SR95531 showed no changes in saturation binding analysis of receptor affinity or density. Muscimol-activated [sup 36]Cl[sup [minus

  16. Gamma-aminobutyric acid-modulated benzodiazepine binding sites in bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lummis, S.C.R.; Johnston, G.A.R. (Univ. of Sydney, New South Wales (Australia)); Nicoletti, G. (Royal Melbourne Inst. of Tech. (Australia)); Holan, G. (CSIRO, Melbourne (Australia))

    1991-01-01

    Benzodiazepine binding sites, which were once considered to exist only in higher vertebrates, are here demonstrated in the bacteria E. coli. The bacterial ({sup 3}H)diazepam binding sites are modulated by GABA; the modulation is dose dependent and is reduced at high concentrations. The most potent competitors of E.Coli ({sup 3}H)diazepam binding are those that are active in displacing ({sup 3}H)benzodiazepines from vertebrate peripheral benzodiazepine binding sites. These vertebrate sites are not modulated by GABA, in contrast to vertebrate neuronal benzodiazepine binding sites. The E.coli benzodiazepine binding sites therefore differ from both classes of vertebrate benzodiazepine binding sites; however the ligand spectrum and GABA-modulatory properties of the E.coli sites are similar to those found in insects. This intermediate type of receptor in lower species suggests a precursor for at least one class of vertebrate benzodiazepine binding sites may have existed.

  17. Individual and combined manipulation of muscarinic, NMDA, and benzodiazepine receptor activity in the water maze task: implications for a rat model of Alzheimer dementia.

    Science.gov (United States)

    Cain, D P; Ighanian, K; Boon, F

    2000-06-15

    Recent evidence indicates that Alzheimer disease typically involves different degrees of impairment in a variety of neurotransmitter systems, behaviors, and cognitive abilities in different patients. To investigate the relations between neurotransmitter system, behavioral, and cognitive impairments in an animal model of Alzheimer disease we studied spatial learning in a Morris water maze in male Long-Evans rats given neurochemical agents that targeted muscarinic cholinergic, NMDA, or benzodiazepine systems. Naive rats given a single agent or a combination of agents were severely impaired in place responding and had behavioral strategy impairments. Rats made familiar with the required water maze behavioral strategies by non-spatial pretraining performed as well as controls if given a single agent. Non-spatially pretrained rats with manipulation of both muscarinic cholinergic and NMDA or muscarinic cholinergic and benzodiazepine systems had a specific place response impairment but no behavioral strategy impairments. The results suggest that impairment of both muscarinic cholinergic and NMDA, or muscarinic cholinergic and benzodiazepine systems may model some aspects of human Alzheimer disease (impairments in navigation in familiar environments), but not other aspects of this disorder (global dementia leading to general loss of adaptive behavior). Previous research suggests that impairment of both muscarinic cholinergic and serotonergic systems may provide a better model of global dementia. The water maze testing and detailed behavioral analysis techniques used here appear to provide a means of investigating the contributions of various combinations of neurotransmitter system impairments to an animal model of Alzheimer disease.

  18. Interaction of Plant Extracts with Central Nervous System Receptors

    Directory of Open Access Journals (Sweden)

    Kenneth Lundstrom

    2017-02-01

    Full Text Available Background: Plant extracts have been used in traditional medicine for the treatment of various maladies including neurological diseases. Several central nervous system receptors have been demonstrated to interact with plant extracts and components affecting the pharmacology and thereby potentially playing a role in human disease and treatment. For instance, extracts from Hypericum perforatum (St. John’s wort targeted several CNS receptors. Similarly, extracts from Piper nigrum, Stephania cambodica, and Styphnolobium japonicum exerted inhibition of agonist-induced activity of the human neurokinin-1 receptor. Methods: Different methods have been established for receptor binding and functional assays based on radioactive and fluorescence-labeled ligands in cell lines and primary cell cultures. Behavioral studies of the effect of plant extracts have been conducted in rodents. Plant extracts have further been subjected to mood and cognition studies in humans. Results: Mechanisms of action at molecular and cellular levels have been elucidated for medicinal plants in support of standardization of herbal products and identification of active extract compounds. In several studies, plant extracts demonstrated affinity to a number of CNS receptors in parallel indicating the complexity of this interaction. In vivo studies showed modifications of CNS receptor affinity and behavioral responses in animal models after treatment with medicinal herbs. Certain plant extracts demonstrated neuroprotection and enhanced cognitive performance, respectively, when evaluated in humans. Noteworthy, the penetration of plant extracts and their protective effect on the blood-brain-barrier are discussed. Conclusion: The affinity of plant extracts and their isolated compounds for CNS receptors indicates an important role for medicinal plants in the treatment of neurological disorders. Moreover, studies in animal and human models have confirmed a scientific basis for the

  19. Is central benzodiazepine receptor imaging useful for the identification of epileptogenic foci in localization-related epilepsies?

    Energy Technology Data Exchange (ETDEWEB)

    Goethals, Ingeborg; Van de Wiele, Christophe; Dierckx, Rudi [Division of Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000, Ghent (Belgium); Boon, Paul [Department of Neurology, Ghent University Hospital, Ghent (Belgium)

    2003-02-01

    In the presurgical evaluation of patients with partial epilepsies, the most extensively studied functional neuro-imaging modality to define the origin of seizure onset is fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET). Generally, this technique reveals a widespread zone of interictal glucose hypometabolism in the region of the epileptogenic focus. However, the technique may miss the epileptogenic region and FDG PET abnormalities may extend beyond the seizure onset zone. Consequently, for the precise identification of epileptogenic regions more specific imaging probes than FDG are warranted. This review considers the clinical utility of iomazenil (IMZ) SPET and flumazenil (FMZ) PET for the precise localization of epileptogenic foci in partial epilepsy syndromes. (orig.)

  20. Chemokines and their receptors in central nervous system disease.

    Science.gov (United States)

    Biber, Knut; de Jong, Eiko K; van Weering, Hilmar R J; Boddeke, Hendrikus W G M

    2006-01-01

    Almost a decade ago, it was discovered that the human deficiency virus (HIV) makes use of chemokine receptors to infect blood cells. This appreciation of the clinical relevance of specific chemokine receptors has initiated a considerable boost in the field of chemokine research. It is clear today that chemokine signaling orchestrates the immune system and is widely involved in both physiological and pathophysiological processes. Since the chemokine system offers various targets through which pathology could be influenced, most pharmaceutical companies have chosen this system as a therapeutic target for a variety of diseases. Here recent developments concerning the role of chemokines in diseases of the central nervous system (CNS) as well as their possible therapeutic relevance are discussed.

  1. Central serotonergic and noradrenergic receptors in functional dyspepsia

    Institute of Scientific and Technical Information of China (English)

    S O'Mahony; TG Dinan; PW Keeling; ASB Chua

    2006-01-01

    Functional dyspepsia is a symptom complex characterised by upper abdominal discomfort or pain, early satiety,motor abnormalities, abdominal bloating and nausea in the absence of organic disease. The central nervous system plays an important role in the conducting and processing of visceral signals. Alterations in brain processing of pain, perception and affective responses may be key factors in the pathogenesis of functional dyspepsia. Central serotonergic and noradrenergic receptor systems are involved in the processing of motor,sensory and secretory activities of the gastrointestinal tract. Visceral hypersensitivity is currently regarded as the mechanism responsible for both motor alterations and abdominal pain in functional dyspepsia. Some studies suggest that there are alterations in central serotonergic and noradrenergic systems which may partially explain some of the symptoms of functional dyspepsia. Alterations in the autonomic nervous system may be implicated in the motor abnormalities and increases in visceral sensitivity in these patients.Noradrenaline is the main neurotransmitter in the sympathetic nervous system and again alterations in the functioning of this system may lead to changes in motor function. Functional dyspepsia causes considerable burden on the patient and society. The pathophysiology of functional dyspepsia is not fully understood but alterations in central processing by the serotonergic and noradrenergic systems may provide plausible explanations for at least some of the symptoms and offer possible treatment targets for the future.

  2. High density of benzodiazepine binding sites in the substantia innominata of the rat

    Energy Technology Data Exchange (ETDEWEB)

    Sarter, M.; Schneider, H.H.

    1988-07-01

    In order to study the neuronal basis of the pharmacological interactions between benzodiazepine receptor ligands and cortical cholinergic turnover, we examined the regional distribution of specific benzodiazepine binding sites using in vitro autoradiography. In the basal forebrain, the substantia innominata contained a high density of (/sup 3/H)lormetazepam (LMZ) binding sites (Bmax = 277 fmol/mg tissue; Kd = 0.55 nM). The label could be displaced by diazepam (IC50 = 100 nM), the benzodiazepine receptor antagonist beta-carboline ZK 93426 (45 nM) and the partial inverse agonist beta-carboline FG 7142 (540 nM). It is hypothesized that the amnesic effects of benzodiazepine receptor agonists are exerted through benzodiazepine receptors which are situated on cholinergic neurons in the substantia innominata and are involved in a tonic inhibition of cortical acetylcholine release. The benzodiazepine receptor antagonist ZK 93426 may exert its nootropic effects via benzodiazepine receptors in the substantia innominata and, consequently, by disinhibiting cortical acetylcholine release.

  3. Central phencyclidine (PCP) receptor binding is glutamate dependent: evidence for a PCP/excitatory amino acid receptor (EAAR) complex

    Energy Technology Data Exchange (ETDEWEB)

    Loo, P.; Braunwalder, A.; Lehmann, J.; Williams, M.

    1986-03-01

    PCP and other dissociative anesthetica block the increase in neuronal firing rate evoked by the EAAR agonist, N-methyl-Daspartate. NMDA and other EAAs such as glutamate (glu) have not been previously shown to affect PCP ligand binding. In the present study, using once washed rat forebrain membranes, 10 ..mu..M-glu was found to increase the binding of (/sup 3/H)TCP, a PCP analog, to defined PCP recognition sites by 20%. Removal of glu and aspartate (asp) by extensive washing decreased TCP binding by 75-90%. In these membranes, 10 ..mu..M L-glu increased TCP binding 3-fold. This effect was stereospecific and evoked by other EAAs with the order of activity, L-glu > D-asp > L- asp > NMDA > D-glu > quisqualate. Kainate, GABA, NE, DA, 5-HT, 2-chloroadenosine, oxotremorine and histamine had no effect on TCP binding at concentrations up to 100 ..mu..M. The effects of L-glu were attenuated by the NMDA-type receptor antagonist, 2-amino-7--phosphonoheptanoate (AP7; 10 ..mu..M-1 mM). These findings indicate that EAAS facilitate TCP binding, possibly through NMDA-type receptors. The observed interaction between the PCP receptor and EAARs may reflect the existence of a macromolecular receptor complex similar to that demonstrated for the benzodiazepines and GABA.

  4. Benzodiazepine use, abuse, and dependence.

    Science.gov (United States)

    O'brien, Charles P

    2005-01-01

    Although benzodiazepines are invaluable in the treatment of anxiety disorders, they have some potential for abuse and may cause dependence or addiction. It is important to distinguish between addiction to and normal physical dependence on benzodiazepines. Intentional abusers of benzodiazepines usually have other substance abuse problems. Benzodiazepines are usually a secondary drug of abuse-used mainly to augment the high received from another drug or to offset the adverse effects of other drugs. Few cases of addiction arise from legitimate use of benzodiazepines. Pharmacologic dependence, a predictable and natural adaptation of a body system long accustomed to the presence of a drug, may occur in patients taking therapeutic doses of benzodiazepines. However, this dependence, which generally manifests itself in withdrawal symptoms upon the abrupt discontinuation of the medication, may be controlled and ended through dose tapering, medication switching, and/or medication augmentation. Due to the chronic nature of anxiety, long-term low-dose benzodiazepine treatment may be necessary for some patients; this continuation of treatment should not be considered abuse or addiction.

  5. Role of cholecystokinin and central serotonergic receptors in functional dyspepsia

    Institute of Scientific and Technical Information of China (English)

    Andrew Seng Boon Chua; PWN Keeling; TG Dinan

    2006-01-01

    Symptoms of functional dyspepsia are characterized by upper abdominal discomfort or pain, early satiety, postprandial fullness, bloating, nausea and vomiting. It is a chronic disorder, with symptoms more than 3 mo per year, and no evidence of organic diseases. Dysfunctional motility, altered visceral sensation, and psychosocial factors have all been identified as major pathophysiological mechanisms. It is believed that these pathophysiological mechanisms interact to produce the observed symptoms.Dyspepsia has been categorized into three subgroups based on dominant symptoms. Dysmotility-like dyspepsia describes a subgroup of patients whose symptom complex is usually related to a gastric sensorimotor dysfunction. The brain-gut peptide cholecystokinin (CCK)and serotonin (5-HT) share certain physiological effects.Both have been shown to decrease gastric emptying and affect satiety. Furthermore the CCK induced anorexia depended on serotonergic functions probably acting via central pathways. We believe that abnormalities of central serotonergic receptors functioning together with a hyper responsiveness to CCK or their interactions may be responsible for the genesis of symptoms in functional dyspepsia (FD).

  6. GABA(A) receptor subtype-selectivity of novel bicuculline derivatives.

    Science.gov (United States)

    Ramerstorfer, Joachim; Foppa, Verena; Thiery, Hanna; Hermange, Philippe; Janody, Simon; Berger, Michael L; Dodd, Robert H; Sieghart, Werner

    2015-01-01

    GABA(A) receptors are the major inhibitory neurotransmitter receptors in the central nervous system and are targets of clinically important drugs modulating GABA induced ion flux by interacting with distinct allosteric binding sites. ROD 185 is a previously investigated structural analogue of the GABA site antagonist bicuculline, and a positive allosteric modulator acting via the benzodiazepine binding site. Here, we investigated 13 newly synthesized structural analogues of ROD 185 for their interaction with rat GABA(A) receptors. Using [(3)H]flunitrazepam binding assays, we identified four compounds exhibiting a higher affinity for the benzodiazepine binding site than ROD 185. Two electrode voltage clamp electrophysiology at recombinant GABA(A) receptors indicated that most of these compounds positively modulated GABA-induced currents at these receptors. Additionally, these experiments revealed that this compound class not only interacts with the benzodiazepine binding site at αβγ receptors but also with a novel, so far unidentified binding site present in αβ receptors. Compounds with a high affinity for the benzodiazepine binding site stimulated GABA-induced currents stronger at αβγ than at αβ receptors and preferred α3β3γ2 receptors. Compounds showing equal or smaller effects at αβγ compared to αβ receptors differentially interacted with various αβ or αβγ receptor subtypes. Surprisingly, five of these compounds interacting with αβ receptors showed a strong stimulation at α6β3γ2 receptors. The absence of any direct effects at GABA(A) receptors, as well as their potential selectivity for receptor subtypes not being addressed by benzodiazepines, make this compound class to a starting point for the development of drugs with a possible clinical importance.

  7. Predictors of long-term benzodiazepine abstinence in participants of a randomized controlled benzodiazepine withdrawal program.

    NARCIS (Netherlands)

    Oude Voshaar, R.C.; Gorgels, W.J.M.J.; Mol, A.J.J.; Balkom, A.J.L.M. van; Mulder, J.; Lisdonk, E.H. van de; Breteler, M.H.M.; Zitman, F.G.

    2006-01-01

    OBJECTIVE: To identify predictors of resumed benzodiazepine use after participation in a benzodiazepine discontinuation trial. METHOD: We performed multiple Cox regression analyses to predict the long-term outcome of a 3-condition, randomized, controlled benzodiazepine discontinuation trial in gener

  8. Treating acute seizures with benzodiazepines: does seizure duration matter?

    Science.gov (United States)

    Naylor, David E

    2014-10-01

    Several clinical trials have shown improved seizure control and outcome by early initiation of treatment with benzodiazepines, before arrival in the emergency department and before intravenous access can be established. Here, evidence is provided and reviewed for rapid treatment of acute seizures in order to avoid the development of benzodiazepine pharmacoresistance and the emergence of self-sustaining status epilepticus. Alterations in the physiology, pharmacology, and postsynaptic level of GABA-A receptors can develop within minutes to an hour and hinder the ability of synaptic inhibition to stop seizures while also impairing the efficacy of GABAergic agents, such as benzodiazepines, to boost impaired inhibition. In addition, heightened excitatory transmission further exacerbates the inhibitory/excitatory balance and makes seizure control even more resistant to treatment. The acute increase in the surface expression of NMDA receptors during prolonged seizures also may cause excitotoxic injury, cell death, and other pathological expressions and re-arrangements of receptor subunits that all contribute to long-term sequelae such as cognitive impairment and chronic epilepsy. In conclusion, a short window of opportunity exists when seizures are maximally controlled by first-line benzodiazepine treatment. After that, multiple pathological mechanisms quickly become engaged that make seizures increasingly more difficult to control with high risk for long-term harm.

  9. Automated radiosynthesis of [{sup 18}F]PBR111 and [{sup 18}F]PBR102 using the Tracerlab FX{sub FN} and Tracerlab MX{sub FDG} module for imaging the peripheral benzodiazepine receptor with PET

    Energy Technology Data Exchange (ETDEWEB)

    Bourdier, Thomas, E-mail: thomas@nucmed.rpa.cs.nsw.gov.au [PET and Nuclear Medicine Department, Royal Prince Alfred Hospital, Missenden road, Camperdown NSW 2050, Sydney (Australia); Pham, Tien Q. [LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC NSW 2232, Sydney (Australia); Henderson, David [PET and Nuclear Medicine Department, Royal Prince Alfred Hospital, Missenden road, Camperdown NSW 2050, Sydney (Australia); Jackson, Timothy [LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC NSW 2232, Sydney (Australia); Lam, Peter [PET and Nuclear Medicine Department, Royal Prince Alfred Hospital, Missenden road, Camperdown NSW 2050, Sydney (Australia); Izard, Michael; Katsifis, Andrew [LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC NSW 2232, Sydney (Australia)

    2012-01-15

    [{sup 18}F]PBR111 and [{sup 18}F]PBR102 are selective radioligands for imaging of the Peripheral Benzodiazepine Receptor (PBR). We have developed a fully automated method for the radiosynthesis of [{sup 18}F]PBR111 and [{sup 18}F]PBR102 in the Tracerlab FX{sub FN} (30{+-}2% radiochemical yield non-decay-corrected for both tracers) and Tracerlab MX{sub FDG} (25{+-}2% radiochemical yield non-decay-corrected for both tracers) from the corresponding p-toluenesulfonyl precursors. For all tracers, radiochemical purity was >99% and specific activity was >150 GBq/{mu}mol after less than 60 min of preparation time. - Highlights: Black-Right-Pointing-Pointer Radiosynthesis of novel ligands PBR111 and PBR102 with fluorine-18. Black-Right-Pointing-Pointer Fully automated synthesis undertaken using the GE Tracerlab FX{sub FN} and MX{sub FDG} modules. Black-Right-Pointing-Pointer Reproducible high yields suitable for clinical applications. Black-Right-Pointing-Pointer Radiosynthesis and formulation achieved in less than 60 mins. Black-Right-Pointing-Pointer PBR111 and PBR102 prepared in high radiochemical yield and specific activity.

  10. The GABA-A benzodiazepine receptor complex: Role of pet and spect in neurology and psychiatry; Der GABA-A-benzodiazepinrezeptorkomplex: Rolle von PET und SPECT in Neurologie und Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Juengling, F.D. [Abt. fuer Nuklearmedizin, Radiologie III, Universitaetsklinik Ulm (Germany); Schaefer, M.; Heinz, A. [Klinik fuer Psychiatrie und Psychotherapie, Charite, Humboldt-Univ. zu Berlin (Germany)

    2002-09-01

    Nuclear medicine imaging techniques such as positron emission tomography (PET) and single photon emission tomography (SPECT) for selective depiction of GABA-A-benzodiazepine receptor (GBZR) binding are complementary investigations in the diagnostic process of neurological and psychiatric disorders. This review summarizes the current knowledge about options and limitations of PET and SPECT for in vivo diagnostics in neurology and psychiatry. The growing importance of GBZR-imaging for the understanding of pathophysiology and pharmacological treatment in different psychiatric syndromes is discussed. (orig.) [German] Mit der Entwicklung selektiver Liganden fuer den GABA-A-Benzodiazepinrezeptorkomplex (GBZR) hat die nuklearmedizinische Bildgebung mittels positronen-emissionstomographie (PET) und single-photon-emissionscomputertomographie (SPECT) einen festen Stellenwert fuer Klinik und Forschung in der Neurologie und Psychiatrie erlangt. Die vorliegende Ueberblicksarbeit fasst den aktuellen Wissensstand von Anwendungsmoeglichkeiten und -grenzen der nuklearmedizinischen Bildgebung der GBZR in vivo zusammen und beleuchtet ihren klinischen Nutzen. Die wachsende Bedeutung fuer das Verstaendnis der Pathophysiologie und pharmakotherapeutischer Konzepte unterschiedlicher psychiatrischer Erkrankungen wird herausgestellt. (orig.)

  11. Contribution of prolonged-release melatonin and anti-benzodiazepine campaigns to the reduction of benzodiazepine and z-drugs consumption in nine European countries

    OpenAIRE

    2012-01-01

    Background Benzodiazepines (BZD) and benzodiazepine receptor agonists (zolpidem, zaleplon, zopiclone, altogether Z-drugs) are most commonly prescribed for the treatment of insomnia. However, long-term use of BZD/Z-drugs is associated with major adverse events including, but not limited to, falls and fractures, domestic and traffic accidents, confusion, cognitive impairment, Alzheimer's disease and cancer. The prolonged use of these drugs is thought to be related to severe withdrawal symptoms ...

  12. Central N/OFQ-NOP Receptor System in Pain Modulation.

    Science.gov (United States)

    Kiguchi, Norikazu; Ding, Huiping; Ko, Mei-Chuan

    2016-01-01

    Two decades have passed since the peptide, nociceptin/orphanin FQ (N/OFQ), and its cognate (NOP) receptor were discovered. Although NOP receptor activation causes a similar pattern of intracellular actions as mu-opioid (MOP) receptors, NOP receptor-mediated pain modulation in rodents are more complicated than MOP receptor activation. This review highlights the functional evidence of spinal, supraspinal, and systemic actions of NOP receptor agonists for regulating pain. In rodents, effects of the N/OFQ-NOP receptor system in spinal and supraspinal sites for modulating pain are bidirectional depending on the doses, assays, and pain modalities. The net effect of systemically administered NOP receptor agonists may depend on relative contribution of spinal and supraspinal actions of the N/OFQ-NOP receptor signaling in rodents under different pain states. In stark contrast, NOP receptor agonists produce only antinociception and antihypersensitivity in spinal and supraspinal regions of nonhuman primates regardless of doses and assays. More importantly, NOP receptor agonists and a few bifunctional NOP/MOP receptor agonists do not exhibit reinforcing effects (abuse liability), respiratory depression, itch pruritus, nor do they delay the gastrointestinal transit function (constipation) in nonhuman primates. Depending upon their intrinsic efficacies for activating NOP and MOP receptors, bifunctional NOP/MOP receptor agonists warrant additional investigation in primates regarding their side effect profiles. Nevertheless, NOP receptor-related agonists display a much wider therapeutic window as compared to that of MOP receptor agonists in primates. Both selective NOP receptor agonists and bifunctional NOP/MOP receptor agonists hold great potential as effective and safe analgesics without typical opioid-associated side effects in humans.

  13. [Benzodiazepines in the treatment of catatonia].

    Science.gov (United States)

    Van Dalfsen, A N; Van Den Eede, F; Van Den Bossche, B; Sabbe, B G C

    2006-01-01

    A patient who developed acute catatonia during benzodiazepine withdrawal is discussed. The case prompted us to review the literature on the role of benzodiazepines in the treatment of acute catatonia. Only retrospective and open studies were found which indicate that benzodiazepines do have a beneficial effect. Lorazepam is the most widely studied benzodiazepine and at present is the best treatment option. In the specific case of acute catatonia brought on by benzodiazepine withdrawal the recommended dosage is the same as for acute catatonia caused by something other than benzodiazepine withdrawal.

  14. CB2 receptors in the brain: role in central immune function

    OpenAIRE

    Cabral, G. A.; Raborn, E S; Griffin, L.; Dennis, J.; Marciano-Cabral, F

    2007-01-01

    Recently, it has been recognized that the cannabinoid receptor CB2 may play a functionally relevant role in the central nervous system (CNS). This role is mediated primarily through microglia, a resident population of cells in the CNS that is morphologically, phenotypically, and functionally related to macrophages. These cells also express the cannabinoid receptor CB1. The CB1 receptor (CB1R) is constitutively expressed at low levels while the CB2 receptor (CB2R) is expressed at higher levels...

  15. Chemokines and their receptors in central nervous system disease

    NARCIS (Netherlands)

    Biber, K; de Jong, EK; van Weering, HRJ; Boddeke, HWGM

    2006-01-01

    Almost a decade ago, it was discovered that the human deficiency virus (HIV) makes use of chemokine receptors to infect blood cells. This appreciation of the clinical relevance of specific chemokine receptors has initiated a considerable boost in the field of chemokine research. It is clear today th

  16. Pattern recognition receptors and central nervous system repair.

    Science.gov (United States)

    Kigerl, Kristina A; de Rivero Vaccari, Juan Pablo; Dietrich, W Dalton; Popovich, Phillip G; Keane, Robert W

    2014-08-01

    Pattern recognition receptors (PRRs) are part of the innate immune response and were originally discovered for their role in recognizing pathogens by ligating specific pathogen associated molecular patterns (PAMPs) expressed by microbes. Now the role of PRRs in sterile inflammation is also appreciated, responding to endogenous stimuli referred to as "damage associated molecular patterns" (DAMPs) instead of PAMPs. The main families of PRRs include Toll-like receptors (TLRs), Nod-like receptors (NLRs), RIG-like receptors (RLRs), AIM2-like receptors (ALRs), and C-type lectin receptors. Broad expression of these PRRs in the CNS and the release of DAMPs in and around sites of injury suggest an important role for these receptor families in mediating post-injury inflammation. Considerable data now show that PRRs are among the first responders to CNS injury and activation of these receptors on microglia, neurons, and astrocytes triggers an innate immune response in the brain and spinal cord. Here we discuss how the various PRR families are activated and can influence injury and repair processes following CNS injury.

  17. A comparative autoradiography study in post mortem whole hemisphere human brain slices taken from Alzheimer patients and age-matched controls using two radiolabelled DAA1106 analogues with high affinity to the peripheral benzodiazepine receptor (PBR) system.

    Science.gov (United States)

    Gulyás, Balázs; Makkai, Boglárka; Kása, Péter; Gulya, Károly; Bakota, Lidia; Várszegi, Szilvia; Beliczai, Zsuzsa; Andersson, Jan; Csiba, László; Thiele, Andrea; Dyrks, Thomas; Suhara, Tetsua; Suzuki, Kazutoshi; Higuchi, Makato; Halldin, Christer

    2009-01-01

    The binding of two radiolabelled analogues (N-(5-[125I]Iodo-2-phenoxyphenyl)-N-(2,5-dimethoxybenzyl)acetamide ([125I]desfluoro-DAA1106) and N-(5-[125I]Fluoro-2-phenoxyphenyl)-N-(2-[125I]Iodo-5-methoxybenzyl)acetamide ([125I]desmethoxy-DAA1106) of the peripheral benzodiazepine receptor (PBR) (or TSPO, 18kDa translocator protein) ligand DAA1106 was examined by in vitro autoradiography on human post mortem whole hemisphere brain slices obtained from Alzheimer's disease (AD) patients and age-matched controls. Both [(125)I]desfluoro-IDAA1106 and [(125)I]desmethoxy-IDAA1106 were effectively binding to various brain structures. The binding could be blocked by the unlabelled ligand as well as by other PBR specific ligands. With both radiolabelled compounds, the binding showed regional inhomogeneity and the specific binding values proved to be the highest in the hippocampus, temporal and parietal cortex, the basal ganglia and thalamus in the AD brains. Compared with age-matched control brains, specific binding in several brain structures (temporal and parietal lobes, thalamus and white matter) in Alzheimer brains was significantly higher, indicating that the radioligands can effectively label-activated microglia and the up-regulated PBR/TSPO system in AD. Complementary immunohistochemical studies demonstrated reactive microglia activation in the AD brain tissue and indicated that increased ligand binding coincides with increased regional microglia activation due to neuroinflammation. These investigations yield further support to the PBR/TSPO binding capacity of DAA1106 in human brain tissue, demonstrate the effective usefulness of its radio-iodinated analogues as imaging biomarkers in post mortem human studies, and indicate that its radiolabelled analogues, labelled with short half-time bioisotopes, can serve as prospective in vivo imaging biomarkers of activated microglia and the up-regulated PBR/TSPO system in the human brain.

  18. A Way of Conceptualizing Benzodiazepines to Guide Clinical Use.

    Science.gov (United States)

    Preskorn, Sheldon H

    2015-11-01

    Benzodiazepines are medications that are widely used for a number of different therapeutic indications and in a wide range of patients in terms of age and health status. Presented here is a simple 2 by 2 way of classifying all of the most commonly used benzodiazepines. This conceptualization is based on the most clinically relevant ways of differentiating these drugs: (a) their affinity for their common and predominant mechanism of action, the benzodiazepine-binding site of the γ-aminobutyric acid (GABA)-A iontropic receptor (ie, the chloride ion channel); and (b) their pharmacokinetics (ie, their half-lives and metabolism). The science underlying this conceptualization is presented and then its clinical applicability is discussed. This system can help clinicians select the most appropriate benzodiazepine for their patients and better understand how to switch between these medications to minimize withdrawal symptoms; it also provides a rational basis for cautiously using these agents in combination when necessary, in a manner analogous to the combined use of short-acting and long-acting forms of insulin.

  19. [Benzodiazepine dependence: causalities and treatment options].

    Science.gov (United States)

    Heberlein, A; Bleich, S; Kornhuber, J; Hillemacher, T

    2009-01-01

    Benzodiazepines are very often prescribed because of their anxiolytic, sedative and hypnotic properties. However, long term treatment is associated with development of benzodiazepine dependence. Besides development of physical dependence, which is linked to a typical benzodiazepine withdrawal syndrome when drug intake is discontinued, also behavioural addiction to benzodiazepines has been described. Benzodiazepines are known to enhance GABAergic neurotransmission. Counter regulation of enhanced GABAergic neurotransmission by enhancement of glutamatergic neurotransmission is thought to be one reason underlying the typical symptoms of benzodiazepine withdrawal. Also alterations in the expression of neuropeptides like Corticotropin Releasing Hormone and Neuropeptide Y are thought to be involved in the development of benzodiazepine dependence. However, until today the knowledge of neural mechanisms underlying the development of benzodiazepine dependence remains incomplete. Because even long term treatment with small doses of benzodiazepines is associated with adverse reactions like cognitive dysfunctions withdrawal from benzodiazepines should be aimed. Anticonvulsants and antidepressants seem to reduce the intensity of benzodiazepine withdrawal and to enhance long term prognosis of dependence.

  20. Strategy for improved [{sup 11}C]DAA1106 radiosynthesis and in vivo peripheral benzodiazepine receptor imaging using microPET, evaluation of [{sup 11}C]DAA1106

    Energy Technology Data Exchange (ETDEWEB)

    Probst, Katrin C. [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom)]|[BHF Carotid Imaging Group, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom)]. E-mail: kp296@wbic.cam.ac.uk; Izquierdo, David [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom)]|[BHF Carotid Imaging Group, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom); Bird, Joseph L.E. [BHF Carotid Imaging Group, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom)]|[Department of Medicine, Cardiovascular Medicine Division, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom); Brichard, Laurent; Franck, Dominic; Fryer, Tim D.; Clark, John C. [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom); Davies, John R. [Cardiovascular Medicine Division, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom); Richards, Hugh K. [Neurology Unit, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom); Davenport, Anthony P. [Clinical Pharmacology Unit, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom); Weissberg, Peter L. [Cardiovascular Medicine Division, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom); Warburton, Elizabeth A. [BHF Carotid Imaging Group, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom)]|[Department of Clinical Neurosciences, University of Cambridge, Addenbrooke' s Hospital, CB2 2QQ Cambridge (United Kingdom)

    2007-05-15

    Introduction: The peripheral benzodiazepine receptor (PBR) has shown considerable potential as a clinical marker of neuroinflammation and tumour progression. [{sup 11}C]DAA1106 ([{sup 11}C]N-(2,5-dimethoxybenzyl)-N-(5-fluoro-2-phenoxyphenyl)-acetamide) is a promising positron emission tomography (PET) radioligand for imaging PBRs. Methods: A four-step synthetic route was devised to prepare DAA1123, the precursor for [{sup 11}C]DAA1106. Two robust, high yielding methods for radiosynthesis based on [{sup 11}C]-O-methylation of DAA1123 were developed and implemented on a nuclear interface methylation module, producing [{sup 11}C]DAA1106 with up to 25% radiochemical yields at end-of-synthesis based on [{sup 11}C]CH{sub 3}I trapped. Evaluation of [{sup 11}C]DAA1106 for in vivo imaging was performed in a rabbit model with microPET, and the presence of PBR receptor in the target organ was further corroborated by immunohistochemistry. Results: The standard solution method produced 2.6-5.2 GBq (n=19) of [{sup 11}C]DAA1106, whilst the captive solvent method produced 1.6-6.3 GBq (n=10) of [{sup 11}C]DAA1106. Radiochemical purities obtained were 99% and specific radioactivity at end-of-synthesis was up to 200 GBq/{mu}mol for both methods. Based on radiochemical product, shorter preparation times and simplicity of synthesis, the captive solvent method was chosen for routine productions of [{sup 11}C]DAA1106. In vivo microPET [{sup 11}C]DAA1106 scans of rabbit kidney demonstrated high levels of binding in the cortex. The subsequent introduction of nonradioactive DAA1106 (0.2 {mu}mol) produced considerable displacement of the radioactive signal in this region. The presence of PBR in kidney cortex was further corroborated by immunohistochemistry. Conclusions: A robust, high yielding captive solvent method of [{sup 11}C]DAA1106 production was developed which enabled efficacious in vivo imaging of PBR expressing tissues in an animal model.

  1. Withdrawing benzodiazepines in primary care.

    Science.gov (United States)

    Lader, Malcolm; Tylee, Andre; Donoghue, John

    2009-01-01

    The use of benzodiazepine anxiolytics and hypnotics continues to excite controversy. Views differ from expert to expert and from country to country as to the extent of the problem, or even whether long-term benzodiazepine use actually constitutes a problem. The adverse effects of these drugs have been extensively documented and their effectiveness is being increasingly questioned. Discontinuation is usually beneficial as it is followed by improved psychomotor and cognitive functioning, particularly in the elderly. The potential for dependence and addiction have also become more apparent. The licensing of SSRIs for anxiety disorders has widened the prescribers' therapeutic choices (although this group of medications also have their own adverse effects). Melatonin agonists show promise in some forms of insomnia. Accordingly, it is now even more imperative that long-term benzodiazepine users be reviewed with respect to possible discontinuation. Strategies for discontinuation start with primary-care practitioners, who are still the main prescribers.This review sets out the stratagems that have been evaluated, concentrating on those of a pharmacological nature. Simple interventions include basic monitoring of repeat prescriptions and assessment by the doctor. Even a letter from the primary-care practitioner pointing out the continuing usage of benzodiazepines and questioning their need can result in reduction or cessation of use. Pharmacists also have a role to play in monitoring the use of benzodiazepines, although mobilizing their assistance is not yet routine. Such stratagems can avoid the use of specialist back-up services such as psychiatrists, home care, and addiction and alcohol misuse treatment facilities.Pharmacological interventions for benzodiazepine dependence have been reviewed in detail in a recent Cochrane review, but only eight studies proved adequate for analysis. Carbamazepine was the only drug that appeared to have any useful adjunctive properties for

  2. Nociceptive transmission and modulation via P2X receptors in central pain syndrome.

    Science.gov (United States)

    Kuan, Yung-Hui; Shyu, Bai-Chuang

    2016-05-26

    Painful sensations are some of the most frequent complaints of patients who are admitted to local medical clinics. Persistent pain varies according to its causes, often resulting from local tissue damage or inflammation. Central somatosensory pathway lesions that are not adequately relieved can consequently cause central pain syndrome or central neuropathic pain. Research on the molecular mechanisms that underlie this pathogenesis is important for treating such pain. To date, evidence suggests the involvement of ion channels, including adenosine triphosphate (ATP)-gated cation channel P2X receptors, in central nervous system pain transmission and persistent modulation upon and following the occurrence of neuropathic pain. Several P2X receptor subtypes, including P2X2, P2X3, P2X4, and P2X7, have been shown to play diverse roles in the pathogenesis of central pain including the mediation of fast transmission in the peripheral nervous system and modulation of neuronal activity in the central nervous system. This review article highlights the role of the P2X family of ATP receptors in the pathogenesis of central neuropathic pain and pain transmission. We discuss basic research that may be translated to clinical application, suggesting that P2X receptors may be treatment targets for central pain syndrome.

  3. Bombesin-like receptor 3 regulates blood pressure and heart rate via a central sympathetic mechanism

    OpenAIRE

    Lateef, Dalya M.; Xiao, Cuiying; Brychta, Robert J.; Diedrich, Andr?; Schnermann, Jurgen; Reitman, Marc L.

    2016-01-01

    MK-5046, a bombesin-like receptor 3 (BRS-3) agonist, increases heart rate and blood pressure via increased central sympathetic tone. Brs3 null mice have a reduced resting heart rate that increases disproportionately with physical activity. BRS-3 contributes to the central regulation of heart rate and blood pressure.

  4. Synthesis of substituted [{sup 123}I]imidazo[1,2-a]pyridines as potential probes for the study of the peripheral benzodiazepine receptors using SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Katsifis, A.; Mattner, F.; Dikic, B.; Papazian, V. [Radiopharmaceuticals Div. R and D, ANSTO, Menai, NSW (Australia)

    2000-07-01

    The imidazo[1,2-a]pyridines N,N'-dimethyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 1. N,N'-diethyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 2, and N-methyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 3, are high affinity and selective ligands for the peripheral benzodiazepineodiazepine receptors (PBR). The [{sup 123}I]1-3 labelled analogues of these compounds were subsequently synthesised for the potential study of the PBR in vivo using SPECT. Radioiodination was achieved by iododestannylation reactions of the corresponding tributyl tin precursors with Na[{sup 123}I] in the presence of peracetic acid, chloramine-T or Iodogen. Purification of the crude product was achieved by semipreparative C-18 RP HPLC to give the products in radiochemical yields of 40-85%. The products were obtained in >97% chemical and radiochemical purity and with specific activities >80 GBq/{mu}mol. (orig.)

  5. [Opiate receptors and endorphins at the central nervous system level].

    Science.gov (United States)

    Simon, E J

    1978-01-01

    Four years ago, sterospecific sites for the bending of opiates were discovered within the brain of animals and the human being. All of the properties of these sites are in conformity with the proposition that they are pharmacological receptors which have long been postulated for these drugs. The binding of morphine or of one of its derivatives to these sites should result in chemical or physical reactions leading to well known pharmacological responses. These reactions following the binding of drugs to the receptors are not yet known, but there is some evidence that cyclical nucleotides play a role. The affinity of a whole series of morphine derivatives, agonists and atagonists, is well correlated with their pharmacological effectiveness. In the presence of sodium salts, antagonists become more strongly bound and agonists less strongly than in the absence of sodium. The evidence is presented. This is explained by an equilibrium between two formations of the receptor: one characteristic of the absence of sodium and one of its presence. Receptors are found in the nervous system of all vertebrates and their distribution has been studied in the human brain. The regions with the highest concentration of receptors are those of the limbic system. A high level exists also in the "substantia gelatinosa" of the spinal cord, which is involved in the passage of painful messages. Study of the function of morphine receptors has led to the isolation, in animal brain, of a number of peptides with morphine properties named endorphines. The first two endorphines isolated were pentapeptides named encephalins. The properties of endorphines from the subject of several lecture in this course.

  6. Two Distinct Central Serotonin Receptors with Different Physiological Functions

    Science.gov (United States)

    Peroutka, Stephen J.; Lebovitz, Richard M.; Snyder, Solomon H.

    1981-05-01

    Two distinct serotonin (5-hydroxytryptamine) receptors designated serotonin 1 and serotonin 2 bind tritium-labeled serotonin and tritium-labeled spiroperidol, respectively. Drug potencies at serotonin 2 sites, but not at serotonin 1 sites, predict their effects on the ``serotonin behavioral syndrome,'' indicating that serotonin 2 sites mediate these behaviors. The limited correlation of drug effects with regulation by guanine nucleotides suggests that serotonin 1 sites might be linked to adenylate cyclase. Drug specificities of serotonin-elicited synaptic inhibition and excitation may reflect serotonin 1 and serotonin 2 receptor interactions, respectively.

  7. Benzodiazepine use and mortality of incident dialysis patients in the United States.

    Science.gov (United States)

    Winkelmayer, W C; Mehta, J; Wang, P S

    2007-12-01

    Benzodiazepines and other omega-receptor agonists are frequently used for sleep and anxiety disorders. We studied the rates, correlates, and safety of individual benzodiazepines and zolpidem use from the records of 3690 patients in a national cohort of Dialysis Morbidity and Mortality Study Wave 2 data. We assessed drug utilization and an association between drug use and all-cause mortality. Overall, 14% of incident dialysis patients used a benzodiazepine or zolpidem. Women, Caucasians, current smokers, and patients with chronic obstructive pulmonary disease were more likely to use these drugs, whereas patients with cerebrovascular disease were less likely to use these drugs. In adjusted analyses, benzodiazepine or zolpidem use was associated with a 15% higher mortality rate. Chronic obstructive pulmonary disease significantly modified this association, suggesting that these patients were at higher risk. No association was found between benzodiazepine use and greater risk for hip fracture. We conclude that benzodiazepine or zolpidem use is common in incident dialysis patients and may be associated with greater mortality. Further studies are needed to elucidate the safety of these drugs in the dialysis population, which may lead to cautious and restrictive utilization of omega-receptor agonists in dialysis patients.

  8. Central nicotinic receptors: structure, function, ligands, and therapeutic potential.

    Science.gov (United States)

    Romanelli, M Novella; Gratteri, Paola; Guandalini, Luca; Martini, Elisabetta; Bonaccini, Claudia; Gualtieri, Fulvio

    2007-06-01

    The growing interest in nicotinic receptors, because of their wide expression in neuronal and non-neuronal tissues and their involvement in several important CNS pathologies, has stimulated the synthesis of a high number of ligands able to modulate their function. These membrane proteins appear to be highly heterogeneous, and still only incomplete information is available on their structure, subunit composition, and stoichiometry. This is due to the lack of selective ligands to study the role of nAChR under physiological or pathological conditions; so far, only compounds showing selectivity between alpha4beta2 and alpha7 receptors have been obtained. The nicotinic receptor ligands have been designed starting from lead compounds from natural sources such as nicotine, cytisine, or epibatidine, and, more recently, through the high-throughput screening of chemical libraries. This review focuses on the structure of the new agonists, antagonists, and allosteric ligands of nicotinic receptors, it highlights the current knowledge on the binding site models as a molecular modeling approach to design new compounds, and it discusses the nAChR modulators which have entered clinical trials.

  9. Process for determining the concentration of benzodiazepines in a body fluid

    Energy Technology Data Exchange (ETDEWEB)

    Braestrup, C.; Squires, R.F.

    1981-07-28

    A process for determining the concentration of benzodiazepines in a body liquid comprising the steps of contacting freeze-dried brain tissue with tritium labelled flunitrazepam to bond labelled flunitrazepam to receptor sites of the brain tissue, determining the concentration of labelled flunitrazepam of the brain tissue, incubating the brain tissue containing labelled flunitrazepam with a sample of body liquid containing benzodiazepine, the concentration of which is to be determined, to induce displacement of labelled flunitrazepam from said brain tissue, determining the concentration of labelled flunitrazepam bonded to the brain tissue after establishing equilibrium conditions and determining the concentration of benzodiazepine in the body liquid based on the change of concentration of labelled flunitrazepam induced by benzodiazepine contained in the sample.

  10. Learning and memory deficits in male adult mice treated with a benzodiazepine sleep-inducing drug during the juvenile period

    Directory of Open Access Journals (Sweden)

    Yusuke Furukawa

    2016-07-01

    Full Text Available Gamma-aminobutyric acid (GABA, the major inhibitory neurotransmitter in the mammalian central nervous system, is also known to be important for brain development. Therefore, disturbances of GABA receptor (GABA-R mediated signaling (GABA-R signal during brain development may influence normal brain maturation and cause late-onset brain malfunctions. In this study, we examined whether the temporal stimulation of the GABA-R signal during brain development induces late-onset adverse effects on the brain in adult male mice. To stimulate the GABA-R signal, we used either the benzodiazepine sleep-inducing drug triazolam (TZ or the non-benzodiazepine drug zolpidem (ZP. We detected deficits in learning and memory in mice treated with TZ during the juvenile period, as seen in the fear conditioning test. On the other hand, ZP administration during the juvenile period had little effect. In addition, decreased protein expression of GluR1 and GluR4, which are excitatory neurotransmitter receptors, was detected in the hippocampi of mice treated with TZ during the juvenile period. We measured mRNA expression of the immediate early genes (IEGs, which are neuronal activity markers, in the hippocampus shortly after the administration of TZ or ZP to juvenile mice. Decreased IEG expression was detected in mice with juvenile TZ administration, but not in mice with juvenile ZP administration. Our findings demonstrate that TZ administration during the juvenile period can induce irreversible brain dysfunction in adult mice. It may need to take an extra care for the prescription of benzodiazepine sleep-inducing drugs to juveniles because it might cause late onset learning and memory defects.

  11. Radiosynthesis of [{sup 11}C]D.P.A.-713, [{sup 11}C]D.P.A.-715 and [{sup 11}C]clinme, selected carbon-11-labelled novel potential radioligands for imaging the peripheral benzodiazepine receptors with PET

    Energy Technology Data Exchange (ETDEWEB)

    Dolle, F.; Thominiaux, C.; Hinnen, F.; Demphel, S.; Le helleix, S.; Chauveau, F.; Boutin, H.; Herard, A.S.; Hantraye, P.; Tavitian, B. [Service Hospitalier Frederic Joliot, I2BM/DSV, 91 - Orsay (France); Kassiou, M.; James, M.; Creelman, A.; Fulton, R. [Sydney Univ., Brain and Mind Research Institute, NSW (Australia); Kassiou, M. [Sydney Univ., Discipline of Medical Radiations, Sciences and School of Chemistry, NSW (Australia); Katsifis, A.; Greguric, I.; Mattner, F.; Loch, C. [Radiopharmaceuticals Research Institute, ANSTO, NSW (Australia); Selleri, S. [Degli Studi di Firenze Univ., Dipt. di Scienze Farmaceutiche (Italy)

    2008-02-15

    {sup 11}C P.K.11195 is not only the oldest, but also the most widely used PET radiotracer for in vivo imaging of the peripheral benzodiazepine receptors (P.B.R. or translocator protein (18 kDa, T.S.P.O.). With the aim of developing a new PET imaging probe for the in vivo study of the P.B.R., two pyrazol [1,5-a]pyrimidineacetamides (D.P.A.-713 and D.P.A.-715) and one imidazol[1,2-a]pyridine-acetamide (C.L.I.N.M.E.) were radiolabelled with the positron emitters carbon{sup 11} (half life: 20.38 min) [1-5]. Briefly, C.L.I.N.M.E. (2-[6-chloro-2(4-iodophenyl)-imidazol[1,2-a]pyridin-3-yl] -N-ethyl-N-methyl-acetamide) was labelled at its methyl-acetamide moity chain from the corresponding nor-analogue using[{sup 11}C]methyl iodide (in D.M.S.O./D.M.F (100/200 {mu}L) containing powdered K.O.H. (3-5 mg) at 110 degrees C for 3 min. D.P.A.-713 (N,N-diethyl-2-[2-(4-methoxy-phenyl)-5,7-dimethyl-pyrazolo[1,5-a]pyrimidin -3-yl]acetamide) and D.P.A.-715 (N,N-diethyl-2-[2-(4-methoxy-phenyl)-5,7-bis-tri-fluoro-methyl-pyrazolo [1,5-a]pyrimidin-3-yl]acetamide) were labelled at their aromatic methoxy groups from the corresponding nor-derivatives using [{sup 11}C]methyl triflate (in acetone (300{mu}L) containing aq. 3 M NaOH (4{mu}L) at 110 degrees C for 1 min). All radioligands were purified using semi preparative Zorbax reverse phase H.P.L.C., were adequately formulated for in vivo injection within 30 min and were found to be > 95% chemically and radiochemically pure. (N.C.)

  12. [{sup 18}F]D.P.A.-714: a novel fluorine-18-labelled pyrazolo[1,5-a]pyrimidine acetamide for imaging the peripheral benzodiazepine receptors with PET - radiosynthesis on a zymate-xp robotic system

    Energy Technology Data Exchange (ETDEWEB)

    Dolle, F.; Damont, A.; Hinnen, F.; Kuhnast, B.; Chauveau, F.; Van camp, N.; Hantraye, P.; Tavitian, B. [Servvice Hospitalier Frederic Joliot, I2BM/DSV, 91 - Orsay (France); James, M.; Creelman, A.; Fulton, R.; Kassiou, M. [Sydney Univ., Brain and Mind Research Institute, NSW (Australia); Vercouillie, J.; Guilloteau, D. [Universite Francois Rabelais de Tours, 37 (France); Vercouillie, J.; Guilloteau, D. [Centre Hospitalier Regional Universitaire, 37 - Tours (France); Selleri, S.; Kassiou, M. [Sydney Univ., Discipline of Medical Radiations, Sciences and School of Chemistry, NSW (Australia)

    2008-02-15

    {sup 11}C D.P.A.-713 (N,N-diethyl-2-[2-(4-[{sup 11}C]methoxy-phenyl)-5,7-dimethyl-pyrazolo [1,5-a]pyrimidin-3-yl]acetamide) is a recently developed carbon-11-labelled (half life: 20.4 min)pyrazolo[1,5-a]pyrimidine acetamide for the in vivo imaging of the peripheral benzodiazepine receptors (P.B.R. or translocator protein (18 kDa, T.S.P.O.)). Preliminary results obtained in a rodent-model demonstrates that {sup 11}C D.P.A.-713 showed a high potential to in vivo image neuro-inflammation and additionally, this radioligand allowed a higher contrast between the lesioned area and the corresponding area in the intact contralateral hemisphere when compared to the radioligand of reference. D.P.A-714 (N,N-diethyl-2-[2-[4-(2-fluoro-ethoxy)phenyl] -5,7-dimethyl-pyrazolo[1,5-a]pyrimidin-3-yl]acetamide), a chemically closely related derivative of D.P.A.-713, had been designed with a fluorine atom in its structure, allowing ultimate labelling with fluorine-18, a longer-lived positron-emitter (half life:109.8 min) and today one of the most attractive PET isotopes for radiopharmaceutical chemistry. D.P.A.-714 as well as its corresponding tosylated derivative have been re-synthesized in 2 chemicals steps from D.P.A.-713. D.P.A.-714 has then been labelled at its aromatic fluoro-ethoxy group from the corresponding tosyl-derivative using the K{sup 18}FF-kryptofix{sub 222} (in CH{sub 3}CN (3 mL) at 85 degrees C for 5 min or D.M.S.O. (600 {mu}L) at 130 degrees C for 5 min). {sup 18}FD.P.A.-714 was then purified using semi preparative X terra reverse phase H.P.L.C., adequately formulated for i.v. injection and was found to be > 95% chemically and radiochemically pure. The total synthesis time was less than 90 min and the specific radioactivities at the end of the radiosynthesis ranged from 1 to 3 Ci/micro-mole. (N.C.)

  13. Synthesis and evaluation of N-(5-fluoro-2-phenoxyphenyl)-N-(2-[(18)F]fluoromethoxy-d(2)-5-methoxybenzyl)acetamide: a deuterium-substituted radioligand for peripheral benzodiazepine receptor.

    Science.gov (United States)

    Zhang, Ming-Rong; Maeda, Jun; Ito, Takehito; Okauchi, Takashi; Ogawa, Masanao; Noguchi, Junko; Suhara, Tetsuya; Halldin, Christer; Suzuki, Kazutoshi

    2005-03-01

    N-(5-Fluoro-2-phenoxyphenyl)-N-(2-[(18)F]fluoromethoxy-d(2)-5-methoxybenzyl)acetamide ([(18)F]2) is a potent ligand (IC(50): 1.71 nM) for peripheral benzodiazepine receptor (PBR). However, in vivo evaluation on rodents and primates showed that this ligand was unstable and rapidly metabolized to [(18)F]F(-) by defluorination of the [(18)F]fluoromethyl moiety. In this study, we designed a deuterium-substituted analogue, N-(5-fluoro-2-phenoxyphenyl)-N-(2-[(18)F]fluoromethoxy-d(2)-5-methoxybenzyl)acetamide ([(18)F]5) as a radioligand for PBR to reduce the in vivo metabolic rate of the non-deuterated [(18)F]2. The design principle was based on the hypothesis that the deuterium substitution may reduce the rate of defluorination initiated by cleavage of the C-H bond without altering the binding affinity for PBR. The non-radioactive 5 was prepared by reacting diiodomethane-d(2) (CD(2)I(2), 6) with a phenol precursor 7, followed by treatment with tetrabutylammonium fluoride. The ligand [(18)F]5 was synthesized by the alkylation of 7 with [(18)F]fluoromethyl iodide-d(2) ([(18)F]FCD(2)I, [(18)F]9). Compound 5 displayed a similar in vitro affinity to PBR (IC(50): 1.90 nM) with 2. In vivo evaluation demonstrated that [(18)F]5 was metabolized by defluorination to [(18)F]F(-) as a main radioactive component, but its metabolic rate was slower than that of [(18)F]2 in the brain of mice. The deuterium substitution decreased the radioactivity level of [(18)F]5 in the bone of mouse, augmented by the percentage of specific binding to PBR in the rat brain determined by ex vivo autoradiography. However, the PET image of [(18)F]5 for monkey brain showed high radioactivity in the brain and skull, suggesting a possible species difference between rodents and primates.

  14. Development of a new radioligand, N-(5-fluoro-2-phenoxyphenyl)-N-(2-[18F]fluoroethyl-5-methoxybenzyl)acetamide, for pet imaging of peripheral benzodiazepine receptor in primate brain.

    Science.gov (United States)

    Zhang, Ming-Rong; Maeda, Jun; Ogawa, Masanao; Noguchi, Junko; Ito, Takehito; Yoshida, Yuichiro; Okauchi, Takashi; Obayashi, Shigeru; Suhara, Tetsuya; Suzuki, Kazutoshi

    2004-04-22

    To develop a positron emission tomography (PET) ligand for imaging the 'peripheral benzodiazepine receptor' (PBR) in brain and elucidating the relationship between PBR and brain diseases, four analogues (4-7) of N-(2,5-dimethoxybenzyl)-N-(5-fluoro-2-phenoxyphenyl)acetamide (2) were synthesized and evaluated as ligands for PBR. Of these compounds, fluoromethyl (4) and fluoroethyl (5) analogues had similar or higher affinities for PBR than the parent compound 2 (K(i) = 0.16 nM for PBR in rat brain sections). Iodomethyl analogue 6 displayed a moderate affinity, whereas tosyloxyethyl analogue 7 had weak affinity. Radiolabeling was performed for the fluoroalkyl analogues 4 and 5 using fluorine-18 ((18)F, beta(+); 96.7%, T(1/2) = 109.8 min). Ligands [(18)F]4 and [(18)F]5 were respectively synthesized by the alkylation of desmethyl precursor 3 with [(18)F]fluoromethyl iodide ([(18)F]8) and 2-[(18)F]fluoroethyl bromide ([(18)F]9). The distribution patterns of [(18)F]4 and [(18)F]5 in mice were consistent with the known distribution of PBR. However, compared with [(18)F]5, [(18)F]4 displayed a high uptake in the bone of mice. The PET image of [(18)F]4 for monkey brain also showed significant radioactivity in the bone, suggesting that this ligand was unstable for in vivo defluorination and was not a useful PET ligand. Ligand [(18)F]5 displayed a high uptake in monkey brain especially in the occipital cortex, a region with richer PBR than the other regions in the brain. The radioactivity level of [(18)F]5 in monkey brain was 1.5 times higher than that of [(11)C]2, and 6 times higher than that of (R)-(1-(2-chlorophenyl)-N-[(11)C]methyl,N-(1-methylpropyl)isoquinoline ([(11)C]1). Moreover, the in vivo binding of [(18)F]5 was significantly inhibited by PBR-selective 2 or 1, indicating that the binding of [(18)F]5 in the monkey brain was mainly due to PBR. Metabolite analysis revealed that [(18)F]4 was rapidly metabolized by defluorination to [(18)F]F(-) in the plasma and brain of

  15. Small Molecule Receptor Ligands for PET Studies of the Central Nervous System-Focus on G Protein Coupled Receptors.

    Science.gov (United States)

    Mach, Robert H

    2017-09-01

    G protein-coupled receptors (GPRCs) are a class of proteins that are expressed in high abundance and are responsible for numerous signal transduction pathways in the central nervous system. Consequently, alterations in GPRC function have been associated with a wide variety of neurologic and neuropsychiatric disorders. The development of PET probes for imaging GPRCs has served as a major emphasis of PET radiotracer development and PET imaging studies over the past 30 years. In this review, a basic description of the biology of G proteins and GPRCs is provided. This includes recent evidence of the existence of dimeric and multimeric species of GPRCs that have been termed "receptor mosaics," with an emphasis on the different GPRCs that form complexes with the dopamine D2 receptor. An overview of the different PET radiotracers for imaging the component GPRC within these different multimeric complexes of the D2 receptor is also provided. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Benzodiazepine dependence: focus on withdrawal syndrome.

    Science.gov (United States)

    Authier, N; Balayssac, D; Sautereau, M; Zangarelli, A; Courty, P; Somogyi, A A; Vennat, B; Llorca, P-M; Eschalier, A

    2009-11-01

    Benzodiazepines are potentially addictive drugs: psychological and physical dependence can develop within a few weeks or years of regular or repeated use. The socioeconomic costs of the present high level of long-term benzodiazepine use are considerable. These consequences could be minimised if prescriptions for long-term benzodiazepines were decreased. However, many physicians continue to prescribe benzodiazepines and patients wishing to withdraw receive little advice or support. Particular care should be taken in prescribing benzodiazepines for vulnerable patients such as elderly persons, pregnant women, children, alcohol- or drug-dependent patients and patients with comorbid psychiatric disorders. The following update gives recent research results on the withdrawal pathophysiology and practical information in order to treat or prevent benzodiazepine withdrawal syndrome.

  17. Benzodiazepine metabolism: an analytical perspective.

    Science.gov (United States)

    Mandrioli, Roberto; Mercolini, Laura; Raggi, Maria Augusta

    2008-10-01

    Benzodiazepines are currently among the most frequently prescribed drugs all over the world. They act as anxiolytics, sedatives, hypnotics, amnesics, antiepileptics and muscle relaxants. Despite their common chemical scaffold, these drugs differ in their pharmacokinetic and metabolic properties. In particular, they are biotransformed by different cytochrome P450 isoforms and also by different UDP-glucuronosyltransferase subtypes. The most important studies on the metabolic characteristics of several 1,4-benzodiazepines, carried out from 1998 onwards, are reported and briefly discussed in this review. Moreover, the analytical methods related to these studies are also described and commented upon and their most important characteristics are highlighted. Most methods are based on liquid chromatography, which provides wide applicability and good analytical performance granting high precision, accuracy and feasibility. Mass spectrometry is gaining widespread acceptance, particularly if the matrix is very complex and variable, such as human or animal blood. However, spectrophotometric detection is still used for this purpose and can grant sufficient selectivity and sensitivity when coupled to suitable sample pre-treatment procedures. A monograph is included for each of the following benzodiazepines: alprazolam, bromazepam, brotizolam, clotiazepam, diazepam, etizolam, flunitrazepam, lorazepam, midazolam, oxazepam and triazolam.

  18. [The addicted patient in anaesthesia - benzodiazepine dependence].

    Science.gov (United States)

    Schneemilch, Christine; Brinkers, Michael

    2015-06-01

    As a result of the demographic change, the proportions of elderly patients undergoing operations and anesthesia are increasingly important. The consumption of benzodiazepines evidently rises with increasing age. Associated with the increasing consumption in the elderly is the risk of cognitive impairment, delirium, falls and fractures. Also long-term benzodiazepine use in low-dose may induce perioperative withdrawal syndrome. The following article will present characteristics and complications accompanied by critical benzodiazepine use especially in the elderly patients.

  19. Relation of central alpha-adrenoceptor and other receptors to the control of renin secretion.

    Science.gov (United States)

    Ganong, W F

    1983-02-01

    The location and nature of the receptors in the brain on which clonidine acts to decrease renin secretion have been investigated in dogs. Clonidine was injected into the vertebral and carotid arteries, and its effects were compared with those of norepinephrine and epinephrine when injected into the third ventricle. It was also injected intravenously (IV) after transection of the brain stem and following treatment with intraventricular 6-hydroxydopamine. The results suggest that the renin-regulating receptors are located in the brain stem in a region different from the receptors mediating the depressor response, that they are alpha 2-adrenoceptors, and that they are postsynaptic in location. Central alpha 1-adrenoceptors appear to mediate increased renin secretion. Central serotonergic receptors also mediate increased renin secretion, but it is not known how the alpha 1- and alpha 2-adrenoceptors interact with the serotonergic systems.

  20. Do benzodiazepines contribute to respiratory problems?

    Science.gov (United States)

    Vozoris, Nicholas T

    2014-12-01

    Non-selective benzodiazepines are a class of sedative and anxiolytic medication that are commonly prescribed. Physiology studies and animal studies suggest that non-selective benzodiazepines may adversely impact respiration through a variety of mechanisms. Several recent, well-designed, population-based observational studies confirm that benzodiazepine-related negative respiratory outcomes are a concern. In this article, the mechanisms and clinical evidence for non-selective benzodiazepine-related adverse respiratory outcomes, as well as the methodological issues relating to the evaluation of adverse drug effects are reviewed.

  1. The effects of lorazepam on extrastriatal dopamine D(2/3)-receptors-A double-blind randomized placebo-controlled PET study.

    Science.gov (United States)

    Vilkman, Harry; Kajander, Jaana; Aalto, Sargo; Vahlberg, Tero; Någren, Kjell; Allonen, Topias; Syvälahti, Erkka; Hietala, Jarmo

    2009-11-30

    Lorazepam is a widely used anxiolytic drug of the benzodiazepine class. The clinical actions of benzodiazepines are thought to be mediated via specific allosteric benzodiazepine binding sites and enhancement of GABAergic neurotransmission in the brain. However, the indirect effects of benzodiazepines on other neurotransmitter systems have not been extensively studied. Previous experimental evidence suggests that benzodiazepines inhibit striatal dopamine release by enhancing the GABAergic inhibitory effect on dopamine neurons whereas very little is known about cortical or thalamic gamma-amino-butyric (GABA)-dopamine interactions during benzodiazepine administration. We explored the effects of lorazepam (a single 2.5 mg dose) on cortical and thalamic D(2/3) receptor binding using Positron-Emission Tomography (PET) and the high-affinity D(2/3)-receptor ligand [(11)C]FLB 457 in 12 healthy male volunteers. We used a randomized, double-blind and placebo-controlled study design. Dopamine D(2)/D(3) receptor binding potential was measured with the reference tissue method in several extrastriatal D(2)-receptor areas including frontal, parietal, temporal cortices and thalamus. The main subjective effect of lorazepam was sedation. Lorazepam induced a statistically significant decrease of D(2)/D(3) receptor BP(ND) in medial temporal and dorsolateral prefrontal cortex (DLPFC) that was also confirmed by a voxel-level analysis. The sedative effect of lorazepam was associated with a decrease in D(2)/D(3) receptor BP(ND) in the DLPFC. In conclusion, lorazepam decreased [(11)C]FLB 457 binding in frontal and temporal cortex, suggesting that cortical GABA-dopamine interaction may be involved in the central actions of lorazepam in healthy volunteers. The correlation between lorazepam-induced sedation and D(2)/D(3) receptor binding potential (BP) change further supports this hypothesis.

  2. Attention Span, Anxiety and Benzodiazepine Receptors

    Science.gov (United States)

    1991-02-26

    membranes from Ro 15-1788 exposed animals: in the nontreated animals, CABA +NaCl significantly increased the Bmax by 11% (Pɘ.OI), while in the Ro 15-1788...3Hlflunitrazepam binding (Squires, 1981). Thus, the small but significant increase in Bmax values might represent cooperativity of CABA and NaCI in...facilitating [ 3 Hjflunitrazepam binding. 9. TABLE 2 CABA (10 tiM) +~ NaCl (200 m;’) enhancement of 13H-1flunitrazeoam binding to synaptosomal membranes of

  3. Benzodiazepines and postoperative cognitive dysfunction in the elderly

    DEFF Research Database (Denmark)

    Rasmussen, L.S.; Steentoft, Anni; Rasmussen, H.

    1999-01-01

    hypnotics benzodiazepine,diazepam,age factor,anaesthesia,geriatric,psychological responses,postoperative......hypnotics benzodiazepine,diazepam,age factor,anaesthesia,geriatric,psychological responses,postoperative...

  4. Cannabinoid CB1 receptor-interacting proteins: novel targets for central nervous system drug discovery?

    Science.gov (United States)

    Smith, Tricia H; Sim-Selley, Laura J; Selley, Dana E

    2010-06-01

    The main pharmacological effects of marijuana, as well as synthetic and endogenous cannabinoids, are mediated through G-protein-coupled receptors (GPCRs), including CB(1) and CB(2) receptors. The CB(1) receptor is the major cannabinoid receptor in the central nervous system and has gained increasing interest as a target for drug discovery for treatment of nausea, cachexia, obesity, pain, spasticity, neurodegenerative diseases and mood and substance abuse disorders. Evidence has accumulated to suggest that CB(1) receptors, like other GPCRs, interact with and are regulated by several other proteins beyond the established role of heterotrimeric G-proteins. These proteins, which include the GPCR kinases, beta-arrestins, GPCR-associated sorting proteins, factor associated with neutral sphingomyelinase, other GPCRs (heterodimerization) and the novel cannabinoid receptor-interacting proteins: CRIP(1a/b), are thought to play important roles in the regulation of intracellular trafficking, desensitization, down-regulation, signal transduction and constitutive activity of CB(1) receptors. This review examines CB(1) receptor-interacting proteins, including heterotrimeric G-proteins, but with particular emphasis on non-G-protein entities, that might comprise the CB(1) receptosomal complex. The evidence for direct interaction with CB(1) receptors and potential functional roles of these interacting proteins is discussed, as are future directions and challenges in this field with an emphasis on the possibility of eventually targeting these proteins for drug discovery.

  5. Prescribing of benzodiazepines by casualty officers.

    OpenAIRE

    1989-01-01

    The prescribing of benzodiazepines by casualty officers in a busy district hospital over a three month period was examined by a retrospective review of case notes. Benzodiazepines, mainly diazepam, were given to 1.1% of attenders, the majority of whom had disorders involving minor muscle spasm. The efficacy of diazepam in these conditions, as well as its potential for dependence, is discussed.

  6. Targeting the chemokine receptor CXCR3 and its ligand CXCL10 in the central nervous system

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke

    2004-01-01

    focuses on the present data regarding CXCL10 (previously known as IP-10) and CXRC3 in multiple sclerosis, since consistent data has suggested that this chemokine/chemokine receptor pair has a pivotal role in leukocyte recruitment into the central nervous system (CNS) in multiple sclerosis....

  7. Thyroid Hormone Receptor beta Mediates Acute Illness-Induced Alterations in Central Thyroid Hormone Metabolism

    NARCIS (Netherlands)

    A. Boelen; J. Kwakkel; O. Chassande; E. Fliers

    2009-01-01

    Acute illness in mice profoundly affects thyroid hormone metabolism in the hypothalamus and pituitary gland. It remains unknown whether the thyroid hormone receptor (TR)-beta is involved in these changes. In the present study, we investigated central thyroid hormone metabolism during lipopolysacchar

  8. Management of benzodiazepine misuse and dependence.

    Science.gov (United States)

    Brett, Jonathan; Murnion, Bridin

    2015-10-01

    There are well-recognised harms from long-term use of benzodiazepines. These include dependency, cognitive decline and falls. It is important to prevent and recognise benzodiazepine dependence. A thorough risk assessment guides optimal management and the necessity for referral. The management of dependence involves either gradual benzodiazepine withdrawal or maintenance treatment. Prescribing interventions, substitution, psychotherapies and pharmacotherapies can all contribute. Unless the patient is elderly, it is helpful to switch to a long-acting benzodiazepine in both withdrawal and maintenance therapy. The dose should be gradually reduced over weeks to lower the risk of seizures. Harms from drugs such as zopiclone and zolpidem are less well characterised. Dependence is managed in the same manner as benzodiazepine dependence.

  9. Benzodiazepines: risks and benefits. A reconsideration.

    Science.gov (United States)

    Baldwin, David S; Aitchison, Katherine; Bateson, Alan; Curran, H Valerie; Davies, Simon; Leonard, Brian; Nutt, David J; Stephens, David N; Wilson, Sue

    2013-11-01

    Over the last decade there have been further developments in our knowledge of the risks and benefits of benzodiazepines, and of the risks and benefits of alternatives to benzodiazepines. Representatives drawn from the Psychopharmacology Special Interest Group of the Royal College of Psychiatrists and the British Association for Psychopharmacology together examined these developments, and have provided this joint statement with recommendations for clinical practice. The working group was mindful of widespread concerns about benzodiazepines and related anxiolytic and hypnotic drugs. The group believes that whenever benzodiazepines are prescribed, the potential for dependence or other harmful effects must be considered. However, the group also believes that the risks of dependence associated with long-term use should be balanced against the benefits that in many cases follow from the short or intermittent use of benzodiazepines and the risk of the underlying conditions for which treatment is being provided.

  10. Involvement of central TRPV1 receptors in pentylenetetrazole and amygdala-induced kindling in male rats.

    Science.gov (United States)

    Shirazi, Mohsen; Izadi, Mahin; Amin, Masoud; Rezvani, Mohammad Ebrahim; Roohbakhsh, Ali; Shamsizadeh, Ali

    2014-08-01

    Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel that is involved in modulation of diverse physiological processes. The role of this receptor in epilepsy has not been studied well. Therefore, we investigated the role of central TRPV1 receptors on the development of pentylenetetrazole (PTZ) and amygdala-induced kindling in rats. Male Wistar rats received subconvulsive dose of PTZ intraperitoneally, every other day. TRPV1 receptor agonist, OLDA and its antagonist, AMG-9810 were injected intracerebroventricularly 30 min prior to PTZ administration. In electrical kindling, stimulating and recording electrodes were implanted in the right amygdala of male rats. After kindling, the effect of TRPV1 receptor agonist or antagonist on afterdischarge duration (ADD), latency to the onset of bilateral forelimb clonuses (S4L) and duration of loss of equilibrium (stage 5 seizures, S5D) were measured. The results demonstrated that, OLDA at the doses of 0.01, 0.1 and 1 μg/rat, significantly accelerated the incidence of all seizure stages, increased S5D and decreased S4L in the PTZ model of kindling. Also, in amygdala kindling, S5D and ADD were significantly reduced following the administration of AMG-9810. In contrast, OLDA significantly aggravated the indices of seizure in both models of epileptic seizure. This study demonstrated that central TRPV1 receptors may be involved in the development of electrical and PTZ-induced kindling.

  11. On the existence and function of galanin receptor heteromers in the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Kjell eFuxe

    2012-10-01

    Full Text Available Galanin receptor (GalR subtypes1-3 linked to central galanin neurons may form heteromers with each other and other types of G protein coupled receptors (GPCRs in the Central Nervous System (CNS. These heteromers may be one molecular mechanism for galanin peptides and their N-terminal fragments (gal 1-15 to modulate the function of different types of glia-neuronal networks in the CNS, especially the emotional and the cardiovascular networks. GalR-5-HT1A heteromers likely exist with antagonistic GalR-5-HT1A receptor-receptor interactions in the ascending midbrain raphe 5-HT neuron systems and their target regions. They represent a novel target for antidepressant drugs. Evidence is given for the existence of GalR1-5-HT1A heteromers in cellular models with transinhibition of the protomer signaling. A GalR1-GalR2 heteromer is proposed to be a galanin N-terminal fragment preferring receptor (1-15 in the CNS. Furthermore, a GalR1-GalR2-5-HT1A heterotrimer is postulated to explain why only galanin (1-15 but not galanin (1-29 can antagonistically modulate the 5-HT1A receptors in the dorsal hippocampus rich in gal fragment binding sites. The results underline a putative role of different types of GalR-5-HT1A heteroreceptor complexes in depression. GalR antagonists may also have therapeutic actions in depression by blocking the antagonistic GalR-NPYY1 receptor interactions in putative GalR-NPYY1 receptor heteromers in the CNS resulting in increases in NPYY1 transmission and antidepressant effects. In contrast the galanin fragment receptor (a postulated GalR1-GalR2 heteromer appears to be linked to the NPYY2 receptor enhancing the affinity of the NPYY2 binding sites in a putative GalR1-GalR2-NPYY2 heterotrimer. Finally, putative GalR-α2-adrenoreceptor heteromers with antagonistic receptor-receptor interactions may be a widespread mechanism in the CNS for integration of galanin and noradrenaline signals also of likely relevance for depression.

  12. Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation

    Science.gov (United States)

    Busquets-Garcia, Arnau; Gomis-González, Maria; Srivastava, Raj Kamal; Cutando, Laura; Ortega-Alvaro, Antonio; Ruehle, Sabine; Remmers, Floortje; Bindila, Laura; Bellocchio, Luigi; Marsicano, Giovanni; Lutz, Beat; Maldonado, Rafael

    2016-01-01

    Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories. We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation. Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific cell types revealed that the CB1 receptor population specifically in dopamine β-hydroxylase (DBH)-expressing cells is both necessary and sufficient for stress-induced impairment of memory consolidation, but CB1 receptors present in other neuronal populations are not involved. Strikingly, pharmacological manipulations in mice expressing CB1 receptors exclusively in DBH+ cells revealed that both hippocampal and peripheral receptors mediate the impact of stress on memory consolidation. Thus, CB1 receptors on adrenergic and noradrenergic cells provide previously unrecognized cross-talk between central and peripheral mechanisms in the stress-dependent regulation of nonemotional memory consolidation, suggesting new potential avenues for the treatment of cognitive aspects on stress-related disorders. PMID:27528659

  13. Assessing the efficacy of melatonin to curtail benzodiazepine/Z drug abuse.

    Science.gov (United States)

    Cardinali, Daniel P; Golombek, Diego A; Rosenstein, Ruth E; Brusco, Luis I; Vigo, Daniel E

    2016-07-01

    The abuse of benzodiazepine (BZP) and Z drugs has become, due to the tolerance and dependence they produce, a serious public health problem. Thirty years ago, we demonstrated in experimental animals the interaction of melatonin with central BZD receptors, and in 1997 we published the first series of elderly patients who reduced BZP consumption after melatonin treatment. Almost every single neuron in the hypothalamic suprachiasmatic nuclei (SCN), the central pacemaker of the circadian system, contains γ-aminobutyric acid (GABA) and many results in animals point out to a melatonin interaction with GABA-containing neurons. In addition, central-type BZD antagonism, that obliterates GABAA receptor function, blunted most behavioral effects of melatonin including sleep. Melatonin is involved in the regulation of human sleep. This is supported by the temporal relationship between the rise of plasma melatonin levels and sleep propensity as well as by the sleep-promoting effects of exogenously administered melatonin. Both meta-analyses and consensus agreements give support to the therapeutic use of melatonin in sleep disorders. This action is attributed to MT1 and MT2 melatoninergic receptors localized in the SCN, as well as in other brain areas. This review discusses available data on the efficacy of melatonin to curtail chronic BZD/Z drug use in insomnia patients. A major advantage is that melatonin has a very safe profile, it is usually remarkably well tolerated and, in some studies, it has been administered to patients at very large doses and for long periods of time, without any potentiality of abuse. Further studies on this application of melatonin are warranted.

  14. 21 CFR 862.3170 - Benzodiazepine test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Benzodiazepine test system. 862.3170 Section 862....3170 Benzodiazepine test system. (a) Identification. A benzodiazepine test system is a device intended to measure any of the benzodiazepine compounds, sedative and hypnotic drugs, in blood, plasma,...

  15. Application of radioreceptor assay of benzodiazepines for toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, L.; Scheinin, M. (Department of Pharmacology and the Department of Internal Medicine, University of Turku, Finland)

    1982-01-01

    A radioreceptor assay (RRA) for determining benzodiazepines (BZ) has been developed and applied to toxicological analysis of serum samples from 21 patients with acute BZ overdosage. The method was sensitive (e.g., lorazepam 17 nM, diazepam 41 nM), and specific for pharmacologically active BZ derivatives. The reproducibility of the results was good (intra-assay variation < 8%, inter-assay variation < 10%). Concentrations measured by the RRA showed a good correlation with those obtained by gas-liquid chromatographic analysis of the same samples. The quantitative results represent the sum of one or several parent substances and all biologically active metabolites, in proportion to their receptor binding affinities.

  16. AHR-11797: a novel benzodiazepine antagonist

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.N.; Kilpatrick, B.F.; Hannaman, P.K.

    1986-03-01

    AHR-11797(5,6-dihydro-6-methyl-1-phenyl-/sup 3/H-pyrrolo(3,2,1-ij)quinazolin-3-one) displaced /sup 3/H-flunitrazepam (IC/sub 50/ = 82 nM) and /sup 3/H-Ro 15-1877 (IC/sub 50/ = 104 nM) from rat brain synaptosomes. AHR-11797 did not protect mice from seizures induced by maximal electroshock or subcutaneous Metrazol (scMET), nor did it induce seizures in doses up to the lethal dose. However, at 31.6 mg/kg, IP, it significantly increased the anticonvulsant ED/sub 50/ of chlordiazepoxide (CDPX) from 1.9 to 31.6 mg/kg, IP. With 56.7 mg/kg, IP, of AHR-11797, CDPX was inactive in doses up to 100 mg/kg, IP. AHR-11797 did not significantly increase punished responding in the Geller and Seifter conflict procedure, but it did attenuate the effects of diazepam. Although the compound is without anticonvulsant or anxiolytic activity, it did have muscle relaxant properties. AHR-11797 blocked morphine-induced Straub tail in mice (ED/sub 50/ = 31 mg/kg, IP) and it selectively suppressed the polysnaptic linguomandibular reflex in barbiturate-anesthetized cats. The apparent muscle relaxant activity of AHR-11797 suggests that different receptor sites are involved for muscle relaxant vs. anxiolytic/anticonvulsant activities of the benzodiazepines.

  17. [Knowledge regarding Proper Use Guidelines for Benzodiazepines].

    Science.gov (United States)

    Inada, Ken

    2016-01-01

      Benzodiazepines (BZs) work by agonising gamma-aminobutyric acid (GABA)-BZ-receptor complex and thereby produce sedation and anti-anxiety effects. BZs are commonly used in several clinical areas as hypnotics or anti-anxiety drugs. However, these drugs once supplied by medical institutions often lead to abuse and dependence. Thus it is important for institutions to supply and manage BZs properly. At Tokyo Women's Medical University Hospital educational activities about proper use of BZs are performed by not only medical doctors but also pharmacists. We coordinate distribution of leaflets and run an educational workshop. As a result of these activities, the number of patients receiving BZ prescriptions was reduced. Performing these activities, pharmacists were required to work for patients, doctors, and nurses; they acquired knowledge about BZs such as action mechanisms, efficacy, adverse effects, problems about co-prescription, and methods of discontinuing BZs, as well as information on coping techniques other than medication. The most important point to attend the patients is to answer their anxieties.

  18. Perceptions of Benzodiazepine Dependence Among Women Age 65 and Older

    OpenAIRE

    Canham, Sarah L.; Gallo, Joseph; Simoni-Wastila, Linda

    2014-01-01

    A phenomenological study explored whether older women who are chronic benzodiazepine users identified themselves as dependent, how dependence was perceived, and how meanings and understandings shaped experiences of benzodiazepine use. Self-reported benzodiazepine dependence was associated with being unable to reduce use or a desire to discontinue use and reliance on benzodiazepines to remain comfortable and able to handle daily life. Themes included: 1) benzodiazepine dependence is similar to...

  19. Benzodiazepines consumption: does dependence vary with age?

    Science.gov (United States)

    Gérardin, Marie; Victorri-Vigneau, Caroline; Guerlais, Marylène; Guillou-Landreat, Morgane; Grall-Bronnec, Marie; Jolliet, Pascale

    2014-09-01

    We have compared two groups of chronic benzodiazepines (or zolpidem/zopiclone) users: "Seniors," aged 65 years or more, and "Adults," aged less than 65 years. The study took place in the Pays de Loire region. The questionnaire assesses dependence based on items from the DSM-IV. The analysis was based on 176 Senior questionnaires and 212 Adult questionnaires. Whereas Senior patients take benzodiazepines routinely with little negative consequences, Adults suffer from underlying psychological trouble, mention a higher consumption than planned, which causes negative consequences. 35.2% of Seniors are dependent on benzodiazepines versus 49.8% of Adults.

  20. On the G-Protein-Coupled Receptor Heteromers and Their Allosteric Receptor-Receptor Interactions in the Central Nervous System: Focus on Their Role in Pain Modulation

    Directory of Open Access Journals (Sweden)

    Dasiel O. Borroto-Escuela

    2013-01-01

    Full Text Available The modulatory role of allosteric receptor-receptor interactions in the pain pathways of the Central Nervous System and the peripheral nociceptors has become of increasing interest. As integrators of nociceptive and antinociceptive wiring and volume transmission signals, with a major role for the opioid receptor heteromers, they likely have an important role in the pain circuits and may be involved in acupuncture. The delta opioid receptor (DOR exerts an antagonistic allosteric influence on the mu opioid receptor (MOR function in a MOR-DOR heteromer. This heteromer contributes to morphine-induced tolerance and dependence, since it becomes abundant and develops a reduced G-protein-coupling with reduced signaling mainly operating via β-arrestin2 upon chronic morphine treatment. A DOR antagonist causes a return of the Gi/o binding and coupling to the heteromer and the biological actions of morphine. The gender- and ovarian steroid-dependent recruitment of spinal cord MOR/kappa opioid receptor (KOR heterodimers enhances antinociceptive functions and if impaired could contribute to chronic pain states in women. MOR1D heterodimerizes with gastrin-releasing peptide receptor (GRPR in the spinal cord, mediating morphine induced itch. Other mechanism for the antinociceptive actions of acupuncture along meridians may be that it enhances the cross-desensitization of the TRPA1 (chemical nociceptor-TRPV1 (capsaicin receptor heteromeric channel complexes within the nociceptor terminals located along these meridians. Selective ionotropic cannabinoids may also produce cross-desensitization of the TRPA1-TRPV1 heteromeric nociceptor channels by being negative allosteric modulators of these channels leading to antinociception and antihyperalgesia.

  1. Central Administration of Galanin Receptor 1 Agonist Boosted Insulin Sensitivity in Adipose Cells of Diabetic Rats

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    Zhenwen Zhang

    2016-01-01

    Full Text Available Our previous studies testified the beneficial effect of central galanin on insulin sensitivity of type 2 diabetic rats. The aim of the study was further to investigate whether central M617, a galanin receptor 1 agonist, can benefit insulin sensitivity. The effects of intracerebroventricular administration of M617 on insulin sensitivity and insulin signaling were evaluated in adipose tissues of type 2 diabetic rats. The results showed that central injection of M617 significantly increased plasma adiponectin contents, glucose infusion rates in hyperinsulinemic-euglycemic clamp tests, GLUT4 mRNA expression levels, GLUT4 contents in plasma membranes, and total cell membranes of the adipose cells but reduced the plasma C-reactive protein concentration in nondiabetic and diabetic rats. The ratios of GLUT4 contents were higher in plasma membranes to total cell membranes in both nondiabetic and diabetic M617 groups than each control. In addition, the central administration of M617 enhanced the ratios of pAkt/Akt and pAS160/AS160, but not phosphorylative cAMP response element-binding protein (pCREB/CREB in the adipose cells of nondiabetic and diabetic rats. These results suggest that excitation of central galanin receptor 1 facilitates insulin sensitivity via activation of the Akt/AS160 signaling pathway in the fat cells of type 2 diabetic rats.

  2. AMPA receptor trafficking in inflammation-induced dorsal horn central sensitization

    Institute of Scientific and Technical Information of China (English)

    Yuan-Xiang Tao

    2012-01-01

    Activity-dependent postsynaptic receptor trafficking is critical for long-term synaptic plasticity in the brain,but it is unclear whether this mechanism actually mediates the spinal cord dorsal horn central sensitization (a specific form of synaptic plasticity) that is associated with persistent pain.Recent studies have shown that peripheral inflammation drives changes in α-amino-3-hydroxy-5-methy1-4-isoxazolepropionic acid receptor (AMPAR) subunit trafficking in the dorsal horn and that such changes contribute to the hypersensitivity that underlies persistent pain.Here,we review current evidence to illustrate how spinal cord AMPARs participate in the dorsal horn central sensitization associated with persistent pain.Understanding these mechanisms may allow the development of novel therapeutic strategies for treating persistent pain.

  3. Do benzodiazepines mimic reverse-turn structures?

    Science.gov (United States)

    Hata, Masayuki; Marshall, Garland R.

    2006-05-01

    The role of benzodiazepine derivatives (BZD) as a privileged scaffold that mimics β-turn structures (Ripka et al. (1993) Tetrahedron 49:3593-3608) in peptide/protein recognition was reexamined in detail. Stable BZD ring conformers were determined with MM3, and experimental reverse-turn structures were extracted from the basis set of protein crystal structures previously defined by Ripka et al. Ideal β-turns were also modeled and similarly compared with BZD conformers. Huge numbers of conformers were generated by systematically scanning the torsional degrees of freedom for BZDs, as well as those of ideal β-turns for comparison. Using these structures, conformers of BZDs were fit to experimental structures as suggested by Ripka et al., or modeled classical β-turn conformers, and the root-mean-square deviation (RMSD) values were calculated for each pairwise comparison. Pairs of conformers with the smallest RMSD values for overlap of the four α-β side-chain orientations were selected. All overlaps of BZD conformers with experimental β-turns yielded one or more comparisons where the least RMSD was significantly small, 0.48-0.86 Å, as previously suggested. Utilizing a different methodology, the overall conclusion that benzodiazepines could serve as reverse-turn mimetics of Ripka et al. is justified. The least RMSD values for the overlap of BZDs and modeled classical β-turns were also less than 1 Å. When comparing BZDs with experimental or classical β-turns, the set of experimental β-turns selected by Ripka et al. fit the BZD scaffolds better than modeled classical β-turns; however, all the experimental β-turns did not fit a particular BZD scaffold better. A single BZD ring conformation, and/or chiral orientation, can mimic some, but not all, of the experimental β-turn structures. BZD has two central ring conformations and one chiral center that explains why the four variations of the BZD scaffold can mimic all types of β-turn structure examined. It was

  4. REGULATION OF CENTRAL NERVOUS SYSTEM AUTOIMMUNITY BY THE ARYL HYDROCARBON RECEPTOR

    OpenAIRE

    Quintana, Francisco J.

    2013-01-01

    The ligand-activated transcription factor aryl hydrocarbon receptor controls the activity of several components of the immune system, many of which play an important role in neuroinflammation. This review discusses the role of AhR in T cells and dendritic cells, its relevance for the control of autoimmunity in the central nervous system, and its potential as a therapeutic target for immune mediated disorders.

  5. Role of Nuclear Receptors in Central Nervous System Development and Associated Diseases

    Science.gov (United States)

    Olivares, Ana Maria; Moreno-Ramos, Oscar Andrés; Haider, Neena B.

    2015-01-01

    The nuclear hormone receptor (NHR) superfamily is composed of a wide range of receptors involved in a myriad of important biological processes, including development, growth, metabolism, and maintenance. Regulation of such wide variety of functions requires a complex system of gene regulation that includes interaction with transcription factors, chromatin-modifying complex, and the proper recognition of ligands. NHRs are able to coordinate the expression of genes in numerous pathways simultaneously. This review focuses on the role of nuclear receptors in the central nervous system and, in particular, their role in regulating the proper development and function of the brain and the eye. In addition, the review highlights the impact of mutations in NHRs on a spectrum of human diseases from autism to retinal degeneration. PMID:27168725

  6. Role of the Histamine H3 Receptor in the Central Nervous System.

    Science.gov (United States)

    Schlicker, Eberhard; Kathmann, Markus

    2016-10-28

    The Gi/o protein-coupled histamine H3 receptor is distributed throughout the central nervous system including areas like cerebral cortex, hippocampus and striatum with the density being highest in the posterior hypothalamus, i.e. the area in which the histaminergic cell bodies are located. In contrast to the other histamine receptor subtypes (H1, H2 and H4), the H3 receptor is located presynaptically and shows a constitutive activity. In detail, H3 receptors are involved in the inhibition of histamine release (presynaptic autoreceptor), impulse flow along the histaminergic neurones (somadendritic autoreceptor) and histamine synthesis. Moreover, they occur as inhibitory presynaptic heteroreceptors on serotoninergic, noradrenergic, dopaminergic, glutamatergic, GABAergic and perhaps cholinergic neurones. This review shows for four functions of the brain that the H3 receptor represents a brake against the wake-promoting, anticonvulsant and anorectic effect of histamine (via postsynaptic H1 receptors) and its procognitive activity (via postsynaptic H1 and H2 receptors). Indeed, H1 agonists and H3 inverse agonists elicit essentially the same effects, at least in rodents; these effects are opposite in direction to those elicited by brain-penetrating H1 receptor antagonists in humans. Although the benefit for H3 inverse agonists for the symptomatic treatment of dementias is inconclusive, several members of this group have shown a marked potential for the treatment of disorders associated with excessive daytime sleepiness. In March 2016, the European Commission granted a marketing authorisation for pitolisant (Wakix(R)) (as the first representative of the H3 inverse agonists) for the treatment of narcolepsy.

  7. The use of benzodiazepines in the workplace.

    Science.gov (United States)

    Roy-Byrne, P P; Cowley, D S

    1990-01-01

    Benzodiazepines differ from many of the other abused substances in that there are legitimate medical indications for their use. Any prescription for benzodiazepines must be preceded by a careful risk-benefit analysis that considers the specifics of an individual's particular life situation, personality style, and psychiatric diagnosis. The risk of benzodiazepine abuse by chemically dependent individuals and the problems of cognitive and/or psychomotor impairment and dependence for all individuals have to be balanced against the therapeutic benefits of these drugs for patients who experience disabling anxiety disorders or anxiety that accompanies chronic medical illness. Problems of dependence can be minimized by utilizing a variety of pharmacologic and psychotherapeutic strategies to ameliorate withdrawal symptoms that might accompany the discontinuation of long-term benzodiazepine treatment.

  8. Central muscarinic receptor subtypes involved in pilocarpine-induced salivation, hypertension and water intake.

    Science.gov (United States)

    Borella, T L; De Luca, L A; Colombari, D S A; Menani, J V

    2008-12-01

    Recent evidence has suggested that pilocarpine (ACh receptor agonist) injected peripherally may act centrally producing salivation and hypertension. In this study, we investigated the effects of specific M(1) (pirenzepine), M(2)/M(4) (methoctramine), M(1)/M(3) (4-DAMP) and M(4) (tropicamide) muscarinic receptor subtype antagonists injected into the lateral cerebral ventricle (LV) on salivation, water intake and pressor responses to peripheral pilocarpine. Male Holtzman rats with stainless steel cannulae implanted in the LV were used. Salivation was measured in rats anaesthetized with ketamine (100 mg per kg body weight) and arterial pressure was recorded in unanaesthetized rats. Salivation induced by i.p. pilocarpine (4 micromol per kg body weight) was reduced only by 4-DAMP (25-250 nmol) injected into the LV, not by pirenzepine, methoctramine or tropicamide at the dose of 500 nmol. Pirenzepine (0.1 and 1 nmol) and 4-DAMP (5 and 10 nmol) injected into the LV reduced i.p. pilocarpine-induced water intake, whereas metoctramine (50 nmol) produced nonspecific effects on ingestive behaviours. Injection of pirenzepine (100 nmol) or 4-DAMP (25 and 50 nmol) into the LV reduced i.v. pilocarpine-induced pressor responses. Tropicamide (500 nmol) injected into the LV had no effect on pilocarpine-induced salivation, pressor responses or water intake. The results suggest that central M(3) receptors are involved in peripheral pilocarpine-induced salivation and M(1) receptors in water intake and pressor responses. The involvement of M(3) receptors in water intake and pressor responses is not clear because 4-DAMP blocks both M(1) and M(3) receptors.

  9. Pharmacological analysis of the effects of benzodiazepines on punished schedule-induced polydipsia in rats.

    Science.gov (United States)

    Pellón, Ricardo; Ruíz, Ana; Lamas, Esmeralda; Rodríguez, Cilia

    2007-02-01

    Food-deprived Wistar rats were exposed to a fixed-time 60-s food delivery schedule until they developed schedule-induced polydipsia. Every fifth lick was then followed by an electric shock during two, signalled, 5-min periods, which ran concurrently with the food delivery schedule. Shock intensities were adjusted to reduce licking to 60-70% of the unpunished licking rates. The benzodiazepine full agonists, diazepam (0.3-3.0 mg/kg), chlordiazepoxide (0.3-10.0 mg/kg), oxazepam (0.3-3.0 mg/kg) and the benzodiazepine partial agonist, RU-32698 (3.0-17.0 mg/kg), led to increases in punished responding at intermediate doses and decreases at the highest doses tested. All benzodiazepine agonists brought about dose-dependent decreases in unpunished schedule-induced polydipsia, with doses required to reduce drinking proving higher than doses required to increase punished schedule-induced polydipsia. The antipunishment effect of 0.3 mg/kg of diazepam was dose-dependently antagonized by flumazenil and the benzodiazepine inverse agonist, RU-34000. Flumazenil effects, however, could reflect actions of flumazenil as a partial inverse agonist at GABAA receptors. RU-32698 at 10.0 mg/kg further facilitated the rate-increasing effect of 0.3 mg/kg of diazepam, but at 17.0 mg/kg partially blocked such antipunishment effect. Overall, the present results extend the similarities of the effects of benzodiazepine compounds on adjunctive and operant patterns of behaviour by showing similar interactions within the benzodiazepine receptor complex.

  10. Behavioral and neurophysiological signatures of benzodiazepine-related driving impairments

    Directory of Open Access Journals (Sweden)

    Bradly T Stone

    2015-11-01

    Full Text Available Impaired driving due to drug use is a growing problem, worldwide; estimates show that 18-23.5% of fatal accidents, and up to 34% of injury accidents may be caused by drivers under the influence of drugs (Drummer et al., 2003; NHTSA, 2010; Walsh et al., 2004. Furthermore, at any given time, up to 16% of drivers may be using drugs that can impair one’s driving abilities (NHTSA, 2009. Currently, drug recognition experts (law enforcement officers with specialized training to identify drugged driving, have the most difficult time with identifying drivers potentially impaired on central nervous system (CNS depressants (Smith, Hayes, Yolton, Rutledge, & Citek, 2002. The fact that the use of benzodiazepines, a type of CNS depressant, is also associated with the greatest likelihood of causing accidents (Dassanayake, Michie, Carter, & Jones, 2011, further emphasizes the need to improve research tools in this area which can facilitate the refinement of, or additions to, current assessments of impaired driving. Our laboratories collaborated to evaluate both the behavioral and neurophysiological effects of a benzodiazepine, alprazolam, in a driving simulation (miniSim™. This drive was combined with a neurocognitive assessment utilizing time synched neurophysiology (EEG, ECG. While the behavioral effects of benzodiazepines are well characterized (Rapoport et al., 2009, we hypothesized that, with the addition of real-time neurophysiology and the utilization of simulation and neurocognitive assessment, we could find objective assessments of drug impairment that could improve the detection capabilities of drug recognition experts. Our analyses revealed that 1 specific driving conditions were significantly more difficult for benzodiazepine impaired drivers and; 2 the neurocognitive tasks’ metrics were able to classify impaired vs. unimpaired with up to 80% accuracy based on lane position deviation and lane departures. While this work requires replication in

  11. [Why benzodiazepines are still in wide use?].

    Science.gov (United States)

    Vlastelica, Mirela; Jelaska, Marin

    2012-05-01

    The advent of benzodiazepines in the 1960s provided their wide use in neurology and psychiatry. They proved to be myorelaxant and anticonvulsive therapy in neurology; their anxiolytic and hypnotic properties have made them the treatment of choice for insomnia and anxiety problems; they have also been used in alcohol withdrawal and in anesthesia, and for a wide range of treatments in other clinical branches. However, reports giving rise to a prescription controversy including abuse, harmful effects, intoxication and dependence toward addiction appeared soon. On the other hand, the revolutionary appearance of selective serotonin reuptake inhibitors (SSRIs) overshadowed benzodiazepines. According to recommendations of many scientific and professional institutions, the use of benzodiazepines has been gradually excluded or reduced or limited to short-term use. However, clinical experience showed that benzodiazepines are frequently used for long-term treatment, and there are many reasons for this, e.g., prescribing tradition, patient preference, difficulties associated with benzodiazepine withdrawal (even in patients taking low doses) because they have a rapid clinical onset of action, and good efficacy with few initial adverse effects. Moreover, SSRIs as alternative drugs are associated with incomplete therapeutic response and more uncomfortable adverse effects. Some authors therefore point out that the rationale for the shift from benzodiazepines to SSRIs is inappropriate.

  12. Cannabinoid Receptors in the Central Nervous System: Their Signaling and Roles in Disease

    Science.gov (United States)

    Kendall, Debra A.; Yudowski, Guillermo A.

    2017-01-01

    The identification and cloning of the two major cannabinoid (CB1 and CB2) receptors together with the discovery of their endogenous ligands in the late 80s and early 90s, resulted in a major effort aimed at understanding the mechanisms and physiological roles of the endocannabinoid system (ECS). Due to its expression and localization in the central nervous system (CNS), the CB1 receptor together with its endogenous ligands (endocannabinoids (eCB)) and the enzymes involved in their synthesis and degradation, has been implicated in multiple pathophysiological events ranging from memory deficits to neurodegenerative disorders among others. In this review, we will provide a general overview of the ECS with emphasis on the CB1 receptor in health and disease. We will describe our current understanding of the complex aspects of receptor signaling and trafficking, including the non-canonical signaling pathways such as those mediated by β-arrestins within the context of functional selectivity and ligand bias. Finally, we will highlight some of the disorders in which CB1 receptors have been implicated. Significant knowledge has been achieved over the last 30 years. However, much more research is still needed to fully understand the complex roles of the ECS, particularly in vivo and to unlock its true potential as a source of therapeutic targets. PMID:28101004

  13. Novel receptor targets for production and action of allopregnanolone in the central nervous system: a focus on pregnane xenobiotic receptor

    Directory of Open Access Journals (Sweden)

    Cheryl A Frye

    2014-04-01

    Full Text Available Neurosteroids are cholesterol-based hormones that can be produced in the brain, independent of secretion from peripheral endocrine glands, such as the gonads and adrenals. A focus in our laboratory for over 25 years has been how production of the pregnane neurosteroid, allopregnanolone, is regulated and the novel (i.e. non steroid receptor targets for steroid action for behavior. One endpoint of interest has been lordosis, the mating posture of female rodents. Allopregnanolone is necessary and sufficient for lordosis, and the brain circuitry underlying it, such as actions in the midbrain ventral tegmental area (VTA, has been well-characterized. Published and recent findings supporting a dynamic role of allopregnanolone are included in this review. First, contributions of ovarian and adrenal sources of precursors of allopregnanolone, and the requisite enzymatic actions for de novo production in the central nervous system will be discussed. Second, how allopregnanolone produced in the brain has actions on behavioral processes that are independent of binding to steroid receptors, but instead involve rapid modulatory actions via neurotransmitter targets (e.g. -amino butyric acid-GABA, n-methyl-D-aspartate- NMDA will be reviewed. Third, a recent focus on characterizing the role of a promiscuous nuclear receptor, pregnane xenobiotic receptor (PXR, involved in cholesterol metabolism and expressed in the VTA, as a target for allopregnanolone and how this relates to both actions and production of allopregnanolone will be addressed. For example, allopregnanolone can bind PXR and knocking down expression of PXR in the midbrain VTA attenuates actions of allopregnanolone via NMDA and/or GABAA for lordosis. Our understanding of allopregnanolone’s actions in the VTA for lordosis has been extended to reveal the role of allopregnanolone for broader, clinically-relevant questions, such as neuropsychiatric disorders, epilepsy, and aging.

  14. Benzodiazepine-like discriminative stimulus effects of toluene vapor.

    Science.gov (United States)

    Shelton, Keith L; Nicholson, Katherine L

    2013-11-15

    In vitro studies show that the abused inhalant toluene affects a number of ligand-gated ion channels.The two most consistently implicated of these are γ-aminobutyric acid type A(GABAA) receptors which are positively modulated by toluene and N-methyl-D-aspartate(NMDA) receptors which are negatively modulated by toluene. Behavioral studies also suggest an interaction of toluene with GABAA and/or NMDA receptors but it is unclear if these receptors underlie the abuse-related intoxicating effects of toluene. Seventeen B6SJLF1/J mice were trained using a two-choice operant drug discrimination procedure to discriminate 10 min of exposure to 2000 ppm toluene vapor from 10 min of exposure to air. The discrimination was acquired in a mean of 65 training sessions. The stimulus effects of 2000 ppm toluene vapor were exposure concentration-dependent but rapidly diminished following the cessation of vapor exposure. The stimulus effects of toluene generalized to the chlorinated hydrocarbon vapor perchloroethylene but not 1,1,2-trichloroethane nor the volatile anesthetic isoflurane. The competitive NMDA antagonist CGS-19755, the uncompetitive antagonist dizocilpine and the glycine-site antagonist L701,324 all failed to substitute for toluene. The classical nonselective benzodiazepines midazolam and chlordiazepoxide produced toluene-like stimulus effects but the alpha 1 subunit preferring positive GABAA modulator zaleplon failed to substitute for toluene. The barbiturates pentobarbital and methohexital and the GABAA positive modulator neurosteroid allopregnanolone did not substitute for toluene. These data suggest that the stimulus effects of toluene may be at least partially mediated by benzodiazepine-like positive allosteric modulation of GABAA receptors containing alpha 2, 3 or 5 subunits.

  15. Cross-validation of the benzodiazepine dependence self-report questionnaire in outpatient benzodiazepine users.

    NARCIS (Netherlands)

    Kan, C.C.; Breteler, M.H.M.; Ven, A.H.G.S. van der; Zitman, F.G.

    2001-01-01

    The aim of this study was to cross-validate the Benzodiazepine Dependence Self-Report Questionnaire (Bendep-SRQ), which reflects the severity of benzodiazepine (BZD) dependence. The Bendep-SRQ, Symptom Checklist-90 (SCL-90) Schedules for Clinical Assessments in Neuropsychiatry (SCAN), and Addiction

  16. Cross-validation of the Benzodiazepine Dependence Self-Report Questionnaire in Outpatient Benzodiazepine Users

    NARCIS (Netherlands)

    Kan, C.C.; Breteler, M.H.M.; Ven, A.H.G.S. van der; Zitman, F.G.

    2001-01-01

    The aim of this study was to cross-validate the Benzodiazepine Dependence Self-Report Questionnaire (Bendep-SRQ), which reflects the severity of benzodiazepine (BZD) dependence. The Bendep-SRQ, Symptom Checklist-90 (SCL-90) Schedules for Clinical Assessments in Neuropsychiatry (SCAN), and Addiction

  17. Social-cognitive predictors of intended and actual benzodiazepine cessation among chronic benzodiazepine users

    NARCIS (Netherlands)

    Ten Wolde, Geeske B.; Dijkstra, Arie; Van Empelen, Pepijn; Neven, Arie Knuistingh; Zitman, Frans G.

    2008-01-01

    Long-term benzodiazepine use is associated with a variety of negative health consequences. Cessation of long-term use is therefore an important health goal. In a prospective study among chronic benzodiazepinc users (N=356) social-cognitive factors of benzodiazepine cessation were examined with a nin

  18. Perceptions of benzodiazepine dependence among women age 65 and older.

    Science.gov (United States)

    Canham, Sarah L; Gallo, Joseph; Simoni-Wastila, Linda

    2014-01-01

    A phenomenological study explored whether older women who are chronic benzodiazepine users identified themselves as dependent, how dependence was perceived, and how meanings and understandings shaped experiences of benzodiazepine use. Self-reported benzodiazepine dependence was associated with being unable to reduce use or a desire to discontinue use and reliance on benzodiazepines to remain comfortable and able to handle daily life. Themes included: (a) benzodiazepine dependence is similar to dependence to diabetes or blood pressure medications; (b) dependence is distinctive from addiction/abuse; (c) addiction/abuse is perceived as worse than dependence; and (d) concerns of addiction/abuse result in low-dose benzodiazepine use.

  19. Poliovirus trafficking toward central nervous system via human poliovirus receptor-dependent and -independent pathway.

    Directory of Open Access Journals (Sweden)

    Seii eOHKA

    2012-04-01

    Full Text Available In humans, paralytic poliomyelitis results from the invasion of the central nervous system by circulating poliovirus (PV via the blood-brain barrier (BBB. After the virus enters the central nervous system (CNS, it replicates in neurons, especially in motor neurons (MNs, inducing the cell death that causes paralytic poliomyelitis. Along with this route of dissemination, neural pathway has been reported in humans, monkeys, and PV-sensitive human PV receptor (hPVR/CD155-transgenic (Tg mice. We demonstrated that a fast retrograde axonal transport process is required for PV dissemination through the sciatic nerve of hPVR-Tg mice and that intramuscularly inoculated PV causes paralysis in a hPVR-dependent manner. We also showed that hPVR-independent axonal transport of PV exists in hPVR-Tg and non-Tg mice, indicating that several different pathways for PV axonal transport exist in these mice. Circulating PV after intravenous inoculation in mice cross the BBB at a high rate in a hPVR-independent manner. Recently, we identified transferrin receptor 1 (TfR1 of mouse brain capillary endothelial cells as a binding protein to PV, implicating that TfR1 is a possible receptor for PV to permeate the BBB.

  20. P2 receptors in the central and peripheral nervous systems modulating sympathetic vasomotor tone.

    Science.gov (United States)

    Ralevic, V

    2000-07-01

    Arterial pressure depends on the level of activity of sympathetic vasoconstrictor outflow to blood vessels. This activity is generated in the central nervous system, and involves inputs from a variety of brain regions projecting to sympathetic preganglionic neurones. Of especial interest are a group of neurones in the rostral ventrolateral medulla (RVLM), as they have been demonstrated to have a fundamental role in reflex regulation of the cardiovascular system, and in generation of tonic drive to sympathetic outflow. Sympathetic outflow to blood vessels is additionally modulated at sympathetic ganglia, and at the peripheral terminals of sympathetic nerves. This review considers the role of P2 purine receptors in this neural pathway. Ionotropic P2X receptors are expressed in the RVLM, in sympathetic ganglia, and at the sympathetic neuromuscular junction, and mediate fast excitatory neurotransmission, indicating a general role for ATP as a regulator of sympathetic vasomotor tone. P2Y receptors couple to G proteins and mediate slower signalling to ATP; they have been reported to inhibit prejunctionally neurotransmission at the peripheral terminals of sympathetic nerves, but little is known about their possible role in the central nervous system and in sympathetic ganglia.

  1. Disability pension as predictor of later use of benzodiazepines among benzodiazepine users.

    Science.gov (United States)

    Hartz, Ingeborg; Tverdal, Aage; Skille, Eivind; Skurtveit, Svetlana

    2010-03-01

    The proportion of Norwegians on disability pensions has doubled since the 1980s. The Norwegian Government wants action to stimulate the working capacity in those disability pensioners who have the potential to work. Information on factors that may impair rehabilitation efforts, including the unfavourable use of benzodiazepines, may be useful in this context. A longitudinal design, including data on 40-42 year old participants in Norwegian health surveys (year 1985-1989) linked to a prescription database (year 2004-2006), was used to describe risk of long-term use of benzodiazepines among disability pension recipients. The study population constituted benzodiazepine users at baseline. More than half of those on disability pensions, 57% of all men and 65% of all women, retrieved benzodiazepine prescriptions 20 years later, a span covering a large part of the potential active workforce period. Further, the observed amount of benzodiazepines dispensed over a three-year period indicated more than sporadic use e.g. half of the female disability pensioners were dispensed an amount of benzodiazepines corresponding to the use of a daily dose every second day over a three year period (median 450 daily doses). The majority of those who were dispensed benzodiazepines, were dispensed opioids as well: half of all men and 3 out of four women. And last, being on a disability pension was a predictor of benzodiazepine use 20 years later. Our study suggests that benzodiazepines are extensively and unfavourably used among disability pensioners, and that disability pension may have an independent effect on long-term use. Improved management of benzodiazepine use may be one alternative to get disability pensioners with the potential to work back into employment.

  2. Chronic use of benzodiazepines among older adults

    Directory of Open Access Journals (Sweden)

    Jussara Mendonça Alvarenga

    2014-12-01

    Full Text Available OBJECTIVE To analyze the perception of and motivation for the chronic use of benzodiazepine among older adults. METHODS A qualitative study was conducted on 22 older adults living in Bambuí, MG, Southeastern Brazil, who were taking benzodiazepines and had the clinical and cognitive ability to respond to interview questions. The collected data were analyzed on the basis of the “signs, meanings, and actions” model. RESULTS The main reasons pointed out for the use of benzodiazepines were “nervousness”, “sleep problems”, and “worry” due to family and financial problems, everyday problems, and existential difficulties. None of the interviewees said that they used benzodiazepines in a dose higher than that recommended or had been warned by health professionals about any risks of their continuous use. Different strategies were used to obtain the prescription for the medication, and any physician would prescribe it, indicating that a bond was established with the drug and not with the health professional or healthcare service. Obtaining and consuming the medication turned into a crucial issue because benzodiazepine assumes the status of an essential food, which leads users to not think but sleep. It causes a feeling of relief from their problems such as awareness of human finitude and fragility, existential difficulties, and family problems. CONCLUSIONS Benzodiazepine assumes the characteristics of polyvalence among older adults, which extrapolate specific clinical indications, and of essentiality to deal with life’s problems in old age. Although it relieves the “nerves”, the chronic use of benzodiazepines buffers suffering and prevents older adults from going through the suffering. This shows important difficulties in the organization and planning of strategies that are necessary for minimizing the chronic use in this population.

  3. Chronic use of benzodiazepines among older adults.

    Science.gov (United States)

    Alvarenga, Jussara Mendonça; Giacomin, Karla Cristina; Loyola Filho, Antônio Ignácio de; Uchoa, Elizabeth; Firmo, Josélia Oliveira Araújo

    2014-12-01

    OBJECTIVE To analyze the perception of and motivation for the chronic use of benzodiazepine among older adults. METHODS A qualitative study was conducted on 22 older adults living in Bambuí, MG, Southeastern Brazil, who were taking benzodiazepines and had the clinical and cognitive ability to respond to interview questions. The collected data were analyzed on the basis of the "signs, meanings, and actions" model. RESULTS The main reasons pointed out for the use of benzodiazepines were "nervousness", "sleep problems", and "worry" due to family and financial problems, everyday problems, and existential difficulties. None of the interviewees said that they used benzodiazepines in a dose higher than that recommended or had been warned by health professionals about any risks of their continuous use. Different strategies were used to obtain the prescription for the medication, and any physician would prescribe it, indicating that a bond was established with the drug and not with the health professional or healthcare service. Obtaining and consuming the medication turned into a crucial issue because benzodiazepine assumes the status of an essential food, which leads users to not think but sleep. It causes a feeling of relief from their problems such as awareness of human finitude and fragility, existential difficulties, and family problems. CONCLUSIONS Benzodiazepine assumes the characteristics of polyvalence among older adults, which extrapolate specific clinical indications, and of essentiality to deal with life's problems in old age. Although it relieves the "nerves", the chronic use of benzodiazepines buffers suffering and prevents older adults from going through the suffering. This shows important difficulties in the organization and planning of strategies that are necessary for minimizing the chronic use in this population.

  4. Alcohol involvement in opioid pain reliever and benzodiazepine drug abuse-related emergency department visits and drug-related deaths - United States, 2010.

    Science.gov (United States)

    Jones, Christopher M; Paulozzi, Leonard J; Mack, Karin A

    2014-10-10

    The abuse of prescription drugs has led to a significant increase in emergency department (ED) visits and drug-related deaths over the past decade. Opioid pain relievers (OPRs) and benzodiazepines are the prescription drugs most commonly involved in these events. Excessive alcohol consumption also accounts for a significant health burden and is common among groups that report high rates of prescription drug abuse. When taken with OPRs or benzodiazepines, alcohol increases central nervous system depression and the risk for overdose. Data describing alcohol involvement in OPR or benzodiazepine abuse are limited. To quantify alcohol involvement in OPR and benzodiazepine abuse and drug-related deaths and to inform prevention efforts, the Food and Drug Administration (FDA) and CDC analyzed 2010 data for drug abuse-related ED visits in the United States and drug-related deaths that involved OPRs and alcohol or benzodiazepines and alcohol in 13 states. The analyses showed alcohol was involved in 18.5% of OPR and 27.2% of benzodiazepine drug abuse-related ED visits and 22.1% of OPR and 21.4% of benzodiazepine drug-related deaths. These findings indicate that alcohol plays a significant role in OPR and benzodiazepine abuse. Interventions to reduce the abuse of alcohol and these drugs alone and in combination are needed.

  5. Cannabinoid CB2 receptors regulate central sensitization and pain responses associated with osteoarthritis of the knee joint.

    Directory of Open Access Journals (Sweden)

    James J Burston

    Full Text Available Osteoarthritis (OA of the joint is a prevalent disease accompanied by chronic, debilitating pain. Recent clinical evidence has demonstrated that central sensitization contributes to OA pain. An improved understanding of how OA joint pathology impacts upon the central processing of pain is crucial for the identification of novel analgesic targets/new therapeutic strategies. Inhibitory cannabinoid 2 (CB2 receptors attenuate peripheral immune cell function and modulate central neuro-immune responses in models of neurodegeneration. Systemic administration of the CB2 receptor agonist JWH133 attenuated OA-induced pain behaviour, and the changes in circulating pro- and anti-inflammatory cytokines exhibited in this model. Electrophysiological studies revealed that spinal administration of JWH133 inhibited noxious-evoked responses of spinal neurones in the model of OA pain, but not in control rats, indicating a novel spinal role of this target. We further demonstrate dynamic changes in spinal CB2 receptor mRNA and protein expression in an OA pain model. The expression of CB2 receptor protein by both neurones and microglia in the spinal cord was significantly increased in the model of OA. Hallmarks of central sensitization, significant spinal astrogliosis and increases in activity of metalloproteases MMP-2 and MMP-9 in the spinal cord were evident in the model of OA pain. Systemic administration of JWH133 attenuated these markers of central sensitization, providing a neurobiological basis for analgesic effects of the CB2 receptor in this model of OA pain. Analysis of human spinal cord revealed a negative correlation between spinal cord CB2 receptor mRNA and macroscopic knee chondropathy. These data provide new clinically relevant evidence that joint damage and spinal CB2 receptor expression are correlated combined with converging pre-clinical evidence that activation of CB2 receptors inhibits central sensitization and its contribution to the manifestation

  6. Cannabinoid CB2 receptors regulate central sensitization and pain responses associated with osteoarthritis of the knee joint.

    Science.gov (United States)

    Burston, James J; Sagar, Devi Rani; Shao, Pin; Bai, Mingfeng; King, Emma; Brailsford, Louis; Turner, Jenna M; Hathway, Gareth J; Bennett, Andrew J; Walsh, David A; Kendall, David A; Lichtman, Aron; Chapman, Victoria

    2013-01-01

    Osteoarthritis (OA) of the joint is a prevalent disease accompanied by chronic, debilitating pain. Recent clinical evidence has demonstrated that central sensitization contributes to OA pain. An improved understanding of how OA joint pathology impacts upon the central processing of pain is crucial for the identification of novel analgesic targets/new therapeutic strategies. Inhibitory cannabinoid 2 (CB2) receptors attenuate peripheral immune cell function and modulate central neuro-immune responses in models of neurodegeneration. Systemic administration of the CB2 receptor agonist JWH133 attenuated OA-induced pain behaviour, and the changes in circulating pro- and anti-inflammatory cytokines exhibited in this model. Electrophysiological studies revealed that spinal administration of JWH133 inhibited noxious-evoked responses of spinal neurones in the model of OA pain, but not in control rats, indicating a novel spinal role of this target. We further demonstrate dynamic changes in spinal CB2 receptor mRNA and protein expression in an OA pain model. The expression of CB2 receptor protein by both neurones and microglia in the spinal cord was significantly increased in the model of OA. Hallmarks of central sensitization, significant spinal astrogliosis and increases in activity of metalloproteases MMP-2 and MMP-9 in the spinal cord were evident in the model of OA pain. Systemic administration of JWH133 attenuated these markers of central sensitization, providing a neurobiological basis for analgesic effects of the CB2 receptor in this model of OA pain. Analysis of human spinal cord revealed a negative correlation between spinal cord CB2 receptor mRNA and macroscopic knee chondropathy. These data provide new clinically relevant evidence that joint damage and spinal CB2 receptor expression are correlated combined with converging pre-clinical evidence that activation of CB2 receptors inhibits central sensitization and its contribution to the manifestation of chronic OA

  7. Strychnine Binding Associated with Glycine Receptors of the Central Nervous System

    Science.gov (United States)

    Young, Anne B.; Snyder, Solomon H.

    1973-01-01

    [3H]Strychnine binds to synaptic-membrane fractions of the spinal cord in a selective fashion, indicating an interaction with postsynaptic glycine receptors. Displacement of strychnine by glycine and other amino acids parallels their glycine-like neurophysiologic activity. The regional localization of strychnine binding in the central nervous system correlates closely with endogenous glycine concentrations. In subcellular fractionation experiments, strychnine binding is most enhanced in synaptic-membrane fractions. Strychnine binding is saturable, with affinity constants for glycine and strychnine of 10 and 0.03 μM, respectively. PMID:4200724

  8. Pleiotropic effect of histamine H4 receptor modulation in the central nervous system

    OpenAIRE

    Nicoletta Galeotti; Maria Domenica Sanna; Carla Ghelardini

    2013-01-01

    The histamine H4 receptor (H4R) is expressed primarily on cells involved in inflammation and immune responses. Recently, it has been reported the functional expression of H4R within neurons of the central nervous system, but their role has been poorly understood. The present study aimed to elucidate the physiopathological role of cerebral H4R in animal models by the intracerebroventricular administration of the H4R agonist VUF 8430 (20e40 mg per mouse). Selectivity of results was ...

  9. Synthesis of cyclic analogues of cholecystokinin highly selective for central receptors.

    Science.gov (United States)

    Rodriguez, M; Amblard, M; Galas, M C; Lignon, M F; Aumelas, A; Martinez, J

    1990-05-01

    Cyclic CCK analogues in which positions 28 and 31 have been replaced by lysine residues and whose side chains are bridged by a succinic moiety, were synthesized. They were tested for their ability to inhibit the binding of 125I-BH-CCK-8 to isolated rat pancreatic acini and to guinea pig brain membranes. These cyclic CCK-analogues were compared to the potent CCK analogue Boc-[Nle28,31]-CCK-7 and to Boc-Trp-Leu-Asp-Phe-NH2, analogue of CCK-4. These cyclic compounds appeared to be highly selective for central CCK receptors.

  10. Views of general practitioners and benzodiazepine users on benzodiazepines: a qualitative analysis.

    Science.gov (United States)

    Parr, Jannette M; Kavanagh, David J; Young, Ross McD; McCafferty, Kelly

    2006-03-01

    Effectively assisting benzodiazepine users to cease use requires a greater understanding of general practitioners' (GPs) and benzodiazepine users' views on using and ceasing benzodiazepines. This paper reports the findings from a qualitative study that examined the views of 28 GPs and 23 benzodiazepine users (BUs) in Cairns, Australia. A semi-structured interview was conducted with all participants and the information gained was analysed using the Consensual Qualitative Research Approach, which allowed comparisons to be made between the views of the two groups of interviewees. There was commonality between GPs and BUs on reasons for commencing benzodiazepines, the role of dependence in continued use, and the importance of lifestyle change in its cessation. However, several differences emerged regarding commencement of use and processes of cessation. In particular, users felt there was greater need for GPs to routinely advise patients about non-pharmacological management of their problems and potential adverse consequences of long-term use before commencing benzodiazepines. Cessation could be discussed with all patients who use benzodiazepines for longer than 3 months, strategies offered to assist in management of withdrawal and anxiety, and referral to other health service providers for additional support. Lifestyle change could receive greater focus at all stages of treatment.

  11. Electrocardiographic Manifestations of Benzodiazepine Toxicity

    Directory of Open Access Journals (Sweden)

    Nahid Kazemzadeh

    2014-11-01

    Full Text Available Background: The aim of this study was to evaluate and compare the clinical and electrocardiographic (ECG manifestations of benzodiazepines (BZs. Methods: In this retrospective study, all BZ-poisoned patients hospitalized at Loghman Hakim Hospital between September 2010 and March 2011 were evaluated. Patients’ information including age, sex, time elapsed between the ingestion and presentation, and type of the BZ used were extracted from the patients' charts and recorded. ECGs on presentation to the emergency department (ED were evaluated and parameters such as PR interval, QRS duration, corrected QT, amplitude of S wave in lead I, height of R wave and R/S ratio in the lead aVR were also measured and recorded. Results: Oxazepam, chlordiazepoxide, lorazepam, alprazolam, diazepam, and clonazepam were ingested by 9 (3%, 13 (4.4%, 29 (9.9%, 105 (35.8%, 65 (22.2%, and 72 (24.6% patients, respectively. Mean PR interval was reported to be 0.16 ± 0.03 sec and PR interval of greater than 200 msec was detected in 12 (4.5% patients. Mean QRS duration was 0.07 ± 0.01sec and QRS≥120 msec was observed in 7 (2.6% cases. Conclusion: Diazepam is the only BZ that does not cause QRS widening and oxazepam is the only one not causing PR prolongation. It can be concluded that if a patient refers with a decreased level of consciousness and accompanying signs of BZ toxicity, QRS widening in ECG rules out diazepam, whereas PR prolongation rules out oxazepam toxicity.

  12. Characteristics of gamma-aminobutyric acid (GABA receptors in the rat central nervous system.

    Directory of Open Access Journals (Sweden)

    Kuroda,Hiroo

    1983-04-01

    Full Text Available Characteristics of gamma-aminobutyric acid (GABA were investigated in the rat central nervous system by radioreceptor assay (RRA. Scatchard analysis revealed that the rat brain had two distinct GABA binding sites with an apparent dissociation constant (Kd of 11.7 nM and 34.7 nM. The highest level of specific [3H]-GABA binding was found in the rat cerebellum. Imidazole acetic acid, a potent GABA agonist, was effective in displacing [3H]-GABA binding but beta-alanine was slightly effective in inhibiting [3H]-GABA binding. Muscimol, the most potent GABA agonist, has been used as a ligand to characterize the postsynaptic GABA receptors. However, the maximal binding capacity (Bmax of muscimol-RRA was about 3 times larger than that of GABA-RRA, suggesting that muscimol might label not only GABA receptors but other unknown receptors as well. An endogenous inhibitor of GABA receptor binding was purified from the P2 fraction of rat brain with 0.05% Triton X-100. The endogenous inhibitor was competitive with GABA on GABA binding sites. The inhibition by the endogenous inhibitor of GABA receptor binding was blocked by the allosteric effect of diazepam. In the presence of diazepam, [3H]-GABA binding with the endogenous inhibitor was larger than that with GABA, whereas there was no difference in the absence of diazepam. This indicated that the endogenous inhibitor was not GABA itself. The molecular weight of the endogenous inhibitor was estimate by gel filtration to be less than 3,000 daltons.

  13. Modulation of central glucocorticoid receptors in short- and long-term experimental hyperthyroidism.

    Science.gov (United States)

    Nikolopoulou, Elena; Mytilinaios, Dimitrios; Calogero, Aldo E; Kamilaris, Themis C; Troupis, Theodore; Chrousos, George P; Johnson, Elizabeth O

    2015-08-01

    Hyperthyroidism is associated with a significant increase in circulating glucocorticoid levels and hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. The aim of this study was to examine whether the HPA axis hyperactivity observed in hyperthyroidism may be explained by a disturbed feedback inhibition of endogenous glucocorticoids through two specific intracellular receptors in the brain: the high affinity mineralocorticoid receptor (MR) and the lower affinity glucocorticoid receptor (GR). Cytosolic receptor binding and gene expression was assessed in rats with short (7 days) and long standing (60 days) eu- and hyperthyroidism. Glucocorticoid receptor number and binding affinity (Kd) in the hippocampus were measured using [(3)H2]-dexamethasone radioreceptor assay. In situ hybridization was employed to examine the effects of hyperthyroidism on the GR and MR mRNA levels in the hippocampus and the pituitary. Both short- and long-term hyperthyroid rats showed pronounced reduction in the concentration of cytosolic GR in the hippocampus, without changes in binding affinity or changes in GR expression. In contrast, GR mRNA in the pituitary increased after 7 days and decreased after 60 days of thyroxin treatment. MR mRNA was moderately affected. Hyperthyroidism is associated with significant decreases in hippocampal GR levels supporting the hypothesis that hyperactivity of the HPA axis observed in experimentally induced hyperthyroidism may be attributed, at least in part, to decreased negative feedback at the level of the hippocampus. These findings further support the notion that a central locus is principally responsible for the hyperactivity of the HPA axis observed in hyperthyroidism.

  14. Benzodiazepine dependence and its prevention and treatment%苯二氮类药物依赖及其防治

    Institute of Scientific and Technical Information of China (English)

    李林艳; 徐建

    2012-01-01

    Benzodiazepines are mainly used to treat anxiety and insomnia. Prolonged use: of benzodiazepines can lead to physical and psychological dependence. The: mechanism of benzodiazepine dependence is related to central neurotransmitters such as ?-aminobutyric acid and glutamate acid. The risk factors for benzodiazepine dependence include drug selection, drug administration, and individual difference. The clinical manifestations of benzodiazepine dependence are increased tolerance to the drug, withdrawal symptoms, and psychological dependence. The treatment strategies for benzodiazepine dcpc;ndc;ncc include the drug withdrawal, adjuvant treatment with drug, substitntivc trcatmcnt, combincd thcrapy of Chinese and wcstcrn mcdicinc, and psychotherapy.%苯二氮类药物(BZD)主要用于治疗焦虑和失眠,长期使用可导致躯体及精神依赖.BZD依赖的发生机制与γ-氨基丁酸和谷氨酸等中枢神经递质有关.药物选择、给药方法 和个体差异是BZD依赖的影响因素.BZD依赖表现为药物耐受性增加、戒断症状和心理依赖.BZD依赖的治疗包括停药、药物辅助治疗、替代治疗、中西医结合治疗和心理治疗.

  15. Influence of benzodiazepines on antiparkinsonian drug treatment in levodopa users

    NARCIS (Netherlands)

    van de Vijver, D A M C; Roos, R A C; Jansen, P A F; Porsius, A J; de Boer, A

    2002-01-01

    OBJECTIVES: Animal studies showed that benzodiazepines decrease the concentration of dopamine in the striatum. Benzodiazepines may therefore affect the treatment of Parkinson's disease. This study determined whether start of a benzodiazepine in patients on levodopa was followed by a faster increase

  16. Synthesis of 3-Substituted 1,4-Benzodiazepin-2-ones

    Directory of Open Access Journals (Sweden)

    Kyungjin Kim

    1998-01-01

    Full Text Available The preparation of 3-substituted 1,4-benzodiazepines by benzodiazepine enolate alkylation has been explored. Employing this approach, multigram quantities of benzodiazepine 1 have been prepared for animal studies to evaluate a new approach for the treatment of the autoimmune disease systemic lupus erythematosus (SLE.

  17. AC-3933, a benzodiazepine partial inverse agonist, improves memory performance in MK-801-induced amnesia mouse model.

    Science.gov (United States)

    Hashimoto, Takashi; Iwamura, Yoshihiro

    2016-05-01

    AC-3933, a novel benzodiazepine receptor partial inverse agonist, is a drug candidate for cognitive disorders including Alzheimer's disease. We have previously reported that AC-3933 enhances acetylcholine release in the rat hippocampus and ameliorates scopolamine-induced memory impairment and age-related cognitive decline in both rats and mice. In this study, we further evaluated the procognitive effect of AC-3933 on memory impairment induced by MK-801, an N-methyl-d-aspartate receptor antagonist, in mice. Unlike the acetylcholinesterase inhibitor donepezil and the benzodiazepine receptor inverse agonist FG-7142, oral administration of AC-3933 significantly ameliorated MK-801-induced memory impairment in the Y-maze test and in the object location test. Interestingly, the procognitive effects of AC-3933 on MK-801-induced memory impairment were not affected by the benzodiazepine receptor antagonist flumazenil, although this was not the case for the beneficial effects of AC-3933 on scopolamine-induced memory deficit. Moreover, the onset of AC-3933 ameliorating effect on scopolamine- or MK-801-induced memory impairment was different in the Y-maze test. Taken together, these results indicate that AC-3933 improves memory deficits caused by both cholinergic and glutamatergic hypofunction and suggest that the ameliorating effect of AC-3933 on MK-801-induced memory impairment is mediated by a mechanism other than inverse activation of the benzodiazepine receptor.

  18. Identification, characterization, and purification of a 65,000 dalton protein in rat brain is photolabeled by nitro-containing benzodiazepines

    Energy Technology Data Exchange (ETDEWEB)

    Bowling, A.C.

    1988-01-01

    Benzodiazepines bind to two well-characterized classes of nanomolar-affinity binding sites, the central and the peripheral types. Although these sites appear to mediate many of the effects of these compounds, they cannot account for all of the biochemical and physiologic effects of the benzodiazepines. In this investigation, a protein that is photolabeled by NO{sub 2}-containing benzodiazepines was identified and characterized in rat brain by performing photaffinity labeling experiments with ({sup 3}H)-clonazepam and ({sup 3}H)-flunitrazepam. These experiments demonstrate that this photolabeled protein has a molecular weight of 65,000 daltons. Photolabeling of the protein was saturable, inhibited in a stereoselective manner by benzodiazepine enantiomers, inhibited by therapeutically-relevant concentrations of many different NO{sub 2}-containing benzodiazepines, and was not inhibited by more than 70 non-benzodiazepine compounds. The photolabeled protein is distinct from the central and peripheral sites on the basis of molecular weight, benzodiazepine inhibitory potencies, subcellular localization, and tissue distribution.

  19. The muscle relaxant thiocolchicoside is an antagonist of GABAA receptor function in the central nervous system.

    Science.gov (United States)

    Carta, Mario; Murru, Luca; Botta, Paolo; Talani, Giuseppe; Sechi, GianPietro; De Riu, PierLuigi; Sanna, Enrico; Biggio, Giovanni

    2006-09-01

    Thiocolchicoside (TCC) is used clinically for its muscle relaxant, anti-inflammatory, and analgesic properties, and it has been shown to interact with gamma-aminobutyric acid (GABA) type A receptors (GABAARs) and strychnine-sensitive glycine receptors in the rat central nervous system. In contrast to a proposed agonistic action at these two types of inhibitory receptors, pharmacological evidence has shown that, under certain conditions, TCC manifests convulsant activity in animals and humans. We now show that the phasic and tonic GABAAR-mediated currents recorded from Purkinje cells and granule neurons, respectively, in parasagittal cerebellar slices from adult male rats were inhibited by TCC in a concentration-dependent manner. The median inhibitory concentrations of TCC for these effects were approximately 0.15 and approximately 0.9 microM, respectively. TCC did not potentiate GABABR-mediated currents in hippocampal slices, suggesting that its muscle relaxant action is not mediated by GABABRs. Intraperitoneal injection of TCC in rats either alone or in combination with negative modulators of GABAergic transmission revealed convulsant and proconvulsant actions of this drug. Our data, consistent with clinical observations of the epileptogenic effect of this compound, suggest that TCC is a potent competitive antagonist of GABAAR function.

  20. The Aversive Agent Lithium Chloride Suppresses Phasic Dopamine Release Through Central GLP-1 Receptors

    Science.gov (United States)

    Fortin, Samantha M; Chartoff, Elena H; Roitman, Mitchell F

    2016-01-01

    Unconditioned rewarding stimuli evoke phasic increases in dopamine concentration in the nucleus accumbens (NAc) while discrete aversive stimuli elicit pauses in dopamine neuron firing and reductions in NAc dopamine concentration. The unconditioned effects of more prolonged aversive states on dopamine release dynamics are not well understood and are investigated here using the malaise-inducing agent lithium chloride (LiCl). We used fast-scan cyclic voltammetry to measure phasic increases in NAc dopamine resulting from electrical stimulation of dopamine cell bodies in the ventral tegmental area (VTA). Systemic LiCl injection reduced electrically evoked dopamine release in the NAc of both anesthetized and awake rats. As some behavioral effects of LiCl appear to be mediated through glucagon-like peptide-1 receptor (GLP-1R) activation, we hypothesized that the suppression of phasic dopamine by LiCl is GLP-1R dependent. Indeed, peripheral pretreatment with the GLP-1R antagonist exendin-9 (Ex-9) potently attenuated the LiCl-induced suppression of dopamine. Pretreatment with Ex-9 did not, however, affect the suppression of phasic dopamine release by the kappa-opioid receptor agonist, salvinorin A, supporting a selective effect of GLP-1R stimulation in LiCl-induced dopamine suppression. By delivering Ex-9 to either the lateral or fourth ventricle, we highlight a population of central GLP-1 receptors rostral to the hindbrain that are involved in the LiCl-mediated suppression of NAc dopamine release. PMID:26211731

  1. The imidazoline receptors and the central regulation of the arterial blood pressure: a minireview

    Directory of Open Access Journals (Sweden)

    Eduardo Tibiriça

    1993-06-01

    Full Text Available Recently, we proposed the hypothesis according to wich the central hypotensive effect of clonidine and related substances could be related to an action upon specific receptors, requiring the imidazoline or imidazoline-like structures, rather than alpha2-adrenoceptors. Since then, direct evidences have been accumulated to confirm the existence of a population of imidazoline specific binding sites in the brainstem of animals and man, more precisely in the Nucleus Reticularis Lateralis (NRL region of the ventrolateral medulla (VLM, site of the antihypertensive action of clonidine. The purification of the putative endogenous ligand of the imidazoline receptors - named endazoline - is currently being attempted from human brain extracts. This new concept might at last lead to the expected dissociation of the pharmacological mechanisms involved, on the one hand, in the therapeutic antihypertensive effect, and on the other, in their major side-effect, which is sedation. In fact, it has been recently confirmed that hypotension is mediated by the activation of imidazoline preferring receptors (IPR within the NRL region, while sedation is attributed to the inhibition of alpha2-adrenergic mechanisms in the locus coeruleus, which is involved in the control of the sleep-waking cycle. The IPRmay constitute on interesting target for new drugs in the treatment of arterial hypertension. Finally, dysfunctions of this modulatory system which could be involved in the pathophysiologyof some forms of the hypertensive disease are under investigation.

  2. Participation of central GABAA receptors in the trigeminal processing of mechanical allodynia in rats

    Science.gov (United States)

    Kim, Min Ji; Park, Young Hong; Yang, Kui Ye; Ju, Jin Sook; Bae, Yong Chul

    2017-01-01

    Here we investigated the central processing mechanisms of mechanical allodynia and found a direct excitatory link with low-threshold input to nociceptive neurons. Experiments were performed on male Sprague-Dawley rats weighing 230-280 g. Subcutaneous injection of interleukin 1 beta (IL-1β) (1 ng/10 µL) was used to produce mechanical allodynia and thermal hyperalgesia. Intracisternal administration of bicuculline, a gamma aminobutyric acid A (GABAA) receptor antagonist, produced mechanical allodynia in the orofacial area under normal conditions. However, intracisternal administration of bicuculline (50 ng) produced a paradoxical anti-allodynic effect under inflammatory pain conditions. Pretreatment with resiniferatoxin (RTX), which depletes capsaicin receptor protein in primary afferent fibers, did not alter the paradoxical anti-allodynic effects produced by the intracisternal injection of bicuculline. Intracisternal injection of bumetanide, an Na-K-Cl cotransporter (NKCC 1) inhibitor, reversed the IL-1β-induced mechanical allodynia. In the control group, application of GABA (100 µM) or muscimol (3 µM) led to membrane hyperpolarization in gramicidin perforated current clamp mode. However, in some neurons, application of GABA or muscimol led to membrane depolarization in the IL-1β-treated rats. These results suggest that some large myelinated Aβ fibers gain access to the nociceptive system and elicit pain sensation via GABAA receptors under inflammatory pain conditions. PMID:28066142

  3. Central sensitization of nociceptive neurons in rat medullary dorsal horn involves purinergic P2X7 receptors.

    Science.gov (United States)

    Itoh, K; Chiang, C-Y; Li, Z; Lee, J-C; Dostrovsky, J O; Sessle, B J

    2011-09-29

    Central sensitization is a crucial process underlying the increased neuronal excitability of nociceptive pathways following peripheral tissue injury and inflammation. Our previous findings have suggested that extracellular adenosine 5'-triphosphate (ATP) molecules acting at purinergic receptors located on presynaptic terminals (e.g., P2X2/3, P2X3 subunits) and glial cells are involved in the glutamatergic-dependent central sensitization induced in medullary dorsal horn (MDH) nociceptive neurons by application to the tooth pulp of the inflammatory irritant mustard oil (MO). Since growing evidence indicates that activation of P2X7 receptors located on glia is involved in chronic inflammatory and neuropathic pain, the aim of the present study was to test in vivo for P2X7 receptor involvement in this acute inflammatory pain model. Experiments were carried out in anesthetized Sprague-Dawley male rats. Single unit recordings were made in MDH functionally identified nociceptive neurons for which mechanoreceptive field, mechanical activation threshold and responses to noxious stimuli were tested. We found that continuous intrathecal (i.t.) superfusion over MDH of the potent P2X7 receptor antagonists brilliant blue G and periodated oxidized ATP could each significantly attenuate the MO-induced MDH central sensitization. MDH central sensitization could also be produced by i.t. superfusion of ATP and even more effectively by the P2X7 receptor agonist benzoylbenzoyl ATP. Superfusion of the microglial blocker minocycline abolished the MO-induced MDH central sensitization, consistent with reports that dorsal horn P2X7 receptors are mostly expressed on microglia. In control experiments, superfusion over MDH of vehicle did not produce any significant changes. These novel findings suggest that activation of P2X7 receptors in vivo may be involved in the development of central sensitization in an acute inflammatory pain model.

  4. Quantitative structure-activity relationship study on some benzodiazepine derivatives as anti-Alzheimer agents.

    Science.gov (United States)

    Debnath, Bikash; Gayen, Shovanlal; Basu, Anindya; Srikanth, Kolluru; Jha, Tarun

    2004-12-01

    A QSAR study was performed in an attempt to explore the pharmacophore of some benzodiazepine derivatives as anti-Alzheimer agents for the inhibition of gamma-secretase. The study, which used the electrotopological state atom (ETSA) index, which encodes electronic and topological information, reveals the importance of two phenyl rings-one substituted and another unsubstituted, for the inhibition of the enzyme. Fluorine substitution on the substituted phenyl ring has an important contribution to the activity. R-configurations of the aliphatic chain substituents provide the exact conformation of the molecules to enter into the binding pockets of the receptor(s). [figure: see text]. General structure of benzodiazepine containing gamma-secretase inhibitors.

  5. Cannabinoids alleviate experimentally induced intestinal inflammation by acting at central and peripheral receptors.

    Directory of Open Access Journals (Sweden)

    Jakub Fichna

    Full Text Available In an attempt to further investigate the role of cannabinoid (CB system in the pathogenesis of inflammatory bowel diseases, we employed two recently developed ligands, AM841 (a covalently acting CB agonist and CB13 (a peripherally-restricted CB agonist to establish whether central and peripheral CB sites are involved in the anti-inflammatory action in the intestine.AM841 (0.01, 0.1 and 1 mg/kg, i.p. significantly decreased inflammation scores in dextran sulfate sodium (DSS- and 2,4,6-trinitrobenzene sulfonic acid (TNBS-treated mice when administered before induction of colitis or as a treatment of existing intestinal inflammation. The effect was absent in CB1, CB2 and CB(1/2-deficient mice. A peripherally-restricted agonist CB13 did not alleviate colitis when given i.p. (0.1 mg/kg, but significantly decreased inflammation score after central administration (0.1 µg/animal.This is the first evidence that central and peripheral CB receptors are responsible for the protective and therapeutic action of cannabinoids in mouse models of colitis. Our observations provide new insight to CB pharmacology and validate the use of novel ligands AM841 and CB13 as potent tools in CB-related research.

  6. Predictors of benzodiazepine discontinuation in subjects manifesting complicated dependence.

    Science.gov (United States)

    Vorma, Helena; Naukkarinen, Hannu H; Sarna, Seppo J; Kuoppasalmi, Kimmo I

    2005-01-01

    We described characteristics of subjects with benzodiazepine dependence that was typically complicated by harmful and hazardous alcohol use or high benzodiazepine doses, and assessed predictors of successful discontinuation of benzodiazepines for this group. Seventy-six patients who participated in a randomized clinical trial of two different gradual withdrawal treatment approaches were assessed. The trial was conducted between February 1995 and July 1999. The mean age +/- SD of subjects was 40.0 +/- 9.6 years, 55% were male, 38% were married or cohabiting, and 70% had received more than nine years of education. The median benzodiazepine dose was 35 mg/day (range 2.5-180) in diazepam equivalents. The median duration of benzodiazepine use was 84 (range 8-360) months. Subjects with lower benzodiazepine doses and no previous withdrawal attempts were more successful at benzodiazepine discontinuation. Cluster B personality/borderline personality disorder was associated with an inability to stop benzodiazepine use and with "dropping out" of treatment. Alcohol use-related disorders or other psychiatric diagnoses were not associated with outcome. Further studies on predictors of successful benzodiazepine discontinuation in different populations are required. Patients manifesting cluster B personality/borderline personality disorder and benzodiazepine dependence may need concomitant treatment for their personality disorders to benefit from benzodiazepine discontinuation treatment.

  7. Defining benzodiazepine dependence: The confusion persists

    NARCIS (Netherlands)

    Linsen, S.M.; Zitman, F.G.; Breteler, M.H.M.

    1995-01-01

    Little consensus exists on the risk of benzodiazepine (BZD) dependence. We investigated how often BZD dependence and related concepts have been defined in the literature on BZD effects in humans. In addition, the definitions of BZD dependence were compared in order to assess the similarity of conten

  8. Benzodiazepine pathways in the chronically ill

    NARCIS (Netherlands)

    Van Hulten, Rolf; Heerdink, Eibert R.; Bakker, Albert; Leufkens, Hubert G.

    1999-01-01

    The association between patterns of use of benzodiazepines and chronic somatic morbidity was examined by applying the Chronic Disease Score (CDS). In the only pharmacy in a Dutch community, 6921 patients with data available covering a 10-year period (1983-1992) were included. In 1992, two-thirds of

  9. [Benzodiazepines in the treatment of epilepsy].

    Science.gov (United States)

    Nakken, Karl O; Rytter, Elisif M; Brockmeier, Frans

    2010-04-22

    In epilepsy benzodiazepines are mainly used to stop ongoing attacks. In hospitals intravenous diazepam is the drug of choice for status epilepticus. Outside of hospitals buccal midazolam is in the process of replacing rectal diazepam. Clonazepam, clobazam and nitrazepam (to children) are partially used as additional medication to prevent seizures.

  10. Catatonia in mixed alcohol and benzodiazepine withdrawal

    Directory of Open Access Journals (Sweden)

    Aniruddha Basu

    2014-01-01

    Full Text Available Catatonia is mostly caused by different neuropsychiatric conditions. We report a case of a 30 year old man suffering from both alcohol and benzodiazepine dependence who exhibited catatonic features soon after stopping the intake of substances. This case will help clinicians to recognize catatonic features within the varied symptomatology of substance withdrawal and thereby helping in its early diagnosis and management.

  11. Benzodiazepine use in Denmark 1997-2008

    DEFF Research Database (Denmark)

    Holm, E.; Pedersen, H.; Fosbol, E.

    2012-01-01

    Purpose: Analysis of the pattern of benzodiazepine (BZD) use over time in the period 1997-2008 in relation to age and comorbidity. Methods: All Danish citizens more than or equal to 10 years on January 1, 1997 were included in the study based on data from national databases. Main outcome measures...

  12. Benzodiazepine Synthesis and Rapid Toxicity Assay

    Science.gov (United States)

    Fletcher, James T.; Boriraj, Grit

    2010-01-01

    A second-year organic chemistry laboratory experiment to introduce students to general concepts of medicinal chemistry is described. Within a single three-hour time window, students experience the synthesis of a biologically active small molecule and the assaying of its biological toxicity. Benzodiazepine rings are commonly found in antidepressant…

  13. Benzodiazepines, benzodiazepine-like drugs, and typical antipsychotics impair manual dexterity in patients with schizophrenia.

    Science.gov (United States)

    Sasayama, Daimei; Hori, Hiroaki; Teraishi, Toshiya; Hattori, Kotaro; Ota, Miho; Matsuo, Junko; Kinoshita, Yukiko; Okazaki, Mitsutoshi; Arima, Kunimasa; Amano, Naoji; Higuchi, Teruhiko; Kunugi, Hiroshi

    2014-02-01

    Impaired dexterity is a major psychomotor deficit reported in patients with schizophrenia. In the present study, the Purdue pegboard test was used to compare the manual dexterity in patients with schizophrenia and healthy controls. We also examined the influence of antipsychotics, benzodiazepines, and benzodiazepine-like drugs on manual dexterity. Subjects were 93 patients with schizophrenia and 93 healthy controls, matched for sex and age distributions. Control subjects scored significantly higher on all scores of Purdue pegboard than patients with schizophrenia. Age, PANSS negative symptom scale, typical antipsychotic dose, and use of benzodiazepines and/or benzodiazepine-like drugs were negatively correlated with the pegboard scores in patients with schizophrenia. The present results indicate that patients with schizophrenia have impaired gross and fine fingertip dexterity compared to healthy controls. The use of typical antipsychotics and benzodiazepines and/or benzodiazepine-like drugs, but not atypical antipsychotics, had significant negative impact on dexterity in patients with schizophrenia. Psychiatrists should be aware that some psychotropic medications may enhance the disability caused by the impairment of dexterity in patients with schizophrenia.

  14. Synthesis of new N-substituted benzodiazepine derivatives with potential anxiolytic activity.

    Science.gov (United States)

    Kossakowski, J; Zawadowski, T; Turło, J

    1997-01-01

    In continuation of the development of antipsychotic and anxiolytic agents with a reduced propensity toward extrapyramidal side-effects, a series of N-aminoalkyl derivatives of (s)-(+)-2,3-dihydro-1H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11-(10H, 11aH)-dione was prepared. Evaluation of these compounds in revealed a very low affinity for 5-HT1A receptor.

  15. Baclofen in the short-term maintenance treatment of benzodiazepine dependence

    Directory of Open Access Journals (Sweden)

    Lekhansh Shukla

    2014-01-01

    Full Text Available Benzodiazepine (BZD dependence is a significant public health problem. Apart from the long-term tapering doses of BZD, no others drugs are available for the maintenance treatment of BZD dependence. Baclofen has been used in alcohol and other drug dependence as long-term anti-craving agent. Since alcohol and BZD act through the GABA receptor, we attempted to study the effect of Baclofen as maintenance treatment in a series of five cases with BZD dependence.

  16. Baclofen in the short-term maintenance treatment of benzodiazepine dependence.

    Science.gov (United States)

    Shukla, Lekhansh; Kandasamy, Arun; Kesavan, Muralidharan; Benegal, Vivek

    2014-11-01

    Benzodiazepine (BZD) dependence is a significant public health problem. Apart from the long-term tapering doses of BZD, no others drugs are available for the maintenance treatment of BZD dependence. Baclofen has been used in alcohol and other drug dependence as long-term anti-craving agent. Since alcohol and BZD act through the GABA receptor, we attempted to study the effect of Baclofen as maintenance treatment in a series of five cases with BZD dependence.

  17. Peripheral and central localization of the nesfatin-1 receptor using autoradiography in rats

    Energy Technology Data Exchange (ETDEWEB)

    Prinz, Philip [Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12203 Berlin (Germany); Goebel-Stengel, Miriam [Department of Internal Medicine, Martin-Luther Krankenhaus, Caspar-Theyß-Str. 27-31, 14193 Berlin (Germany); Teuffel, Pauline; Rose, Matthias; Klapp, Burghard F. [Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12203 Berlin (Germany); Stengel, Andreas, E-mail: andreas.stengel@charite.de [Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12203 Berlin (Germany)

    2016-02-12

    Nesfatin-1 was recently identified and introduced as food intake-regulatory hormone. Soon thereafter, mounting evidence indicated a much broader role for nesfatin-1 with an involvement in the regulation of food intake, gastrointestinal motility, glucose homeostasis, blood pressure and stress. Despite the growing knowledge on the physiological regulation and functions of nesfatin-1, the receptor mediating these effects remains to be characterized. Therefore, the aim of this study was to investigate the peripheral and central localization of the nesfatin-1 receptor by autoradiography. Male Sprague–Dawley rats were used and peripheral as well as brain tissue was processed for {sup 125}I-nesfatin-1 autoradiography. In peripheral tissues, an autoradiographic signal was observed in the gastric mucosa of corpus and antrum, in duodenum, jejunum and ileum, while no signal was detected in the colon. Preabsorption of {sup 125}I-nesfatin-1 with non-labeled nesfatin-1 greatly diminished the autoradiographic signal in the stomach indicating specificity (−32%, p < 0.001). A displacement assay showed an effective concentration by which 50% of {sup 125}I-nesfatin-1 bound to the receptor (EC{sub 50}) in the gastric corpus of 80 pM. Moreover, autoradiography was observed in endocrine tissues including the pituitary, pancreas, adrenal gland, testis and visceral adipose tissue. In addition, also heart, skeletal muscle, lung, liver and kidney showed autoradiographic signals. In the brain, strong {sup 125}I-nesfatin-1 autoradiography was detected in the cortex, paraventricular nucleus of the hypothalamus, area postrema, dorsal motor nucleus of the vagus nerve and cerebellum. Based on the distribution of nesfatin-1 autoradiography, nesfatin-1 is a pleiotropic hormone that is involved in the regulation of several homeostatic functions. - Highlights: • Although our knowledge on nesfatin-1 is increasing, the receptor is still unknown. • {sup 125}I-nesfatin-1 autoradiography was

  18. Imaging of peripheral-type benzodiazepine receptor in tumor: in vitro binding and in vivo biodistribution of N-benzyl-N-[{sup 11}C]methyl-2- (7-methyl-8-oxo-2-phenyl-7,8-dihydro-9H-purin-9-yl) acetamide

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, Tomoteru; Kumata, Katsushi; Yanamoto, Kazuhiko; Hatori, Akiko [Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Takei, Makoto; Nakamura, Yukio [Tokyo Nuclear Service Co. Ltd., Tokyo 141-8686 (Japan); Koike, Sachiko; Ando, Koichi [Heavy-ion Radiobiology Research Group, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Suzuki, Kazutoshi [Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Zhang, Ming-Rong [Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan)], E-mail: zhang@nirs.go.jp

    2009-10-15

    Introduction: The aim of this study was to evaluate N-benzyl-N-[{sup 11}C]methyl-2- (7-methyl-8-oxo-2-phenyl-7,8-dihydro-9H-purin-9-yl) acetamide ([{sup 11}C]DAC) as a novel peripheral-type benzodiazepine receptor (PBR) ligand for tumor imaging. Methods: [{sup 11}C]DAC was synthesized by the reaction of a desmethyl precursor with [{sup 11}C]CH{sub 3}I. In vitro uptake of [{sup 11}C]DAC was examined in PBR-expressing C6 glioma and intact murine fibrosarcoma (NFSa) cells. In vivo distribution of [{sup 11}C]DAC was determined using NFSa-bearing mice and small-animal positron emission tomography (PET). Results: [{sup 11}C]DAC showed specific binding to PBR in C6 glioma cells, a standard cell line with high PBR expression. Specific binding of [{sup 11}C]DAC was also confirmed in NFSa cells, a target tumor cell line in this study. Results of PET experiments using NFSa-bearing mice, showed that [{sup 11}C]DAC was taken up specifically into the tumor, and pretreatment with PK11195 abolished the uptake. Conclusions: [{sup 11}C]DAC was taken up into PBR-expressing NFSa. [{sup 11}C]DAC is a promising PET ligand that can be used for imaging PBR in tumor-bearing mice.

  19. Kinin Receptor Antagonists as Potential Neuroprotective Agents in Central Nervous System Injury

    Directory of Open Access Journals (Sweden)

    Anna V Leonard

    2010-09-01

    Full Text Available Injury to the central nervous system initiates complex physiological, cellular and molecular processes that can result in neuronal cell death. Of interest to this review is the activation of the kinin family of neuropeptides, in particular bradykinin and substance P. These neuropeptides are known to have a potent pro-inflammatory role and can initiate neurogenic inflammation resulting in vasodilation, plasma extravasation and the subsequent development of edema. As inflammation and edema play an integral role in the progressive secondary injury that causes neurological deficits, this review critically examines kinin receptor antagonists as a potential neuroprotective intervention for acute brain injury, and more specifically, traumatic brain and spinal cord injury and stroke.

  20. EP2 receptor antagonism reduces peripheral and central hyperalgesia in a preclinical mouse model of endometriosis

    Science.gov (United States)

    Greaves, Erin; Horne, Andrew W.; Jerina, Helen; Mikolajczak, Marta; Hilferty, Lisa; Mitchell, Rory; Fleetwood-Walker, Sue M.; Saunders, Philippa T. K.

    2017-01-01

    Endometriosis is an incurable gynecological disorder characterized by debilitating pain and the establishment of innervated endometriosis lesions outside the uterus. In a preclinical mouse model of endometriosis we demonstrated overexpression of the PGE2-signaling pathway (including COX-2, EP2, EP4) in endometriosis lesions, dorsal root ganglia (DRG), spinal cord, thalamus and forebrain. TRPV1, a PGE2-regulated channel in nociceptive neurons was also increased in the DRG. These findings support the concept that an amplification process occurs along the pain neuroaxis in endometriosis. We then tested TRPV1, EP2, and EP4 receptor antagonists: The EP2 antagonist was the most efficient analgesic, reducing primary hyperalgesia by 80% and secondary hyperalgesia by 40%. In this study we demonstrate reversible peripheral and central hyperalgesia in mice with induced endometriosis. PMID:28281561

  1. Psychological stress impairs hepatic blood flow via central CRF receptors in mice.

    Science.gov (United States)

    Chida, Yoichi; Sudo, Nobuyuki; Kubo, Chiharu

    2005-02-25

    Some previous works have further expanded the 'Brain-Gut axis', that is a bi-directional interaction between the gut and brain function, into a relationship of the brain with the liver. However, all the details of such brain-liver relationship were not fully understood because appropriate animal models had not been established yet. Here we developed a novel animal model, in which hepatic blood flow of conscious mice could be measured in real-time. In addition, using this model, we also demonstrated that exposure to psychological stress considerably reduced hepatic blood flow via central CRF receptors. Thus, this new model is considered to be a useful and promising tool for elucidating the precise effects of emotional factors on liver function.

  2. Bombesin-like receptor 3 regulates blood pressure and heart rate via a central sympathetic mechanism.

    Science.gov (United States)

    Lateef, Dalya M; Xiao, Cuiying; Brychta, Robert J; Diedrich, André; Schnermann, Jurgen; Reitman, Marc L

    2016-04-01

    Bombesin-like receptor 3 (BRS-3) is an orphan G protein-coupled receptor that regulates energy expenditure, food intake, and body weight. We examined the effects of BRS-3 deletion and activation on blood pressure and heart rate. In free-living, telemetered Brs3 null mice the resting heart rate was 10% lower than wild-type controls, while the resting mean arterial pressure was unchanged. During physical activity, the heart rate and blood pressure increased more in Brs3 null mice, reaching a similar heart rate and higher mean arterial pressure than control mice. When sympathetic input was blocked with propranolol, the heart rate of Brs3 null mice was unchanged, while the heart rate in control mice was reduced to the level of the null mice. The intrinsic heart rate, measured after both sympathetic and parasympathetic blockade, was similar in Brs3 null and control mice. Intravenous infusion of the BRS-3 agonist MK-5046 increased mean arterial pressure and heart rate in wild-type but not in Brs3 null mice, and this increase was blocked by pretreatment with clonidine, a sympatholytic, centrally acting α2-adrenergic agonist. In anesthetized mice, hypothalamic infusion of MK-5046 also increased both mean arterial pressure and heart rate. Taken together, these data demonstrate that BRS-3 contributes to resting cardiac sympathetic tone, but is not required for activity-induced increases in heart rate and blood pressure. The data suggest that BRS-3 activation increases heart rate and blood pressure via a central sympathetic mechanism.

  3. Clinical features and ryanodine receptor type 1 gene mutation analysis in a Chinese family with central core disease.

    Science.gov (United States)

    Chang, Xingzhi; Jin, Yiwen; Zhao, Haijuan; Huang, Qionghui; Wang, Jingmin; Yuan, Yun; Han, Ying; Qin, Jiong

    2013-03-01

    Central core disease is a rare inherited neuromuscular disorder caused by mutations in ryanodine receptor type 1 gene. The clinical phenotype of the disease is highly variable. We report a Chinese pedigree with central core disease confirmed by the gene sequencing. All 3 patients in the family presented with mild proximal limb weakness. The serum level of creatine kinase was normal, and electromyography suggested myogenic changes. The histologic analysis of muscle biopsy showed identical central core lesions in almost all of the muscle fibers in the index case. Exon 90-106 in the C-terminal domain of the ryanodine receptor type 1 gene was amplified using polymerase chain reaction. One heterozygous missense mutation G14678A (Arg4893Gln) in exon 102 was identified in all 3 patients. This is the first report of a familial case of central core disease confirmed by molecular study in mainland China.

  4. Cannabinoid Type-1 Receptor Gene Polymorphisms Are Associated with Central Obesity in a Southern Brazilian Population

    Directory of Open Access Journals (Sweden)

    Janaína P. Jaeger

    2008-01-01

    Full Text Available The CB1 cannabinoid receptor and its endogenous ligands, the endocannabinoids, are involved in energy balance control, stimulating appetite and increasing body weight in wasting syndromes. Different studies have investigated the relationship between polymorphisms of the cannabinoid receptor 1 (CNR1 gene and obesity with conflicting results. In the present study, we investigated the 1359G/A (rs1049353, 3813A/G (rs12720071 and 4895A/G (rs806368 polymorphisms in the CNR1 gene in a Brazilian population of European descent. To verify the association between these variants and obesity-related traits in this population, 756 individuals were genotyped by PCR-RFLP methods. The 4895G allele was associated with waist to hip ratio (WHR (P = 0.014; P = 0.042 after Bonferroni correction. An additive effect with the GAA haplotype was associated with WHR (P = 0.028, although this statistical significance disappeared after Bonferroni correction (P = 0.084. No significant association was observed between the genotypes of the 1359G/A and 3813A/G polymorphisms and any of the quantitative variables investigated. Our findings suggest that CNR1 gene polymorphism is associated with central obesity in this Brazilian population of European ancestry.

  5. Immunohistochemical localization of the neuropeptide S receptor in the rat central nervous system.

    Science.gov (United States)

    Leonard, S K; Ring, R H

    2011-01-13

    The neuropeptide S receptor (NPSR) is a G-protein coupled receptor that is potently activated by the linear 20 amino acid peptide, neuropeptide S (NPS). Central administration of NPS promotes arousal and anxiolytic-like effects in rodents, and fails to promote such effects in NPSR knockout animals or in the presence of NPSR-selective antagonists. In situ hybridization (ISH) studies in rat brain have revealed that the mRNAs encoding the NPS precursor and the NPS receptor are expressed at high levels in discrete regions of the rat CNS. The distribution of the NPSR protein in brain has not been reported due to a lack of available antibodies. We have generated and validated a NPSR-specific antibody and used it to determine the distribution of the NPSR in male Sprague-Dawley (SD) rat brain. The anti-NPSR antibody identified a single protein by Western blot with an estimated molecular weight of 65 kD, which was prevented by pre-incubation of the antibody with the immunizing peptide. The protein distribution identified with this antibody in rat brain was consistent both with the mRNA distribution identified by in situ hybridization, and to the localization pattern identified by a second NPSR-specific antibody against a distinct NPSR epitope. NPSR protein was identified in the medial amygdala (MeA), substantia nigra pars compacta, subiculum, dorsal raphe, and several hypothalamic and thalamic regions. Additionally, NPSR protein was localized in the pyramidal cell layer of the ventral hippocampus, the medial habenula (MHb), and was widely distributed in the cortex. The distribution of NPSR protein provides further insight into the organization of the NPS system and may guide future studies on the role of the NPSR in brain.

  6. Sodium excretion following central administration of an I1 imidazoline receptor agonist, moxonidine.

    Science.gov (United States)

    Penner, S. B.; Smyth, D. D.

    1994-01-01

    1. Previously we have shown that an intrarenal infusion of moxonidine, an I1-imidazoline receptor agonist, resulted in a natriuresis which was inhibited by intravenous idazoxan, a selective imidazoline receptor antagonist. Therefore we examined the effects of renal function of intracerebroventricular (i.c.v.) administration of moxonidine with or without i.c.v. idazoxan. 2. Seven days after unilateral nephrectomy, Sprague-Dawley rats had i.c.v. cannulae implanted. Three days later the rats were anaesthetized (pentobarbitone), followed by cannulation of the jugular vein (fluid and drug administration), carotid artery (blood pressure) and the ureter (urine collection). 3. After a 45 min stabilization period, the effect of moxonidine was investigated by the i.c.v. administration of either isotonic saline or moxonidine (0.1, 0.3 or 1 nmol in isotonic saline) administered in 5 microliters over 1 min. All doses of moxonidine resulted in an increase in urine flow with a concomitant increase in sodium excretion without affecting blood pressure. The highest dose of moxonidine (1 nmol) also increased free water clearance. 4. In a second series of experiments, the effects of idazoxan on the natriuretic response to i.c.v. moxonidine were determined. Moxonidine (0.3 nmol) again increased sodium and water excretion as compared to the i.c.v. saline control animals. Pretreatment with i.c.v. idazoxan (0.3 nmol), at a dose which alone failed to alter sodium and water excretion, completely attenuated the renal response to moxonidine. These results are consistent with central I1-imidazoline receptors mediating a moxonidine-induced increase in sodium and water excretion at doses that do not alter blood pressure. PMID:7952868

  7. Chronic ethanol exposure decreases CB1 receptor function at GABAergic synapses in the rat central amygdala.

    Science.gov (United States)

    Varodayan, Florence P; Soni, Neeraj; Bajo, Michal; Luu, George; Madamba, Samuel G; Schweitzer, Paul; Parsons, Loren H; Roberto, Marisa

    2016-07-01

    The endogenous cannabinoids (eCBs) influence the acute response to ethanol and the development of tolerance, dependence and relapse. Chronic alcohol exposure alters eCB levels and Type 1 cannabinoid receptor (CB1 ) expression and function in brain regions associated with addiction. CB1 inhibits GABA release, and GABAergic dysregulation in the central nucleus of the amygdala (CeA) is critical in the transition to alcohol dependence. We investigated possible disruptions in CB1 signaling of rat CeA GABAergic transmission following intermittent ethanol exposure. In the CeA of alcohol-naive rats, CB1 agonist WIN 55,212-2 (WIN) decreased the frequency of spontaneous and miniature GABAA receptor-mediated inhibitory postsynaptic currents (s/mIPSCs). This effect was prevented by CB1 antagonism, but not Type 2 cannabinoid receptor (CB2 ) antagonism. After 2-3 weeks of intermittent ethanol exposure, these WIN inhibitory effects were attenuated, suggesting ethanol-induced impairments in CB1 function. The CB1 antagonist AM251 revealed a tonic eCB/CB1 control of GABAergic transmission in the alcohol-naive CeA that was occluded by calcium chelation in the postsynaptic cell. Chronic ethanol exposure abolished this tonic CB1 influence on mIPSC, but not sIPSC, frequency. Finally, acute ethanol increased CeA GABA release in both naive and ethanol-exposed rats. Although CB1 activation prevented this effect, the AM251- and ethanol-induced GABA release were additive, ruling out a direct participation of CB1 signaling in the ethanol effect. Collectively, these observations demonstrate an important CB1 influence on CeA GABAergic transmission and indicate that the CeA is particularly sensitive to alcohol-induced disruptions of CB1 signaling.

  8. Functional Characterization of C-terminal Ryanodine Receptor 1 Variants Associated with Central Core Disease or Malignant Hyperthermia.

    Science.gov (United States)

    Parker, Remai; Schiemann, Anja H; Langton, Elaine; Bulger, Terasa; Pollock, Neil; Bjorksten, Andrew; Gillies, Robyn; Hutchinson, David; Roxburgh, Richard; Stowell, Kathryn M

    2017-01-01

    Central core disease and malignant hyperthermia are human disorders of skeletal muscle resulting from aberrant Ca2+ handling. Most malignant hyperthermia and central core disease cases are associated with amino acid changes in the type 1 ryanodine receptor (RyR1), the skeletal muscle Ca2+-release channel. Malignant hyperthermia exhibits a gain-of-function phenotype, and central core disease results from loss of channel function. For a variant to be classified as pathogenic, functional studies must demonstrate a correlation with the pathophysiology of malignant hyperthermia or central core disease. We assessed the pathogenicity of four C-terminal variants of the ryanodine receptor using functional analysis. The variants were identified in families affected by either malignant hyperthermia or central core disease. Four variants were introduced separately into human cDNA encoding the skeletal muscle ryanodine receptor. Following transient expression in HEK-293T cells, functional studies were carried out using calcium release assays in response to an agonist. Two previously characterized variants and wild-type skeletal muscle ryanodine receptor were used as controls. The p.Met4640Ile variant associated with central core disease showed no difference in calcium release compared to wild-type. The p.Val4849Ile variant associated with malignant hyperthermia was more sensitive to agonist than wild-type but did not reach statistical significance and two variants (p.Phe4857Ser and p.Asp4918Asn) associated with central core disease were completely inactive. The p.Val4849Ile variant should be considered a risk factor for malignant hyperthermia, while the p.Phe4857Ser and p.Asp4918Asn variants should be classified as pathogenic for central core disease.

  9. Insights into the structural biology of G-protein coupled receptors impacts drug design for central nervous system neurodegenerative processes**

    Institute of Scientific and Technical Information of China (English)

    Farfán-García Eunice Dalet; Soriano-Ursúa Marvin Antonio

    2013-01-01

    In the last few years, there have been important new insights into the structural biology of G-protein coupled receptors. It is now known that al osteric binding sites are involved in the affinity and selec-tivity of ligands for G-protein coupled receptors, and that signaling by these receptors involves both G-protein dependent and independent pathways. The present review outlines the physiological and pharmacological implications of this perspective for the design of new drugs to treat disorders of the central nervous system. Specifical y, new possibilities are explored in relation to al osteric and orthosteric binding sites on dopamine receptors for the treatment of Parkinson’s disease, and on muscarinic receptors for Alzheimer’s disease. Future research can seek to identify ligands that can bind to more than one site on the same receptor, or simultaneously bind to two receptors and form a dimer. For example, the design of bivalent drugs that can reach homo/hetero-dimers of D2 dopa-mine receptor holds promise as a relevant therapeutic strategy for Parkinson’s disease. Regarding the treatment of Alzheimer’s disease, the design of dualsteric ligands for mono-oligomeric musca-rinic receptors could increase therapeutic effectiveness by generating potent compounds that could activate more than one signaling pathway.

  10. LPA receptor expression in the central nervous system in health and following injury.

    Science.gov (United States)

    Goldshmit, Yona; Munro, Kathryn; Leong, Soo Yuen; Pébay, Alice; Turnley, Ann M

    2010-07-01

    Lysophosphatidic acid (LPA) is released from platelets following injury and also plays a role in neural development but little is known about its effects in the adult central nervous system (CNS). We have examined the expression of LPA receptors 1-3 (LPA(1-3)) in intact mouse spinal cord and cortical tissues and following injury. In intact and injured tissues, LPA(1) was expressed by ependymal cells in the central canal of the spinal cord and was upregulated in reactive astrocytes following spinal cord injury. LPA(2) showed low expression in intact CNS tissue, on grey matter astrocytes in spinal cord and in ependymal cells lining the lateral ventricle. Following injury, its expression was upregulated on astrocytes in both cortex and spinal cord. LPA(3) showed low expression in intact CNS tissue, viz. on cortical neurons and motor neurons in the spinal cord, and was upregulated on neurons in both regions after injury. Therefore, LPA(1-3) are differentially expressed in the CNS and their expression is upregulated in response to injury. LPA release following CNS injury may have different consequences for each cell type because of this differential expression in the adult nervous system.

  11. Activation of mesolimbic dopaminergic neurons following central administration of histamine is mediated by H1 receptors.

    Science.gov (United States)

    Fleckenstein, A E; Lookingland, K J; Moore, K E

    1993-01-01

    The effect of intracerebroventricular administration of histamine on the activity of mesolimbic and nigrostriatal dopaminergic (DA) neurons was determined in male rats. The activity of these neurons was estimated by measuring: (1) the accumulation of 3,4-dihydroxyphenylalanine (DOPA) after administration of a decarboxylase inhibitor, and (2) the concentration of 3,4-dihydroxyphenylacetic acid (DOPAC) in the nucleus accumbens and striatum, which contain the terminals of these neurons. Central administration of histamine increased both DOPA accumulation and DOPAC concentrations in the nucleus accumbens, but was without effect in the striatum. The increase in DOPAC concentrations in the nucleus accumbens occurred within 10 min and was sustained for at least 120 min. The H1 antagonist mepyramine blocked whereas the H2 antagonist zolantidine did not affect histamine-induced increases in DOPAC concentrations in the nucleus accumbens. Neither mepyramine nor zolantidine affected basal DOPAC concentrations in the nucleus accumbens. These results indicate that central administration of histamine stimulates mesolimbic DA neurons through an action at the H1 receptor, but has no effect upon the activity of nigrostriatal DA neurons.

  12. EXPRESSION PATTERNS OF ESTROGEN RECEPTORS IN THE CENTRAL AUDITORY SYSTEM CHANGE IN PREPUBERTAL AND AGED MICE

    Science.gov (United States)

    Charitidi, K.; Frisina, R. D.; Vasilyeva, O. N.; Zhu, X.; Canlon, B.

    2011-01-01

    Estrogens are important in the development, maintenance and physiology of the CNS. Several studies have shown their effects on the processing of hearing in both males and females, and these effects, in part, are thought to result from regulation of the transcription of genes via their classical estrogen receptor (ER) pathway. In order to understand the spatiotemporal changes that occur with age, we have studied the expression of ERs in the central auditory pathway in prepubertal and aged CBA mice with immunohistochemistry. In prepubertal mice a clear dichotomy was noted between the expression of ERα and ERβ. ERβ-positive neurons were found in the metencephalon whereas the majority of ERα was found in mesencephalon, diencephalon or the telencephalon. In the aged animals a different pattern of ER expression was found in terms of location and overall intensity. These age-induced changes in the expression pattern were generally not uniform, suggesting that region-specific mechanisms regulate the ERs’ age-related expression. Neither the prepubertal nor the aged animals showed sex differences in any auditory structure. Our results demonstrate different age-dependent spatial and temporal changes in the pattern of expression of ERα and ERβ, suggesting that each ER type may be involved in distinct roles across the central auditory pathway in different periods of maturation. PMID:20736049

  13. Partial chemical characterization of cyclopyrrolones ((/sup 3/H) suriclone) and benzodiazepines ((/sup 3/H)flunitrazepam) binding site: Differences

    Energy Technology Data Exchange (ETDEWEB)

    Zundel, J.L.; Blanchard, J.C.; Julou, L.

    1985-06-10

    Rat hippocampus membranes were treated with several protein modifying reagents (iodoacetamide, N-ethylmaleimide, tetranitromethane and N-acetylimidazole). The effects of these treatments on the binding sites of cyclopyrrolones ((/sup 3/H) suriclone), a new chemical family of minor tranquilizers, and benzodiazepines ((/sup 3/H) flunitrazepam) were investigated. Here the authors show that both ligands are similarly sensitive to cysteine alkylation: (/sup 3/H) suriclone and (/sup 3/H) flunitrazepam binding are reduced by iodoacetamide and slightly increased by N-ethylmaleimide. On the contrary they are clearly differentiated by tyrosine modification: (/sup 3/H) suriclone binding is not changed whereas (/sup 3/H) flunitrazepam binding is increased by tetranitromethane and decreased by N-acetylimidazole. The present findings and published evidence suggest cyclopyrrolones and benzodiazepines bind to distinct sites or to different allosteric forms of the benzodiazepine receptor. 28 references, 6 figures.

  14. Presynaptic CRF1 Receptors Mediate the Ethanol Enhancement of GABAergic Transmission in the Mouse Central Amygdala

    Directory of Open Access Journals (Sweden)

    Zhiguo Nie

    2009-01-01

    Full Text Available Corticotropin-releasing factor (CRF is a 41-amino-acid neuropeptide involved in stress responses initiated from several brain areas, including the amygdala formation. Research shows a strong relationship between stress, brain CRF, and excessive alcohol consumption. Behavioral studies suggest that the central amygdala (CeA is significantly involved in alcohol reward and dependence. We recently reported that the ethanol augmentation of GABAergic synaptic transmission in rat CeA involves CRF1 receptors, because both CRF and ethanol significantly enhanced the amplitude of evoked GABAergic inhibitory postsynaptic currents (IPSCs in CeA neurons from wild-type (WT and CRF2 knockout (KO mice, but not in neurons of CRF1 KO mice. The present study extends these findings using selective CRF receptor ligands, gene KO models, and miniature IPSC (mIPSC analysis to assess further a presynaptic role for the CRF receptors in mediating ethanol effects in the CeA. In whole-cell patch recordings of pharmacologically isolated GABAAergic IPSCs from slices of mouse CeA, both CRF and ethanol augmented evoked IPSCs in a concentration-dependent manner, with low EC50s. A CRF1 (but not CRF2 KO construct and the CRF1-selective nonpeptide antagonist NIH-3 (LWH-63 blocked the augmenting effect of both CRF and ethanol on evoked IPSCs. Furthermore, the new selective CRF1 agonist stressin1, but not the CRF2 agonist urocortin 3, also increased evoked IPSC amplitudes. Both CRF and ethanol decreased paired-pulse facilitation (PPF of evoked IPSCs and significantly enhanced the frequency, but not the amplitude, of spontaneous miniature GABAergic mIPSCs in CeA neurons of WT mice, suggesting a presynaptic site of action. The PPF effect of ethanol was abolished in CeA neurons of CRF1 KO mice. The CRF1 antagonist NIH-3 blocked the CRF- and ethanol-induced enhancement of mIPSC frequency in CeA neurons. These data indicate that presynaptic CRF1 receptors play a critical role in permitting

  15. Role of central arginine vasopressin receptors in the analgesic effect of CDP-choline on acute and neuropathic pain.

    Science.gov (United States)

    Bagdas, Deniz; Yucel-Ozboluk, Hasret; Orhan, Fulya; Kanat, Ozkan; Isbil-Buyukcoskun, Naciye; Gurun, Mine S

    2013-12-04

    Recent studies have demonstrated that arginine vasopressin (AVP) plays a crucial role in pain modulation. In addition, our previous studies have proven that centrally administered cytidine-5'-diphosphate-choline (CDP-choline; citicoline) elicits an analgesic effect in different pain models in rats. Given that CDP-choline enhances central and peripheral vasopressin levels, the present study was designed to investigate the role of central AVP receptors in the analgesic effect of CDP-choline in acute and chronic constriction injury-induced neuropathic pain models. For this purpose, rats were pretreated intracerebroventricularly with the AVP V1 or AVP V2 receptor antagonist 15 min before intracerebroventricular injection of CDP-choline or saline, and pain threshold was determined using the Randall-Selitto test. AVP V1 and AVP V2 receptor antagonist blocked the CDP-choline-induced analgesic effect either in acute or neuropathic models of pain in rats. These results suggest, for the first time, that central AVP receptors are involved in the CDP-choline-elicited analgesic effect.

  16. [Drug dependence on benzodiazepines and antidepressants].

    Science.gov (United States)

    Verbanck, P

    2009-09-01

    Since years, the concepts of drug abuse and drug dependence changed, due to new knowledge coming from the neurosciences. Specifically, the role of a brain structure called "reward circuit" was emphasized. Therefore, the diagnosis criteria for abuse and dependence on drugs are presently defined mostly from a behavioral point of view: both in animal models and in clinical situations, it was stressed the importance of drug-seeking behavior and of the loss of control of the consumption. The occurrence of a pharmacological dependence is in fact of concern for only some of addictive drugs. According to these new criteria, dependence on benzodiazepines or antidepressants is certainly not frequent, even if withdrawal manifestations can occur after a long-term exposition. Furthermore, it is important to keep in mind the risk for non-medical use of benzodiazepines in persons with illicit drug use.

  17. Defining benzodiazepine dependence: The confusion persists

    OpenAIRE

    1995-01-01

    Little consensus exists on the risk of benzodiazepine (BZD) dependence. We investigated how often BZD dependence and related concepts have been defined in the literature on BZD effects in humans. In addition, the definitions of BZD dependence were compared in order to assess the similarity of contents. From a total of 250 papers (published between 1988 and 1991) 51 provided 126 dependence-related definitions. Six studies referred to the DSM definitions and one to the WHO definition. The obsol...

  18. [Isoforms of the human histamine H3 receptor: Generation, expression in the central nervous system and functional implications].

    Science.gov (United States)

    García-Gálvez, Ana Maricela; Arias-Montaño, José Antonio

    2016-01-01

    Histamine plays a significant role as a neuromodulator in the human central nervous system. Histamine-releasing neurons are exclusively located in the tuberomammillary nucleus of the hypothalamus, project to all major areas of the brain, and participate in functions such as the regulation of sleep/wakefulness, locomotor activity, feeding and drinking, analgesia, learning, and memory. The functional effects of histamine are exerted through the activation of four G protein-coupled receptors (H1, H2, H3 and H4), and in the central nervous system the first three receptors are widely expressed. The H3 receptor (H3R) is found exclusively in neuronal cells, where it functions as auto- and hetero-receptor. One remarkable characteristic of the H3R is the existence of isoforms, generated by alternative splicing of the messenger RNA. For the human H3R, 20 isoforms have been reported; although a significant number lack those regions required for agonist binding or receptor signaling, at least five isoforms appear functional upon heterologous expression. In this work we review the evidence for the generation of human H3R isoforms, their expression, and the available information regarding the functionality of such receptors.

  19. Brain concentrations of benzodiazepines are elevated in an animal model of hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Basile, A.S.; Pannell, L.; Jaouni, T.; Gammal, S.H.; Fales, H.M.; Jones, E.A.; Skolnick, P. (National Institutes of Health, Bethesda, MD (USA))

    1990-07-01

    Brain extracts from rats with hepatic encephalopathy due to thioacetamide-induced fulminant hepatic failure contained 4- to 6-fold higher concentrations of substances that inhibit radioligand binding to benzodiazepine receptors than corresponding control rat extracts. Both isocratic and gradient-elution HPLC indicated that this inhibitory activity was localized in 3-8 peaks with retention times corresponding to deschlorodiazepam, deschlorolorazepam, lorazepam, oxazepam, diazepam, and N-desmethyldiazepam. The presence of diazepam and N-desmethyldiazepam was confirmed by mass spectroscopy. Both mass spectroscopic and radiometric techniques indicated that the concentrations of N-desmethyldiazepam and diazepam in brain extracts from encephalopathic rats were 2-9 and 5-7 times higher, respectively, than in control brain extracts. While benzodiazepines have been identified previously in mammalian and plant tissues, this report demonstrates that concentrations of these substances are increased in a pathophysiological condition. These findings provide a rational basis for the use of benzodiazepine receptor antagonists in the management of hepatic encephalopathy in humans.

  20. Benzodiazepines in epilepsy: pharmacology and pharmacokinetics.

    Science.gov (United States)

    Riss, J; Cloyd, J; Gates, J; Collins, S

    2008-08-01

    Benzodiazepines (BZDs) remain important agents in the management of epilepsy. They are drugs of first choice for status epilepticus and seizures associated with post-anoxic insult and are also frequently used in the treatment of febrile, acute repetitive and alcohol withdrawal seizures. Clinical advantages of these drugs include rapid onset of action, high efficacy rates and minimal toxicity. Benzodiazepines are used in a variety of clinical situations because they have a broad spectrum of clinical activity and can be administered via several routes. Potential shortcomings of BZDs include tolerance, withdrawal symptoms, adverse events, such as cognitive impairment and sedation, and drug interactions. Benzodiazepines differ in their pharmacologic effects and pharmacokinetic profiles, which dictate how the drugs are used. Among the approximately 35 BZDs available, a select few are used for the management of seizures and epilepsy: clobazam, clonazepam, clorazepate, diazepam, lorazepam and midazolam. Among these BZDs, clorazepate has a unique profile that includes a long half-life of its active metabolite and slow onset of tolerance. Additionally, the pharmacokinetic characteristics of clorazepate (particularly the sustained-release formulation) could theoretically help minimize adverse events. However, larger, controlled studies of clorazepate are needed to further examine its role in the treatment of patients with epilepsy.

  1. Differences in muscarinic acetylcholine receptor subtypes in the central nervous system of long sleep and short sleep mice. [Ethanol effects

    Energy Technology Data Exchange (ETDEWEB)

    Watson, M.; Ming, X.; McArdle, J.J. (Univ of Medical, Newark, NJ (USA))

    1989-02-09

    Differences in voluntary ethanol consumption have been noted in various inbred strains of mice and pharmacogenetic approaches have been used to study the mechanisms of action of many drugs such as ethanol. Long-sleep (LS) and short-sleep (SS) mice, selectively bred for differences in ethanol induced narcosis, provide a method by which a relationship between the differential responsiveness of these geno-types and muscarinic acetylcholine receptors (mAChR) may be evaluated. Sleep times after injection of 3ml ethanol/kg (i.p.) verified the higher sensitivity of LS vs. SS. Mean body weights of LS (26.5g) vs. SS (22g) were also significantly (p<.01) greater. Binding assays for ({sup 3}H)(-) quinuclidinylbenzilate (({sup 3}H)(-)QNB), a specific but nonsubtype selective mAChR antagonist, ({sup 3}H)pirenzepine (({sup 3}H)PZ), a specific M1 mAChR antagonist and ({sup 3}H)11-2-((2-((diethylamino) methyl)-1-piperidinyl) acetyl)-5,11-dihydro-6H-pyrido (2,3-b) (1,4) benzodiazepine-6-one, (({sup 3}H)AF-DX 116), an M2 selective antagonist were performed to determine mAChR affinity (K{sub d}) and density (B{sub max}) in CNS regions such as the cerebral cortex, hippocampus, corpus striatum and other areas. Significantly lower (30-40%) ({sup 3}H)(-)QNB binding suggests that SS have fewer mAChR's than LS in many areas. These differences may relate to their differential ethanol sensitivity.

  2. Enhanced regional brain metabolic responses to benzodiazepines in cocaine abusers

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Wang, G.J.; Fowler, J.S. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1997-05-01

    While dopamine (DA) appears to be crucial for cocaine reinforcement, its involvement in cocaine addiction is much less clear. Using PET we have shown persistent reductions in striatal DA D2 receptors (which arc predominantly located on GABA cells) in cocaine abusers. This finding coupled to GABA`s role as an effector for DA led us to investigate if there were GABAergic abnormalities in cocaine abusers. In this study we measured regional brain metabolic responses to lorazepam, to indirectly assess GABA function (benzodiazepines facilitate GABAergic neurotransmission). Methods: The experimental subjects consisted of 12 active cocaine abusers and 32 age matched controls. Each subject underwent two PET FDG scans obtained within 1 week of each other. The first FDG scan was obtained after administration of placebo (3 cc of saline solution) given 40-50 minutes prior to FDG; and the second after administration of lorazepam (30 {mu}g/kg) given 40-50 minutes prior to FDG. The subjects were blind to the drugs received. Results: Lorazepam-induced sleepiness was significantly greater in abusers than in controls (p<0.001). Lorazepam-induced decreases in brain glucose metabolism were significantly larger in cocaine abusers than in controls. Whereas in controls whole brain metabolism decreased 13{+-}7 %, in cocaine abusers it decreased 21{+-}13 % (p < 0.05). Lorazepam-induced decrements in regional metabolism were significantly larger in striatum (p < 0.0 1), thalamus (p < 0.01) and cerebellum (p < 0.005) of cocaine abusers than of controls (ANOVA diagnosis by condition (placebo versus lorazepam) interaction effect). The only brain region for which the absolute metabolic changes-induced by lorazepam in cocaine abusers were equivalent to those in controls was the orbitofrontal cortex. These results document an accentuated sensitivity to benzodiazepines in cocaine abusers which is compatible with disrupted GABAergic function in these patients.

  3. Benzodiazepine use among the elderly in the community.

    Science.gov (United States)

    Kirby, M; Denihan, A; Bruce, I; Radic, A; Coakley, D; Lawlor, B A

    1999-04-01

    Benzodiazepines are the most commonly prescribed psychotropic drug in the elderly. Benzodiazepines with a long duration of action can produce marked sedation and psychomotor impairment in older people, and are associated with an increased risk of hip fracture and of motor vehicle crash. One thousand seven hundred and one individuals of 65 years and over, identified from General Practitioner lists, were interviewed using the Geriatric Mental State-AGECAT package and current psychotropic drug use was recorded. Benzodiazepines were classified as having a short or long elimination half-life. Two hundred and ninety-five (17.3%) individuals were taking a benzodiazepine, with use in females being twice that in males. Of the 295, 152 (51.5%) were taking a long acting benzodiazepine and the use of long acting anxiolytic type benzodiazepines was particularly common. Fifty-two (17.6%) benzodiazepine users were taking one or more other psychotropic drugs. A benzodiazepine was used by eight of 18 (44.4%) subjects with an anxiety disorder, 62 of 180 (34.4%) individuals with depression, and seven of 71 (9.9%) people with dementia. Four-fifths of older people on a psychotropic drug were taking a benzodiazepine, highlighting the importance of this class of drug in the elderly population. The choice of a benzodiazepine with a long duration of action, which have been shown to be associated with serious adverse events in the elderly in over one half of benzodiazepine users, is of concern. The potential for adverse effects was further accentuated by polypharmacy practices. The choice of benzodiazepine for an older person has important consequences and should be addressed in greater detail with primary care.

  4. Influence of benzodiazepines on antiparkinsonian drug treatment in levodopa users

    OpenAIRE

    2002-01-01

    OBJECTIVES: Animal studies showed that benzodiazepines decrease the concentration of dopamine in the striatum. Benzodiazepines may therefore affect the treatment of Parkinson's disease. This study determined whether start of a benzodiazepine in patients on levodopa was followed by a faster increase of antiparkinsonian drug treatment. METHODS: Data came from the PHARMO database, which includes information on drug dispensing for all residents of six Dutch cities. Selected were all patients aged...

  5. Central and direct regulation of testicular activity by gonadotropin-inhibitory hormone and its receptor

    Directory of Open Access Journals (Sweden)

    Takayoshi eUbuka

    2014-01-01

    Full Text Available Gonadotropin-inhibitory hormone (GnIH was first identified in Japanese quail to be an inhibitor of gonadotropin synthesis and release. GnIH peptides have since been identified in all vertebrates, and all share an LPXRFamide (X = L or Q motif at their C-termini. The receptor for GnIH is the G protein-coupled receptor 147 (GPR147, which inhibits cAMP signaling. Cell bodies of GnIH neurons are located in the paraventricular nucleus (PVN in birds and the dorsomedial hypothalamic area (DMH in most mammals. GnIH neurons in the PVN or DMH project to the median eminence to control anterior pituitary function via GPR147 expressed in gonadotropes. Further, GnIH inhibits gonadotropin-releasing hormone (GnRH -induced gonadotropin subunit gene transcription by inhibiting the adenylate cyclase/cAMP/PKA -dependent ERK pathway in an immortalized mouse gonadotrope cell line (LT2 cells. GnIH neurons also project to GnRH neurons that express GPR147 in the preoptic area (POA in birds and mammals. Accordingly, GnIH can inhibit gonadotropin synthesis and release by decreasing the activity of GnRH neurons as well as by directly inhibiting pituitary gonadotrope activity. GnIH and GPR147 can thus centrally suppress testosterone secretion and spermatogenesis by acting in the hypothalamic-pituitary-gonadal axis. GnIH and GPR147 are also expressed in the testis of birds and mammals, possibly acting in an autocrine/paracrine manner to suppress testosterone secretion and spermatogenesis. GnIH expression is also regulated by melatonin, stress and social environment in birds and mammals. Accordingly, the GnIH-GPR147 system may play a role in transducing physical and social environmental information to regulate optimal testicular activity in birds and mammals. This review discusses central and direct inhibitory effects of GnIH and GPR147 on testosterone secretion and spermatogenesis in birds and mammals.

  6. Targeting central melanocortin receptors: a promising novel approach for treating alcohol abuse disorders

    Directory of Open Access Journals (Sweden)

    Jeffrey eOlney

    2014-06-01

    Full Text Available The melanocortin (MC peptides are produced centrally by propiomelanocortin (POMC neurons within the arcuate nucleus of the hypothalamus and act through five seven-transmembrane G-protein coupled melanocortin receptor (MCR subtypes. The MC3R and MC4R subtypes, the most abundant central MCRs, are widely expressed in brain regions known to modulate neurobiological responses to ethanol, including regions of the hypothalamus and extended amygdala. Agouti-related protein (AgRP, also produced in the arcuate nucleus, is secreted in terminals expressing MCRs and functions as an endogenous MCR antagonist. This review highlights recent genetic and pharmacological findings that have implicated roles for the MC and AgRP systems in modulating ethanol consumption. Ethanol consumption is associated with significant alterations in the expression levels of various MC peptides/protein, which suggests that ethanol-induced perturbations of MC/AgRP signaling may modulate excessive ethanol intake. Consistently, MCR agonists decrease, and AgRP increases, ethanol consumption in mice. MCR agonists fail to blunt ethanol intake in mutant mice lacking the MC4R, suggesting that the protective effects of MCR agonists are modulated by the MC4R. Interestingly, recent evidence reveals that MCR agonists are more effective at blunting binge-like ethanol intake in mutant mice lacking the MC3R, suggesting that the MC3R has opposing effects on the MC4R. Finally, mutant mice lacking AgRP exhibit blunted voluntary and binge-like ethanol drinking, consistent with pharmacological studies. Collectively, these preclinical observations provide compelling evidence that compounds that target the MC system may provide therapeutic value for treating alcohol abuse disorders and that the utilization of currently available MC-targeting compounds- such as those being used to treat eating disorders- may be used as effective treatments to this end.

  7. Benzodiazepines and adequacy of initial antidepressant treatment for depression.

    Science.gov (United States)

    Pfeiffer, Paul N; Ganoczy, Dara; Zivin, Kara; Valenstein, Marcia

    2011-06-01

    In short-term efficacy studies, coprescription of a benzodiazepine improves first-month adherence and response to antidepressant treatment. We used Veterans Health Administration data to examine the impact of coprescribed benzodiazepines on initial antidepressant adherence in routine clinical practice and the risks of long-term benzodiazepine use, abuse, and dependence. Our study population was 43,915 Veterans Health Administration patients diagnosed with depression and started on an antidepressant between October 2006 and September 2007. Using logistic regression, adjusting for demographic and clinical covariates, we predicted the likelihood that patients received antidepressant treatment for an adequate duration (90 days), with our primary independent variable of interest being receipt of a benzodiazepine on the same day as the start of the antidepressant. We also assessed the frequency and characteristics of patients whose benzodiazepine use persisted for 1 year or who were diagnosed with anxiolytic abuse or dependence after receiving combined treatment. The adjusted probability of receiving antidepressant treatment of adequate duration was 42.4% for patients who received a benzodiazepine with their initial antidepressant compared with 39.3% for patients initially treated with an antidepressant alone (P benzodiazepines for at least 1 year, and 0.7% were diagnosed with anxiolytic abuse or dependence. Anxiolytic abuse or dependence, but not long-term benzodiazepine use, was associated with other substance use disorders. These findings should be considered by clinicians when assessing the individual risks and benefits of combining a benzodiazepine with antidepressant treatment.

  8. Benzodiazepines and amphetamine on avoidance behaviour in mice.

    Science.gov (United States)

    Sansone, M

    1975-11-01

    Six benzodiazepine derivatives, given alone or in combination with amphetamine, were tested in mice subjected to five 100-trial avoidance sessions in the shuttle-box. All derivatives, execpt bromazepam, showed some facilitating effects on avoidance responding when given alone. Facilitation was particularly evident following the administration of chlordiazepoxide (2.5 mg/kg), medazepam (10 mg/kg) and nitrazepam (0.25, 0.5 and 1 mg/kg). Favourable effects were obtained by combining each benzodiazepine compound with amphetamine. The levels of avoidance respinses were usually higher under benzodiazepine-amphetamine combinations than under benzodiazepines alone.

  9. Selective adenosine A2A receptor agonists and antagonists protect against spinal cord injury through peripheral and central effects

    Directory of Open Access Journals (Sweden)

    Esposito Emanuela

    2011-04-01

    Full Text Available Abstract Background Permanent functional deficits following spinal cord injury (SCI arise both from mechanical injury and from secondary tissue reactions involving inflammation. Enhanced release of adenosine and glutamate soon after SCI represents a component in the sequelae that may be responsible for resulting functional deficits. The role of adenosine A2A receptor in central ischemia/trauma is still to be elucidated. In our previous studies we have demonstrated that the adenosine A2A receptor-selective agonist CGS21680, systemically administered after SCI, protects from tissue damage, locomotor dysfunction and different inflammatory readouts. In this work we studied the effect of the adenosine A2A receptor antagonist SCH58261, systemically administered after SCI, on the same parameters. We investigated the hypothesis that the main action mechanism of agonists and antagonists is at peripheral or central sites. Methods Spinal trauma was induced by extradural compression of SC exposed via a four-level T5-T8 laminectomy in mouse. Three drug-dosing protocols were utilized: a short-term systemic administration by intraperitoneal injection, a chronic administration via osmotic minipump, and direct injection into the spinal cord. Results SCH58261, systemically administered (0.01 mg/kg intraperitoneal. 1, 6 and 10 hours after SCI, reduced demyelination and levels of TNF-α, Fas-L, PAR, Bax expression and activation of JNK mitogen-activated protein kinase (MAPK 24 hours after SCI. Chronic SCH58261 administration, by mini-osmotic pump delivery for 10 days, improved the neurological deficit up to 10 days after SCI. Adenosine A2A receptors are physiologically expressed in the spinal cord by astrocytes, microglia and oligodendrocytes. Soon after SCI (24 hours, these receptors showed enhanced expression in neurons. Both the A2A agonist and antagonist, administered intraperitoneally, reduced expression of the A2A receptor, ruling out the possibility that the

  10. Differential interactions engendered by benzodiazepine and neuroactive steroid combinations on schedule-controlled responding in rats

    Science.gov (United States)

    Gunter, Barak W.; Platt, Donna M.; Rowlett, James K.

    2015-01-01

    Benzodiazepines are positive allosteric modulators of the GABAA receptor and are prescribed as anxiolytics, hypnotics, and anticonvulsants. While these drugs clearly have clinical value, their use is associated with unwanted side effects such as sedation and motor impairment. Neuroactive steroids are endogenous modulators of GABAA receptors and recent evidence has shown that combinations of the triazolo-benzodiazepine triazolam and the endogenous neuroactive steroid pregnanolone can produce both supra-additive anxiolytic effects and infra-additive reinforcing effects. In the present study, we investigated these same combinations as well as combinations of two clinically-relevant drugs from different chemical classes, the 1, 4 substituted (7-nitro) benzodiazepine clonazepam and the synthetic neuroactive steroid ganaxolone, in rats trained under a 10-response, fixed ratio (FR) schedule of food reinforcement. All four drugs induced a significant and dose-dependent suppression of food-maintained responding. From the dose-response functions, ED50s (i.e., the doses that engendered 50% of the maximum rate-decreasing effect) were generated for each drug. Dose-response functions for combinations of triazolam/pregnanolone, clonazepam/ganaxolone, triazolam/ganaxolone, and clonazepam/pregnanolone were then determined. Isobolographic analysis of the rate-decreasing effects of these combinations revealed that the potencies of the triazolam/pregnanolone combinations were supra-additive while the clonazepam/ganaxolone combinations were additive or infra-additive in relation to predicted values based on dose-additive effects. Furthermore, mixtures of clonazepam/pregnanolone were supra-additive while triazolam/ganaxolone combinations were additive, infra-additive and supra-additive. These results suggest that the ability of benzodiazepine and neuroactive steroid combinations to attenuate rates of food-maintained responding depends critically on both the constituent drugs and the

  11. Role of the 5-HT7 receptor in the central nervous system: from current status to future perspectives.

    Science.gov (United States)

    Matthys, Anne; Haegeman, Guy; Van Craenenbroeck, Kathleen; Vanhoenacker, Peter

    2011-06-01

    Pharmacological and genetic tools targeting the 5-hydroxytryptamine (5-HT)7 receptor in preclinical animal models have implicated this receptor in diverse (patho)physiological processes of the central nervous system (CNS). Some data obtained with 5-HT7 receptor knockout mice, selective antagonists, and, to a lesser extent, agonists, however, are quite contradictory. In this review, we not only discuss in detail the role of the 5-HT7 receptor in the CNS but also propose some hypothetical models, which could explain the observed inconsistencies. These models are based on two novel concepts within the field of G protein-coupled receptors (GPCR), namely biphasic signaling and G protein-independent signaling, which both have been shown to be mediated by GPCR dimerization. This led us to suggest that the 5-HT7 receptor could reside in different dimeric contexts and initiate different signaling pathways, depending on the neuronal circuitry and/or brain region. In conclusion, we highlight GPCR dimerization and G protein-independent signaling as two promising future directions in 5-HT7 receptor research, which ultimately might lead to the development of more efficient dimer- and/or pathway-specific therapeutics.

  12. Whole-body distribution and metabolism of [N-methyl-{sup 11}C](R)-1-(2-chlorophenyl)-N-(1-methylpropyl)-3-isoquinolinecarboxamide in humans; an imaging agent for in vivo assessment of peripheral benzodiazepine receptor activity with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Roivainen, Anne; Hirvonen, Jussi; Oikonen, Vesa; Virsu, Pauliina; Tolvanen, Tuula [Turku University Hospital, Turku PET Centre, Turku (Finland); Naagren, Kjell [University of Turku, Radiopharmaceutical Chemistry Laboratory, Turku (Finland); Rinne, Juha O. [Turku University Hospital, Turku PET Centre, Turku (Finland); Turku Imanet, GE Healthcare Medical Diagnostics, Turku (Finland)

    2009-04-15

    {sup 11}C-PK11195 is a radiopharmaceutical for in vivo assessment of peripheral benzodiazepine receptor (PBR) activity using PET. We sought to clarify the metabolic fate of {sup 11}C-PK11195 in a test-retest setting using radio-HPLC in comparison with radio-TLC, and the whole-body distribution in humans. In order to evaluate the reproducibility of radio-HPLC metabolite analyses, ten patients with Alzheimer's disease (AD) underwent two successive {sup 11}C-PK11195 examinations on separate days. For comparison of different analytical methods, plasma samples from seven patients were also analysed by radio-TLC. In addition, we evaluated the whole-body distribution of {sup 11}C-PK11195 and its uptake in the brain. The level of unmetabolized {sup 11}C-PK11195 decreased slowly from 96.3 {+-} 1.6% (mean{+-}SD) at 5 min to 62.7 {+-} 8.3% at 40 min after injection. Large individual variation was observed in the amount of plasma {sup 11}C-PK11195 radiometabolites. The whole-body distribution of {sup 11}C-PK11195 showed the highest radioactivity levels in urinary bladder, adrenal gland, liver, salivary glands, heart, kidneys, and vertebral column. In addition, the hip bone and breast bone were clearly visualized by PET. In patients with AD, {sup 11}C-PK11195 uptake in the brain was the highest in the basal ganglia and thalamus, followed by the cortical grey matter regions and the cerebellum. Low {sup 11}C-PK11195 uptake was observed in the white matter. Our results indicate that {sup 11}C-PK11195 is eliminated both through the renal and hepatobiliary systems. Careful analysis of plasma metabolites is required to determine the accurate arterial input function for quantitative PET measurement. (orig.)

  13. Central and peripheral consequences of the chronic blockade of CB1 cannabinoid receptor with rimonabant or taranabant.

    Science.gov (United States)

    Martín-García, Elena; Burokas, Aurelijus; Martín, Miquel; Berrendero, Fernando; Rubí, Blanca; Kiesselbach, Christoph; Heyne, Andrea; Gispert, Juan Domingo; Millán, Olga; Maldonado, Rafael

    2010-03-01

    The endocannabinoid system plays a crucial role in the pathophysiology of obesity. However, the clinical use of cannabinoid antagonists has been recently stopped because of its central side-effects. The aim of this study was to compare the effects of a chronic treatment with the CB(1) cannabinoid antagonist rimonabant or the CB(1) inverse agonist taranabant in diet-induced obese female rats to clarify the biological consequences of CB(1) blockade at central and peripheral levels. As expected, chronic treatment with rimonabant and taranabant reduced body weight and fat content. Interestingly, a decrease in the number of CB(1) receptors and its functional activity was observed in all the brain areas investigated after chronic taranabant treatment in both lean and obese rats. In contrast, chronic treatment with rimonabant did not modify the density of CB(1) cannabinoid receptor binding, and decreased its functional activity to a lower degree than taranabant. Six weeks after rimonabant and taranabant withdrawal, CB(1) receptor density and activity recovered to basal levels. These results reveal differential adaptive changes in CB(1) cannabinoid receptors after chronic treatment with rimonabant and taranabant that could be related to the central side-effects reported with the use of these cannabinoid antagonists.

  14. Receptor mapping in psychiatric patients with SPECT; Rezeptor-SPECT-Untersuchungen bei psychiatrischen Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, S. [Mainz Univ. (Germany). Psychiatrische Klinik

    1997-06-01

    This paper summarizes some data of our studies with the single-photon-emission-computerized tomography (SPECT), focussing on the dopamine-D2- and the benzodiazepine receptor mapping. Benzodiazepine receptors: Central benzodiazepine receptors (BZr) can be visualized with iomazenil which is an analogue of the benzodiazepine antagonist flumazenil, labeled with 123-iodine. Since the involvement of the BZr system is discussed in the pathogenesis of anxiety and depression, patients with these disorders were investigated. A third study investigated the BZr-occupancy during benzodiazepine treatment (lorazepam). Results: (a) Patients with panic disorders had lower iomazenil uptake values compared to epileptic patients. (b) Depressed patients showed a positive correlation between severity of illness and frontal uptake. (c) BZr occupancy during lorazepam treatment was measurable, but not associated with lorazepam plasma levels. Dopamine-D2-receptors: With 123-I-iodobenzamide (IBZM), and iodine-labeled dopamine receptor ligand, the D2 receptor density can be measured by a semiquantitative approach (striatum/frontal cortex=ST/FC). Therefore, we investigated the D2-receptor occupancy during treatment with typical and atypical neuroleptics in relationship to dosages (normalized with different formulas of chlorpromazine equivalents), side effects, and prolactin plasma levels. Results: Dependent on the selected formula for chlorpromazine equivalents, the ST/FC ratio was correlated with dosages. Side effects and prolactin plasma levels showed a negative association with lower ST/FC ratios. (orig.) [Deutsch] Der Beitrag soll einen Ueberblick ueber verschiedene eigene Studien geben, die die Darstellung von Dopamin-D2- und Benzodiazepinrezeptoren mit der Single-Photon-Emissions-Computertomographie (SPECT) untersuchten. Benzodiazepinrezeptoren: Jomazenil, der mit 123-Jod markierte Benzodiazepinantagonist Flumazenil, ermoeglicht die Darstellung der zentralen Benzodiazepinrezeptoren (BZr

  15. Similar chemokine receptor profiles in lymphomas with central nervous system involvement - possible biomarkers for patient selection for central nervous system prophylaxis, a retrospective study.

    Science.gov (United States)

    Lemma, Siria A; Pasanen, Anna Kaisa; Haapasaari, Kirsi-Maria; Sippola, Antti; Sormunen, Raija; Soini, Ylermi; Jantunen, Esa; Koivunen, Petri; Salokorpi, Niina; Bloigu, Risto; Turpeenniemi-Hujanen, Taina; Kuittinen, Outi

    2016-05-01

    Central nervous system (CNS) relapse occurs in around 5% of diffuse large B-cell lymphoma (DLBCL) cases. No biomarkers to identify high-risk patients have been discovered. We evaluated the expression of lymphocyte-guiding chemokine receptors in systemic and CNS lymphomas. Immunohistochemical staining for CXCR4, CXCR5, CCR7, CXCL12, and CXCL13 was performed on 89 tissue samples, including cases of primary central nervous system lymphoma (PCNSL), secondary CNS lymphoma (sCNSL), and systemic DLBCL. Also, 10 reactive lymph node samples were included. Immunoelectron microscopy was performed on two PCNSLs, one sCNSL, one systemic DLBCL, and one reactive lymph node samples, and staining was performed for CXCR4, CXCR5, CXCL12, and CXCL13. Chi-square test was used to determine correlations between clinical parameters, diagnostic groups, and chemokine receptor expression. Strong nuclear CXCR4 positivity correlated with systemic DLBCL, whereas strong cytoplasmic CXCR5 positivity correlated with CNS involvement (P = 0.003 and P = 0.039). Immunoelectron microscopy revealed a nuclear CXCR4 staining in reactive lymph node, compared with cytoplasmic and membranous localization seen in CNS lymphomas. We found that CNS lymphoma presented a chemokine receptor profile different from systemic disease. Our findings give new information on the CNS tropism of DLBCL and, if confirmed, may contribute to more effective targeting of CNS prophylaxis among patients with DLBCL.

  16. Protracted treatment with diazepam increases the turnover of putative endogenous ligands for the benzodiazepine/. beta. -carboline recognition site

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, M.; Mocchetti, I.; Ferrarese, C.; Guidotti, A.; Costa, E.

    1987-03-01

    DBI (diazepam-binding inhibitor) is a putative neuromodulatory peptide isolated from rat brain that acts on ..gamma..-aminobutyric acid-benzodiazepine-Cl/sup -/ ionosphore receptor complex inducing ..beta..-carboline-like effects. The authors used a cDNA probe complementary to DBI mRNA and a specific antibody for rat DBI to study in rat brain how the dynamic state of DBI can be affected after protected (three times a day for 10 days) treatment with diazepam and chlordiazepoxide by oral gavage. Both the content of DBI and DBI mRNA increased in the cerebellum and cerebral cortex but failed to change in the hippocampus and striatum of rats receiving this protracted benzodiazepine treatment. Acute treatment with diazepam did not affect the dynamic state of brain DBI. An antibody was raised against a biologically active octadecaneuropeptide derived from the tryptic digestion of DBI. The combined HPLC/RIA analysis of rat cerebellar extracts carried out with this antibody showed that multiple molecular forms of the octadecaneuropeptide-like reactivity are present and all of them are increased in rats receiving repeated daily injections of diazepam. It is inferred that tolerance to benzodiazepines in associated with an increase in the turnover rate of DBI, which may be responsible for the ..gamma..-aminobutyric acid receptor desensitization that occurs after protracted benzodiazepine administration.

  17. Molecular analysis of central feeding regulation by neuropeptide Y (NPY) neurons with NPY receptor small interfering RNAs (siRNAs).

    Science.gov (United States)

    Higuchi, Hiroshi

    2012-11-01

    Hypothalamic neuropeptides play important roles in central feeding behavior. Among them, neuropeptide Y (NPY) has the strongest orexigenic action. It is synthesized in NPY-expressing neurons in the arcuate nucleus (ARC), which projects to other nuclei, mainly to the paraventricular nucleus (PVN). PVN, which possesses NPY-Y1, -Y2 and -Y4, -Y5 receptors, is considered as feeding center for central feeding behavior. Herein I review recent results on feeding behavior obtained by gene knockdown technologies. The small interfering RNA (siRNA) plasmid-based vectors, which drive transcription of siRNA by U6 RNA polymerase III promoter to produce knockdown of the NPY and its receptor (Y1, Y2, Y4 and Y5) genes, were stereotaxically injected into mouse ARC and PVN. Feeding behaviors were measured for 6days after siRNA vector injection. NPY and its receptor mRNA levels were decreased, which were measured by RT-PCR and in situ hybridization, and simultaneous decrease in their proteins was also detected in separate nuclei by immunohistochemistry. In the NPY system, decrease in NPY, Y1 and Y5 expressions in specialized nuclei diminished central feeding behavior, whereas decrease in Y2 or Y4 expression in both ARC or PVN did not affect feeding behavior. Thus, specialized change in expressions of NPY and its receptors (especially Y1 and Y5) are important for regulation of endogenous feeding behavior in central regulation. Further analysis of NPY receptors may provide better understanding of feeding behavior and of potential therapeutic targets.

  18. Modulation of the vagal bradycardia evoked by stimulation of upper airway receptors by central 5-HT1 receptors in anaesthetized rabbits

    Science.gov (United States)

    Dando, Simon B; Skinner, Matthew R; Jordan, David; Ramage, Andrew G

    1998-01-01

    The effects of central application of 5-HT1A and 5-HT1B/1D receptor ligands on the reflex bradycardia, apnoea, renal sympathoexcitation and pressor response evoked by stimulating upper airway receptors with smoke in atenolol-pretreated anaesthetized rabbits were studied.Intracisternal administration of the 5-HT1A receptor antagonists WAY-100635 (100 μg kg−1) and (−)pindolol (100 μg kg−1) significantly reduced the smoke-induced bradycardia, attenuated the pressor response and in the case of (−)pindolol, sympathetic nerve activity. The same dose of WAY-100635 i.v. was without effect.Buspirone (200 μg kg−1, i.c.) potentiated the reflex bradycardia. This action was prevented if the animals were pretreated with WAY-100635 (100 μg kg−1, i.v.)(+)8-OH-DPAT (25 μg kg−1, i.c.) attenuated the evoked bradycardia, pressor response, apnoea and renal sympathoexcitation. The attenuation of the apnoea and renal sympathoexcitation, but not the bradycardia or pressor response was prevented in animals pretreated with WAY-100635 (100 μg kg−1, i.v.). The attenuation of the reflex bradycardia and the reduction in the renal sympathoexcitation were reduced by pretreatment with the 5-HT1B/1D receptor antagonist GR127935 (100 μg kg−1, i.v.).In WAY-100635 (100 μg kg−1, i.v.) pretreated animals, sumatriptan (a 5-HT1B/1D receptor agonist) reduced the reflex bradycardia and the pressor response. The 5-HT1B/1D receptor antagonist GR127935 (20 μg kg−1, i.c. or 100 μg kg−1, i.v.) had no effect on the reflex responses.In conclusion, the present data are consistent with the hypothesis that activation of central 5-HT1A receptors potentiate whilst activation of 5-HT1B/1D receptors attenuate the reflex activation of cardiac preganglionic vagal motoneurones evoked by stimulation of upper airway receptors with smoke in rabbits. PMID:9786516

  19. Scalability, reliability and validity of the benzodiazepine dependence self report questionnaire in outpatient benzodiazepine users

    NARCIS (Netherlands)

    Kan, C.C.; Breteler, M.H.M.; Timmermans, M.A.Y.; Ven, A.H.G.S. van der; Zitman, F.G.

    1999-01-01

    As there is no multidimensional instrument available which reflects the severity of BZD dependence comprehensively, the Benzodiazepine Dependence Self-Report Questionnaire (Bendep-SRQ) was developed and investigated. The Bendep-SRQ, Symptom Checlist-90, Schedules for Clinical Assessments in Neuropsy

  20. Development and psychometric evaluation of the Benzodiazepine Craving Questionnaire.

    NARCIS (Netherlands)

    Mol, A.J.J.; Oude Voshaar, R.C.; Gorgels, W.J.M.J.; Breteler, M.H.M.; Balkom, A.J.L.M. van; Lisdonk, E.H. van de; Ven, A.H. van der; Zitman, F.G.

    2003-01-01

    AIM: To assess the scalability, reliability and validity of a newly constructed self-report questionnaire on craving for benzodiazepines (BZs), the Benzodiazepine Craving Questionnaire (BCQ). SETTING AND PARTICIPANTS: The BCQ was administered once to a sample of 113 long-term and 80 former long-term

  1. [Leo Sternbach, an inventor of benzodiazepines].

    Science.gov (United States)

    Uchibayashi, Masao

    2007-01-01

    A biography of Leo Sternbach, an inventor of benzodiazepine tranquillizers, is presented. It consists of (1) a societal desire for lifestyle pills, (2) Leo's birth in 1908 and youth, (3) education, (4) in Vienna, (5) in Zurich, (6) at Hoffmann-La Roche, Basel, (7) to the New World, (8) at Roche, Nutley NJ, (9) invention of the new drugs, (10) revolution of people's lifestyle, and (11) reward, retirement and obituary in 2005. This paper may be the first comprehensive biography of this remarkable chemist written in Japanese.

  2. Intracerebroventricular urocortin 3 counteracts central acyl ghrelin-induced hyperphagic and gastroprokinetic effects via CRF receptor 2 in rats

    Directory of Open Access Journals (Sweden)

    Yeh C

    2016-10-01

    Full Text Available Chun Yeh,1 Ching-Heng Ting,2 Ming-Luen Doong,3 Chin-Wen Chi,4,5 Shou-Dong Lee,1 Chih-Yen Chen6–8 1Division of Gastroenterology, Department of Internal Medicine, Cheng-Hsin General Hospital, 2Department of Pathology, Mackay Memorial Hospital, 3Institute of Physiology, 4Institute of Pharmacology, National Yang-Ming University School of Medicine, 5Department of Medical Research, Taipei Veterans General Hospital, 6Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, 7Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, 8Taiwan Association for the Study of Small Intestinal Diseases, Guishan, Taiwan Purpose: Urocortin 3 is a key neuromodulator in the regulation of stress, anxiety, food intake, gut motility, and energy homeostasis, while ghrelin elicits feeding behavior and enhances gastric emptying, adiposity, and positive energy balance. However, the interplays between urocortin 3 and ghrelin on food intake and gastric emptying remain uninvestigated.Methods: We examined the differential effects of central O-n-octanoylated ghrelin, des-Gln14-ghrelin, and urocortin 3 on food intake, as well as on charcoal nonnutrient semiliquid gastric emptying in conscious rats that were chronically implanted with intracerebroventricular (ICV catheters. The functional importance of corticotropin-releasing factor (CRF receptor 2 in urocortin 3-induced responses was examined by ICV injection of the selective CRF receptor 2 antagonist, astressin2-B.Results: ICV infusion of urocortin 3 opposed central acyl ghrelin-elicited hyperphagia via CRF receptor 2 in satiated rats. ICV injection of O-n-octanoylated ghrelin and des-Gln14-ghrelin were equally potent in accelerating gastric emptying in fasted rats, whereas ICV administration of urocortin 3 delayed gastric emptying. In addition, ICV infusion of urocortin 3 counteracted central acyl ghrelin-induced gastroprokinetic effects via CRF receptor 2

  3. Pleiotropic effect of histamine H4 receptor modulation in the central nervous system.

    Science.gov (United States)

    Galeotti, Nicoletta; Sanna, Maria Domenica; Ghelardini, Carla

    2013-08-01

    The histamine H4 receptor (H4R) is expressed primarily on cells involved in inflammation and immune responses. Recently, it has been reported the functional expression of H4R within neurons of the central nervous system, but their role has been poorly understood. The present study aimed to elucidate the physiopathological role of cerebral H4R in animal models by the intracerebroventricular administration of the H4R agonist VUF 8430 (20-40 μg per mouse). Selectivity of results was confirmed by the prevention of the effects produced by the H4R antagonist JNJ 10191584 (3-9 mg/kg p.o.). Neuronal H4R activation induced acute thermal antinociception, indicating that neuronal histamine H4R might be involved in the production of antinociception in the absence of an inflammatory process. An anxiolytic-like effect of intensity comparable to that exerted by diazepam, used as reference drug, was produced in the light-dark box test. VUF 8430 reversed the scopolamine-induced amnesia in the passive avoidance test and showed anorexant activity in food deprived mice. Conversely, the H4R activation did not modify the immobility time in the tail suspension test. Rotarod performance test was employed to demonstrate that the effects observed following the administration of VUF 8430 and JNJ 10191584 were not due to impaired motor function of animals. Furthermore, both compounds did not alter spontaneous mobility and exploratory activity in the hole board test. These results show the antinociceptive, antiamnesic, anxiolytic and anorexant effects induced by neuronal H4R agonism, suggesting that H4 modulators may have broader utility further the control of inflammatory and immune processes.

  4. Using Tutte polynomials to analyze the structure of the benzodiazepines

    Science.gov (United States)

    Cadavid Muñoz, Juan José

    2014-05-01

    Graph theory in general and Tutte polynomials in particular, are implemented for analyzing the chemical structure of the benzodiazepines. Similarity analysis are used with the Tutte polynomials for finding other molecules that are similar to the benzodiazepines and therefore that might show similar psycho-active actions for medical purpose, in order to evade the drawbacks associated to the benzodiazepines based medicine. For each type of benzodiazepines, Tutte polynomials are computed and some numeric characteristics are obtained, such as the number of spanning trees and the number of spanning forests. Computations are done using the computer algebra Maple's GraphTheory package. The obtained analytical results are of great importance in pharmaceutical engineering. As a future research line, the usage of the chemistry computational program named Spartan, will be used to extent and compare it with the obtained results from the Tutte polynomials of benzodiazepines.

  5. The application of supported liquid extraction in the analysis of benzodiazepines using surface enhanced Raman spectroscopy.

    Science.gov (United States)

    Doctor, Erika L; McCord, Bruce

    2015-11-01

    Benzodiazepines are among the most frequently prescribed medicines for anxiety disorders and are present in many toxicological screens. These drugs are often administered in the commission of drug facilitated sexual assaults due their effects on the central nervous system. Due to the potency of the drugs, only small amounts are usually given to victims; therefore, the target detection limit for these compounds in biological samples has been set at 50 ng/mL. Currently the standard screening method for detection of this class of drug is the immunoassay; however, screening methods that are more sensitive and selective than immunoassays are needed to encompass the wide range of structural variants of this class of compounds. Surface enhanced Raman spectroscopy (SERS) can be highly sensitive and has been shown to permit analysis of various benzodiazepines with limits of detection as low as 6 ng/mL. This technique permits analytical results in less than 2 min when used on pure drug samples. For biological samples, a key issue for analysis by SERS is removal of exogenous salts and matrix components. In this paper we examine supported liquid extraction as a useful preparation technique for SERS detection. Supported liquid extraction has many of the benefits of liquid-liquid extraction along with the ability to be automated. This technique provides a fast and clean extraction for benzodiazepines from urine at a pH of 5.0, and does not produce large quantities of solvent waste. To validate this procedure we have determined figures of merit and examined simulated urine samples prepared with commonly appearing interferences. It was shown that at a pH 5.0 many drugs that are prevalent in urine samples can be removed, permitting a selective detection of the benzodiazepine of interest. This technique has been shown to provide rapid (less than 20 min), sensitive, and specific detection of benzodiazepines with limits of detection between 32 and 600 ng/mL and dynamic range of 32

  6. Use of benzodiazepines or benzodiazepine related drugs and the risk of cancer: a population-based case-control study

    DEFF Research Database (Denmark)

    Pottegård, Anton; Friis, Søren; Andersen, Morten

    2013-01-01

    AIM: Studies of the carcinogenic potential of benzodiazepines and related drugs (BZRD) have been equivocal. A recent study reported a 35% excess cancer risk among users of hypnotics, including benzodiazepines. METHOD: Using Danish nationwide registers, we conducted a matched case-control study...

  7. Inhibition of cancer cell proliferation by midazolam by targeting transient receptor potential melastatin 7.

    Science.gov (United States)

    Dou, Yunling; Li, Yuan; Chen, Jingkao; Wu, Sihan; Xiao, Xiao; Xie, Shanshan; Tang, Lipeng; Yan, Min; Wang, Youqiong; Lin, Jun; Zhu, Wenbo; Yan, Guangmei

    2013-03-01

    Transient receptor potential melastatin 7 (TRPM7), a Ca(2+)-permeable channel, has been demonstrated to be present in cancer cells and involved in their growth and proliferation. The present study used midazolam, a benzodiazepine class anesthesic, to pharmacologically intervene in the expression of TRPM7 and to inhibit cancer cell proliferation. Midazolam significantly inhibited the growth and proliferation of FaDu human hypopharyngeal squamous cell carcinoma cells, concurring with the induction of G(0)/G(1) cell cycle arrest and blockage of Rb activation. Central-type and peripheral-type benzodiazepine receptor antagonists did not abrogate proliferation inhibition by midazolam, while the specific TRPM7 agonist bradykinin reversed this effect. In addition, other benzodiazepines, diazepam and clonazepam also exhibited anti-proliferative activities. The inhibitory activity on cancer cell growth and proliferation, combined with the TRPM-dependent mechanism, reveals the anticancer potential of midazolam as a TRPM7 inhibitor and supports the suggestion that TRPM7 is a valuable target for pharmaceutical intervention.

  8. Expression of the very low-density lipoprotein receptor (VLDL-r), an apolipoprotein-E receptor, in the central nervous system and in Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Christie, R.H.; Chung, Haeyong; Rebeck, G.W.; Hyman, B.T. [Massachusetts General Hospital, Boston, MA (United States)] [and others

    1996-04-01

    The very low density lipoprotein receptor (VLDL-r) is a cell-surface molecule specialized for the internalization of multiple diverse ligands, including apolipoprotein E (apoE)-containing lipoprotein particles, via clathrin-coated pits. Its structure is similar to the low-density lipoprotein receptor (LDL-r), although the two have substantially different systemic distributions and regulatory pathways. The present work examines the distribution of VLDL-r in the central nervous system (CNS) and in relation to senile plaques in Alzheimer disease (AD). VLDL-r is present on resting and activated microglia, particularly those associated with senile plaques (SPs). VLDL-r immunoreactivity is also found in cortical neurons. Two exons of VLDL-r mRNA are differentially spliced in the mature receptor mRNA. One set of splice forms gives rise to receptors containing (or lacking) an extracellular O-linked glycosylation domain near the transmembrane portion of the molecule. The other set of splice forms appears to be brain-specific, and is responsible for the presence or absence of one of the cysteine-rich repeat regions in the binding region of the molecule. Ratios of the receptor variants generated from these splice forms do not differ substantially across different cortical areas or in AD. We hypothesize that VLDL-r might contribute to metabolism of apoE and apoE/A{beta} complexes in the brain. Further characterization of apoE receptors in Alzheimer brain may help lay the groundwork for understanding the role of apoE in the CNS and in the pathophysiology of AD. 43 refs., 5 figs.

  9. Withdrawing Benzodiazepines in Patients With Anxiety Disorders.

    Science.gov (United States)

    Lader, Malcolm; Kyriacou, Andri

    2016-01-01

    The large class of CNS-depressant medications-the benzodiazepines-have been extensively used for over 50 years, anxiety disorders being one of the main indications. A substantial proportion (perhaps up to 20-30 %) of long-term users becomes physically dependent on them. Problems with their use became manifest, and dependence, withdrawal difficulties and abuse were documented by the 1980s. Many such users experience physical and psychological withdrawal symptoms on attempted cessation and may develop clinically troublesome syndromes even during slow tapering. Few studies have been conducted to establish the optimal withdrawal schedules. The usual management comprises slow withdrawal over weeks or months together with psychotherapy of various modalities. Pharmacological aids include antidepressants such as the SSRIs especially if depressive symptoms supervene. Other pharmacological agents such as the benzodiazepine antagonist, flumazenil, and the hormonal agent, melatonin, remain largely experimental. The purpose of this review is to analyse the evidence for the efficacy of the usual withdrawal regimes and the newer agents. It is concluded that little evidence exists outside the usual principles of drug withdrawal but there are some promising leads.

  10. Benzodiazepines for the relief of breathlessness in advanced malignant and non-malignant diseases in adults.

    Science.gov (United States)

    Simon, Steffen T; Higginson, Irene J; Booth, Sara; Harding, Richard; Weingärtner, Vera; Bausewein, Claudia

    2016-10-20

    This is an updated version of the original Cochrane review published in Issue 1, 2010, on 'Benzodiazepines for the relief of breathlessness in advanced malignant and non-malignant diseases in adults'. Breathlessness is one of the most common symptoms experienced in the advanced stages of malignant and non-malignant disease. Benzodiazepines are widely used for the relief of breathlessness in advanced diseases and are regularly recommended in the literature. At the time of the previously published Cochrane review, there was no evidence for a beneficial effect of benzodiazepines for the relief of breathlessness in people with advanced cancer and chronic obstructive pulmonary disease (COPD). The primary objective of this review was to determine the efficacy of benzodiazepines for the relief of breathlessness in people with advanced disease. Secondary objectives were to determine the efficacy of different benzodiazepines, different doses of benzodiazepines, different routes of application, adverse effects of benzodiazepines, and the efficacy in different disease groups. This is an update of a review published in 2010. We searched 14 electronic databases up to September 2009 for the original review. We checked the reference lists of all relevant studies, key textbooks, reviews, and websites. For the update, we searched CENTRAL, MEDLINE, and EMBASE and registers of clinical trials for further ongoing or unpublished studies, up to August 2016. We contacted study investigators and experts in the field of palliative care asking for further studies, unpublished data, or study details when necessary. We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) assessing the effect of benzodiazepines compared with placebo or active control in relieving breathlessness in people with advanced stages of cancer, chronic obstructive pulmonary disease (COPD), chronic heart failure (CHF), motor neurone disease (MND), and idiopathic pulmonary fibrosis (IPF

  11. Control of spasticity in a multiple sclerosis model using central nervous system-excluded CB1 cannabinoid receptor agonists.

    Science.gov (United States)

    Pryce, Gareth; Visintin, Cristina; Ramagopalan, Sreeram V; Al-Izki, Sarah; De Faveri, Lia E; Nuamah, Rosamond A; Mein, Charles A; Montpetit, Alexandre; Hardcastle, Alison J; Kooij, Gijs; de Vries, Helga E; Amor, Sandra; Thomas, Sarah A; Ledent, Catherine; Marsicano, Giovanni; Lutz, Beat; Thompson, Alan J; Selwood, David L; Giovannoni, Gavin; Baker, David

    2014-01-01

    The purpose of this study was the generation of central nervous system (CNS)-excluded cannabinoid receptor agonists to test the hypothesis that inhibition of spasticity, due to CNS autoimmunity, could be controlled by affecting neurotransmission within the periphery. Procedures included identification of chemicals and modeling to predict the mode of exclusion; induction and control of spasticity in the ABH mouse model of multiple sclerosis; conditional deletion of CB1 receptor in peripheral nerves; side-effect profiling to demonstrate the mechanism of CNS-exclusion via drug pumps; genome-wide association study in N2(129×ABH) backcross to map polymorphic cannabinoid drug pump; and sequencing and detection of cannabinoid drug-pump activity in human brain endothelial cell lines. Three drugs (CT3, SAB378 and SAD448) were identified that control spasticity via action on the peripheral nerve CB1 receptor. These were peripherally restricted via drug pumps that limit the CNS side effects (hypothermia) of cannabinoids to increase the therapeutic window. A cannabinoid drug pump is polymorphic and functionally lacking in many laboratory (C57BL/6, 129, CD-1) mice used for transgenesis, pharmacology, and toxicology studies. This phenotype was mapped and controlled by 1-3 genetic loci. ABCC1 within a cluster showing linkage is a cannabinoid CNS-drug pump. Global and conditional CB1 receptor-knockout mice were used as controls. In summary, CNS-excluded CB1 receptor agonists are a novel class of therapeutic agent for spasticity.

  12. Central Insulin Action Activates Kupffer Cells by Suppressing Hepatic Vagal Activation via the Nicotinic Alpha 7 Acetylcholine Receptor

    Directory of Open Access Journals (Sweden)

    Kumi Kimura

    2016-03-01

    Full Text Available Central insulin action activates hepatic IL-6/STAT3 signaling, which suppresses the gene expression of hepatic gluconeogenic enzymes. The vagus nerve plays an important role in this centrally mediated hepatic response; however, the precise mechanism underlying this brain-liver interaction is unclear. Here, we present our findings that the vagus nerve suppresses hepatic IL-6/STAT3 signaling via α7-nicotinic acetylcholine receptors (α7-nAchR on Kupffer cells, and that central insulin action activates hepatic IL-6/STAT3 signaling by suppressing vagal activity. Indeed, central insulin-mediated hepatic IL-6/STAT3 activation and gluconeogenic gene suppression were impeded in mice with hepatic vagotomy, pharmacological cholinergic blockade, or α7-nAchR deficiency. In high-fat diet-induced obese and insulin-resistant mice, control of the vagus nerve by central insulin action was disturbed, inducing a persistent increase of inflammatory cytokines. These findings suggest that dysregulation of the α7-nAchR-mediated control of Kupffer cells by central insulin action may affect the pathogenesis of chronic hepatic inflammation in obesity.

  13. Identification of a site critical for kinase regulation on the central processing unit (CPU) helix of the aspartate receptor.

    Science.gov (United States)

    Trammell, M A; Falke, J J

    1999-01-05

    Ligand binding to the homodimeric aspartate receptor of Escherichia coli and Salmonella typhimurium generates a transmembrane signal that regulates the activity of a cytoplasmic histidine kinase, thereby controlling cellular chemotaxis. This receptor also senses intracellular pH and ambient temperature and is covalently modified by an adaptation system. A specific helix in the cytoplasmic domain of the receptor, helix alpha6, has been previously implicated in the processing of these multiple input signals. While the solvent-exposed face of helix alpha6 possesses adaptive methylation sites known to play a role in kinase regulation, the functional significance of its buried face is less clear. This buried region lies at the subunit interface where helix alpha6 packs against its symmetric partner, helix alpha6'. To test the role of the helix alpha6-helix alpha6' interface in kinase regulation, the present study introduces a series of 13 side-chain substitutions at the Gly 278 position on the buried face of helix alpha6. The substitutions are observed to dramatically alter receptor function in vivo and in vitro, yielding effects ranging from kinase superactivation (11 examples) to complete kinase inhibition (one example). Moreover, four hydrophobic, branched side chains (Val, Ile, Phe, and Trp) lock the kinase in the superactivated state regardless of whether the receptor is occupied by ligand. The observation that most side-chain substitutions at position 278 yield kinase superactivation, combined with evidence that such facile superactivation is rare at other receptor positions, identifies the buried Gly 278 residue as a regulatory hotspot where helix packing is tightly coupled to kinase regulation. Together, helix alpha6 and its packing interactions function as a simple central processing unit (CPU) that senses multiple input signals, integrates these signals, and transmits the output to the signaling subdomain where the histidine kinase is bound. Analogous CPU

  14. Chlordiazepoxide enhances the anxiogenic action of CGS 8216 in the social interaction test: evidence for benzodiazepine withdrawal?

    Science.gov (United States)

    File, S E; Pellow, S

    1985-07-01

    The benzodiazepine receptor 'inverse agonist' CGS 8216 has a specific anxiogenic action in the social interaction test that cannot be reversed by other compounds acting at the benzodiazepine site: Ro 15-1788, FG 7142 or beta-CCE. We tried to reverse the anxiogenic effect with chlordiazepoxide, which is able to antagonise the anxiogenic effects of several other compounds acting at benzodiazepine or related sites. Chlordiazepoxide given acutely (10-20 mg/kg) was unable to antagonise the anxiogenic action of CGS 8216 (5-10 mg/kg); instead there was a tendency to enhance its effects. The effects of chlordiazepoxide after 5 days pretreatment were then assessed, since chronic treatment is necessary to reverse the anxiogenic actions of Ro 15-1788 and Ro 5-4864. At 5 mg/kg chronically, chlordiazepoxide was unable to antagonise the anxiogenic effect of CGS 8216, and at 20 mg/kg there was a significant enhancement of the effects of CGS 8216 on social interaction without an effect on locomotor activity. These results are discussed in terms of withdrawal from benzodiazepine treatment.

  15. The clobazam metabolite N-desmethyl clobazam is an α2 preferring benzodiazepine with an improved therapeutic window for antihyperalgesia

    OpenAIRE

    2016-01-01

    Data from genetically modified mice suggest that benzodiazepine (BDZ)-site agonists with improved selectivity for α2-subtype GABAA receptors (α2GABAAR) are potentially useful for the treatment of neuropathic pain. Subtype-selective compounds available for preclinical tests in rodents support this concept but have not been approved for human use, hindering proof-of-concept studies in patients. We recently proposed that N-desmethyl clobazam (NDMC), the main metabolite of the licensed BDZ clobaz...

  16. Rapid detoxification of benzodiazepine or Z-drugs dependence using acetylcholinesterase inhibitors.

    Science.gov (United States)

    Lin, Shih-Ku

    2014-07-01

    Dependence on benzodiazepines (BZDs) or Z-drugs (zolpidem, zopicline and zaleplon) is a common clinical phenomenon. Traditional detoxification of BZDs dependence includes tapering used dose gradually and using equivalent doses of long-acting BZDs as substitutes. This kind of regimen tends to take a long time (up to 4weeks) and may require hospitalization. Acetylcholinesterase inhibitors have been shown to reverse BZDs induced sedation. We propose that oral form acetylcholinesterase inhibitors (donepezil, galantamine and rivastigmine) also posses the effect of inhibiting GABA receptors, and act as indirect antagonist, to be applied in the rapid detoxification treatment of BZDs and Z-drug dependence.

  17. Prevalence and correlates of inappropriate use of benzodiazepines in Kosovo.

    Science.gov (United States)

    Tahiri, Zejdush; Kellici, Suela; Mone, Iris; Shabani, Driton; Qazimi, Musa; Burazeri, Genc

    2017-08-01

    In post-war Kosovo, the magnitude of inappropriate use of benzodiazepines is unknown to date. The aim of this study was to assess the prevalence and correlates of continuation of intake of benzodiazepines beyond prescription (referred to as "inappropriate use") in the adult population of Gjilan region in Kosovo. A cross-sectional study was conducted in Gjilan region in 2015 including a representative sample of 780 individuals attending different pharmacies and reporting use of benzodiazepines (385 men and 395 women; age range 18-87 years; response rate: 90%). A structured questionnaire was administered to all participants inquiring about the use of benzodiazepines and socio-demographic characteristics. Overall, the prevalence of inappropriate use of benzodiazepines was 58%. In multivariable-adjusted models, inappropriate use of benzodiazepines was significantly associated with older age (OR 1.7, 95% CI 1.1-2.7), middle education (OR 1.8, 95% CI 1.2-2.7), daily use (OR 1.4, 95% CI 1.1-2.0) and addiction awareness (OR 2.7, 95% CI 2.0-3.8). Furthermore, there was evidence of a borderline relationship with rural residence (OR 1.2, 95% CI 0.9-1.7). Our study provides novel evidence about the prevalence and selected correlates of inappropriate use of benzodiazepines in Gjilan region of Kosovo. Health professionals and policymakers in Kosovo should be aware of the magnitude and determinants of drug misuse in this transitional society.

  18. Reduction of aggression during benzodiazepine withdrawal: effects of flumazenil.

    Science.gov (United States)

    Saxon, L; Borg, S; Hiltunen, A J

    2010-08-01

    Benzodiazepine withdrawal has been associated with hostile and aggressive behavior. The benzodiazepine antagonist flumazenil has reduced, increased or not affected hostility and aggression in animal and human studies. In the present study we analyzed data collected in a placebo-controlled study of the effects of the benzodiazepine antagonist flumazenil in patients previously treated for benzodiazepine dependency, and healthy controls. The aim was to analyze the effects of flumazenil on hostility and aggression. Ten patients and 10 controls received, on two separate occasions, cumulative doses of flumazenil (0.05, 0.1, 0.25, 0.5 and 1mg at 15min intervals) or placebo. Withdrawal symptoms were rated after each injection. Patients had been free from benzodiazepines for 47 (4-266) weeks on the first occasion. A three-way interaction (groupxtreatmentxdose) was found, and was explained by: 1) patients rating aggression and hostility higher than controls at all times during placebo, while 2) during the flumazenil provocation i) the initial significant difference between patients and controls was no longer significant above the 0.5mg dose, and ii) patients rated aggression and hostility significantly lower above the 0.5mg dose compared to base-line. The results suggest that self-rated aggression and hostility in patients treated for benzodiazepine dependency was reduced by the partial benzodiazepine agonist flumazenil.

  19. Opioid and benzodiazepine withdrawal symptoms in paediatric intensive care patients.

    Science.gov (United States)

    Franck, Linda S; Naughton, Ita; Winter, Ira

    2004-12-01

    The purposes of this prospective repeated measures study were to: (a) describe the occurrence of withdrawal symptoms with the use of a standardised protocol to slowly taper opioids and benzodiazepines; and (b) to test the predictive validity of an opioid and benzodiazepine withdrawal assessment scoring tool in critically ill infants and young children after prolonged opioid and benzodiazepine therapy. Fifteen children (6 weeks-28 months of age) with complex congenital heart disease and/or respiratory failure who received opioids and benzodiazepines for 4 days or greater were evaluated for withdrawal symptoms using a standardized assessment tool. Thirteen children showed moderate to severe withdrawal symptoms a median 3 days after commencement of tapering. Symptom intensity was not related to prior opioid or benzodiazepine exposure, extracorporeal membrane oxygenation (ECMO) therapy or length of tapering. Children who received fentanyl in addition to morphine more often exhibited signs of withdrawal. This study demonstrated that significant withdrawal symptoms occur in critically ill children even with the use of a standardised assessment tool and tapering management protocol. The predictive validity and utility of the Opioid and Benzodiazepine Withdrawal Score (OBWS) was adequate for clinical use, but areas for further improvement of the tool were identified. Problems with the clinical withdrawal prevention and management guidelines were also identified. More research is needed to establish the optimal methods for prevention and management of iatrogenic opioid and benzodiazepine withdrawal in paediatric critical care.

  20. Benzodiazepine stability in postmortem samples stored at different temperatures.

    Science.gov (United States)

    Melo, Paula; Bastos, M Lourdes; Teixeira, Helena M

    2012-01-01

    Benzodiazepine (lorazepam, estazolam, chlordiazepoxide, and ketazolam) stability was studied in postmortem blood, bile, and vitreous humor stored at different temperatures over six months. The influence of NaF, in blood and bile samples, was also investigated. A solid-phase extraction technique was used on all the studied samples, and benzodiazepine quantification was performed by high-performance liquid chromatography-diode-array detection. Benzodiazepine concentration remained almost stable in all samples stored at -20°C and -80°C. Estazolam appeared to be a stable benzodiazepine during the six-month study, and ketazolam proved to be the most unstable benzodiazepine. A 100% loss of ketazolam occurred in all samples stored over 1 or 2 weeks at room temperature and over 8 or 12 weeks at 4°C, with the simultaneous detection of diazepam. Chlordiazepoxide suffered complete degradation in all samples, except preserved bile samples, stored at room temperature. Samples stored at 4°C for 6 months had a 29-100% decrease in chlordiazepoxide concentration. The data obtained suggest that results from samples with these benzodiazepines stored long-term should be cautiously interpreted. Bile and vitreous humor proved to be the most advantageous samples in cases where degradation of benzodiazepines by microorganisms may occur.

  1. Central CRF, urocortins and stress increase colonic transit via CRF1 receptors while activation of CRF2 receptors delays gastric transit in mice.

    Science.gov (United States)

    Martínez, Vicente; Wang, Lixin; Rivier, Jean; Grigoriadis, Dimitri; Taché, Yvette

    2004-04-01

    Recently characterized selective agonists and developed antagonists for the corticotropin releasing factor (CRF) receptors are new tools to investigate stress-related functional changes. The influence of mammalian CRF and related peptides injected intracerebroventricularly (i.c.v.) on gastric and colonic motility, and the CRF receptor subtypes involved and their role in colonic response to stress were studied in conscious mice. The CRF(1)/CRF(2) agonists rat urocortin 1 (rUcn 1) and rat/human CRF (r/h CRF), the preferential CRF(1) agonist ovine CRF (oCRF), and the CRF(2) agonist mouse (m) Ucn 2, injected i.c.v. inhibited gastric emptying and stimulated distal colonic motor function (bead transit and defecation) while oCRF(9-33)OH (devoid of CRF receptor affinity) showed neither effects. mUcn 2 injected peripherally had no colonic effect. The selective CRF(2) antagonist astressin(2)-B (i.c.v.), at a 20 : 1 antagonist: agonist ratio, blocked i.c.v. r/hCRF and rUcn 1 induced inhibition of gastric transit and reduced that of mUcn 2, while the CRF(1) antagonist NBI-35965 had no effect. By contrast, the colonic motor stimulation induced by i.c.v. r/hCRF and rUcn 1 and 1h restraint stress were antagonized only by NBI-35965 while stimulation induced by mUcn 2 was equally blocked by both antagonists. None of the CRF antagonists injected i.c.v. alone influenced gut transit. These data establish in mice that brain CRF(1) receptors mediate the stimulation of colonic transit induced by central CRF, urocortins (1 and 2) and restraint stress, while CRF(2) receptors mediate the inhibitory actions of these peptides on gastric transit.

  2. Benzodiazepines misuse: The study community level Thailand

    Directory of Open Access Journals (Sweden)

    Puangkot Sukdepat

    2010-01-01

    Full Text Available Context: Benzodiazepines (BZD misuse, abuse, and dependence are becoming a new problem in medicine, in Thailand, and the pharmacoepidemiology knowledge is insufficient. The aim of this study is to estimate the prevalence of benzodiazepine use, misuse, abuse, and dependence in the general population of the Ubon Rachathani province, in Thailand. Aims: To estimate the prevalence of benzodiazepine use, misuse, abuse, and dependence in the general population. Settings and Design: The cross-sectional household survey research was conducted from October 2008 to June 2009, with a target population age of 15 years and above. This took place in Ubon Ratchathani Province, in Thailand. Materials and Methods: A total sample size of 2280 were selected from three-stage stratified random sampling. BZD were identified with an accuracy of generic name, trade name, and drug characteristics. The DSM-IV questionnaire was used to define misuse, abuse, and dependence. The accuracy of dependence was interpreted with the help of the judgment of a psychiatric nurse. Statistical analysis: For the statistical analyses, prevalence was estimated with weight adjustment, variances estimated by the Teylor Series Linearization method, and interpreted with 95% confidence interval (CI. Results: There were 46,805 current users [3.9% (95% CI: 2.2-6.4], 26,404 misusers [2.2% (95% CI: 1.6-6.2], 7,203 abusers [0.6% (95% CI: 0.1 - 4.1], and 2,402 with dependence [0.2% (0.1-9.2]. When considering the group of current users in this study, 57.2% misusers, 16.6% abusers, and 5.9% with dependence were found, respectively. Conclusions: All prevalence of use was higher than previously reported, in Thailand, while more than half of the current users had a behavior of misuse. Surveillance of misuse should be undertaken in the current use. The medical professional should counsel the patient on the harm of misuse and limit the amount of medicine, with necessary dispensing.

  3. [Dependence on benzodiazepines. Clinical and biological aspects].

    Science.gov (United States)

    Pelissolo, A; Bisserbe, J C

    1994-01-01

    The high rate of benzodiazepines (BZD) consumption has been repeatedly confirmed by epidemiological surveys in most major western world countries. In a recent french survey 7% of chronic users of BZD (use in 5/7 days for the last 12 months) were found the general population (17% in the population aged above 65). It has been suggested that the high BZD consumption rate could be related to dependence. The existence of BZD dependence was described in the early sixties with very high dose of chlordiazepoxide but it has become a real concern for the medical community since the late seventies with increasing number of reports of withdrawal symptoms. The extend of the actual rate of withdrawal symptoms at BZD tapering is still very controversial and according to the different studies it varies from 39 to 90%. The between studies difference in parameters such as: the patient populations (psychopathology, treatment duration), the type of tapering employed (duration, nature of the medical and psychological support) and the used operational criteria for withdrawal definition most likely explain this wide variation in the rate of occurrence of withdrawal manifestations. According to the American Psychiatric Association Task Force on Benzodiazepine Dependence, Toxicity and Abuse three type of pathological events can happen after treatment discontinuation: rebound, withdrawal syndrome and recurrence. The rebound consists in the early and transitory reappearance of the anxiety symptoms pre-existing to the treatment but in an exacerbated from; the withdrawal syndrome associates the resurgence of the pre-existing anxiety symptoms and new symptoms as sensory disturbances (metallic taste, hyperosmia, cutaneous exacerbated sensitivity, photophobia...) nausea, headache, motor disturbance in some rare cases depersonalization, paranoid reaction, confusion, convulsion. Rebound or withdrawal syndrome appearance delay varies from hours to few days according mostly to compounds elimination

  4. Reducing elevated plasma LDL cholesterol: the central role of the LDL receptor.

    Science.gov (United States)

    Vincent, J

    2014-07-01

    Elevated low-density lipoprotein cholesterol (LDL-C) is an established risk factor for cardiovascular disease (CVD), and reduction of elevated LDL-C reduces mortality in patients at risk. This benefit has evolved from the use of statins and knowledge of the LDL receptor (LDLR). The most potent drugs used for dyslipidemias act by mechanisms that involve this receptor. Advances in molecular genetics and understanding of the regulation of this receptor have revealed several pharmacological targets that are being explored to develop more targeted therapies for dyslipidemias.

  5. Safety and efficacy of flumazenil for reversal of iatrogenic benzodiazepine-associated delirium toxicity during treatment of alcohol withdrawal, a retrospective review at one center.

    Science.gov (United States)

    Moore, Philip W; Donovan, J Ward; Burkhart, Keith K; Waskin, Jeffrey A; Hieger, Michelle A; Adkins, Audrey R; Wert, Yijin; Haggerty, David A; Rasimas, J J

    2014-06-01

    Both alcohol withdrawal syndrome (AWS) and benzodiazepines can cause delirium. Benzodiazepine-associated delirium can complicate AWS and prolong hospitalization. Benzodiazepine delirium can be diagnosed with flumazenil, a GABA-A receptor antagonist. By reversing the effects of benzodiazepines, flumazenil is theorized to exacerbate symptoms of AWS and precludes its use. For patients being treated for alcohol withdrawal, flumazenil can diagnose and treat benzodiazepine delirium without precipitating serious or life-threatening adverse events. Hospital admission records were retrospectively reviewed for patients with the diagnosis of AWS who received both benzodiazepines and flumazenil from December 2006 to June 2012 at a university-affiliated inpatient toxicology center. The day of last alcohol consumption was estimated from available blood alcohol content or subjective history. Corresponding benzodiazepine, flumazenil, and adjunctive sedative pharmacy records were reviewed, as were demographic, clinical course, and outcome data. Eighty-five patients were identified (average age 50.3 years). Alcohol concentrations were detectable for 42 patients with average 261 mg/dL (10-530 mg/dL). Eighty patients were treated with adjunctive agents for alcohol withdrawal including antipsychotics (n = 57), opioids (n = 27), clonidine (n = 35), and phenobarbital (n = 23). Average time of flumazenil administration was 4.7 days (1-11 days) after abstinence, and average dose was 0.5 mg (0.2-1 mg). At the time of flumazenil administration, delirium was described as hypoactive (n = 21), hyperactive (n = 15), mixed (n = 41), or not specified (n = 8). Response was not documented in 11 cases. Sixty-two (72.9 %) patients had significant objective improvement after receiving flumazenil. Fifty-six patients required more than one dose (average 5.6 doses). There were no major adverse events and minor adverse effects included transiently increased anxiety

  6. Transfer in vitro of three benzodiazepines across the human placenta.

    Science.gov (United States)

    Guerre-Millo, M; Rey, E; Challier, J C; Turquais, J M; d'Athis, P; Olive, G

    1979-04-17

    A comparative study of the placental transfer to the foetus of three benzodiazepines was performed using a dual perfusion system of the human placental lobule. A transport fraction was calculated for each benzodiazepine and was compared with reference substances. Relative to antipyrine, the transport fraction of diazepam was 85%, and that of nordiazepam was 84%. The transport fraction of clorazepate represented only 20% of that of tritiated water. The relatively high transfer of diazepam and nordiazepam can be attributed to their high lipid solubility, and the lower transfer of clorazepate is due to its polar nature. It is suggested that in certain instances this benzodiazepine may be of especial value to obstetricians.

  7. A pivotal role for enhanced brainstem Orexin receptor 1 signaling in the central cannabinoid receptor 1-mediated pressor response in conscious rats.

    Science.gov (United States)

    Ibrahim, Badr Mostafa; Abdel-Rahman, Abdel A

    2015-10-05

    Orexin receptor 1 (OX1R) signaling is implicated in cannabinoid receptor 1 (CB1R) modulation of feeding. Further, our studies established the dependence of the central CB1R-mediated pressor response on neuronal nitric oxide synthase (nNOS) and extracellular signal-regulated kinase1/2 (ERK1/2) phosphorylation in the RVLM. Here, we tested the novel hypothesis that brainstem orexin-A/OX1R signaling plays a pivotal role in the central CB1R-mediated pressor response. Our multiple labeling immunofluorescence findings revealed co-localization of CB1R, OX1R and the peptide orexin-A within the C1 area of the rostral ventrolateral medulla (RVLM). Activation of central CB1R following intracisternal (i.c.) WIN55,212-2 (15μg/rat) in conscious rats caused significant increases in BP and orexin-A level in RVLM neuronal tissue. Additional studies established a causal role for orexin-A in the central CB1R-mediated pressor response because (i) selective blockade of central CB1R (AM251, 30μg/rat; i.c.) abrogated WIN55,212-2-evoked increases in RVLM orexin-A level, (ii) the selective OX1R antagonist SB-408124 (10nmol/rat; i.c.) attenuated orexin-A (3nmol/rat; i.c.) or WIN55,212-2 (15μg/rat; i.c.)-evoked pressor response while selective CB1R blockade (AM251) had no effect on orexin-A (3nmol/rat; i.c.)-evoked pressor response, (iii) direct CB1R activation in the RVLM (WIN55,212-2; 0.1μg/rat) increased RVLM orexin-A and BP. Finally, SB-408124 attenuated WIN55,212-2-evoked increases in RVLM nNOS and ERK1/2 phosphorylation and BP. Our findings suggest that orexin-A/OX1R dependent activation of the RVLM nNOS/ERK1/2 cascade is essential neurochemical mechanism for the central CB1R-mediated pressor response in conscious rats.

  8. Emotional Eating Phenotype is Associated with Central Dopamine D2 Receptor Binding Independent of Body Mass Index.

    Science.gov (United States)

    Eisenstein, Sarah A; Bischoff, Allison N; Gredysa, Danuta M; Antenor-Dorsey, Jo Ann V; Koller, Jonathan M; Al-Lozi, Amal; Pepino, Marta Y; Klein, Samuel; Perlmutter, Joel S; Moerlein, Stephen M; Black, Kevin J; Hershey, Tamara

    2015-06-12

    PET studies have provided mixed evidence regarding central D2/D3 dopamine receptor binding and its relationship with obesity as measured by body mass index (BMI). Other aspects of obesity may be more tightly coupled to the dopaminergic system. We characterized obesity-associated behaviors and determined if these related to central D2 receptor (D2R) specific binding independent of BMI. Twenty-two obese and 17 normal-weight participants completed eating- and reward-related questionnaires and underwent PET scans using the D2R-selective and nondisplaceable radioligand (N-[(11)C]methyl)benperidol. Questionnaires were grouped by domain (eating related to emotion, eating related to reward, non-eating behavior motivated by reward or sensitivity to punishment). Normalized, summed scores for each domain were compared between obese and normal-weight groups and correlated with striatal and midbrain D2R binding. Compared to normal-weight individuals, the obese group self-reported higher rates of eating related to both emotion and reward (pemotional eating and non-food reward behavior positively correlated with striatal (pemotional eating phenotype may reflect altered central D2R function better than other commonly used obesity-related measures such as BMI.

  9. Central delta-opioid receptor interactions and the inhibition of reflex urinary bladder contractions in the rat.

    Science.gov (United States)

    Dray, A.; Nunan, L.; Wire, W.

    1985-01-01

    The in vivo effects of a number of opioid agonists and antagonists were studied on the spontaneous reflex contractions of the urinary bladder recorded isometrically in the rat anesthetized with urethane. All substances were administered into the central nervous system by the intracereboventricular (i.c.v.) or spinal intrathecal (i.t.) route. The conformationally restricted enkephalin analogues [2-D-penicillamine, 5-L-cysteine] enkephalin (DPLCE), [2-D-penicillamine, 5-L-penicillamine] enkephalin (DPLPE) and [2-D-penicillamine, 5-D-penicillamine] enkephalin (DPDPE) produced dose-related inhibition of reflex bladder contractions when administered by the i.c.v. or i.t. route. Both the novel delta-opioid receptor antagonist ICI 154,129 (200-600 micrograms) [N,N-bisallyl-Tyr-Gly-Gly-Psi-(CH2S)-Phe-Leu-OH) and ICI 174,864 (1-3 micrograms) [N,N-dially-Tyr-Aib-Aib-Phe-Leu-OH: Aib = alpha-aminoisobutyric acid] attenuated or abolished the effects of DPLCE, DPLPE and DPDPE when administered by the i.c.v. or i.t. route. The antagonism observed was selective since the equipotent inhibition produced by the mu-opioid receptor agonist [D-Ala2, Me-Phe4, Gly(ol)5] enkephalin (DAGO) was unaffected. Overall, ICI 154,129 was considerably weaker than ICI 174,864 and both antagonists inhibited bladder activity at doses higher than those required to demonstrate delta-receptor antagonism. Further studies of the agonistic effect of ICI 174,864 showed that it was insensitive to low doses of naloxone (2 micrograms, i.c.v. or i.t.) but could be abolished by higher (10-15 micrograms) doses of naloxone. These observations suggested that the agonistic effect of ICI 174,864 was not mediated by mu-opioid receptor. beta-Endorphin (0.2-1.0 micrograms, i.c.v.) inhibited bladder contractions but following recovery from this effect, appeared to prevent the expression of delta-receptor antagonism by ICI 174,864. In addition a previously subthreshold dose of ICI 174,864 now exhibited marked agonistic

  10. Terahertz spectroscopic study of benzodiazepine sedative hypnotics

    Science.gov (United States)

    Deng, Fusheng; Shen, Jingling; Wang, Xianfeng

    2011-08-01

    Terahertz time domain spectroscopy (THz-TDS) is used to the pure active ingredient of three benzodiazepine sedative hypnotics with similar molecular structure. The absorption spectra of them are studied in the range of 0.2~2.6THz. Based on the experiment, the theoretical simulation results of diazepam, nitrazepam and clonazepam are got by the Gaussian03 package of DFT/B3LYP/6-31G* method in single-molecule models. The experimental results show that even if the molecular structure and medicine property of them are similar, the accurate identification of them can still be done with their characteristic absorption spectra. Theoretical simulation results are well consistent with the experimental results. It demonstrates that absorption peaks of them in THz range mainly come from intra-molecular forces and are less affected by the intermolecular interaction and crystal effects.ô

  11. Radioiodinated benzodiazepines: agents for mapping glial tumors

    Energy Technology Data Exchange (ETDEWEB)

    Van Dort, M.E.; Ciliax, B.J.; Gildersleeve, D.L.; Sherman, P.S.; Rosenspire, K.C.; Young, A.B.; Junck, L.; Wieland, D.M.

    1988-11-01

    Two isomeric iodinated analogues of the peripheral benzodiazepine binding site (PBS) ligand Ro5-4864 have been synthesized and labeled in high specific activity with iodine-125. Competitive binding assays conducted with the unlabeled analogues indicate high affinity for PBS. Tissue biodistribution studies in rats with these /sup 125/I-labeled ligands indicate high uptake of radioactivity in the adrenals, heart, and kidney--tissues known to have high concentrations of PBS. Preadministration of the potent PBS antagonist PK 11195 blocked in vivo uptake in adrenal tissue by over 75%, but to a lesser degree in other normal tissues. In vivo binding autoradiography in brain conducted in C6 glioma bearing rats showed dense, PBS-mediated accumulation of radioactivity in the tumor. Ligand 6 labeled with /sup 123/I may have potential for scintigraphic localization of intracranial glioma.

  12. Anticholinesterase Effects on Number and Function of Brain Muscarinic Receptors and Central Cholinergic Activity: Drug Intervention.

    Science.gov (United States)

    1986-04-11

    chloride; pirenzepine ;scopolamine;N-methyL- scopolamine; McN-A-343; quinpiroLe; putative neurotransmitters;dopamine;noradrenaline; glutamate;serotonin... pirenzepine /( H)QNB competition experiments revealed the presence of two muscarinic receptor subtypes :-1, . . - the high affinity site,and M-2...also to occur through activation of the M-2 type, e.g. pretreatment with pirenzepine , a selective and potent M- 1 receptor antagonist failed to block

  13. Central Serotonin-2A (5-HT2A Receptor Dysfunction in Depression and Epilepsy: The Missing Link?

    Directory of Open Access Journals (Sweden)

    Bruno Pierre Guiard

    2015-03-01

    Full Text Available 5-Hydroxytryptamine 2A receptors (5-HT2A-Rs are G-protein coupled receptors. In agreement with their location in the brain, they have been implicated not only in various central physiological functions including memory, sleep, nociception, eating and reward behaviors, but also in many neuropsychiatric disorders. Interestingly, a bidirectional link between depression and epilepsy is suspected since patients with depression and especially suicide attempters have an increased seizure risk, while a significant percentage of epileptic patients suffer from depression. Such epidemiological data led us to hypothesize that both pathologies may share common anatomical and neurobiological alteration of the 5-HT2A signaling. After a brief presentation of the pharmacological properties of the 5-HT2A-Rs, this review illustrates how these receptors may directly or indirectly control neuronal excitability in most networks involved in depression and epilepsy through interactions with the monoaminergic, GABAergic and glutamatergic neurotransmissions. It also synthetizes the preclinical and clinical evidence demonstrating the role of these receptors in antidepressant and antiepileptic responses.

  14. Stress and central Urocortin increase anxiety-like behavior in the social interaction test via the CRF1 receptor.

    Science.gov (United States)

    Gehlert, Donald R; Shekhar, Anantha; Morin, S Michelle; Hipskind, Phillip A; Zink, Charity; Gackenheimer, Susan L; Shaw, Janice; Fitz, Stephanie D; Sajdyk, Tammy J

    2005-02-21

    Corticotropin releasing factor (CRF) and Urocortin are important neurotransmitters in the regulation of physiological and behavioral responses to stress. Centrally administered CRF or Urocortin produces anxiety-like responses in numerous animal models of anxiety disorders. Previous studies in our lab have shown that Urocortin infused into the basolateral nucleus of the amygdala produces anxiety-like responses in the social interaction test. Subsequently, in the current study we prepared a specific CRF1 receptor antagonist (N-Cyclopropylmethyl-2,5-dimethyl-N-propyl-N'-(2,4,6-trichloro-phenyl)-pyrimidine-4,6-diamine, NBI3b1996) to examine in this paradigm. This CRF1 receptor antagonist inhibited the ex vivo binding of 125I-sauvagine to rat cerebellum with an ED50 of 6 mg/kg, i.p. NBI3b1996 produced a dose-dependent antagonism of Urocortin-induced anxiety-like behavior in Social Interaction test with an ED50 of 6 mg/kg, i.p. The compound had no effect on baseline social interaction. In addition, the CRF1 receptor antagonist prevented the stress-induced decrease in social interaction. These results provide further support for the CRF1 receptor in anxiety-like behavior and suggest this pathway is quiescent in unstressed animals.

  15. Specific binding of benzodiazepines to human breast cancer cell lines.

    Science.gov (United States)

    Beinlich, A; Strohmeier, R; Kaufmann, M; Kuhl, H

    1999-01-01

    Binding of [3H]Ro5-4864, a peripheral benzodiazepine receptor (PBR) agonist, to BT-20 human, estrogen- (ER) and progesterone- (PR) receptor negative breast cancer cells was characterized. It was found to be specific, dose-dependent and saturable with a single population of binding sites. Dissociation constant (K(D)) was 8.5 nM, maximal binding capacity (Bmax) 339 fM/10(6) cells. Ro5-4864 (IC50 17.3 nM) and PK 11195 (IC50 12.3 nM) were able to compete with [3H]Ro5-4864 for binding, indicating specificity of interaction with PBR. Diazepam was able to displace [3H]Ro5-4864 from binding only at high concentrations (>1 microM), while ODN did not compete for PBR binding. Thymidine-uptake assay showed a biphasic response of cell proliferation. While low concentrations (100 nM) of Ro5-4864, PK 11195 and diazepam increased cell growth by 10 to 20%, higher concentrations (10-100 microM) significantly inhibited cell proliferation. PK 11195, a potent PBR ligand, was able to attenuate growth of BT-20 cells stimulated by 100 nM Ro5-4864 and to reverse growth reduction caused by 1 and 10 microM Ro5-4864, but not by 50 microM and 100 microM. This indicates that the antimitotic activity of higher concentrations of Ro5-4864 is independent of PBR binding. It is suggested, that PBR are involved in growth regulation of certain human breast cancer cell lines, possibly by supplying proliferating cells with energy, as their endogenous ligand is a polypeptide transporting Acyl-CoA.

  16. Ethanol and corticotropin releasing factor receptor modulation of central amygdala neurocircuitry: An update and future directions.

    Science.gov (United States)

    Silberman, Yuval; Winder, Danny G

    2015-05-01

    The central amygdala is a critical brain region for many aspects of alcohol dependence. Much of the work examining the mechanisms by which the central amygdala mediates the development of alcohol dependence has focused on the interaction of acute and chronic ethanol with central amygdala corticotropin releasing factor signaling. This work has led to a great deal of success in furthering the general understanding of central amygdala neurocircuitry and its role in alcohol dependence. Much of this work has primarily focused on the hypothesis that ethanol utilizes endogenous corticotropin releasing factor signaling to upregulate inhibitory GABAergic transmission in the central amygdala. Work that is more recent suggests that corticotropin releasing factor also plays an important role in mediating anxiety-like behaviors via the enhancement of central amygdala glutamatergic transmission, implying that ethanol/corticotropin releasing factor interactions may modulate excitatory neurotransmission in this brain region. In addition, a number of studies utilizing optogenetic strategies or transgenic mouse lines have begun to examine specific central amygdala neurocircuit dynamics and neuronal subpopulations to better understand overall central amygdala neurocircuitry and the role of neuronal subtypes in mediating anxiety-like behaviors. This review will provide a brief update on this literature and describe some potential future directions that may be important for the development of better treatments for alcohol addiction.

  17. Studies of the electronic structure and biological activity of chosen 1,4-benzodiazepines by {sup 35}Cl NQR spectroscopy and DFT calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bronisz, K. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Ostafin, M. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)], E-mail: ostifnqr@amu.edu.pl; Poleshchuk, O. Kh. [Department of Chemistry, Tomsk Pedagogical University, Komsomolskii 75, 634041 Tomsk (Russian Federation); Mielcarek, J. [Faculty of Pharmacy, University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan (Poland); Nogaj, B. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)

    2006-11-08

    Selected derivatives of 1,4-benzodiazepine: lorazepam, lormetazepam, oxazepam and temazepam, used as active substances in anxiolytic drugs, have been studied by {sup 35}Cl NQR method in order to find the correlation between electronic structure and biological activity. The {sup 35}Cl NQR resonance frequencies ({nu} {sub Q}) measured at 77 K have been correlated with the following parameters characterising their biological activity: biological half-life period (t {sub 0.5}), affinity to benzodiazepine receptor (IC{sub 50}) and mean dose equivalent. The results of experimental study of some benzodiazepine derivatives by nuclear quadrupole resonance of {sup 35}Cl nuclei are compared with theoretical results based on DFT calculations which were carried out by means of Gaussian'98 W software.

  18. Studies of the electronic structure and biological activity of chosen 1,4-benzodiazepines by 35Cl NQR spectroscopy and DFT calculations

    Science.gov (United States)

    Bronisz, K.; Ostafin, M.; Poleshchuk, O. Kh.; Mielcarek, J.; Nogaj, B.

    2006-11-01

    Selected derivatives of 1,4-benzodiazepine: lorazepam, lormetazepam, oxazepam and temazepam, used as active substances in anxiolytic drugs, have been studied by 35Cl NQR method in order to find the correlation between electronic structure and biological activity. The 35Cl NQR resonance frequencies ( νQ) measured at 77 K have been correlated with the following parameters characterising their biological activity: biological half-life period ( t0.5), affinity to benzodiazepine receptor (IC 50) and mean dose equivalent. The results of experimental study of some benzodiazepine derivatives by nuclear quadrupole resonance of 35Cl nuclei are compared with theoretical results based on DFT calculations which were carried out by means of Gaussian'98 W software.

  19. The effect of activation of central adrenergic receptors by clonidine on the excitability of the solitary tract neurons in cats.

    Science.gov (United States)

    Lipski, J; Solnicka, E

    1976-01-01

    The effect of i.v. administered clonidine (10-15 mug/kg) on the evoked potential recorded in the dosal part of medulla oblongata, during carotid sinus nerve stimulation, was studied in chloralose-urethane anaesthetized cats. Clonidine influenced the amplitude and configuration of the evoked potential and the changes were parallel to the blood pressure depressor response. However, the blood pressure drops, evoked by i.v. infusion of papaverine, did not influence the potential. It is concluded that the synaptic transmission from the carotid sinus nerve to the second order neurons in the solatary tract area can be modulated by the clonidine-induced activation of central adrenergic receptors.

  20. Eight principles for safer opioid prescribing and cautions with benzodiazepines.

    Science.gov (United States)

    Webster, Lynn R; Reisfield, Gary M; Dasgupta, Nabarun

    2015-01-01

    The provision of long-term opioid analgesic therapy for chronic pain requires a careful risk/benefit analysis followed by clinical safety measures to identify and reduce misuse, abuse, and addiction and their associated morbidity and mortality. Multiple data sources show that benzodiazepines, prescribed for comorbid insomnia, anxiety, and mood disorders, heighten the risk of respiratory depression and other adverse outcomes when combined with opioid therapy. Evidence is presented for hazards associated with coadministration of opioids and benzodiazepines and the need for caution when initiating opioid therapy for chronic pain. Clinical recommendations follow, as drawn from 2 previously published literature reviews, one of which proffers 8 principles for safer opioid prescribing; the other review presents risks associated with benzodiazepines, suggests alternatives for co-prescribing benzodiazepines and opioids, and outlines recommendations regarding co-prescribing if alternative therapies are ineffective.

  1. Benzodiazepine absetzen im Alter. Wann und, wenn ja, wie?

    DEFF Research Database (Denmark)

    Wolter, Dirk

    2017-01-01

    Although viewed critically in geriatrics, benzodiazepine use is still common among old people. Before reducing the dosage the following questions must be considered: 1. Are there indications for benzodiazepine treatment and will discontinuation cause relevant rebound symptoms of the initial...... disorder treated? 2. To what extent do the patient and other key persons consider discontinuation to be reasonable and will they support discontinuation? 3. Is the target complete withdrawal, a dose reduction or shift to another benzodiazepine drug which is more suitable in old age for pharmacokinetic...... reasons? This article provides assistance in answering these questions and some guidelines for the practical management of discontinuation. It is mandatory 1) to periodically address the problem of long-term benzodiazepine use when counseling the patient and key persons and 2) to be aware that several...

  2. [Should we continue to use benzodiazepines in clinical practice?].

    Science.gov (United States)

    Sampogna, Gaia; Del Vecchio, Valeria; Luciano, Mario; De Rosa, Corrado; Albert, Umberto; Dell'Osso, Bernardo; Fiorillo, Andrea

    2015-06-01

    The discovery of benzodiazepines has represented a milestone in the history of pharmacological treatments and in relation to the management of anxiety, sleep and other psychiatric disorders. After several decades, these agents still represent one of the largest and most widely prescribed groups of medications, not only in the psychiatric clinical practice, but also in the whole medical field. Over the last decade, however, multiple concerns have been raised on the risks related to the prescription of benzodiazepines, for their addictive potential and for cognitive side-effects. Therefore, benzodiazepines are today considered as a double-edge sword, which should be carefully handled and preferentially prescribed by specialists (or at least under their supervision), after an adequate training. Unfortunately, this is not the case in many situations, and the need to improve training on benzodiazepines management has been recently emphasized.

  3. Targeting cell surface receptors for axon regeneration in the central nervous system

    Science.gov (United States)

    Cheah, Menghon; Andrews, Melissa R.

    2016-01-01

    Axon regeneration in the CNS is largely unsuccessful due to excess inhibitory extrinsic factors within lesion sites together with an intrinsic inability of neurons to regrow following injury. Recent work demonstrates that forced expression of certain neuronal transmembrane receptors can recapitulate neuronal growth resulting in successful growth within and through inhibitory lesion environments. More specifically, neuronal expression of integrin receptors such as alpha9beta1 integrin which binds the extracellular matrix glycoprotein tenascin-C, trk receptors such as trkB which binds the neurotrophic factor BDNF, and receptor PTPσ which binds chondroitin sulphate proteoglycans, have all been show to significantly enhance regeneration of injured axons. We discuss how reintroduction of these receptors in damaged neurons facilitates signalling from the internal environment of the cell with the external environment of the lesion milieu, effectively resulting in growth and repair following injury. In summary, we suggest an appropriate balance of intrinsic and extrinsic factors are required to obtain substantial axon regeneration. PMID:28197173

  4. Targeting cell surface receptors for axon regeneration in the central nervous system

    Directory of Open Access Journals (Sweden)

    Menghon Cheah

    2016-01-01

    Full Text Available Axon regeneration in the CNS is largely unsuccessful due to excess inhibitory extrinsic factors within lesion sites together with an intrinsic inability of neurons to regrow following injury. Recent work demonstrates that forced expression of certain neuronal transmembrane receptors can recapitulate neuronal growth resulting in successful growth within and through inhibitory lesion environments. More specifically, neuronal expression of integrin receptors such as alpha9beta1 integrin which binds the extracellular matrix glycoprotein tenascin-C, trk receptors such as trkB which binds the neurotrophic factor BDNF, and receptor PTPσ which binds chondroitin sulphate proteoglycans, have all been show to significantly enhance regeneration of injured axons. We discuss how reintroduction of these receptors in damaged neurons facilitates signalling from the internal environment of the cell with the external environment of the lesion milieu, effectively resulting in growth and repair following injury. In summary, we suggest an appropriate balance of intrinsic and extrinsic factors are required to obtain substantial axon regeneration.

  5. The Benzodiazepine-Dementia Disorders Link: Current State of Knowledge.

    Science.gov (United States)

    Pariente, Antoine; de Gage, Sophie Billioti; Moore, Nicholas; Bégaud, Bernard

    2016-01-01

    The short-term effects of benzodiazepines on memory are well established and are suspected in the long term. Eleven studies have been published so far concerning benzodiazepine use and the risk of dementia disorders; nine of these studies concluded these drugs have a deleterious effect, one found a protective effect, and one (the most recently published) observed no effect. The positive association found in some studies could be due to a reverse causation bias since the main indications for benzodiazepines (e.g. sleep disorders, anxiety) can also be prodromes of dementia disorders. This bias is less likely for treatments started more than 10 years before the diagnosis. Among others, three mechanisms could underlie the potential influence of benzodiazepines on the development of dementia disorders. First, benzodiazepines can decrease beta-site amyloid precursor protein-cleaving enzyme 1 (BACE-1) and γ-secretase activity and slow down the accumulation of Aβ oligomers in the brain. This potential positive effect has never been confirmed; the same is true for the prevention of excitotoxicity through benzodiazepine anti-glutamatergic action. Second, since astrocytes located in the area of amyloid plaques could have gamma-aminobutyric acid (GABA)-secreting activity, patients with pre-dementia lesions could be at increased risk of presenting with more pronounced deleterious cognitive effects of benzodiazepines. Finally, owing to the neural compensation and cognitive reserve concepts, some subjects could cope with initial lesions by using/developing alternative networks. By lowering the brain activation level, benzodiazepines could limit this capacity. In conclusion, it is essential that animal studies explore the mechanistic hypotheses of this association found by most of the pharmacoepidemiological studies conducted on this topic.

  6. Systemic administration of arecoline reduces ethanol-induced sleeping through activation of central muscarinic receptor in mice.

    Science.gov (United States)

    Sun, Yan-Ping; Liu, Qing; Luo, Juan; Guo, Ping; Chen, Feng; Lawrence, Andrew J; Liang, Jian-Hui

    2010-01-01

    Epidemiological evidence of co-use of alcohol and areca nuts suggests a potential central interaction between arecoline, a major alkaloid of areca and a muscarinic receptor agonist, and ethanol. Moreover, the central cholinergic system plays an important role in the depressant action of ethanol and barbiturates. The purpose of this study was to investigate the effects of arecoline on pentobarbital- and ethanol-induced hypnosis in mice. Male ICR mice were tested for locomotor activity following acute systemic administration of ethanol alone, arecoline alone, or ethanol plus arecoline. For the loss of the righting reflex (LORR) induced by pentobarbital and ethanol, sleep latency and sleeping duration were evaluated in mice treated with arecoline alone or the combination of arecoline and scopolamine or methscopolamine. Ethanol (1.0 to 3.0 g/kg, i.p.) reduced locomotor activity significantly and a declining trend was observed after treatment with arecoline (0.25 to 1.0 mg/kg, i.p.), but there were no synergistic effects of ethanol and arecoline on locomotor activity. The experiments on LORR demonstrated that arecoline (0.125 to 1.0 mg/kg, s.c.) shortened the duration of sleeping induced by ethanol (4.0 g/kg, i.p.), but not pentobarbital (45 mg/kg, i.p.). In addition, alterations of sleep latency were not obvious in both pentobarbital- and ethanol-induced LORR. Statistical analyses revealed that scopolamine (centrally acting), but not methscopolamine (peripherally acting), could antagonize the effect of arecoline on the duration of ethanol-induced LORR in mice. These results suggest that central muscarinic receptor is a pharmacological target for the action of arecoline to modulate ethanol-induced hypnosis.

  7. The central cannabinoid CB1 receptor is required for diet-induced obesity and rimonabant's antiobesity effects in mice.

    Science.gov (United States)

    Pang, Zhen; Wu, Nancy N; Zhao, Weiguang; Chain, David C; Schaffer, Erica; Zhang, Xin; Yamdagni, Preeti; Palejwala, Vaseem A; Fan, Chunpeng; Favara, Sarah G; Dressler, Holly M; Economides, Kyriakos D; Weinstock, Daniel; Cavallo, Jean S; Naimi, Souad; Galzin, Anne-Marie; Guillot, Etienne; Pruniaux, Marie-Pierre; Tocci, Michael J; Polites, H Greg

    2011-10-01

    Cannabinoid receptor CB1 is expressed abundantly in the brain and presumably in the peripheral tissues responsible for energy metabolism. It is unclear if the antiobesity effects of rimonabant, a CB1 antagonist, are mediated through the central or the peripheral CB1 receptors. To address this question, we generated transgenic mice with central nervous system (CNS)-specific knockdown (KD) of CB1, by expressing an artificial microRNA (AMIR) under the control of the neuronal Thy1.2 promoter. In the mutant mice, CB1 expression was reduced in the brain and spinal cord, whereas no change was observed in the superior cervical ganglia (SCG), sympathetic trunk, enteric nervous system, and pancreatic ganglia. In contrast to the neuronal tissues, CB1 was undetectable in the brown adipose tissue (BAT) or the liver. Consistent with the selective loss of central CB1, agonist-induced hypothermia was attenuated in the mutant mice, but the agonist-induced delay of gastrointestinal transit (GIT), a primarily peripheral nervous system-mediated effect, was not. Compared to wild-type (WT) littermates, the mutant mice displayed reduced body weight (BW), adiposity, and feeding efficiency, and when fed a high-fat diet (HFD), showed decreased plasma insulin, leptin, cholesterol, and triglyceride levels, and elevated adiponectin levels. Furthermore, the therapeutic effects of rimonabant on food intake (FI), BW, and serum parameters were markedly reduced and correlated with the degree of CB1 KD. Thus, KD of CB1 in the CNS recapitulates the metabolic phenotype of CB1 knockout (KO) mice and diminishes rimonabant's efficacy, indicating that blockade of central CB1 is required for rimonabant's antiobesity actions.

  8. Comparison of urine and oral fluid as matrices for screening of thirty-three benzodiazepines and benzodiazepine-like substances using immunoassay and LC–MS(–MS).

    NARCIS (Netherlands)

    Smink, B.E. Mathijssen, M.P.M. Lusthof, K.J. Gier, J.J. de Egberts, A.C.G. & Uges, D.R.A.

    2006-01-01

    Benzodiazepines are the most frequently detected medicinal drugs in drivers. The use of benzodiazepines is associated with an increased road accident risk. In this study, the presence of benzodiazepines detected by liquid chromatography–(tandem) mass spectrometry [LC–MS(–MS)] in oral fluid and urine

  9. Selective blockade of central m1 muscarinic cholinergic receptors with pirenzepine impairs cardiovascular and respiratory function in rats with acute hemorrhage.

    Science.gov (United States)

    Kovalenko, N Ya; Matsievskii, D D

    2006-09-01

    Ultrasound studies showed that selective antagonist of central M1 muscarinic cholinergic receptors pirenzepine (50 mg/kg intravenously) causes transitory hypotension and respiratory depression in anesthetized intact rats. The M1 receptor antagonist had no effect on cardiac output and portal blood flow. Pretreatment with pirenzepine increased the sensitivity of rats with acute massive hemorrhage to circulatory hypoxia. After blockade of central M1 muscarinic cholinergic receptors, the posthemorrhagic period was characterized by primary decompensation of blood pressure, portal blood flow, and respiration and development of low cardiac output syndrome. The animals died over the first minutes after bleeding arrest. Our results indicate that central M1 muscarinic cholinergic receptors act as shock-limiting cholinergic structures under conditions of posthemorrhagic changes in systemic and portal blood flow, as well as during respiratory dysfunction.

  10. Targeting P(2)X(7) receptor for the treatment of central post-stroke pain in a rodent model.

    Science.gov (United States)

    Kuan, Yung-Hui; Shih, Hsi-Chien; Tang, Sung-Chun; Jeng, Jiann-Shing; Shyu, Bai-Chuang

    2015-06-01

    Stroke is a leading cause of death and disability in industrialized countries. Approximately 8-14% of stroke survivors suffer from central post-stroke pain (CPSP) when hemorrhagic stroke occurs in lateral thalamic regions, which severely affects their quality of life. Because the mechanisms of CPSP are not well understood, effective treatments have not been developed. In the present study, we tested the hypothesis that persistent CPSP is caused by P(2)X(7)receptor activation after brain tissue damage and subsequent elevations in inflammatory cytokines. A thalamic hemorrhagic rat model was used, characterized by thermal and mechanical allodynia that develops in the subacute to chronic phases upon CPSP onset. We found a significant increase in P(2)X(7) expression in reactive microglia/macrophages in thalamic peri-lesion tissues at 5 weeks post-hemorrhage. Thalamic P(2)X(7) receptors were directly involved in pain transmission and hypersensitivity. The systemic targeting of P(2)X(7) receptors during the acute stage of hemorrhage rescued abnormal pain behaviors and neuronal activity in the thalamocingulate pathway by reducing reactive microglia/macrophage aggregation and associated inflammatory cytokines. After CPSP onset, the targeting of interleukin-1β reversed abnormal pain sensitivity. The aberrant spontaneous thalamocortical oscillations in rats with CPSP were modulated by blocking P(2)X(7) receptors. Taken together, our results suggest that targeting P(2)X(7) may be bi-effective in the treatment of CPSP, as both a pain blocker and immunosuppressant that inhibits inflammatory damage to brain tissue. P(2)X(7)receptors may serve as a potential target to prevent the occurrence of CPSP and may be beneficial for the recovery of patients from stroke.

  11. Effects of exposure to benzodiazepine during fetal life.

    Science.gov (United States)

    Bergman, U; Rosa, F W; Baum, C; Wiholm, B E; Faich, G A

    1992-09-19

    Dysmorphism and mental retardation have been reported in 7 Swedish children born of mothers who had taken high doses of benzodiazepines regularly during pregnancy. To explore this association further, we examined benzodiazepine use during pregnancy in 104,000 women whose deliveries were registered by the US public health insurance system, Medicaid, during 1980-83. Fetal outcomes were assessed from the health claims profiles of their offspring, up to 6-9 years after delivery. 80 pregnant women had received 10 or more benzodiazepine prescriptions during the 4 years. Their records showed heavy general use of health care and frequent alcohol and substance abuse, and other disorders that could confound any effect of the benzodiazepines. For the 80 pregnancies, 3 intrauterine deaths were identified as well as 2 infants with congenital abnormalities whose curtailed records suggested neonatal death. Records of 64 surviving children could be linked to these 80 pregnancies whilst records for 11 apparent survivors could not be located. 6 of the 64 survivors had diagnoses consistent with teratogenic abnormalities. The high rate of teratogenicity after heavy maternal benzodiazepine use occurs with multiple alcohol and substance exposure and thus may not be due to benzodiazepine exposure.

  12. Analytical methodologies for the determination of benzodiazepines in biological samples.

    Science.gov (United States)

    Persona, Karolina; Madej, Katarzyna; Knihnicki, Paweł; Piekoszewski, Wojciech

    2015-09-10

    Benzodiazepine drugs belong to important and most widely used medicaments. They demonstrate such therapeutic properties as anxiolytic, sedative, somnifacient, anticonvulsant, diastolic and muscle relaxant effects. However, despite the fact that benzodiazepines possess high therapeutic index and are considered to be relatively safe, their use can be dangerous when: (1) co-administered with alcohol, (2) co-administered with other medicaments like sedatives, antidepressants, neuroleptics or morphine like substances, (3) driving under their influence, (4) using benzodiazepines non-therapeutically as drugs of abuse or in drug-facilitated crimes. For these reasons benzodiazepines are still studied and determined in a variety of biological materials. In this article, sample preparation techniques which have been applied in analysis of benzodiazepine drugs in biological samples have been reviewed and presented. The next part of the article is focused on a review of analytical methods which have been employed for pharmacological, toxicological or forensic study of this group of drugs in the biological matrices. The review was preceded by a description of the physicochemical properties of the selected benzodiazepines and two, very often coexisting in the same analyzed samples, sedative-hypnotic drugs.

  13. Anxiolytics not acting at the benzodiazepine receptor: beta blockers.

    Science.gov (United States)

    Tyrer, P

    1992-01-01

    1. Although there is clear evidence for many controlled trials in the past 25 years that beta blockers are effective in anxiety disorders clear indications for their use are lacking. 2. The balance of evidence suggests that the mechanism of action of beta-blocking drugs is through peripheral blockade of beta-mediated symptoms. 3. Most evidence to the efficacy of beta-blockers comes from study of their use in generalized anxiety and in acute stress. 4. Because beta-blockers carry no risks of pharmacological dependence they may be preferred to many other anti-anxiety drugs.

  14. Modulation of benzodiazepine by lysine and pipecolic acid on pentylenetetrazol-induced seizures

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.F.; Hargest, V.; Chen, J.S.

    1988-01-01

    L-lysine and its metabolite pipecolic acid (PA) have been studied for their effects on pentylenetetrazol (PTZ)-induced seizures in mice. L-Lysine of L-Pa i.p. significantly increased clonic and tonic latencies in a dose-dependent manner against 90 mg/kg PTZ-induced seizures. L-Lysine but not L-Pa enhanced the anticonvulsant effect of diazepam (DZ). L-Pa i.c.v. showed a slight decrease in clonic latency; it did not enhance the antiseizure activity of DZ; it caused seizures at 0.6 mmol/kg. D-PA i.c.v. displayed an opposite effect compared to its L-isomer. The anticonvulsant effect of L-lysine in terms of increase in seizure latency and survival was even more amplified when tested with a submaximal PTZ concentration. L-Lysine showed an enhancement of specific /sup 3/H-flunitrazepam(FZ) binding to mouse brain membranes both in vitro an din vivo. The possibility of L-lysine acting as a modulator for the GABA/benzodiazepine receptors was demonstrated. Since L-PA showed enhancement of /sup 3/H-FZ binding only in vitro but not in vivo, the anticonvulsant effect of L-PA may not be linked to the GABA/benzodiazepine receptor.

  15. Central role for Melanocortin-4 receptors in offspring hypertension arising from maternal obesity

    NARCIS (Netherlands)

    Samuelsson, Anne Maj S; Mullier, Amandine; Maicas, Nuria; Oosterhuis, Nynke R.; Bae, Sung Eun; Novoselova, Tatiana V.; Chan, Li F.; Pombo, Joaquim M.; Taylor, Paul D.; Joles, Jaap A.; Coen, Clive W.; Balthasar, Nina; Poston, Lucilla

    2016-01-01

    Melanocortin-4 receptor (Mc4r)-expressing neurons in the autonomic nervous system, particularly in the paraventricular nucleus of the hypothalamus (PVH), play an essential role in blood pressure (BP) control. Mc4r-deficient (Mc4rKO) mice are severely obese but lack obesity-related hypertension; they

  16. Toll-like receptors as targets for inflammation, development and repair in the central nervous system

    NARCIS (Netherlands)

    Noort, J.M. van

    2007-01-01

    Toll-like receptors (TLRs) that play key roles in inflammation are also widely expressed in the CNS. While they are well known to activate inflammatory responses to microbial products, TLRs fulfill additional roles in the absence of infection. Emerging evidence suggests that several TLRs play a role

  17. Effect of central muscarinic receptors on passive-avoidance learning deficits induced by prenatal pentylenetetrazol kindling in male offspring.

    Science.gov (United States)

    Pourmotabbed, A; Mahmoodi, G; Mahmoodi, S; Mohammadi-Farani, A; Nedaei, S E; Pourmotabbed, T; Pourmotabbed, T

    2014-10-24

    Occurrence of the epileptic seizures during gestation might affect the neurodevelopment of the fetus resulting in cognitive problems for the child later in life. We have previously reported that prenatal pentylenetetrazol (PTZ)-kindling induces learning and memory deficits in the children born to kindled mothers, later in life but the mechanisms involved in this processes are unknown. The cholinergic system plays a major role in learning and memory. The present study was performed to investigate the possible involvement of central muscarinic cholinergic receptors on learning and memory deficits induced by prenatal PTZ-kindling in male offspring. Pregnant Wistar rats were kindled by repetitive i.p. injection of 25mg/kg of PTZ on day 13 of their pregnancy. The effect of intracerebroventricular (ICV) microinjection of scopolamine and pilocarpine, muscarinic cholinergic receptors antagonist and agonist, respectively on passive-avoidance learning of pups were tested at 12weeks of age using shuttle-box apparatus. Our data showed that the retention latencies of pups that received scopolamine (2 or 3μg) were significantly reduced compared to those received normal saline (pkindled dams and suggest a central mechanism for the cognitive and memory dysfunction, associated with seizures during pregnancy.

  18. Positron emission tomography assessment of effects of benzodiazepines on regional glucose metabolic rate in patients with anxiety disorder

    Energy Technology Data Exchange (ETDEWEB)

    Buchsbaum, M.S.; Wu, J.; Haier, R.; Hazlett, E.; Ball, R.; Katz, M.; Sokolski, K.; Lagunas-Solar, M.; Langer, D.

    1987-06-22

    Patients with generalized anxiety disorder (n = 18) entered a 21-day, double-blind, placebo-controlled random assignment trial of clorazepate. Positron emission tomography with YF-deoxyglucose was carried out before and after treatment. Decreases in glucose metabolic rate in visual cortex and relative increases in the basal ganglia and thalamus were found. A correlation between regional changes in metabolic rate and regional benzodiazepine receptor binding density from other human autopsy studies was observed; brain regions highest in receptor density showed the greatest decrease in rate.

  19. 1,4-Benzodiazepine N-Nitrosoamidines: Useful Intermediates in the Synthesis of Tricyclic Benzodiazepines

    Directory of Open Access Journals (Sweden)

    Carlos del Pozo

    2006-08-01

    Full Text Available 1,4-Benzodiazepine N-nitrosoamidines have been used as scaffolds for the preparation of different tricyclic derivatives. Replacement of the N-nitrosoamidine moiety through treatment with the nucleophiles acetylhydrazine, aminoacetaldehyde dimethylacetal and 1-amino-2-propanol, followed by an acid-catalyzed cyclization step, afforded triazolo and imidazobenzodiazepines 1, 6, and 7, respectively, in good yields. When acetylhydrazine is used as a nucleophile, the overall process provides an alternative route to alprazolam (1b and triazolam (1c, respectively.

  20. N-terminal and Central Segments of the Type 1 Ryanodine Receptor Mediate Its Interaction with FK506-binding Proteins*

    Science.gov (United States)

    Girgenrath, Tanya; Mahalingam, Mohana; Svensson, Bengt; Nitu, Florentin R.; Cornea, Razvan L.; Fessenden, James D.

    2013-01-01

    We used site-directed labeling of the type 1 ryanodine receptor (RyR1) and fluorescence resonance energy transfer (FRET) measurements to map RyR1 sequence elements forming the binding site of the 12-kDa binding protein for the immunosuppressant drug, FK506. This protein, FKBP12, promotes the RyR1 closed state, thereby inhibiting Ca2+ leakage in resting muscle. Although FKBP12 function is well established, its binding determinants within the RyR1 protein sequence remain unresolved. To identify these sequence determinants using FRET, we created five single-Cys FKBP variants labeled with Alexa Fluor 488 (denoted D-FKBP) and then targeted these D-FKBPs to full-length RyR1 constructs containing decahistidine (His10) “tags” placed within N-terminal (amino acid residues 76–619) or central (residues 2157–2777) regions of RyR1. The FRET acceptor Cy3NTA bound specifically and saturably to these His tags, allowing distance analysis of FRET measured from each D-FKBP variant to Cy3NTA bound to each His tag. Results indicate that D-FKBP binds proximal to both N-terminal and central domains of RyR1, thus suggesting that the FKBP binding site is composed of determinants from both regions. These findings further imply that the RyR1 N-terminal and central domains are proximal to one another, a core premise of the domain-switch hypothesis of RyR function. We observed FRET from GFP fused at position 620 within the N-terminal domain to central domain His-tagged sites, thus further supporting this hypothesis. Taken together, these results support the conclusion that N-terminal and central domain elements are closely apposed near the FKBP binding site within the RyR1 three-dimensional structure. PMID:23585572

  1. N-terminal and central segments of the type 1 ryanodine receptor mediate its interaction with FK506-binding proteins.

    Science.gov (United States)

    Girgenrath, Tanya; Mahalingam, Mohana; Svensson, Bengt; Nitu, Florentin R; Cornea, Razvan L; Fessenden, James D

    2013-05-31

    We used site-directed labeling of the type 1 ryanodine receptor (RyR1) and fluorescence resonance energy transfer (FRET) measurements to map RyR1 sequence elements forming the binding site of the 12-kDa binding protein for the immunosuppressant drug, FK506. This protein, FKBP12, promotes the RyR1 closed state, thereby inhibiting Ca(2+) leakage in resting muscle. Although FKBP12 function is well established, its binding determinants within the RyR1 protein sequence remain unresolved. To identify these sequence determinants using FRET, we created five single-Cys FKBP variants labeled with Alexa Fluor 488 (denoted D-FKBP) and then targeted these D-FKBPs to full-length RyR1 constructs containing decahistidine (His10) "tags" placed within N-terminal (amino acid residues 76-619) or central (residues 2157-2777) regions of RyR1. The FRET acceptor Cy3NTA bound specifically and saturably to these His tags, allowing distance analysis of FRET measured from each D-FKBP variant to Cy3NTA bound to each His tag. Results indicate that D-FKBP binds proximal to both N-terminal and central domains of RyR1, thus suggesting that the FKBP binding site is composed of determinants from both regions. These findings further imply that the RyR1 N-terminal and central domains are proximal to one another, a core premise of the domain-switch hypothesis of RyR function. We observed FRET from GFP fused at position 620 within the N-terminal domain to central domain His-tagged sites, thus further supporting this hypothesis. Taken together, these results support the conclusion that N-terminal and central domain elements are closely apposed near the FKBP binding site within the RyR1 three-dimensional structure.

  2. Menin: a tumor suppressor that mediates postsynaptic receptor expression and synaptogenesis between central neurons of Lymnaea stagnalis.

    Directory of Open Access Journals (Sweden)

    Nichole Flynn

    Full Text Available Neurotrophic factors (NTFs support neuronal survival, differentiation, and even synaptic plasticity both during development and throughout the life of an organism. However, their precise roles in central synapse formation remain unknown. Previously, we demonstrated that excitatory synapse formation in Lymnaea stagnalis requires a source of extrinsic NTFs and receptor tyrosine kinase (RTK activation. Here we show that NTFs such as Lymnaea epidermal growth factor (L-EGF act through RTKs to trigger a specific subset of intracellular signalling events in the postsynaptic neuron, which lead to the activation of the tumor suppressor menin, encoded by Lymnaea MEN1 (L-MEN1 and the expression of excitatory nicotinic acetylcholine receptors (nAChRs. We provide direct evidence that the activation of the MAPK/ERK cascade is required for the expression of nAChRs, and subsequent synapse formation between pairs of neurons in vitro. Furthermore, we show that L-menin activation is sufficient for the expression of postsynaptic excitatory nAChRs and subsequent synapse formation in media devoid of NTFs. By extending our findings in situ, we reveal the necessity of EGFRs in mediating synapse formation between a single transplanted neuron and its intact presynaptic partner. Moreover, deficits in excitatory synapse formation following EGFR knock-down can be rescued by injecting synthetic L-MEN1 mRNA in the intact central nervous system. Taken together, this study provides the first direct evidence that NTFs functioning via RTKs activate the MEN1 gene, which appears sufficient to regulate synapse formation between central neurons. Our study also offers a novel developmental role for menin beyond tumour suppression in adult humans.

  3. Menin: A Tumor Suppressor That Mediates Postsynaptic Receptor Expression and Synaptogenesis between Central Neurons of Lymnaea stagnalis

    Science.gov (United States)

    Flynn, Nichole; Getz, Angela; Visser, Frank; Janes, Tara A.; Syed, Naweed I.

    2014-01-01

    Neurotrophic factors (NTFs) support neuronal survival, differentiation, and even synaptic plasticity both during development and throughout the life of an organism. However, their precise roles in central synapse formation remain unknown. Previously, we demonstrated that excitatory synapse formation in Lymnaea stagnalis requires a source of extrinsic NTFs and receptor tyrosine kinase (RTK) activation. Here we show that NTFs such as Lymnaea epidermal growth factor (L-EGF) act through RTKs to trigger a specific subset of intracellular signalling events in the postsynaptic neuron, which lead to the activation of the tumor suppressor menin, encoded by Lymnaea MEN1 (L-MEN1) and the expression of excitatory nicotinic acetylcholine receptors (nAChRs). We provide direct evidence that the activation of the MAPK/ERK cascade is required for the expression of nAChRs, and subsequent synapse formation between pairs of neurons in vitro. Furthermore, we show that L-menin activation is sufficient for the expression of postsynaptic excitatory nAChRs and subsequent synapse formation in media devoid of NTFs. By extending our findings in situ, we reveal the necessity of EGFRs in mediating synapse formation between a single transplanted neuron and its intact presynaptic partner. Moreover, deficits in excitatory synapse formation following EGFR knock-down can be rescued by injecting synthetic L-MEN1 mRNA in the intact central nervous system. Taken together, this study provides the first direct evidence that NTFs functioning via RTKs activate the MEN1 gene, which appears sufficient to regulate synapse formation between central neurons. Our study also offers a novel developmental role for menin beyond tumour suppression in adult humans. PMID:25347295

  4. Cannabinoid- and lysophosphatidylinositol-sensitive receptor GPR55 boosts neurotransmitter release at central synapses

    OpenAIRE

    2013-01-01

    G protein-coupled receptor (GPR) 55 is sensitive to certain cannabinoids, it is expressed in the brain and, in cell cultures, it triggers mobilization of intracellular Ca(2+). However, the adaptive neurobiological significance of GPR55 remains unknown. Here, we use acute hippocampal slices and combine two-photon excitation Ca(2+) imaging in presynaptic axonal boutons with optical quantal analysis in postsynaptic dendritic spines to find that GPR55 activation transiently increases release prob...

  5. Half a century of antipsychotics and still a central role for dopamine D2 receptors.

    Science.gov (United States)

    Kapur, Shitij; Mamo, David

    2003-10-01

    A review of the history of antipsychotics reveals that while the therapeutic effects of chlorpromazine and reserpine were discovered and actively researched almost concurrently, subsequent drug development has been restricted to drugs acting on postsynaptic receptors rather than modulation of dopamine release. The fundamental property of atypical antipsychotics is their ability to produce an antipsychotic effect in the absence of extrapyramidal side effects (EPS) or prolactin elevation. Modulation of the dopamine D2 receptor remains both necessary and sufficient for antipsychotic drug action, with affinity to the D2-receptor being the single most important discriminator between a typical and atypical drug profile. Most antipsychotics, including atypical antipsychotics, show a dose-dependent threshold of D2 receptor occupancy for their therapeutic effects, although the precise threshold is different for different drugs. Some atypical antipsychotics do not appear to reach the threshold for EPS and prolactin elevation, possibly accounting for their atypical nature. To link the biological theories of antipsychotics to their psychological effects, a hypothesis is proposed wherein psychosis is a state of aberrant salience of stimuli and ideas, and antipsychotics, via modulation of the mesolimbic dopamine system, dampen the salience of these symptoms. Thus, antipsychotics do not excise psychosis: they provide the neurochemical platform for the resolution of symptoms. Future generations of antipsychotics may need to move away from a "one-size-fits-all polypharmacy-in-a-pill" approach to treat all the different aspects of schizophrenia. At least in theory a preferred approach would be the development of specific treatments for the different dimensions of schizophrenia (e.g., positive, negative, cognitive, and affective) that can be flexibly used and titrated in the service of patients' presenting psychopathology.

  6. Analysis of histamine receptors in the central thermoregulatory mechanism of Mastomys natalensis.

    OpenAIRE

    Dhawan, B. N.; Shukla, R.; Srimal, R. C.

    1982-01-01

    1 The effect of intracerebroventricular (i.c.v.) injection of histamine on the rectal temperature of Mastomys natalensis at ambient temperatures of 10, 24 and 33 degrees C has been studied. 2 Low doses (0.1-1.0 microgram) of histamine produced hypothermia while larger doses (5-20 micrograms) produced dose-dependent hyperthermia. The hypothermic effect was significantly antagonized by mepyramine while the hyperthermia was blocked by cimetidine. 3 Histamine H1-receptor agonists, 2-methyl-histam...

  7. Prevention of Paclitaxel-Induced Neuropathy Through Activation of the Central Cannabinoid Type 2 Receptor System

    Science.gov (United States)

    Naguib, Mohamed; Xu, Jijun J.; Diaz, Philippe; Brown, David L.; Cogdell, David; Bie, Bihua; Hu, Jianhua; Craig, Suzanne; Hittelman, Walter N.

    2012-01-01

    Background Peripheral neuropathy is a major dose-limiting toxicity of chemotherapy, especially after multiple courses of paclitaxel. The development of paclitaxel-induced neuropathy is associated with the activation of microglia followed by the activation and proliferation of astrocytes, and the expression and release of proinflammatory cytokines in the spinal dorsal horn. Cannabinoid type 2 (CB2) receptors are expressed in the microglia in neurodegenerative disease models. Methods To explore the potential of CB2 agonists for preventing paclitaxel-induced neuropathy, we designed and synthesized a novel CB2-selective agonist, namely MDA7. The effect of MDA7 in preventing paclitaxel-induced allodynia was assessed in rats and in CB2+/+ and CB2–/– mice. We hypothesize that the CB2 receptor functions in a negative-feedback loop and that early MDA7 administration can blunt the neuroinflammatory response to paclitaxel and prevent mechanical allodynia through interference with specific signaling pathways. Results We found that MDA7 prevents paclitaxel-induced mechanical allodynia in rats and mice in a dose- and time-dependent manner without compromising paclitaxel's antineoplastic effect. MDA7's neuroprotective effect was absent in CB2-/- mice and was blocked by CB2 antagonists, suggesting that MDA7's action directly involves CB2 receptor activation. MDA7 treatment was found to interfere with early events in the paclitaxel-induced neuroinflammatory response as evidenced by relatively reduced Toll-like receptor and CB2 expression in the lumbar spinal cord, reduced levels of extracellular signal regulated kinase 1/2 activity, reduced numbers of activated microglia and astrocytes, and reduced secretion of proinflammatory mediators in vivo and in in vitro models. Conclusions Our findings suggest an innovative therapeutic approach to prevent chemotherapy-induced neuropathy and may permit more aggressive use of active chemotherapeutic regimens with reduced long-term sequelae

  8. Effect of Nelumbo nucifera Petal Extracts on Lipase, Adipogenesis, Adipolysis, and Central Receptors of Obesity

    Directory of Open Access Journals (Sweden)

    Chandrasekaran Chinampudur Velusami

    2013-01-01

    Full Text Available N. nucifera is one among the important medicinal plants assessed for its antiobesity action in various preclinical models. The present study was aimed at investigating the antiobesity effect of methanol and successive water extracts of petals of N. nucifera by studying its effect on adipogenesis, adipolysis, lipase, serotonin (5-HT2C, cannabinoid (CNR2, melanocyte concentrating hormone (MCHR1, and melanocortin (MC4R receptors. Both methanol and successive water extracts of N. nucifera petals had an effect on inhibition of lipid storage in adipocytes and on increasing lipolysis. N. nucifera petal methanol extract exhibited the concentration-dependent inhibitory effect on lipase activity with an IC50 value of 47 µg/mL. N. nucifera petal extracts showed evident agonist and antagonist activity towards 5-HT2C and CNR2 receptors, respectively, while it showed no effect towards MCHR1 and MC4R receptors. Overall, methanol extract of N. nucifera petals showed better activity than successive water extract.

  9. Distribution of a GABAB-like receptor protein in the rat central nervous system.

    Science.gov (United States)

    Charles, K J; Calver, A R; Jourdain, S; Pangalos, M N

    2003-11-07

    Using a homology-based bioinformatics approach we have identified the human and rodent orthologues of a novel putative seven transmembrane G protein coupled receptor, termed GABA(BL). The amino acid sequence homology of these cDNAs compared to GABA(B1) and GABA(B2) led us to postulate that GABA(BL) may be a putative novel GABA(B) receptor subunit. We have developed a rabbit polyclonal antisera specific to the GABA(BL) protein and assessed the distribution of GABA(BL) in the rat CNS by immunohistochemistry. Protein expression was particularly dense in regions previously shown to contain known GABA(B) receptor subunits. Dense immunoreactivity was observed in the cortex, major subfields of the hippocampus and the dentate gyrus. GABA(BL) labelling was very conspicuous in the cerebellum, both in the granule cell layer and in Purkinje cells, and was also observed in the substantia gelatinosa and ventral horn motor neurons of the spinal cord. GABA(BL) immunoreactivity was also noted in a subset of parvalbumin positive hippocampal interneurons. Our data suggest a widespread distribution of GABA(BL) throughout the rat CNS.

  10. Receptor-associated protein (RAP plays a central role in modulating Abeta deposition in APP/PS1 transgenic mice.

    Directory of Open Access Journals (Sweden)

    Guilian Xu

    Full Text Available BACKGROUND: Receptor associated protein (RAP functions in the endoplasmic reticulum (ER to assist in the maturation of several membrane receptor proteins, including low density lipoprotein receptor-related protein (LRP and lipoprotein receptor 11 (SorLA/LR11. Previous studies in cell and mouse model systems have demonstrated that these proteins play roles in the metabolism of the amyloid precursor protein (APP, including processes involved in the generation, catabolism and deposition of beta-amyloid (Abeta peptides. METHODOLOGY/PRINCIPAL FINDINGS: Mice transgenic for mutant APPswe and mutant presenilin 1 (PS1dE9 were mated to mice with homozygous deletion of RAP. Unexpectedly, mice that were homozygous null for RAP and transgenic for APPswe/PS1dE9 showed high post-natal mortality, necessitating a shift in focus to examine the levels of amyloid deposition in APPswe/PS1dE9 that were hemizygous null for RAP. Immunoblot analysis confirmed 50% reductions in the levels of RAP with modest reductions in the levels of proteins dependent upon RAP for maturation [LRP trend towards a 20% reduction ; SorLA/LR11 statistically significant 15% reduction (p<0.05]. Changes in the levels of these proteins in the brains of [APPswe/PS1dE9](+/-/RAP(+/- mice correlated with 30-40% increases in amyloid deposition by 9 months of age. CONCLUSIONS/SIGNIFICANCE: Partial reductions in the ER chaperone RAP enhance amyloid deposition in the APPswe/PS1dE9 model of Alzheimer amyloidosis. Partial reductions in RAP also affect the maturation of LRP and SorLA/LR11, which are each involved in several different aspects of APP processing and Abeta catabolism. Together, these findings suggest a central role for RAP in Alzheimer amyloidogenesis.

  11. Receptor-associated protein (RAP) plays a central role in modulating Abeta deposition in APP/PS1 transgenic mice.

    Science.gov (United States)

    Xu, Guilian; Karch, Celeste; Li, Ning; Lin, Nianwei; Fromholt, David; Gonzales, Victoria; Borchelt, David R

    2008-09-08

    Receptor associated protein (RAP) functions in the endoplasmic reticulum (ER) to assist in the maturation of several membrane receptor proteins, including low density lipoprotein receptor-related protein (LRP) and lipoprotein receptor 11 (SorLA/LR11). Previous studies in cell and mouse model systems have demonstrated that these proteins play roles in the metabolism of the amyloid precursor protein (APP), including processes involved in the generation, catabolism and deposition of beta-amyloid (Abeta) peptides. Mice transgenic for mutant APPswe and mutant presenilin 1 (PS1dE9) were mated to mice with homozygous deletion of RAP. Unexpectedly, mice that were homozygous null for RAP and transgenic for APPswe/PS1dE9 showed high post-natal mortality, necessitating a shift in focus to examine the levels of amyloid deposition in APPswe/PS1dE9 that were hemizygous null for RAP. Immunoblot analysis confirmed 50% reductions in the levels of RAP with modest reductions in the levels of proteins dependent upon RAP for maturation [LRP trend towards a 20% reduction ; SorLA/LR11 statistically significant 15% reduction (pRAP(+/-) mice correlated with 30-40% increases in amyloid deposition by 9 months of age. Partial reductions in the ER chaperone RAP enhance amyloid deposition in the APPswe/PS1dE9 model of Alzheimer amyloidosis. Partial reductions in RAP also affect the maturation of LRP and SorLA/LR11, which are each involved in several different aspects of APP processing and Abeta catabolism. Together, these findings suggest a central role for RAP in Alzheimer amyloidogenesis.

  12. Vagal afferent-dependent cholecystokinin modulation of visceral pain requires central amygdala NMDA-NR2B receptors in rats.

    Science.gov (United States)

    Wang, E M; Li, W T; Yan, X J; Chen, X; Liu, Q; Feng, C C; Cao, Z J; Fang, J Y; Chen, S L

    2015-09-01

    Cholecystokinin (CCK), a gut hormone that is released during feeding, exerts gastrointestinal effects in part through vagal pathway. It is reported to be a potential trigger for increased postprandial visceral sensitivity in healthy subjects and, especially in patients with irritable bowel syndrome. NR2B-containing N-methyl-d-aspartate (NMDA) receptors in the central amygdala (CeA) participate in pain modulation. Systemically administered CCK activates the CeA-innervating neurons. Here, we investigated whether CCK modulation of visceral sensitivity is mediated through CeA NMDA-NR2B receptors and whether this modulation involves vagal pathway. We first examined the visceromotor response (VMR) to colorectal distention (CRD) following i.p. injection of CCK octapeptide (CCK-8) in a rat model. Next, the NR2B antagonist ifenprodil and the NR2A antagonist NVP-AAM077 were microinjected into the CeA before systemic CCK injection. NR2B phosphorylation was detected by Western blot. To down-regulate NR2B gene expression, NR2B-specific small interfering RNA (siRNA) was delivered into CeA neurons by electroporation. In addition, the effects of functional deafferentation by perivagal application of capsaicin and pretreatment with the CCK1 receptor antagonist devazepide were investigated. CCK-8 increased VMR to CRD in a dose-dependent manner. This effect was blunted by intra-CeA administration of ifenprodil (but not NVP-AAM077) and was accompanied by phosphorylation of NR2B subunits in the CeA. CCK failed to increase VMR to CRD in NR2B siRNA-treated rats. Perivagal capsaicin application and pretreatment with devazepide prevented CCK-induced pronociception and CeA NR2B phosphorylation. The pronociception induced by systemic CCK, which is vagal afferent-dependent, requires activation of CeA NMDA-NR2B receptors. © 2015 John Wiley & Sons Ltd.

  13. Expression of specific chemokines and chemokine receptors in the central nervous system of multiple sclerosis patients

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke; Tani, M; Jensen, J

    1999-01-01

    Chemokines direct tissue invasion by specific leukocyte populations. Thus, chemokines may play a role in multiple sclerosis (MS), an idiopathic disorder in which the central nervous system (CNS) inflammatory reaction is largely restricted to mononuclear phagocytes and T cells. We asked whether sp...

  14. Glucose intolerance induced by blockade of central FGF receptors is linked to an acute stress response

    Directory of Open Access Journals (Sweden)

    Jennifer M. Rojas

    2015-08-01

    Conclusions: The effect of acute inhibition of central FGFR signaling to impair glucose tolerance likely involves a stress response associated with pronounced, but transient, sympathoadrenal activation and an associated reduction of insulin secretion. Whether this effect is a true consequence of FGFR blockade or involves an off-target effect of the FGFR inhibitor requires additional study.

  15. Benzodiazepine harm: how can it be reduced?

    Science.gov (United States)

    Lader, Malcolm

    2014-02-01

    The benzodiazepines (BZDs) are anxiolytics, hypnotics, anticonvulsants, muscle-relaxants and induce anaesthesia. Adverse effects comprise sedation subjectively and cognitive and psychomotor impairment objectively. Complex skills such as driving can be compromised. Paradoxical excitement can have forensic implications. Long term use beyond the licensed durations is common but both efficacy and adverse effects associated with this have been poorly documented. Withdrawal and dependence have excited particular concern, and even polemic. Perhaps a third of long term (beyond 6  months) users experience symptoms and signs on attempting to withdraw - anxiety, insomnia, muscle spasms and tension and perceptual hypersensitivity. Uncommonly, fits or a psychosis may supervene. The patterns following withdrawal vary widely. The usual method of withdrawal is slow tapering but it may not obviate the problems completely. BZDs are also drugs of abuse either on their own or in conjunction with opioids and stimulants. Claims have been made that the use of BZDs is associated with increased mortality. This is a concern in view of the widespread usage of these drugs, particularly in the elderly. All of these factors impinge on the risk : benefit ratio and the severity of the indications. Harm reduction should focus on choice of alternative treatments both psychological and pharmacological. Guidelines emphasise that BZDs are not drugs of first choice and should only be used short term. Schedules are available to educate about methods of withdrawal in current users, emphasising the slow rate of taper. General principles of harm minimization in the addiction field are appropriate to BZD abuse.

  16. Is benzodiazepine use during pregnancy really teratogenic?

    Science.gov (United States)

    Ornoy, A; Arnon, J; Shechtman, S; Moerman, L; Lukashova, I

    1998-01-01

    Benzodiazepines (BDs) have a widespread use among people suffering from anxiety. These drugs easily cross the placenta and may affect the developing embryo and fetus. The literature is divided as to whether BD may cause an increase in spontaneous abortions or congenital anomalies. From the years 1988 to 1996, 756 women called the Israeli TIS concerning exposures to BD prior to or during pregnancy. Of 599 women who called us during pregnancy, we have follow-up information on 460 pregnancies (76.6%). The incidence of congenital anomalies (3.1%) was not different from that found in 424 control pregnancies (2.6%). There was a significantly higher incidence of induced abortions (14.1% vs. 4.7%, P = 0.00) and of spontaneous abortions (8.7% vs. 5.2%, P = 0.01). From an examination of our results, it does not appear that BD during pregnancy caused an increase in the incidence of birth defects. There was no specific defect in the offspring. The increase in the rate of induced abortions is probably related to the counseling of the callers, and the increase in spontaneous abortions seems to be a result of the lower gestational age at the time of counseling in the women exposed to BD. It is unknown whether BD could be responsible for developmental or behavioral problems, which are observed only at a later stage.

  17. Bilastine and the central nervous system.

    Science.gov (United States)

    Montoro, J; Mullol, J; Dávila, I; Ferrer, M; Sastre, J; Bartra, J; Jáuregui, I; del Cuvillo, A; Valero, A

    2011-01-01

    Antihistamines have been classifed as first or second generation drugs, according to their pharmacokinetic properties, chemical structure and adverse effects. The adverse effects of antihistamines upon the central nervous system (CNS) depend upon their capacity to cross the blood-brain barrier (BBB) and bind to the central H1 receptors (RH1). This in turn depends on the lipophilicity of the drug molecule, its molecular weight (MW), and affinity for P-glycoprotein (P-gp) (CNS xenobiotic substances extractor protein). First generation antihistamines show scant affinity for P-gp, unlike the second generation molecules which are regarded as P-gp substrates. Histamine in the brain is implicated in many functions (waking-sleep cycle, attention, memory and learning, and the regulation of appetite), with numerous and complex interactions with different types of receptors in different brain areas. Bilastine is a new H1 antihistamine that proves to be effective in treating allergic rhinoconjunctivitis (seasonal and perennial) and urticaria. The imaging studies made, as well as the objective psychomotor tests and subjective assessment of drowsiness, indicate the absence of bilastine action upon the CNS. This fact, and the lack of interaction with benzodiazepines and alcohol, define bilastine as a clinically promising drug with a good safety profile as regards adverse effects upon the CNS.

  18. Levodopa acts centrally to induce an antinociceptive action against colonic distension through activation of D2 dopamine receptors and the orexinergic system in the brain in conscious rats

    Directory of Open Access Journals (Sweden)

    Toshikatsu Okumura

    2016-02-01

    Subcutaneously (80 mg/rat or intracisternally (2.5 μg/rat administered levodopa significantly increased the threshold of colonic distension-induced AWR in conscious rats. The dose difference to induce the antinociceptive action suggests levodopa acts centrally to exert its antinociceptive action against colonic distension. While neither sulpiride, a D2 dopamine receptor antagonist, nor SCH23390, a D1 dopamine receptor antagonist by itself changed the threshold of colonic distension-induced AWR, the intracisternally injected levodopa-induced antinociceptive action was significantly blocked by pretreatment with subcutaneously administered sulpiride but not SCH23390. Treatment with intracisternal SB334867, an orexin 1 receptor antagonist, significantly blocked the subcutaneously administered levodopa-induced antinociceptive action. These results suggest that levodopa acts centrally to induce an antinociceptive action against colonic distension through activation of D2 dopamine receptors and the orexinergic system in the brain.

  19. Electrophoretic fingerprinting of benzodiazepine tablets in spike drinks.

    Science.gov (United States)

    Sáiz, Jorge; Ortega-Ojeda, Fernando; López-Melero, Lucía; Montalvo, Gema; García-Ruiz, Carmen

    2014-11-01

    Over the last few years, there has been an increase in the reports of drug-facilitated crimes. The list of drugs associated with these crimes is extensive and benzodiazepines constitute one of the groups of substances more commonly used. The sedative properties, which characterize benzodiazepines, are enhanced when such drugs are combined with alcohol, being more attractive for committing these types of crimes. In this work, a capillary electrophoresis method was applied to the analysis of 63 different samples of club drinks spiked with benzodiazepine tablets. The resulting electropherograms were processed and analyzed with the chemometric multivariate techniques: principal component analysis (PCA) and soft independent modeling of class analogies (SIMCA) classification. The PCA results allowed a clear differentiation of each drug class in a 3D plot. In addition, the SIMCA classification model (5% significance level) showed that eight out of nine test samples were automatically assigned by software to their proper sample class. The conflicting sample was correctly classified in the Coomans' plot (95% confidence). This novel approach based on the comparison of electrophoretic profiles of spiked drinks by chemometric tools allows determining the benzodiazepine used for drink spiking without the use of drug standards. Moreover, it provides an opportunity for the forensic laboratories to incorporate the identification capability provided by the electrophoretic fingerprinting of benzodiazepine solutions in existing or new databases. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. 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...... reduced somatostatin protein expression in the temporal cortex, with aberrant clustering and bulging of tyrosine hydroxylase-immunoreactive afferents. As such, somatostatin receptor 2 (SSTR2) mRNA was highly expressed in the human LC, with its levels significantly decreasing from Braak stages III...

  1. The Nuclear Orphan Receptor NR2F6 Is a Central Checkpoint for Cancer Immune Surveillance

    Directory of Open Access Journals (Sweden)

    Natascha Hermann-Kleiter

    2015-09-01

    Full Text Available Nuclear receptor subfamily 2, group F, member 6 (NR2F6 is an orphan member of the nuclear receptor superfamily. Here, we show that genetic ablation of Nr2f6 significantly improves survival in the murine transgenic TRAMP prostate cancer model. Furthermore, Nr2f6−/− mice spontaneously reject implanted tumors and develop host-protective immunological memory against tumor rechallenge. This is paralleled by increased frequencies of both CD4+ and CD8+ T cells and higher expression levels of interleukin 2 and interferon γ at the tumor site. Mechanistically, CD4+ and CD8+ T cell-intrinsic NR2F6 acts as a direct repressor of the NFAT/AP-1 complex on both the interleukin 2 and the interferon γ cytokine promoters, attenuating their transcriptional thresholds. Adoptive transfer of Nr2f6-deficient T cells into tumor-bearing immunocompetent mice is sufficient to delay tumor outgrowth. Altogether, this defines NR2F6 as an intracellular immune checkpoint in effector T cells, governing the amplitude of anti-cancer immunity.

  2. Ethanol produces corticotropin releasing factor receptor-dependent enhancement of spontaneous glutamatergic transmission in the mouse central amygdala

    Science.gov (United States)

    Silberman, Yuval; Fetterly, Tracy L.; Awad, Elias K.; Milano, Elana J.; Usdin, Ted B.; Winder, Danny G.

    2015-01-01

    Background Ethanol modulation of Central Amygdala (CeA) neurocircuitry plays a key role in the development of alcoholism via activation of the corticotropin releasing factor (CRF) receptor system. Previous work has predominantly focused on ethanol/CRF interactions on the CeA GABA circuitry; however our lab recently showed that CRF enhances CeA glutamatergic transmission. Therefore, this study sought to determine if ethanol modulates CeA glutamate transmission via activation of CRF signaling. Methods The effects of ethanol on spontaneous excitatory postsynaptic currents (sEPSCs) and basal resting membrane potentials were examined via standard electrophysiology methods in adult male C57BL/6J mice. Local ablation of CeA CRF neurons (CRFCeAhDTR) was achieved by targeting the human diphtheria toxin receptor (hDTR) to CeA CRF neurons with an adeno-associated virus. Ablation was quantified post-hoc with confocal microscopy. Genetic targeting of the diphtheria toxin active subunit to CRF neurons (CRFDTA mice) ablated CRF neurons throughout the CNS, as assessed by qRT-PCR quantification of CRF mRNA. Results Acute bath application of ethanol significantly increased sEPSC frequency in a concentration dependent manner in CeA neurons, and this effect was blocked by pretreatment of co-applied CRF receptor 1 and CRF receptor 2 antagonists. In experiments utilizing a CRF-tomato reporter mouse, ethanol did not significantly alter the basal membrane potential of CeA CRF neurons. The ability of ethanol to enhance CeA sEPSC frequency was not altered in CRFCeAhDTR mice despite a ~78% reduction in CeA CRF cell counts. The ability of ethanol to enhance CeA sEPSC frequency was also not altered in the CRFDTA mice despite a three-fold reduction in CRF mRNA levels. Conclusion These findings demonstrate that ethanol enhances spontaneous glutamatergic transmission in the CeA via a CRF receptor dependent mechanism. Surprisingly, our data suggest that this action may not require endogenous CRF

  3. Activation of noradrenergic neurons projecting to the diencephalon following central administration of histamine is mediated by H1 receptors.

    Science.gov (United States)

    Fleckenstein, A E; Lookingland, K J; Moore, K E

    1994-02-28

    The effect of histamine on the activity of noradrenergic neurons terminating in discrete regions of the diencephalon was examined in male rats. Noradrenergic neuronal activity was estimated by measuring the concentration of norepinephrine and its metabolite 3-methoxy-4-hydroxyphenylethyleneglycol [MHPG] in the medial zona incerta [MZI] and in the dorsomedial [DMN], periventricular [PeVN] and medial preoptic hypothalamic nuclei [MPN]. The intracerebroventricular administration of histamine effected a time-related increase in MHPG concentrations in the MZI, DMN, PeVN and MPN; these effects were blocked by the H1 antagonist mepyramine but not the H2 antagonist zolantidine. Neither mepyramine nor zolantidine affected basal MHPG concentrations in any of the brain regions examined. These results indicate that central administration of histamine increases the activity of noradrenergic neurons projecting to the diencephalon via an action at H1 but not H2 receptors.

  4. Diseño de receptor de torre central para generación directa de vapor con perfil de potencia variable longitudinal y transversalmente

    OpenAIRE

    Losada Godoy, Carlos

    2014-01-01

    En este estudio se ha realizado el diseño de un receptor de una central de Torre Central de energía solar para generación directa de vapor, mediante el uso de métodos numéricos, con un perfil de potencia incidente variable longitudinal y transversalmente. Para ello se ha dividido la geometría del receptor según el método de diferencias finitas, y se ha procedido a resolver las ecuaciones del balance de energía. Una vez resuelto el sistema de ecuaciones se dispone de la distribución de tempe...

  5. Long-term Use of Z-Hypnotics and Co-medication with Benzodiazepines and Opioids.

    Science.gov (United States)

    Sakshaug, Solveig; Handal, Marte; Hjellvik, Vidar; Berg, Christian; Ripel, Åse; Gustavsen, Ingebjørg; Mørland, Jørg; Skurtveit, Svetlana

    2017-03-01

    Benzodiazepine-like drugs (z-hypnotics) are the most commonly used drugs for treatment of insomnia in Norway. Z-hypnotics are recommended for short-term treatment not exceeding 4 weeks. We aimed to study the use of z-hypnotics in the adult population in Norway with focus on recurrent use in new users, treatment intensity and co-medication with benzodiazepines and opioids in long-term users. Data were obtained from the Norwegian Prescription Database. New users in 2009 were followed through 2013. Recurrent z-hypnotic use was defined as new fillings at least once in each of the four 365-day follow-up periods. Age groups of 18-39, 40-64 and 65+ years were analysed separately for men and women. In 2013, 354,571 (8.9%) of the population filled at least one prescription of z-hypnotics and the prevalence was relatively stable over time. Among the 92,911 new users of z-hypnotics in 2009, 13,996 (16.8%) received z-hypnotics all four 365-day periods of follow-up. In these long-term recurrent users, the treatment intensity was high already the second year, with mean annual amounts of 199 and 169 DDDs per patient in men and women, respectively. The interquartile differences were greatest in the youngest age group. 27.9% of the long-term recurrent users of z-hypnotics used benzodiazepines the fourth year and 33.9% used opioids. The proportions with co-medication increased with level of z-hypnotic treatment intensity. Overall, many z-hypnotic users had medicines dispensed for longer periods than recommended, and co-medications with drugs that may reinforce the central depressing and intoxicating effects were common.

  6. Withdrawal-induced delirium associated with a benzodiazepine switch: a case report

    Directory of Open Access Journals (Sweden)

    Bosshart Herbert

    2011-05-01

    Full Text Available Abstract Introduction Introduced in the early 1960s, diazepam remains among the most frequently prescribed benzodiazepine-type sedatives and hypnotics. Patients with chronic use of short-acting benzodiazepines are frequently switched to diazepam because the accumulating, long-acting metabolite, N-desmethyl-diazepam, prevents benzodiazepine-associated withdrawal symptoms, which can occur during trough plasma levels of short-acting benzodiazepines. Although mild to moderate withdrawal symptoms are frequently observed during benzodiazepine switching to diazepam, severe medical complications associated with this treatment approach have thus far not been reported. Case presentation A 64-year-old female Caucasian with major depression, alcohol dependence and benzodiazepine dependence was successfully treated for depression and, after lorazepam-assisted alcohol detoxification, was switched from lorazepam to diazepam to facilitate benzodiazepine discontinuation. Subsequent to the benzodiazepine switch, our patient unexpectedly developed an acute delirious state, which quickly remitted after re-administration of lorazepam. A newly diagnosed early form of mixed dementia, combining both vascular and Alzheimer-type lesions, was found as a likely contributing factor for the observed vulnerability to benzodiazepine-induced withdrawal symptoms. Conclusion Chronic use of benzodiazepines is common in the elderly and a switch to diazepam often precedes benzodiazepine discontinuation trials. However, contrary to common clinical practice, benzodiazepine switching to diazepam may require cross-titration with slow tapering of the first benzodiazepine to allow for the build-up of N-desmethyl-diazepam, in order to safely prevent severe withdrawal symptoms. Alternatively, long-term treatment with low doses of benzodiazepines may be considered, especially in elderly patients with chronic use of benzodiazepines and proven vulnerability to benzodiazepine

  7. Substance misuse in young people in Ireland - a focus on benzodiazepines

    OpenAIRE

    2014-01-01

    Benzodiazepines are a class of drugs that are prescribed for the treatment of anxiety and insomnia. Due to the powerful tolerance that can develop as a result of sustained use, benzodiazepines can also be dependence-forming. Benzodiazepine dependence can occur from prescribed and from recreational use, and is a significant issue for young people. The consequences of benzodiazepine dependence include cognitive and learning impairment, depressive symptoms, and increased suicide risk. Despite th...

  8. Withdrawal-induced delirium associated with a benzodiazepine switch: a case report

    OpenAIRE

    2011-01-01

    Abstract Introduction Introduced in the early 1960s, diazepam remains among the most frequently prescribed benzodiazepine-type sedatives and hypnotics. Patients with chronic use of short-acting benzodiazepines are frequently switched to diazepam because the accumulating, long-acting metabolite, N-desmethyl-diazepam, prevents benzodiazepine-associated withdrawal symptoms, which can occur during trough plasma levels of short-acting benzodiazepines. Although mild to moderate withdrawal symptoms ...

  9. Benzodiazepines should still be first-line treatment for alcohol withdrawal

    DEFF Research Database (Denmark)

    Askgaard, Gro; Pottegård, Anton; Fink-Jensen, Anders

    2017-01-01

    In this review, we summarize the evidence for benzodiazepines and barbiturates as alcohol withdrawal treatment and outline a treatment guideline. A number of randomized controlled trials (RCTs) indicate that benzodiazepine treatment decreases alcohol withdrawal seizures and is safe....... For barbiturates, only a few RCTs have been undertaken, and barbiturates were not found to be superior to benzodiazepines. Consequently, we suggest that benzodiazepines should still be first-line treatment for alcohol withdrawal....

  10. Characterization of a novel, brain-penetrating CB1 receptor inverse agonist: metabolic profile in diet-induced obese models and aspects of central activity.

    Science.gov (United States)

    Jacobson, Laura H; Commerford, S Renee; Gerber, Sarah P; Chen, Yu Alice; Dardik, Beatriz; Chaperon, Frederique; Schwartzkopf, Chad; Nguyen-Tran, Van; Hollenbeck, Thomas; McNamara, Peter; He, Xiaohui; Liu, Hong; Seidel, H Martin; Jaton, Anne-Liese; Gromada, Jesper; Teixeira, Sandra

    2011-12-01

    Pharmacologic antagonism of cannabinoid 1 receptors (CB1 receptors) in the central nervous system (CNS) suppresses food intake, promotes weight loss, and improves the metabolic profile. Since the CB1 receptor is expressed both in the CNS and in peripheral tissues, therapeutic value may be gained with CB1 receptor inverse agonists acting on receptors in both domains. The present report examines the metabolic and CNS actions of a novel CB1 receptor inverse agonist, compound 64, a 1,5,6-trisubstituted pyrazolopyrimidinone. Compound 64 showed similar or superior binding affinity, in vitro potency, and pharmacokinetic profile compared to rimonabant. Both compounds improved the metabolic profile in diet-induced obese (DIO) rats and obese cynomolgus monkeys. Weight loss tended to be greater in compound 64-treated DIO rats compared to pair-fed counterparts, suggesting that compound 64 may have metabolic effects beyond those elicited by weight loss alone. In the CNS, reversal of agonist-induced hypothermia and hypolocomotion indicated that compound 64 possessed an antagonist activity in vivo. Dosed alone, compound 64 suppressed extinction of conditioned freezing (10 mg/kg) and rapid eye movement (REM) sleep (30 mg/kg), consistent with previous reports for rimonabant, although for REM sleep, compound 64 was greater than threefold less potent than for metabolic effects. Together, these data suggested that (1) impairment of extinction learning and REM sleep suppression are classic, centrally mediated responses to CB1 receptor inverse agonists, and (2) some separation may be achievable between central and peripheral effects with brain-penetrating CB1 receptor inverse agonists while maintaining metabolic efficacy. Furthermore, chronic treatment with compound 64 contributes to evidence that peripheral CB1