A selective phosphodiesterase 10A inhibitor reduces l-dopa-induced dyskinesias in parkinsonian monkeys.

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Beck, Goichi; Maehara, Shunsuke; Chang, Phat Ly; Papa, Stella M

2018-03-06

chronically. Results show that regulation of striatal cyclic nucleotides by phosphodiesterase 10A inhibition could be a useful therapeutic approach for l-dopa-induced dyskinesia, and therefore data support further studies of selective phosphodiesterase 10A inhibitors for PD therapy. © 2018 International Parkinson and Movement Disorder Society. © 2018 International Parkinson and Movement Disorder Society.

Chronic levodopa administration followed by a washout period increased number and induced phenotypic changes in striatal dopaminergic cells in MPTP-monkeys.

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Carla DiCaudo

Full Text Available In addition to the medium spiny neurons the mammalian striatum contains a small population of GABAergic interneurons that are immunoreactive for tyrosine hydroxylase (TH, which dramatically increases after lesions to the nigrostriatal pathway and striatal delivery of neurotrophic factors. The regulatory effect of levodopa (L-Dopa on the number and phenotype of these cells is less well understood. Eleven macaques (Macaca fascicularis were included. Group I (n = 4 received 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP and L-Dopa; Group II (n = 4 was treated with MPTP plus vehicle and Group III (n = 3 consist of intact animals (control group. L-Dopa and vehicle were given for 1 year and animals sacrificed 6 months later. Immunohistochemistry against TH was used to identify striatal and nigral dopaminergic cells. Double and triple labeling immunofluorescence was performed to detect the neurochemical characteristics of the striatal TH-ir cells using antibodies against: TH, anti-glutamate decarboxylase (GAD(67 anti-calretinin (CR anti-dopa decarboxylase (DDC and anti-dopamine and cyclic AMP-regulated phosphoprotein (DARPP-32. The greatest density of TH-ir striatal cells was detected in the striatum of the L-Dopa treated monkeys and particularly in its associative territory. None of the striatal TH-ir cell expressed DARPP-32 indicating they are interneurons. The percentages of TH-ir cells that expressed GAD67 and DDC was approximately 50%. Interestingly, we found that in the L-Dopa group the number of TH/CR expressing cells was significantly reduced. We conclude that chronic L-Dopa administration produced a long-lasting increase in the number of TH-ir cells, even after a washout period of 6 months. L-Dopa also modified the phenotype of these cells with a significant reduction of the TH/CR phenotype in favor of an increased number of TH/GAD cells that do not express CR. We suggest that the increased number of striatal TH-ir cells might be involved

Induction of dopamine biosynthesis by l-DOPA in PC12 cells: implications of L-DOPA influx and cyclic AMP.

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Jin, Chun Mei; Yang, Yoo Jung; Huang, Hai Shan; Lim, Sung Cil; Kai, Masaaki; Lee, Myung Koo

2008-09-04

The effects of 3,4-dihydroxyphenylalanine (l-DOPA) on dopamine biosynthesis and cytotoxicity were investigated in PC12 cells. l-DOPA treatment (20-200 microM) increased the levels of dopamine by 226%-504% after 3-6 h of treatment and enhanced the activities of tyrosine hydroxylase (TH) and aromatic l-amino acid decarboxylase (AADC). l-DOPA (20-200 muM) treatment led to a 562%-937% increase in l-DOPA influx at 1 h, which inhibited the activity of TH, but not AADC, during the same period. The extracellular releases of dopamine were also increased by 231%-570% after treatment with 20 and 200 microM l-DOPA for 0.5-3 h. l-DOPA at a concentration of 100-200 microM, but not 20 microM, exerted apoptotic cytotoxicity towards PC12 cells for 24-48 h. l-DOPA (20-200 microM) increased the intracellular cyclic AMP levels by 318%-557% after 0.5-1 h in a concentration-dependent manner. However, the elevated cyclic AMP levels by l-DOPA could not protect against l-DOPA (100-200 microM)-induced cytotoxicity after 24-48 h. In addition, l-DOPA (20-200 microM)-induced increases in cyclic AMP and dopamine were significantly reduced by treatment with SCH23390 (dopamine D(1) receptor antagonist). The increased levels of dopamine by l-DOPA were also reduced by H89 (protein kinase A, PKA, inhibitor) and GF109203X (protein kinase C inhibitor); however, the reduction by GF109203X was not significant. l-DOPA at 20-200 microM stimulated the phosphorylation of PKA and cyclic AMP-response element binding protein and induced the biosynthesis of the TH protein. These results indicate that 20-200 microM l-DOPA induces dopamine biosynthesis by two pathways. One pathway involves l-DOPA directly entering the cells to convert dopamine through AADC activity (l-DOPA decarboxylation). The other pathway involves l-DOPA and/or released dopamine activating TH to enhance dopamine biosynthesis by the dopamine D(1) receptor-cyclic AMP-PKA signaling system (dopamine biosynthesis by TH).

Does human presynaptic striatal dopamine function predict social conformity?

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Stokes, Paul R A; Benecke, Aaf; Puraite, Julita; Bloomfield, Michael A P; Shotbolt, Paul; Reeves, Suzanne J; Lingford-Hughes, Anne R; Howes, Oliver; Egerton, Alice

2014-03-01

Socially desirable responding (SDR) is a personality trait which reflects either a tendency to present oneself in an overly positive manner to others, consistent with social conformity (impression management (IM)), or the tendency to view one's own behaviour in an overly positive light (self-deceptive enhancement (SDE)). Neurochemical imaging studies report an inverse relationship between SDR and dorsal striatal dopamine D₂/₃ receptor availability. This may reflect an association between SDR and D₂/₃ receptor expression, synaptic dopamine levels or a combination of the two. In this study, we used a [¹⁸F]-DOPA positron emission tomography (PET) image database to investigate whether SDR is associated with presynaptic dopamine function. Striatal [¹⁸F]-DOPA uptake, (k(i)(cer), min⁻¹), was determined in two independent healthy participant cohorts (n=27 and 19), by Patlak analysis using a cerebellar reference region. SDR was assessed using the revised Eysenck Personality Questionnaire (EPQ-R) Lie scale, and IM and SDE were measured using the Paulhus Deception Scales. No significant associations were detected between Lie, SDE or IM scores and striatal [¹⁸F]-DOPA k(i)(cer). These results indicate that presynaptic striatal dopamine function is not associated with social conformity and suggests that social conformity may be associated with striatal D₂/₃ receptor expression rather than with synaptic dopamine levels.

Linagliptin potentiates the effect of l-dopa on the behavioural, biochemical and immunohistochemical changes in experimentally-induced Parkinsonism: Role of toll-like receptor 4, TGF-β1, NF-κB and glucagon-like peptide 1.

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Kabel, Ahmed M; Omar, Mohamed S; Alhadhrami, A; Alharthi, Salman S; Alrobaian, Majed M

2018-05-01

Our aim was to assess the effect of different doses of linagliptin with or without l-dopa/Carbidopa on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism in mice. Eighty Balb/c mice were divided into 8 equal groups: Control; MPTP; MPTP + l-dopa/Carbidopa; MPTP + linagliptin 3 mg/kg/day; MPTP + linagliptin 10 mg/kg/day; MPTP + Carboxymethyl cellulose; MPTP + l-dopa/Carbidopa + linagliptin 3 mg/kg/day and MPTP + l-dopa/Carbidopa + linagliptin 10 mg/kg/day. Striatal dopamine, tumor necrosis factor alpha (TNF-α), interleukin 10 (IL-10), transforming growth factor beta 1 (TGF-β1), toll-like receptor 4 (TLR4), antioxidant enzymes, adenosine triphosphate (ATP), glucagon-like peptide-1 (GLP-1), receptors of advanced glycation end products (RAGE), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), heme oxygenase-1 (HO-1), mitochondrial complex I activity, catalepsy and total swim scores were measured. Also, the substantia nigra was subjected to immunohistochemical examination. The combination of l-dopa/Carbidopa and linagliptin in a dose-dependent manner resulted in significant improvement of the behavioural changes, striatal dopamine, antioxidant parameters, Nrf2/HO-1 content, GLP-1, ATP and mitochondrial complex I activity with significant decrease in striatal RAGE, TGF-β1, TNF-α, IL-10, TLR4 and alleviated the immunohistochemical changes better than the groups that received either l-dopa/Carbidopa or linagliptin alone. The combination of l-dopa/Carbidopa and linagliptin might represent a promising therapeutic modality for management of parkinsonism. Copyright © 2018 Elsevier Inc. All rights reserved.

[F-18]fluoro-meta-L-tyrosine is a better PET tracer than [F-18]fluoro-L-dopa for the delineation of dopaminergic structures in the human brain

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Firnau, G.; Chirakal, R.; Nahmias, C.; Garnett, E.S.

1990-01-01

Fluorine-18 labelled fluoro-m-L-tyrosine (FmLtyr) and fluoro-L-Dopa (F-Dopa) have been synthesized, and the utility of FmLtyr for PET investigations of dopaminergic brain regions has been compared to that of F-dopa. Experimental results from both monkey and human studies indicate that FmLtyr gives better delineation of striatum, and is a better PET tracer than F-dopa

Delayed O-methylation of l-DOPA in MB-COMT-deficient mice after oral administration of l-DOPA and carbidopa.

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Tammimäki, Anne; Aonurm-Helm, Anu; Männistö, Pekka T

2018-04-01

1. Catechol-O-methyltransferase (COMT) is involved in the O-methylation of l-DOPA, dopamine, and other catechols. The enzyme is expressed in two isoforms: soluble (S-COMT), which resides in the cytoplasm, and membrane-bound (MB-COMT), which is anchored to intracellular membranes. 2. To obtain specific information on the functions of COMT isoforms, we studied how a complete MB-COMT deficiency affects the total COMT activity in the body, peripheral l-DOPA levels, and metabolism after l-DOPA (10 mg kg -1 ) plus carbidopa (30 mg kg -1 ) administration by gastric tube in wild-type (WT) and MB-COMT-deficient mice. l-DOPA and 3-O-methyl-l-DOPA (3-OMD) levels were assayed in plasma, duodenum, and liver. 3. We showed that the selective lack of MB-COMT did not alter the total COMT activity, COMT enzyme kinetics, l-DOPA levels, or the total O-methylation of l-DOPA but delayed production of 3-OMD in plasma and peripheral tissues.

Herbs containing L- Dopa: An update.

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Ramya, Kuber B; Thaakur, Santhrani

2007-07-01

L-Dopa is the drug of choice in the treatment of Parkinson's disease but it has dose related adverse effects such as nausea, vomiting, orthostatic hypotension, end of dose deterioration, on off phenomena and on chronic therapy motor complications synonymous to parkinsonism. Mucuna pruriens (M.P) commonly known as velvet beans or cowitch are used in case of spasms associated with Parkins onism. Clinical efficacy of seeds of this plant was confirmed and the efficacy was contributed to its L-Dopa content. M.P extract showed twice the antiparkinsonism activity compared with synthetic L-Dopa. There is sufficient L-Dopa in broad bean (Vicia faba) pods. One study proved its efficacy in Parkinsonism. Ginkgo biloba extract showed protective effect in vivo and invitro. 50% ethanolic extract of Plumbago zeylanica was effective in rats. The following plants were reported to have L-Dopa but their protective effect is yet to be established in animal models. Vigna aconitifolia, Vigna unguiculata, Vigna vexillata, Prosopis chilensis, Pileostigma malabarica, Phanera vahlis, Parkinsonia acculeata, Macuna urens, Canvavalia glandiata, Cassia floribanda, Casia hirsute and Dalbergia retusa etc.

Common Variation in the DOPA Decarboxylase (DDC) Gene and Human Striatal DDC Activity In Vivo.

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Eisenberg, Daniel P; Kohn, Philip D; Hegarty, Catherine E; Ianni, Angela M; Kolachana, Bhaskar; Gregory, Michael D; Masdeu, Joseph C; Berman, Karen F

2016-08-01

The synthesis of multiple amine neurotransmitters, such as dopamine, norepinephrine, serotonin, and trace amines, relies in part on DOPA decarboxylase (DDC, AADC), an enzyme that is required for normative neural operations. Because rare, loss-of-function mutations in the DDC gene result in severe enzymatic deficiency and devastating autonomic, motor, and cognitive impairment, DDC common genetic polymorphisms have been proposed as a source of more moderate, but clinically important, alterations in DDC function that may contribute to risk, course, or treatment response in complex, heritable neuropsychiatric illnesses. However, a direct link between common genetic variation in DDC and DDC activity in the living human brain has never been established. We therefore tested for this association by conducting extensive genotyping across the DDC gene in a large cohort of 120 healthy individuals, for whom DDC activity was then quantified with [(18)F]-FDOPA positron emission tomography (PET). The specific uptake constant, Ki, a measure of DDC activity, was estimated for striatal regions of interest and found to be predicted by one of five tested haplotypes, particularly in the ventral striatum. These data provide evidence for cis-acting, functional common polymorphisms in the DDC gene and support future work to determine whether such variation might meaningfully contribute to DDC-mediated neural processes relevant to neuropsychiatric illness and treatment.

Role of Serotonin Neurons in L-DOPA- and Graft-Induced Dyskinesia in a Rat Model of Parkinson's Disease

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Eunju Shin

2012-01-01

Full Text Available L-DOPA, the most effective drug to treat motor symptoms of Parkinson's disease, causes abnormal involuntary movements, limiting its use in advanced stages of the disease. An increasing body of evidence points to the serotonin system as a key player in the appearance of L-DOPA-induced dyskinesia (LID. In fact, exogenously administered L-DOPA can be taken up by serotonin neurons, converted to dopamine and released as a false transmitter, contributing to pulsatile stimulation of striatal dopamine receptors. Accordingly, destruction of serotonin fibers or silencing serotonin neurons by serotonin agonists could counteract LID in animal models. Recent clinical work has also shown that serotonin neurons are present in the caudate/putamen of patients grafted with embryonic ventral mesencephalic cells, producing intense serotonin hyperinnervation. These patients experience graft-induced dyskinesia (GID, a type of dyskinesia phenotypically similar to the one induced by L-DOPA but independent from its administration. Interestingly, the 5-HT1A receptor agonist buspirone has been shown to suppress GID in these patients, suggesting that serotonin neurons might be involved in the etiology of GID as for LID. In this paper we will discuss the experimental and clinical evidence supporting the involvement of the serotonin system in both LID and GID.

Overview on the biotechnological production of L-DOPA.

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Min, Kyoungseon; Park, Kyungmoon; Park, Don-Hee; Yoo, Young Je

2015-01-01

L-DOPA (3,4-dihydroxyphenyl-L-alanine) has been widely used as a drug for Parkinson's disease caused by deficiency of the neurotransmitter dopamine. Since Monsanto developed the commercial process for L-DOPA synthesis for the first time, most of currently supplied L-DOPA has been produced by the asymmetric method, especially asymmetric hydrogenation. However, the asymmetric synthesis shows critical limitations such as a poor conversion rate and a low enantioselectivity. Accordingly, alternative biotechnological approaches have been researched for overcoming the shortcomings: microbial fermentation using microorganisms with tyrosinase, tyrosine phenol-lyase, or p-hydroxyphenylacetate 3-hydroxylase activity and enzymatic conversion by immobilized tyrosinase. Actually, Ajinomoto Co. Ltd commercialized Erwinia herbicola fermentation to produce L-DOPA from catechol. In addition, the electroenzymatic conversion system was recently introduced as a newly emerging scheme. In this review, we aim to not only overview the biotechnological L-DOPA production methods, but also to briefly compare and analyze their advantages and drawbacks. Furthermore, we suggest the future potential of biotechnological L-DOPA production as an industrial process.

Dosage-dependent non-linear effect of L-dopa on human motor cortex plasticity.

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Monte-Silva, Katia; Liebetanz, David; Grundey, Jessica; Paulus, Walter; Nitsche, Michael A

2010-09-15

The neuromodulator dopamine affects learning and memory formation and their likely physiological correlates, long-term depression and potentiation, in animals and humans. It is known from animal experiments that dopamine exerts a dosage-dependent, inverted U-shaped effect on these functions. However, this has not been explored in humans so far. In order to reveal a non-linear dose-dependent effect of dopamine on cortical plasticity in humans, we explored the impact of 25, 100 and 200 mg of L-dopa on transcranial direct current (tDCS)-induced plasticity in twelve healthy human subjects. The primary motor cortex served as a model system, and plasticity was monitored by motor evoked potential amplitudes elicited by transcranial magnetic stimulation. As compared to placebo medication, low and high dosages of L-dopa abolished facilitatory as well as inhibitory plasticity, whereas the medium dosage prolonged inhibitory plasticity, and turned facilitatory plasticity into inhibition. Thus the results show clear non-linear, dosage-dependent effects of dopamine on both facilitatory and inhibitory plasticity, and support the assumption of the importance of a specific dosage of dopamine optimally suited to improve plasticity. This might be important for the therapeutic application of dopaminergic agents, especially for rehabilitative purposes, and explain some opposing results in former studies.

Enantioselective synthesis of no-carrier added (NCA) 6-[18F]Fluoro-L-Dopa

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Duanzhi Yin; Lan Zhang; Yongxian Wang; Ganghua Tang; First Military Medical Univ., Guangzhou; Xiaolan Tang

2003-01-01

6-[ 18 F]Fluoro-L-Dopa (6-FDOPA) is the analogue of L-Dopa, the biosynthesis precursor for dopamine. As a PET tracer, it was widely applied for the presynaptic dopamine function studies in human brain. The application of a chiral phase-transfer-catalyst (PTC) in enantioselective synthesis of N.C.A. 6-[ 18 F]Fluoro-L-Dopa has been developed recently. An improved procedure was described. The labeling precursor (6-Trimethylammoniumveratraldehyde Triflate) and PTC (O-Allyl-N-(9)-anthracenylcinchonidinium Bromide) were synthesized. A successful synthesis route was developed for the preparation of 6-[ 18 F]Fluoro-L-Dopa with high radiochemical yields (4-9%, decay uncorrected) and short synthesis time(80min). The radiochemical purity was over 99% and no D-isomer was detected by HPLC analysis using a chiral mobile phase. (author)

L-DOPA is an endogenous ligand for OA1.

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Vanessa M Lopez

2008-09-01

Full Text Available Albinism is a genetic defect characterized by a loss of pigmentation. The neurosensory retina, which is not pigmented, exhibits pathologic changes secondary to the loss of pigmentation in the retina pigment epithelium (RPE. How the loss of pigmentation in the RPE causes developmental defects in the adjacent neurosensory retina has not been determined, but offers a unique opportunity to investigate the interactions between these two important tissues. One of the genes that causes albinism encodes for an orphan GPCR (OA1 expressed only in pigmented cells, including the RPE. We investigated the function and signaling of OA1 in RPE and transfected cell lines. Our results indicate that OA1 is a selective L-DOPA receptor, with no measurable second messenger activity from two closely related compounds, tyrosine and dopamine. Radiolabeled ligand binding confirmed that OA1 exhibited a single, saturable binding site for L-DOPA. Dopamine competed with L-DOPA for the single OA1 binding site, suggesting it could function as an OA1 antagonist. OA1 response to L-DOPA was defined by several common measures of G-protein coupled receptor (GPCR activation, including influx of intracellular calcium and recruitment of beta-arrestin. Further, inhibition of tyrosinase, the enzyme that makes L-DOPA, resulted in decreased PEDF secretion by RPE. Further, stimulation of OA1 in RPE with L-DOPA resulted in increased PEDF secretion. Taken together, our results illustrate an autocrine loop between OA1 and tyrosinase linked through L-DOPA, and this loop includes the secretion of at least one very potent retinal neurotrophic factor. OA1 is a selective L-DOPA receptor whose downstream effects govern spatial patterning of the developing retina. Our results suggest that the retinal consequences of albinism caused by changes in melanin synthetic machinery may be treated by L-DOPA supplementation.

Do the metabolites of 6-[F-18]fluoro-L-dopa and of [F-18]fluoro-meta-L-tyrosine contribute to the F-18 accumulation in the human brain?

International Nuclear Information System (INIS)

Firnau, G.; Chirakal, R.; Nahmias, C.; Garnett, E.S.

1990-01-01

The purpose of this study was to determine if the metabolites of 6-[F-18]fluoro-L-dopa (F-dopa) and of [F-18]fluoro-meta-L-tyrosine (FmLtyr) contribute to the accumulation of fluorine-18 in the brain through unspecific retention. PET studies were conducted on a healthy human subject who was treated with both of the radiopharmaceuticals and their labelled metabolites. Results indicated that in contrast to F-dopa, the metabolite of FmLtyr does not 'contaminate' the brain with extraneous fluorine-18

Management of L-dopa overdose in the competitive inhibition state

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Hinz M

2014-07-01

Full Text Available Marty Hinz,1 Alvin Stein,2 Ted Cole3 1Clinical Research, NeuroResearch Clinics, Inc., Cape Coral, FL, USA; 2Stein Orthopedic Associates, Plantation, FL, USA; 3Cole Center for Healing, Cincinnati, OH, USA Abstract: The amino acid L-3,4-dihydroxyphenylalanine (L-dopa is prescribed for conditions where increased central and/or peripheral dopamine synthesis is desired. Its administration can establish dopamine concentrations higher than can be achieved from an optimal diet. Specific indications include Parkinson's disease and restless leg syndrome. The interaction between serotonin and dopamine exists in one of two distinctly different physiologic states: the endogenous state or the competitive inhibition state. Management with L-dopa in the competitive inhibition state is the focus of this paper. In the past, control of the competitive inhibition state was thought to be so difficult and complex that it was described in the literature as functionally “meaningless”. When administering L-dopa without simultaneous administration of serotonin precursors, the patient is in the endogenous state. Experience gained with patient outcomes during endogenous L-dopa administration does not allow predictability of L-dopa outcomes in the competitive inhibition state. The endogenous approach typically increases the daily L-dopa dosing value in a linear fashion until symptoms of Parkinson's disease are under control. It is the novel observations made during treatment with the competitive inhibition state approach that L-dopa dosing values above or below the optimal therapeutic range are generally associated with the presence of the exact same Parkinson's disease symptoms with identical intensity. This recognition requires a novel approach to optimization of daily L-dopa dosing values from that used in the endogenous state. This paper outlines that novel approach through utilization of a pill stop. This approach enhances patient safety through its ability to

Evaluation of blood-brain barrier transport and CNS drug metabolism in diseased and control brain after intravenous L-DOPA in a unilateral rat model of Parkinson's disease

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Ravenstijn Paulien GM

2012-02-01

Full Text Available Abstract Background Changes in blood-brain barrier (BBB functionality have been implicated in Parkinson's disease. This study aimed to investigate BBB transport of L-DOPA transport in conjunction with its intra-brain conversion, in both control and diseased cerebral hemispheres in the unilateral rat rotenone model of Parkinson's disease. Methods In Lewis rats, at 14 days after unilateral infusion of rotenone into the medial forebrain bundle, L-DOPA was administered intravenously (10, 25 or 50 mg/kg. Serial blood samples and brain striatal microdialysates were analysed for L-DOPA, and the dopamine metabolites DOPAC and HVA. Ex-vivo brain tissue was analyzed for changes in tyrosine hydroxylase staining as a biomarker for Parkinson's disease severity. Data were analysed by population pharmacokinetic analysis (NONMEM to compare BBB transport of L-DOPA in conjunction with the conversion of L-DOPA into DOPAC and HVA, in control and diseased cerebral hemisphere. Results Plasma pharmacokinetics of L-DOPA could be described by a 3-compartmental model. In rotenone responders (71%, no difference in L-DOPA BBB transport was found between diseased and control cerebral hemisphere. However, in the diseased compared with the control side, basal microdialysate levels of DOPAC and HVA were substantially lower, whereas following L-DOPA administration their elimination rates were higher. Conclusions Parkinson's disease-like pathology, indicated by a huge reduction of tyrosine hydroxylase as well as by substantially reduced levels and higher elimination rates of DOPAC and HVA, does not result in changes in BBB transport of L-DOPA. Taking the results of this study and that of previous ones, it can be concluded that changes in BBB functionality are not a specific characteristic of Parkinson's disease, and cannot account for the decreased benefit of L-DOPA at later stages of Parkinson's disease.

Pengaruh Diameter Partikel Terhadap Konsentrasi L-Dopa, Kc Dan De Pada Ekstraksi L-Dopa Dari Biji Kara Benguk (Mucuna Pruriens Dc.

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Eni Budiyati

2013-10-01

Full Text Available Mucuna pruriens (biji kara benguk merupakan tanaman penghasil bahan obat-obatan karena mengandung senyawa L-Dopa. Senyawa tersebut dapat digunakan untuk pengobatan penyakit gangguan syaraf, anti bisa ular, meningkatkan bobot dan kekuatan otot, vitalitas seksual pria, zat anti-aging dan obat cacing pada manusia. Penelitian ini bertujuan untuk mengekstraksi L- Dopa dari biji kara benguk dengan menggunakan pelarut air. Di samping itu, penelitian ini juga mengevaluasi pengaruh dari diameter partikel terhadap konsentrasi L- dopa hasil ekstraksi, koefisien transfer massa (kC, dan difusivitas efektif (De. Tahapan yang digunakan pada penelitian ini adalah, persiapan bahan baku, proses ekstraksi, dan analisis L-Dopa. Proses ekstraksi dilakukan dalam tangki yang dilengkapi dengan thermometer. Analisis L-Dopa dilakukan dengan dengan High Performance Liquid Chromatography (HPLC. Hasil penelitian menunjukkan bahwa semakin kecil diameter partikel maka konsentrasi L-Dopa terekstrak semakin besar. Konsentrasi tertinggi diperoleh pada diameter partikel 0,5 mm yaitu 1739,56 ppm. Nilai difusivitas efektif (De untuk variabel diameter partikel (0,5; 0,675; 2,18; dan 2,5 mm hampir sama yaitu 2,99.10–5 sampai 3,07.10–5 cm2/menit. Sedangkan nilai koefisien transfer massa (kC berbanding terbalik dengan diameter partikel. Nilai kC berkisar antara 2,83.10-2 sampai 3,98.10-2 g/cm2.menit. 

Buspirone anti-dyskinetic effect is correlated with temporal normalization of dysregulated striatal DRD1 signalling in L-DOPA-treated rats.

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Azkona, Garikoitz; Sagarduy, Ainhoa; Aristieta, Asier; Vazquez, Nerea; Zubillaga, Verónica; Ruíz-Ortega, José Angel; Pérez-Navarro, Esther; Ugedo, Luisa; Sánchez-Pernaute, Rosario

2014-04-01

Dopamine replacement with l-DOPA is the most effective therapy in Parkinson's disease. However, with chronic treatment, half of the patients develop an abnormal motor response including dyskinesias. The specific molecular mechanisms underlying dyskinesias are not fully understood. In this study, we used a well-characterized animal model to first establish the molecular differences between rats that did and did not develop dyskinesias. We then investigated the molecular substrates implicated in the anti-dyskinetic effect of buspirone, a 5HT1A partial agonist. Striatal protein expression profile of dyskinetic animals revealed increased levels of the dopamine receptor (DR)D3, ΔFosB and phospho (p)CREB, as well as an over-activation of the DRD1 signalling pathway, reflected by elevated ratios of phosphorylated DARPP32 and ERK2. Buspirone reduced the abnormal involuntary motor response in dyskinetic rats in a dose-dependent fashion. Buspirone (4 mg/kg) dramatically reduced the presence and severity of dyskinesias (by 83%) and normalized DARPP32 and ERK2 phosphorylation ratios, while the increases in DRD3, ΔFosB and pCREB observed in dyskinetic rats were not modified. Pharmacological experiments combining buspirone with 5HT1A and DRD3 antagonists confirmed that normalization of both pDARPP32 and pERK2 is required, but not sufficient, for blocking dyskinesias. The correlation between pDARPP32 ratio and dyskinesias was significant but not strong, pointing to the involvement of convergent factors and signalling pathways. Our results suggest that in dyskinetic rats DRD3 striatal over-expression could be instrumental in the activation of DRD1-downstream signalling and demonstrate that the anti-dyskinetic effect of buspirone in this model is correlated with DRD1 pathway normalization. Copyright © 2013 Elsevier Ltd. All rights reserved.

Levodopa/benserazide microsphere (LBM) prevents L-dopa induced dyskinesia by inactivation of the DR1/PKA/P-tau pathway in 6-OHDA-lesioned Parkinson's rats.

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Xie, Cheng-long; Wang, Wen-Wen; Zhang, Su-fang; Yuan, Ming-Lu; Che, Jun-Yi; Gan, Jing; Song, Lu; Yuan, Wei-En; Liu, Zhen-Guo

2014-12-16

L-3, 4-dihydroxyphenylalanine (L-dopa) is the gold standard for symptomatic treatment of Parkinson's disease (PD), but long-term therapy is associated with the emergence of L-dopa-induced dyskinesia (LID). In the present study, L-dopa and benserazide were loaded by poly (lactic-co-glycolic acid) microspheres (LBM), which can release levodopa and benserazide in a sustained manner in order to continuous stimulate dopaminergic receptors. We investigated the role of striatal DR1/PKA/P-tau signal transduction in the molecular event underlying LID in the 6-OHDA-lesioned rat model of PD. We found that animals rendered dyskinetic by L-dopa treatment, administration of LBM prevented the severity of AIM score, as well as improvement in motor function. Moreover, we also showed L-dopa elicits profound alterations in the activity of three LID molecular markers, namely DR1/PKA/P-tau (ser396). These modifications are totally prevented by LBM treatment, a similar way to achieve continuous dopaminergic delivery (CDD). In conclusion, our experiments provided evidence that intermittent administration of L-dopa, but not continuous delivery, and DR1/PKA/p-tau (ser396) activation played a critical role in the molecular and behavioural induction of LID in 6-OHDA-lesioned rats. In addition, LBM treatment prevented the development of LID by inhibiting the expression of DR1/PKA/p-tau, as well as PPEB mRNA in dyskintic rats.

Tratamento da síndrome parkinsoniana pelo L-dopa Parkinsonism's treatment by L-Dopa

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Roberto Melaragno

1971-12-01

Full Text Available O trabalho refere o tratamento com L-Dopa de 33 pacientes internados, sendo 19 homens e 14 mulheres. Os casos foram agrupados, segundo uma classificação esquemática, em leves, moderados, intensos e severos. As idades dos pacientes, previamente operados ou não, variaram de 42 a 78 anos. O esquema de medicação constou de administração de L-Dopa na dose inicial de 500 mg associado a um inibidor da MAO. A dose de L-Dopa era elevada de 500 mg cada 3 ou 4 dias, segundo a tolerância de cada paciente. Todos os sintomas dependentes, direta ou indiretamente, da rigidez tiveram melhoras mais nítidas em relação aos tremores. Durante a administração do medicamento os teores sangüíneos de ácido úrico e uréia, mostraram tendência para se elevar; a reserva alcalina, pelo contrário, tendeu para a diminuição; o hemograma revelou muitas vezes eosinofilia por vezes intensa. Os efeitos colaterais foram catalogados em dois tipos — efeitos adrenérgicos e efeitos dopaminérgicos — correspondentes a duas fases: uma primeira, de pequena duração, na qual foram usados concomitantemente o L-Dopa e um inibidor da MAO, surgindo cefaléia hipertensão arterial paroxística, rubor facial, sudorese, tenesmo vesical e angina pectoris; numa segunda fase surgiram os efeitos colaterais ditos dopaminérgicos, proporcionais à gravidade clínica do caso, cujas manifestações principais foram hipotensão arterial, sudorese fria, arritmia cardíaca e lipotimia. As complicações clínicas gerais eram representados habitualmente por anorexia, obstipação intestinal, náuseas, vômitos, discretas alterações do estado psíquico com depressão e euforia. Dentre as complicações neurológicas foram assinalados o estado parkinsonóide, discinesias e acatisia.The results of the treatment with L-Dopa of 33 patients (19 males and 14 females are reported. The cases were separated, acording to their symptoms and signs, in slight, moderate, intense and severe ones

High performance microbiological transformation of L-tyrosine to L-dopa by Yarrowia lipolytica NRRL-143

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Shultz Jeffry L

2007-08-01

Full Text Available Abstract Background The 3,4-dihydroxy phenyl L-alanine (L-dopa is a drug of choice for Parkinson's disease, controlling changes in energy metabolism enzymes of the myocardium following neurogenic injury. Aspergillus oryzae is commonly used for L-dopa production; however, potential improvements in ease of handling, growth rate and environmental impact have led to an interest in exploiting alternative yeasts. The two important elements required for L-dopa production are intracellular tyrosinases (thus pre-grown yeast cells are required for the transformation of L-tyrosine to L-dopa and L-ascorbate, which acts as a reducing agent. Results Pre-grown cells of Yarrowia lipolytica NRRL-143 were used for the microbiological transformation of L-tyrosine to L-dopa. Different diatomite concentrations (0.5–3.0 mg/ml were added to the acidic (pH 3.5 reaction mixture. Maximum L-dopa biosynthesis (2.96 mg/ml L-dopa from 2.68 mg/ml L-tyrosine was obtained when 2.0 mg/ml diatomite was added 15 min after the start of the reaction. After optimizing reaction time (30 min, and yeast cell concentration (2.5 mg/ml, an overall 12.5 fold higher L-dopa production rate was observed when compared to the control. Significant enhancements in Yp/s, Qs and qs over the control were observed. Conclusion Diatomite (2.0 mg/ml addition 15 min after reaction commencement improved microbiological transformation of L-tyrosine to L-dopa (3.48 mg/ml; p ≤ 0.05 by Y. lipolytica NRRL-143. A 35% higher substrate conversion rate was achieved when compared to the control.

Depression of Serotonin Synaptic Transmission by the Dopamine Precursor L-DOPA

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Stephanie C. Gantz

2015-08-01

Full Text Available Imbalance between the dopamine and serotonin (5-HT neurotransmitter systems has been implicated in the comorbidity of Parkinson’s disease (PD and psychiatric disorders. L-DOPA, the leading treatment of PD, facilitates the production and release of dopamine. This study assessed the action of L-DOPA on monoamine synaptic transmission in mouse brain slices. Application of L-DOPA augmented the D2-receptor-mediated inhibitory postsynaptic current (IPSC in dopamine neurons of the substantia nigra. This augmentation was largely due to dopamine release from 5-HT terminals. Selective optogenetic stimulation of 5-HT terminals evoked dopamine release, producing D2-receptor-mediated IPSCs following treatment with L-DOPA. In the dorsal raphe, L-DOPA produced a long-lasting depression of the 5-HT1A-receptor-mediated IPSC in 5-HT neurons. When D2 receptors were expressed in the dorsal raphe, application of L-DOPA resulted in a D2-receptor-mediated IPSC. Thus, treatment with L-DOPA caused ectopic dopamine release from 5-HT terminals and a loss of 5-HT-mediated synaptic transmission.

Synthesis and evaluation of radioiodinated 6-Iodo-L-DOPA as a cerebral L-amino acid transport marker

International Nuclear Information System (INIS)

Kawai, K.; Ohta, H.; Kubodera, A.; Channing, M.A.; Eckelman, W.C.

1996-01-01

Regioselective radioiodination of N-trifluoroacetyl 3,4-dimethoxy-6-trifluoroacetoxymercurio-L-phenylalanine ethyl ester 1 under no-carrier-added condition gave 6-[ 125 I]iodo protected L-DOPA with a labeling efficiency of more than 85%, and no-carrier-added 6-[ 125 I]I-L-DOPA was obtained with a radiochemical purity of over 95% after hydrolysis and chromatography. A nonradioactive standard of 6-iodo protected L-DOPA was synthesized by the iododemercuration of 6-mercuric trifluoroacetate protected L-DOPA 1 using I 2 in chloroform. 6-[ 125 I]I-L-DOPA showed high brain accumulation and rapid blood clearance in mice. The rat brain slice studies indicated high affinity of 6-[ 125 I]I-L-DOPA for carrier-mediated and stereoselective active transport systems. The tissue homogenate analysis revealed that most of the accumulated radioactivity was intact 6-[ 125 I]I-L-DOPA. Thus, 6-[ 123 I]I-L-DOPA appears to be a suitable single photon emission computed tomography (SPECT) tracer for the selective measurement of cerebral L-amino acid transport, having no affinity for dopamine metabolism

Changes in kynurenine pathway metabolism in Parkinson patients with L-DOPA-induced dyskinesia.

Science.gov (United States)

Havelund, Jesper F; Andersen, Andreas D; Binzer, Michael; Blaabjerg, Morten; Heegaard, Niels H H; Stenager, Egon; Faergeman, Nils J; Gramsbergen, Jan Bert

2017-09-01

L-3,4-Dihydroxyphenylalanine (L-DOPA) is the most effective drug in the symptomatic treatment of Parkinson's disease, but chronic use is associated with L-DOPA-induced dyskinesia in more than half the patients after 10 years of treatment. L-DOPA treatment may affect tryptophan metabolism via the kynurenine pathway. Altered levels of kynurenine metabolites can affect glutamatergic transmission and may play a role in the development of L-DOPA-induced dyskinesia. In this study, we assessed kynurenine metabolites in plasma and cerebrospinal fluid of Parkinson's disease patients and controls. Parkinson patients (n = 26) were clinically assessed for severity of motor symptoms (UPDRS) and L-DOPA-induced dyskinesia (UDysRS). Plasma and cerebrospinal fluid samples were collected after overnight fasting and 1-2 h after intake of L-DOPA or other anti-Parkinson medication. Metabolites were analyzed in plasma and cerebrospinal fluid of controls (n = 14), Parkinson patients receiving no L-DOPA (n = 8), patients treated with L-DOPA without dyskinesia (n = 8), and patients with L-DOPA-induced dyskinesia (n = 10) using liquid chromatography-mass spectrometry. We observed approximately fourfold increase in the 3-hydroxykynurenine/kynurenic acid ratio in plasma of Parkinson's patients with L-DOPA-induced dyskinesia. Anthranilic acid levels were decreased in plasma and cerebrospinal fluid of this patient group. 5-Hydroxytryptophan levels were twofold increased in all L-DOPA-treated Parkinson's patients. We conclude that a higher 3-hydroxykynurenine/kynurenic acid ratio in plasma may serve as a biomarker for L-DOPA-induced dyskinesia. Longitudinal studies including larger patients cohorts are needed to verify whether the changes observed here may serve as a prognostic marker for L-DOPA-induced dyskinesia. © 2017 International Society for Neurochemistry.

The role of L-DOPA in plants

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Soares, Anderson Ricardo; Marchiosi, Rogério; Siqueira-Soares, Rita de Cássia; Barbosa de Lima, Rogério; Dantas dos Santos, Wanderley; Ferrarese-Filho, Osvaldo

2014-01-01

Since higher plants regularly release organic compounds into the environment, their decay products are often added to the soil matrix and a few have been reported as agents of plant-plant interactions. These compounds, active against higher plants, typically suppress seed germination, cause injury to root growth and other meristems, and inhibit seedling growth. Mucuna pruriens is an example of a successful cover crop with several highly active secondary chemical agents that are produced by its seeds, leaves and roots. The main phytotoxic compound encountered is the non-protein amino acid L-3,4-dihydroxyphenylalanine (L-DOPA), which is used in treating the symptoms of Parkinson disease. In plants, L-DOPA is a precursor of many alkaloids, catecholamines, and melanin and is released from Mucuna into soils, inhibiting the growth of nearby plant species. This review summarizes knowledge regarding L-DOPA in plants, providing a brief overview about its metabolic actions. PMID:24598311

Aspergillus niger PA2: a novel strain for extracellular biotransformation of L-tyrosine into L-DOPA.

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Agarwal, Pragati; Pareek, Nidhi; Dubey, Swati; Singh, Jyoti; Singh, R P

2016-05-01

L-DOPA (3,4-dihydroxyphenyl-L-alanine), an amino acid derivative is the most widely used drug of choice for the treatment of Parkinson's disease and other neurologic injuries. The present study deals with the elevated biochemical transformation of L-tyrosine to L-DOPA by Aspergillus niger PA2, a potent tyrosinase producer, isolated from decomposed food wastes. This appears to be the first report on A. niger as a notable extracellular tyrosinase producer. The extracellular tyrosinase activity produced remarkably higher levels of L-DOPA, i.e. 2.44 mg mL(-1) when the media was supplemented with 5 mg mL(-1) L-tyrosine. The optimum pH for tyrosinase production was 6.0, with the maximal L-DOPA production at the same pH. The product thus produced was analyzed by thin-layer chromatography, UV spectroscopy, high-performance liquid chromatography and Fourier transform infrared spectroscopy, that had denoted this to be L-DOPA. Kinetic parameters viz. Y p/s, Q s and Q p had further indicated the notable levels of production. Thus, Aspergillus niger PA2 could be a promising resource and may be further exploited for large-scale production of L-DOPA.

Pupillometry as an indicator of L-DOPA dosages in Parkinson's disease patients.

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Bartošová, O; Bonnet, C; Ulmanová, O; Šíma, M; Perlík, F; Růžička, E; Slanař, O

2018-04-01

Dopamine was shown to induce mydriasis by excitation of alpha-adrenergic receptors at the dilator pupillae muscle. Pupilla diameter may thus serve as an indirect measure of peripheral pharmacokinetics of L-DOPA and dopamine. The aim of this study is to evaluate the effect of L-DOPA dosage on pupillometric parameters in Parkinson's disease (PD) patients. Sixteen PD patients and 14 healthy control subjects (CS) were studied. The statistical analysis revealed significant differences between CS and PD patients for the mean maximum and minimum pupil diameters (p = 0.017, p = 0.028, respectively), with higher values found in PD. Moreover, a significant dose-response relationship was found between the maximum pupil diameter and both the morning L-DOPA dose (R 2  = 0.78) and the total daily L-DOPA dose (R 2  = 0.93). A sigmoid-shaped curve best describes the dose-response relationship, with a ceiling effect at about 400 mg L-DOPA daily dose. In conclusion, measuring pupillometric parameters represents a sensitive tool for non-invasive evaluation of the peripheral effect of L-DOPA, especially with daily doses below 400 mg L-DOPA.

Enhanced production of L-DOPA in cell cultures of Mucuna pruriens L. and Mucuna prurita H.

Science.gov (United States)

Raghavendra, S; Kumar, V; Ramesh, C K; Khan, M H Moinuddin

2012-01-01

A comparative study on the production of 3,4-dihydroxyphenylalanine (L-DOPA) was carried out in cell cultures of two Mucuna species by elicitor treatment and precursor feeding. The influence of elicitors and the precursor molecule on L-DOPA production, polyphenol oxidase (PPO) and tyrosinase activities was also studied. Callus cultures were initiated in Mucuna pruriens L. and Mucuna prurita H. on MS medium supplemented with BAP and IAA at different concentrations. Suspension cultures were established in MS liquid medium supplemented with BAP, IAA, the elicitors methyl jasmonate, chitin and pectin or the precursor L-tyrosine at different concentrations for L-DOPA production. Compared to the controls, several-fold increases in L-DOPA concentration were observed in elicitor-treated and precursor-fed suspension cultures of both plant species. L-DOPA concentrations were comparatively higher in precursor-fed cultures than those receiving elicitor treatments. A parallel increase in tyrosinase and PPO levels was also observed. Loss of cell viability was observed at high concentrations of elicitor-treated cultures, whereas L-tyrosine did not cause any cell death. Compared to elicitor treatments, precursor feeding resulted in higher concentrations of L-DOPA production and tyrosinase activity. The efficacy of L-DOPA production was found to be higher for suspension cultures of M. pruriens compared to M. prurita in all treatments.

Changes in kynurenine pathway metabolism in Parkinson patients with L-DOPA-induced dyskinesia

DEFF Research Database (Denmark)

Havelund, Jesper F; Dammann Andersen, Andreas; Binzer, Michael

2017-01-01

L-DOPA is the most effective drug in the symptomatic treatment of Parkinson's disease, but chronic use is associated with L-DOPA-induced dyskinesia in more than half the patients after 10 years of treatment. L-DOPA treatment may affect tryptophan metabolism via the kynurenine pathway. Altered...... levels of kynurenine metabolites can affect glutamatergic transmission and may play a role in the development of L-DOPA-induced dyskinesia. In this study we assessed kynurenine metabolites in plasma and cerebrospinal fluid of Parkinson's disease patients and controls. Parkinson patients (n=26) were...... clinically assessed for severity of motor symptoms (UPDRS) and L-DOPA-induced dyskinesia (UDysRS). Plasma and cerebrospinal fluid samples were collected after overnight fasting and 1-2 hours after intake of L-DOPA or other anti-Parkinson medication. Metabolites were analyzed in plasma and cerebrospinal fluid...

Depression of Serotonin Synaptic Transmission by the Dopamine Precursor L-DOPA

OpenAIRE

Gantz, Stephanie C.; Levitt, Erica S.; Llamosas Muñozguren, Nerea; Neve, Kim A.; Williams, John T.

2015-01-01

Imbalance between the dopamine and serotonin (5-HT) neurotransmitter systems has been implicated in the comorbidity of Parkinson's disease (PD) and psychiatric disorders. L-DOPA, the leading treatment of PD, facilitates the production and release of dopamine. This study assessed the action of L-DOPA on monoamine synaptic transmission in mouse brain slices. Application of L-DOPA augmented the D2-receptor-mediated inhibitory postsynaptic current (IPSC) in dopamine neurons of the substantia nigr...

Betalain production is possible in anthocyanin-producing plant species given the presence of DOPA-dioxygenase and L-DOPA.

Science.gov (United States)

Harris, Nilangani N; Javellana, John; Davies, Kevin M; Lewis, David H; Jameson, Paula E; Deroles, Simon C; Calcott, Kate E; Gould, Kevin S; Schwinn, Kathy E

2012-03-12

Carotenoids and anthocyanins are the predominant non-chlorophyll pigments in plants. However, certain families within the order Caryophyllales produce another class of pigments, the betalains, instead of anthocyanins. The occurrence of betalains and anthocyanins is mutually exclusive. Betalains are divided into two classes, the betaxanthins and betacyanins, which produce yellow to orange or violet colours, respectively. In this article we show betalain production in species that normally produce anthocyanins, through a combination of genetic modification and substrate feeding. The biolistic introduction of DNA constructs for transient overexpression of two different dihydroxyphenylalanine (DOPA) dioxygenases (DODs), and feeding of DOD substrate (L-DOPA), was sufficient to induce betalain production in cell cultures of Solanum tuberosum (potato) and petals of Antirrhinum majus. HPLC analysis showed both betaxanthins and betacyanins were produced. Multi-cell foci with yellow, orange and/or red colours occurred, with either a fungal DOD (from Amanita muscaria) or a plant DOD (from Portulaca grandiflora), and the yellow/orange foci showed green autofluorescence characteristic of betaxanthins. Stably transformed Arabidopsis thaliana (arabidopsis) lines containing 35S: AmDOD produced yellow colouration in flowers and orange-red colouration in seedlings when fed L-DOPA. These tissues also showed green autofluorescence. HPLC analysis of the transgenic seedlings fed L-DOPA confirmed betaxanthin production. The fact that the introduction of DOD along with a supply of its substrate (L-DOPA) was sufficient to induce betacyanin production reveals the presence of a background enzyme, possibly a tyrosinase, that can convert L-DOPA to cyclo-DOPA (or dopaxanthin to betacyanin) in at least some anthocyanin-producing plants. The plants also demonstrate that betalains can accumulate in anthocyanin-producing species. Thus, introduction of a DOD and an enzyme capable of converting

Betalain production is possible in anthocyanin-producing plant species given the presence of DOPA-dioxygenase and L-DOPA

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Harris Nilangani N

2012-03-01

Full Text Available Abstract Background Carotenoids and anthocyanins are the predominant non-chlorophyll pigments in plants. However, certain families within the order Caryophyllales produce another class of pigments, the betalains, instead of anthocyanins. The occurrence of betalains and anthocyanins is mutually exclusive. Betalains are divided into two classes, the betaxanthins and betacyanins, which produce yellow to orange or violet colours, respectively. In this article we show betalain production in species that normally produce anthocyanins, through a combination of genetic modification and substrate feeding. Results The biolistic introduction of DNA constructs for transient overexpression of two different dihydroxyphenylalanine (DOPA dioxygenases (DODs, and feeding of DOD substrate (L-DOPA, was sufficient to induce betalain production in cell cultures of Solanum tuberosum (potato and petals of Antirrhinum majus. HPLC analysis showed both betaxanthins and betacyanins were produced. Multi-cell foci with yellow, orange and/or red colours occurred, with either a fungal DOD (from Amanita muscaria or a plant DOD (from Portulaca grandiflora, and the yellow/orange foci showed green autofluorescence characteristic of betaxanthins. Stably transformed Arabidopsis thaliana (arabidopsis lines containing 35S: AmDOD produced yellow colouration in flowers and orange-red colouration in seedlings when fed L-DOPA. These tissues also showed green autofluorescence. HPLC analysis of the transgenic seedlings fed L-DOPA confirmed betaxanthin production. Conclusions The fact that the introduction of DOD along with a supply of its substrate (L-DOPA was sufficient to induce betacyanin production reveals the presence of a background enzyme, possibly a tyrosinase, that can convert L-DOPA to cyclo-DOPA (or dopaxanthin to betacyanin in at least some anthocyanin-producing plants. The plants also demonstrate that betalains can accumulate in anthocyanin-producing species. Thus, introduction

Nociceptive Response to L-DOPA-Induced Dyskinesia in Hemiparkinsonian Rats.

Science.gov (United States)

Nascimento, G C; Bariotto-Dos-Santos, K; Leite-Panissi, C R A; Del-Bel, E A; Bortolanza, M

2018-04-02

Non-motor symptoms are increasingly identified to present clinical and diagnostic importance for Parkinson's disease (PD). The multifactorial origin of pain in PD makes this symptom of great complexity. The dopamine precursor, L-DOPA (L-3,4-dihydroxyphenylalanine), the classic therapy for PD, seems to be effective in pain threshold; however, there are no studies correlating L-DOPA-induced dyskinesia (LID) and nociception development in experimental Parkinsonism. Here, we first investigated nociceptive responses in a 6-hydroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease to a hind paw-induced persistent inflammation. Further, the effect of L-DOPA on nociception behavior at different times of treatment was investigated. Pain threshold was determined using von Frey and Hot Plate/Tail Flick tests. Dyskinesia was measured by abnormal involuntary movements (AIMs) induced by L-DOPA administration. This data is consistent to show that 6-OHDA-lesioned rats had reduced nociceptive thresholds compared to non-lesioned rats. Additionally, when these rats were exposed to a persistent inflammatory challenge, we observed increased hypernociceptive responses, namely hyperalgesia. L-DOPA treatment alleviated pain responses on days 1 and 7 of treatment, but not on day 15. During that period, we observed an inverse relationship between LID and nociception threshold in these rats, with a high LID rate corresponding to a reduced nociception threshold. Interestingly, pain responses resulting from CFA-induced inflammation were significantly enhanced during established dyskinesia. These data suggest a pro-algesic effect of L-DOPA-induced dyskinesia, which is confirmed by the correlation founded here between AIMs and nociceptive indexes. In conclusion, our results are consistent with the notion that central dopaminergic mechanism is directly involved in nociceptive responses in Parkinsonism condition.

Interaction of Human Dopa Decarboxylase with L-Dopa: Spectroscopic and Kinetic Studies as a Function of pH

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Riccardo Montioli

2013-01-01

Full Text Available Human Dopa decarboxylase (hDDC, a pyridoxal 5′-phosphate (PLP enzyme, displays maxima at 420 and 335 nm and emits fluorescence at 384 and 504 nm upon excitation at 335 nm and at 504 nm when excited at 420 nm. Absorbance and fluorescence titrations of hDDC-bound coenzyme identify a single pKspec of ~7.2. This pKspec could not represent the ionization of a functional group on the Schiff base but that of an enzymic residue governing the equilibrium between the low- and the high-pH forms of the internal aldimine. During the reaction of hDDC with L-Dopa, monitored by stopped-flow spectrophotometry, a 420 nm band attributed to the 4′-N-protonated external aldimine first appears, and its decrease parallels the emergence of a 390 nm peak, assigned to the 4′-N-unprotonated external aldimine. The pH profile of the spectral change at 390 nm displays a pK of 6.4, a value similar to that (~6.3 observed in both kcat and kcat/Km profiles. This suggests that this pK represents the ESH+ → ES catalytic step. The assignment of the pKs of 7.9 and 8.3 observed on the basic side of kcat and the PLP binding affinity profiles, respectively, is also analyzed and discussed.

The role of L-DOPA on melanization and mycelial production in Malassezia furfur.

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Sirida Youngchim

Full Text Available Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization.

The Role of L-DOPA on Melanization and Mycelial Production in Malassezia Furfur

Science.gov (United States)

Youngchim, Sirida; Nosanchuk, Joshua D.; Pornsuwan, Soraya; Kajiwara, Susumu; Vanittanakom, Nongnuch

2013-01-01

Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb) labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization. PMID:23762233

Impairment of Serotonergic Transmission by the Antiparkinsonian Drug L-DOPA: Mechanisms and Clinical Implications

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Cristina Miguelez

2017-09-01

Full Text Available The link between the anti-Parkinsonian drug L-3,4-dihydroxyphenylalanine (L-DOPA and the serotonergic (5-HT system has been long established and has received increased attention during the last decade. Most studies have focused on the fact that L-DOPA can be transformed into dopamine (DA and released from 5-HT terminals, which is especially important for the management of L-DOPA-induced dyskinesia. In patients, treatment using L-DOPA also impacts 5-HT neurotransmission; however, few studies have investigated the mechanisms of this effect. The purpose of this review is to summarize the electrophysiological and neurochemical data concerning the effects of L-DOPA on 5-HT cell function. This review will argue that L-DOPA disrupts the link between the electrical activity of 5-HT neurons and 5-HT release as well as that between 5-HT release and extracellular 5-HT levels. These effects are caused by the actions of L-DOPA and DA in 5-HT neurons, which affect 5-HT neurotransmission from the biosynthesis of 5-HT to the impairment of the 5-HT transporter. The interaction between L-DOPA and 5-HT transmission is especially relevant in those Parkinson’s disease (PD patients that suffer dyskinesia, comorbid anxiety or depression, since the efficacy of antidepressants or 5-HT compounds may be affected.

Regulation of dopamine synthesis and release in striatal and prefrontal cortical brain slices

International Nuclear Information System (INIS)

Wolf, M.E.

1986-01-01

Brain slices were used to investigate the role of nerve terminal autoreceptors in modulating dopamine (DA) synthesis and release in striatum and prefrontal cortex. Accumulation of dihydroxyphenylalanine (DOPA) was used as an index of tyrosine hydroxylation in vitro. Nomifensine, a DA uptake blocker, inhibited DOPA synthesis in striatal but not prefrontal slices. This effect was reversed by the DA antagonist sulpiride, suggesting it involved activation of DA receptors by elevated synaptic levels of DA. The autoreceptor-selective agonist EMD-23-448 also inhibited striatal but not prefrontal DOPA synthesis. DOPA synthesis was stimulated in both brain regions by elevated K + , however only striatal synthesis could be further enhanced by sulpiride. DA release was measured by following the efflux of radioactivity from brain slices prelabeled with [ 3 H]-DA. EMD-23-448 and apomorphine inhibited, while sulpiride enhanced, the K + -evoked overflow of radioactivity from both striatal and prefrontal cortical slices. These findings suggest that striatal DA nerve terminals possess autoreceptors which modulate tyrosine hydroxylation as well as autoreceptors which modulate release. Alternatively, one site may be coupled to both functions through distinct transduction mechanisms. In contrast, autoreceptors on prefrontal cortical terminals appear to regulate DA release but not DA synthesis

L-DOPA reverses the elevated density of D/sub 2/ dopamine receptors in Parkinson's diseased striatum

Energy Technology Data Exchange (ETDEWEB)

Guttman, M; Seeman, P

1985-01-01

Striatal dopamine receptors werde studied using (/sup 3/H)-spiperone in postmortem tissues of thirty-six patients with Parkinson's Disease. Each tissue was analyzed by the receptor saturation method. In non-treated patients, the D/sub 2/ dopamine receptor density was elevated in the caudate nucleus and putamen compared to controls. In L-DOPA-treated patients, the receptor density was the same as controls. The dissociation constant for (/sup 3/H)-spiperone was similar in all groups. The elevated density of D/sub 2/ receptors in non-treated patients may indicate dopaminergic supersensitivity in this disease. The elevated density was reversed with dopamine agonist therapy, but the density was not lower than control tissues.

Plasma dihydroxyphenylalanine (DOPA) is independent of sympathetic activity in humans

DEFF Research Database (Denmark)

Eldrup, E; Christensen, N J; Andreasen, J

1989-01-01

in diabetic patients with autonomic neuropathy compared to diabetics without neuropathy, whereas baseline plasma DOPA concentrations were similar in the three groups investigated: 6.55 (5.03-7.26, median [interquartile range], n = 8) nmol l-1 in diabetics with neuropathy, 7.41 (5.79-7.97, n = 8) nmol l-1...... in diabetics without neuropathy, and 6.85 (5.58-7.36, n = 8) nmol l-1 in controls. No relationship was obtained between baseline values of plasma NE and plasma DOPA. Plasma DOPA did not change in the upright position, whereas plasma NE increased significantly. Our results indicate that plasma DOPA...... is not related to sympathetic activity and may be of non-neuronal origin....

Enantioselective synthesis of 6-[18F] fluoro-L-DOPA

International Nuclear Information System (INIS)

Zhang Lan; Tang Ganghua; Zhou Wei; Li Junling; Yin Duanzhi; Wang Yongxian; Tang Xiaolan; Huang Zuhan

2002-01-01

Trimethylammonium veratraldehyde triflate was synthesized and used as a precurser for the synthesis of 6-[ 18 F] Fluoro-L-DOPA by using the chiral phase-transfer catalyst, O-Allyl-N-(9)-anthracenylcinchonidinium bromide which was also synthesized in this study. Based on these, 6-[ 18 F] Fluoro-L-DOPA was prepared with acceptable radiochemical yield (10 ± 3)% in short synthesis time (80 min), with high radiochemical purity, specific activity and chemical purity

Renal hemodynamic response to L-dopa during acute renal failure in man

Energy Technology Data Exchange (ETDEWEB)

Zech, P; Collard, M; Guey, A; Plantier, J; Bernard, M; Berthoux, F; Pinet, A; Traeger, J [Hopital Edouard-Herriot, 69 - Lyon (France)

1975-12-20

Twelve patients with acute renal failure underwent L-dopa infusion into a renal artery and /sup 133/Xenon wash-out recordings before and during the infusion. Urine volume and sodium output were also compared during two 24 hours periods, before and after the procedure. Hemodynamic data were compared with data obtained from a matched group of patients receiving Furosemide (8 patients) in place of L-dopa. Only L-dopa infusion significantly increased outer cortical distribution. No blood flow change could be demonstrated in any component nor did the drug improve unitary excretion or the general course of the disease. Control data shows that reduced cortical distribution is the most consistent feature of acute renal failure, so that L-dopa does partially improve intrarenal hemodynamics in this condition. The failure of the drug to restore kidney function may be explained by the following reasons: inability of the agent to restore a normal wash-out pattern: involvment of non-hemodynamic factors, as suggested by comparing similar wash-out improvements after L-dopa in acute glomerulonephritis and in reversible acute renal failure.

Renal hemodynamic response to L-dopa during acute renal failure in man

International Nuclear Information System (INIS)

Zech, P.; Collard, M.; Guey, A.; Plantier, J.; Bernard, M.; Berthoux, F.; Pinet, A.; Traeger, J.

1975-01-01

Twelve patients with acute renal failure underwent L.dopa infusion into a renal artery and 133 Xenon wash-out recordings before and during the infusion. Urine volume and sodium output were also compared during two 24 hours periods, before and after the procedure. Hemodynamic data were compared with data obtained from a matched group of patients receiving Furosemide (8 patients) in place of L.dopa. Only L.dopa infusion significantly increased outer cortical distribution. No blood flow change could be demonstrated in any component nor did the drug improve unitary excretion or the general course of the disease. Control data shows that reduced cortical distribution is the most consistent feature of acute renal failure, so that L.dopa does partially improve intrarenal hemodynamics in this condition. The failure of the drug to restore kidney function may be explained by the following reasons: inability of the agent to restore a normal wash-out pattern: involvment of non-hemodynamic factors, as suggested by comparing similar wash-out improvements after L.dopa in acute glomerulonephritis and in reversible acute renal failure [fr

Biochemical Evidence of L-Dopa Synthesis in a Cytokine-Resilient Aspergillus oryzae

International Nuclear Information System (INIS)

Ali, S.; Saleem, R.

2016-01-01

The present work describes the microbiological production of 3,4 dihydroxy-L-phenylalanine (L-dopa) from a cytokine-inhibited mold culture of Aspergillus oryzae (strain Ck-R6). A level of 15 μg/ml cytokine was found optimal for culture resistance and better dopa-dopamine activity. Synthetic L-tyrosine was used as a basal carbon source. The aerobic reactions were carried out using pre-grown mycelia as a direct tyrosinase source. The mycelia were cultivated using 200 ml of GPY mineral-salt medium and developed at 30 degree C for 48 h (240 rpm) in 500 ml Erlenmeyer flasks. L-dopa production was found optimal when L-ascorbic acid (5 mg/ml) was added 6 min after starting the reaction (120 rpm). The maximal production (2.2 mg/ml L-dopa) was obtained when L-tyrosine concentration was 2.5 mg/ml. Mycelial level (75 mg/ml) and time of reaction (40 min) were also evaluated. L-Tyrosine consumption was found to be 2.1 mg/ml. After optimizing the reaction conditions, particularly L-ascorbic acid addition, a 30 percent improved L-dopa yield was achieved compared to control when the parameters including time of reaction (40 min), L-tyrosine concentration (2.5 mg/ml) and temperature (50 degree C) were optimized by two-factorial Plackett-Burman design (PBD). (author)

Mutation of Aspergillus oryzae for improved production of 3, 4-dihydroxy phenyl-L-alanine (L-DOPA from L-tyrosine Mutação de Aspergillus orizae para produção melhorada de 3,4-dihidroxi fenil-L-alanina (L-DOPA a partir de L-tirosina

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Ikram-ul Haq

2006-03-01

Full Text Available Aspergillus oryzae mutant strain UV-7 was further improved for the production of L-DOPA from L-tyrosine using chemical mutation. Different putative mutant strains of organism were tested for the production of L-DOPA in submerged fermentation. Among these putative mutant strains, mutant designated SI-12 gave maximum production of L-DOPA (300 mg L-DOPA.g-1 cells. The production of L-DOPA from different carbon source solutions (So= 30 g.l-1 by mutant culture was investigated at different nitrogen sources, initial pH and temperature values. At optimum pH (pHo= 5.0, and temperature (t=30ºC, 100% sugars were utilized for production and cell mass formation, corresponding to final L-DOPA product yield of 150 mg.g-1 substrate utilized, and maximum volumetric and specific productivities of 125 mg.l-1.h-1, and 150 mg.g-1 cells. h-1, respectively. There was up to 3-fold enhancement in product formation rate. This enhancement is the highest reported in literature. To explain the kinetic mechanism of L-DOPA formation and thermal inactivation of tyrosinase, the thermodynamic parameters were determined with the application of Arrhenius model: activation enthalpy and entropy for product formation, in case of mutant derivative, were 40 k j/mol and 0.076 k j/mol. K for L-DOPA production and 116 k j/mol and 0.590 k j/mol. K for thermal inactivation, respectively. The respective values for product formation were lower while those for product deactivation were higher than the respective values for the parental culture. Therefore, the mutant strain was thermodynamically more resistant to thermal denaturation.A produção de L-DOPA a partir de tirosina pela cepa mutante de Aspergillus orizae UV-7 foi melhorada através de mutação química. Diferentes cepas foram testadas quanto a produção de L-DOPA por fermentação submersa, observando-se que a cepa denominada SI-12 foi a melhor produtora (300 mg de L-DOPA por g de células. A produção de L-DOPA pela cepa

Statistically optimized biotransformation protocol for continuous production of L-DOPA using Mucuna monosperma callus culture.

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Inamdar, Shrirang Appasaheb; Surwase, Shripad Nagnath; Jadhav, Shekhar Bhagwan; Bapat, Vishwas Anant; Jadhav, Jyoti Prafull

2013-01-01

L-DOPA (3,4-dihydroxyphenyl-L-alanine), a modified amino acid, is an expansively used drug for the Parkinson's disease treatment. In the present study, optimization of nutritional parameters influencing L-DOPA production was attempted using the response surface methodology (RSM) from Mucuna monosperma callus. Optimization of the four factors was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model include tyrosine 0.894 g l(-1), pH 4.99, ascorbic acid 31.62 mg l(-1)and copper sulphate 23.92 mg l(-1), which resulted in highest L-DOPA yield of 0.309 g l(-1). The optimization of medium using RSM resulted in a 3.45-fold increase in the yield of L-DOPA. The ANOVA analysis showed a significant R (2) value (0.9912), model F-value (112.465) and probability (0.0001), with insignificant lack of fit. Optimized medium was used in the laboratory scale column reactor for continuous production of L-DOPA. Uninterrupted flow column exhibited maximum L-DOPA production rate of 200 mg L(-1) h(-1) which is one of the highest values ever reported using plant as a biotransformation source. L-DOPA production was confirmed by HPTLC and HPLC analysis. This study demonstrates the synthesis of L- DOPA using Mucuna monosperma callus using a laboratory scale column reactor.

L-3,4-Dihydroxyphenylalanine (l-DOPA) induces neuroendocrinological, physiological, and immunological regulation in white shrimp, Litopenaeus vannamei.

Science.gov (United States)

Mapanao, Ratchaneegorn; Kuo, Hsin-Wei; Chang, Chin-Chuan; Liu, Kuan-Fu; Cheng, Winton

2018-03-01

L-3,4-Dihydroxyphenylalanine (l-DOPA) is a precursor for dopamine (DA) synthesis. Assessments were conducted to analyze the effects of l-DOPA on mediating regulation of neuroendocrinological, immunological, and physiological parameters in the shrimp, Litopenaeus vannamei when they were individually injected with 0.01 N HCl or l-DOPA at 0.5 or 1.0 μmol shrimp -1 for 60, 120, and 240 min. For catecholamine synthesis evaluation, tyrosine hydroxylase (TH) and DA beta hydroxylase (DBH) activities, l-DOPA, DA, and norepinephrine (NE) levels in hemolymph were determined. The total hemocyte count (THC), differential hemocyte count (DHC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, phagocytic activity, and clearance efficiency in response to the pathogen, Vibrio alginolyticus were assessed for immune responses, and plasma glucose and lactate levels were for physiological response. Results showed that the TH activity, THC, hyaline cells (HCs), and semigranular cells (SGCs) at 120 min, DA levels at 60-240 min, PO activity in hemocytes per 50 μL of hemolymph at 60-120 min, and PO activity per granulocyte (granular cells (GCs) + SGCs) at 60 min significantly increased, but TH activity, l-DOPA levels, GCs, SGCs, and respiratory bursts in hemocytes per 10 μL of hemolymph at 60 min, respiratory bursts per hemocyte and SOD activity at 120 min, phagocytic activity at 60-240 min, and the clearance efficiency at 60-120 min significantly decreased in shrimp injected with l-DOPA at 1.0 μmol shrimp -1 . In another experiment, 60 min after shrimp had received l-DOPA at 0.5 or 1.0 μmol shrimp -1 , they were challenged with an injection of V. alginolyticus at 2 × 10 5  colony-forming units (cfu) shrimp -1 . The injection of l-DOPA at 1.0 μmol shrimp -1 also significantly increased the cumulative mortality of shrimp by 16.7%, compared to the HCl-challenged control after 120 h. These results suggest

Cerebrospinal Fluid Biomarkers For Parkinson's Disease and L-DOPA-induced Dyskinesia

DEFF Research Database (Denmark)

Dammann Andersen, Andreas

-DOPA, 18 patienter blev behandlet med L-DOPA, hvoraf 10 havde LID. Prøverne blev analyseret ved brug af high-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), western blotting, enzyme linked immune-assays (ELISA), Multiplex og fluorescence-assays. Flere mulige......-patienter, som ikke fik L-DOPA. Patienter med LID havde signifikante forandringer i tryptofan- og katekolamin-metabolismen og en øget fosforylering af enzymet extracellular signal-regulated kinase (ERK 1/2). Disse fund kan bidrage til en bedre forståelse af de sygdomsmekanismer, som giver PS og LID...

Vascular endothelial growth factor is upregulated by l-dopa in the parkinsonian brain: implications for the development of dyskinesia

Science.gov (United States)

Francardo, Veronica; Lindgren, Hanna S.; Sillivan, Stephanie E.; O’Sullivan, Sean S.; Luksik, Andrew S.; Vassoler, Fair M.; Lees, Andrew J.; Konradi, Christine

2011-01-01

Angiogenesis and increased permeability of the blood–brain barrier have been reported to occur in animal models of Parkinson’s disease and l-dopa-induced dyskinesia, but the significance of these phenomena has remained unclear. Using a validated rat model of l-dopa-induced dyskinesia, this study demonstrates that chronic treatment with l-dopa dose dependently induces the expression of vascular endothelial growth factor in the basal ganglia nuclei. Vascular endothelial growth factor was abundantly expressed in astrocytes and astrocytic processes in the proximity of blood vessels. When co-administered with l-dopa, a small molecule inhibitor of vascular endothelial growth factor signalling significantly attenuated the development of dyskinesia and completely blocked the angiogenic response and associated increase in blood–brain barrier permeability induced by the treatment. The occurrence of angiogenesis and vascular endothelial growth factor upregulation was verified in post-mortem basal ganglia tissue from patients with Parkinson’s disease with a history of dyskinesia, who exhibited increased microvascular density, microvascular nestin expression and an upregulation of vascular endothelial growth factor messenger ribonucleic acid. These congruent findings in the rat model and human patients indicate that vascular endothelial growth factor is implicated in the pathophysiology of l-dopa-induced dyskinesia and emphasize an involvement of the microvascular compartment in the adverse effects of l-dopa pharmacotherapy in Parkinson’s disease. PMID:21771855

A specific radioenzymatic assay for dihydroxyphenylalanine (DOPA). Plasma DOPA may be the precursor of urine free dopamine

International Nuclear Information System (INIS)

Brown, M.J.; Dollery, C.T.

1981-01-01

A sensitive radioenzymatic assay was developed, in which DOPA is enzymatically decarboxylated to dopamine and the latter converted to [ 3 H]-methoxytryamine in the presence of [ 3 H]-S-adenosyl-L-methionine and catechol-o-methyltransferase. The assay was specific for DOPA, and was sensitive to 50 pg/ml. Endogenous DOPA was found to be present in the plasma of eight human volunteers at a concentration of 10.46 +- 2.42 nmol/l. Simultaneous urine collections in the same subjects showed a free dopamine excretion of 68.88 +- 17.70 nmol/h. There was a significant correlation (P < 0.01) between plasma DOPA concentration and urine free dopamine excretion (r = 0.84). After the oral administration of 250 mg levodopa, plasma DOPA and urine dopamine both increased by a similar proportion (98 +- 8.4-fold, and 93.4 +- 6.9-fold respectively). These compare with an increase in plasma dopamine of only 26 +- 15-fold (P<0.01). Following the oral dose of DOPA, the increase in plasma DOPA, but not plasma dopamine, could account for the increase in urine dopamine. The calculated clearance of plasma DOPA by renal decarboxylation to dopamine was 114 +- 20 ml/min. This is not significantly different from the apparent clearance of endogenous DOPA by renal decarboxylation to dopamine, and suggests that there is adequate renal decarboxylase activity for DOPA to be the precursor for renal dopamine formation. (author)

Serotonergic modulation of receptor occupancy in rats treated with L-DOPA after unilateral 6-OHDA lesioning

DEFF Research Database (Denmark)

Nahimi, Adjmal; Høltzermann, Mette; Landau, Anne M.

2012-01-01

Recent studies suggest that l-3,4 dihydroxyphenylalanine (L-DOPA)-induced dyskinesia (LID), a severe complication of conventional L-DOPA therapy of Parkinson's disease, may be caused by dopamine (DA) release originating in serotonergic neurons. To evaluate the in vivo effect of a 5-HT(1A) agonist...... [(±)-8-hydroxy-2-(dipropylamino) tetralin hydrobromide, 8-OHDPAT] on the L-DOPA-induced increase in extracellular DA and decrease in [(11) C]raclopride binding in an animal model of advanced Parkinson's disease and LID, we measured extracellular DA in response to L-DOPA or a combination of L......-DOPA and the 5-HT(1A) agonist, 8-OHDPAT, with microdialysis, and determined [(11) C]raclopride binding to DA receptors, with micro-positron emission tomography, as the surrogate marker of DA release. Rats with unilateral 6-hydroxydopamine lesions had micro-positron emission tomography scans with [(11) C...

Biochemical characterization of a novel tyrosine phenol-lyase from Fusobacterium nucleatum for highly efficient biosynthesis of l-DOPA.

Science.gov (United States)

Zheng, Ren-Chao; Tang, Xiao-Ling; Suo, Hui; Feng, Li-Lin; Liu, Xiao; Yang, Jian; Zheng, Yu-Guo

2018-05-01

Tyrosine phenol-lyase (TPL) catalyzes the reversible cleavage of l-tyrosine to phenol, pyruvate and ammonia. When pyrocatechol is substituted for phenol, l-dihydroxyphenylalanine (l-DOPA) is produced. The TPL-catalyzed route was regarded as the most economic process for l-DOPA production. In this study, a novel TPL from Fusobacterium nucleatum (Fn-TPL) was successfully overexpressed in Escherichia coli and screened for l-DOPA synthesis with a specific activity of 2.69Umg -1 . Fn-TPL was found to be a tetramer, and the optimal temperature and pH for α, β-elimination of l-tyrosine was 60°C and pH 8.5, respectively. The enzyme showed broad substrate specificity toward natural and synthetic l-amino acids. Kinetic analysis suggested that the k cat /K m value for l-tyrosine decomposition was much higher than that for l-DOPA decomposition, while Fn-TPL exhibited similar catalytic efficiency for synthesis of l-tyrosine and l-DOPA. With whole cells of recombinant E. coli as biocatalyst, l-DOPA yield reached 110gL -1 with a pyrocatechol conversion of 95%, which was comparable to the reported highest level. The results demonstrated the great potential of Fn-TPL for industrial production of l-DOPA. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of O-methylated metabolite penetrating the blood-brain barrier to estimation of dopamine synthesis capacity in human L-[β-(11)C]DOPA PET.

Science.gov (United States)

Matsubara, Keisuke; Ikoma, Yoko; Okada, Maki; Ibaraki, Masanobu; Suhara, Tetsuya; Kinoshita, Toshibumi; Ito, Hiroshi

2014-02-01

O-methyl metabolite (L-[β-(11)C]OMD) of (11)C-labeled L-3,4-dihydroxyphenylalanine (L-[β-(11)C]DOPA) can penetrate into brain tissue through the blood-brain barrier, and can complicate the estimation of dopamine synthesis capacity by positron emission tomography (PET) study with L-[β-(11)C]DOPA. We evaluated the impact of L-[β-(11)C]OMD on the estimation of the dopamine synthesis capacity in a human L-[β-(11)C]DOPA PET study. The metabolite correction with mathematical modeling of L-[β-(11)C]OMD kinetics in a reference region without decarboxylation and further metabolism, proposed by a previous [(18)F]FDOPA PET study, were implemented to estimate radioactivity of tissue L-[β-(11)C]OMD in 10 normal volunteers. The component of L-[β-(11)C]OMD in tissue time-activity curves (TACs) in 10 regions were subtracted by the estimated radioactivity of L-[β-(11)C]OMD. To evaluate the influence of omitting blood sampling and metabolite correction, relative dopamine synthesis rate (kref) was estimated by Gjedde-Patlak analysis with reference tissue input function, as well as the net dopamine synthesis rate (Ki) by Gjedde-Patlak analysis with the arterial input function and TAC without and with metabolite correction. Overestimation of Ki was observed without metabolite correction. However, the kref and Ki with metabolite correction were significantly correlated. These data suggest that the influence of L-[β-(11)C]OMD is minimal for the estimation of kref as dopamine synthesis capacity.

Characterization of dopaminergic dysfunction in familial progressive supranuclear palsy: an 18F-dopa PET study

International Nuclear Information System (INIS)

Tai, Y.F.; Ahsan, R.L.; Pavese, N.; Brooks, D.J.; Piccini, P.; Yebenes de, J.G.

2007-01-01

We analyzed 18 F-dopa PET data from 11 members of kindreds with familial progressive supranuclear palsy (PSP) to characterize their cerebral dopaminergic dysfunction. Three clinically-affected PSP patients showed reduced 18 F-dopa uptake in the striatum, orbitofrontal cortex and amygdala. One asymptomatic subject exhibited progressive putamen dopaminergic dysfunction. 60 % of subjects with abnormal 18 F-dopa scans developed PSP subsequently. This is the first in vivo documentation of cortical dopaminergic deficiency in PSP. Reduced striatal 18 F-dopa uptake in susceptible relatives may predict later clinical disease. (author)

L-tyrosine and L-DOPA as hormone-like regulators of melanocytes functions

Science.gov (United States)

Slominski, Andrzej; Zmijewski, Michal; Pawelek, John

2011-01-01

Summary Evidence reveals that L-tyrosine and L-DOPA, besides serving as substrates and intermediates of melanogenesis, are also bioregulatory agents acting not only as inducers and positive regulators of melanogenesis but also as regulators of other cellular functions. These can be mediated through action on specific receptors or through non-receptor mediated mechanisms. The substrate induced (L-tyrosine and/or L-DOPA) melanogenic pathway would autoregulate itself as well as it would regulate the melanocyte functions through activity of its structural or regulatory proteins and through intermediates of melanogenesis and melanin itself. Dissection of regulatory and autoregulatory elements of this process may elucidate how substrate induced autoregulatory pathways have evolved from prokaryotic or simple eukaryotic organisms to complex systems in vertebrates. This could substantiate older theory proposing that receptors for amino-acid derived hormones arose from the receptors for those amino acids, and that nuclear receptors evolved from primitive intracellular receptors binding nutritional factors or metabolic intermediates. PMID:21834848

EVALUATING THE ACCUMULATION TREND OF L-DOPA IN DARK-GERMINATED SEEDS AND SUSPENSION CULTURES OF Phaseolus vulgaris L. BY AN EFFICIENT UV-SPECTROPHOTOMETRIC METHOD

Directory of Open Access Journals (Sweden)

Samira Rahmani-Nezhad

Full Text Available Seed germination and plant cell cultures provide an alternative mean for producing secondary metabolites. The present study is an attempt to evaluate the effect of seed dark germination and some elicitors and precursors on the production of L-DOPA in Phaseolus vulgaris L. Callus cultured on Murashige and Skoog medium supplemented with various concentrations of different plant growth regulators. L-DOPA produced was quantified by UV-spectrophotometric method. In this study, a user-friendly, quick, and economical UV-spectrophotometric method was described to determine L-DOPA content in extracts from 33 biotypes of Phaseolus vulgaris L. The method is based on the nitrosation of L-DOPA to form a yellow solution and then formation of a red solution by adding base which is measurable at 470 nm. According to our statistical studies, this method showed high efficiency and selectivity for quantitative determination of L-DOPA in herbal extracts from dried plant seeds, dark-germinated seeds and callus cultures. L-DOPA content in dark-germinated seeds and suspension cultures increased significantly to approximately several-fold compared to the control. The implication from this study is that elicitor treatment and precursor feeding of Phaseolus vulgaris L. can significantly improve the parkinson’s relevant L-DOPA content.

Boronophenylalanine uptake in C6 glioma model is dramatically increased by L-DOPA preloading

Energy Technology Data Exchange (ETDEWEB)

Capuani, S. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Enrico Fermi Center, Compendio Viminale, Rome (Italy)], E-mail: silvia.capuani@roma1.infn.it; Gili, T. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Enrico Fermi Center, Compendio Viminale, Rome (Italy); Bozzali, M. [Neuroimaging Laboratory, Santa Lucia Foundation, Via Ardeatina 306, Rome (Italy); Russo, S. [Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London (United Kingdom); Porcari, P. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Cametti, C. [CNR-INFM SOFT, Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, Rome (Italy); Muolo, M. [Department of Biological Science, University ' Rome III' , Viale G. Marconi 446, Rome (Italy); D' Amore, E. [Serv. Qual./Sicurezza Sperim. Anim., Istituto Superiore di Sanita, Rome (Italy); Maraviglia, B. [Enrico Fermi Center, Compendio Viminale, Rome (Italy); Neuroimaging Laboratory, Santa Lucia Foundation, Via Ardeatina 306, Rome (Italy); Lazzarino, G. [Laboratory of Biochemistry, Department of Chemical Sciences, University of Catania, Viale A. Doria 6, Catania (Italy); Pastore, F.S. [Department of Neuroscience, Institute of Neurosurgery, University ' Tor Vergata' , Via Montpellier 1, Rome (Italy)

2009-07-15

One of the main limitations for BNCT effectiveness is the insufficient intake of {sup 10}B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumulation in C6 glioma cells was assessed, using radiowave dielectric spectroscopy (RDS), with and without L-DOPA preloading. C6 glioma cells were also implanted in the brain of 25 rats, randomly assigned to two experimental branches: (1) intra-carotid BPA infusion; (2) intra-carotid BPA infusion after pre-treatment with L-DOPA, administrated 24 h before BPA infusion. All animals were sacrificed, and assessment of BPA concentrations in tumour tissue, normal brain, and blood samples was performed using high performance liquid chromatography (HPLC). L-DOPA preloading induced a massive increase of BPA concentration either in vitro on C6 glioma cells or in vivo in the animal model tumour. Moreover, no significant difference was found in the normal brain and blood samples between the two animal groups. This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT.

Boronophenylalanine uptake in C6 glioma model is dramatically increased by L-DOPA preloading

International Nuclear Information System (INIS)

Capuani, S.; Gili, T.; Bozzali, M.; Russo, S.; Porcari, P.; Cametti, C.; Muolo, M.; D'Amore, E.; Maraviglia, B.; Lazzarino, G.; Pastore, F.S.

2009-01-01

One of the main limitations for BNCT effectiveness is the insufficient intake of 10 B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumulation in C6 glioma cells was assessed, using radiowave dielectric spectroscopy (RDS), with and without L-DOPA preloading. C6 glioma cells were also implanted in the brain of 25 rats, randomly assigned to two experimental branches: (1) intra-carotid BPA infusion; (2) intra-carotid BPA infusion after pre-treatment with L-DOPA, administrated 24 h before BPA infusion. All animals were sacrificed, and assessment of BPA concentrations in tumour tissue, normal brain, and blood samples was performed using high performance liquid chromatography (HPLC). L-DOPA preloading induced a massive increase of BPA concentration either in vitro on C6 glioma cells or in vivo in the animal model tumour. Moreover, no significant difference was found in the normal brain and blood samples between the two animal groups. This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT.

L-DOPA therapy interferes with urine catecholamine analysis in children with suspected neuroblastoma: a case series.

Science.gov (United States)

Kelly, Alison U; Srivastava, Rajeev; Dow, Ellie; Davidson, D Fraser

2017-09-01

Neuroblastoma is the most common solid extracranial malignancy diagnosed in childhood. Clinical presentation is variable, and metastatic disease is common at diagnosis. Analyses of urinary catecholamines and their metabolites are commonly requested as a first-line investigation when clinical suspicion exists. Levodopa (L-Dopa) therapy is utilized as a treatment for a number of disorders in childhood, including Dopa-responsive dystonia. Neuroblastoma may mimic some of the clinical features of this disorder. L-Dopa can interfere with analysis of urinary catecholamines and their metabolites and complicate the interpretation of results. We present the cases of three children who were prescribed L-dopa at the time of analysis of urinary catecholamines and metabolites as a screen for neuroblastoma, but who did not have the disease. Comparison of their results with those from cases with true neuroblastoma reveal that it is impossible to reliably distinguish true neuroblastoma from L-Dopa therapy using these tests. We recommend that patients should be off L-dopa therapy, if possible when these tests are performed. These cases illustrate the importance of providing clinical details and drug history to the laboratory in order to avoid diagnostic confusion.

The Role of Primary Motor Cortex (M1) Glutamate and GABA Signaling in l-DOPA-Induced Dyskinesia in Parkinsonian Rats.

Science.gov (United States)

Lindenbach, David; Conti, Melissa M; Ostock, Corinne Y; George, Jessica A; Goldenberg, Adam A; Melikhov-Sosin, Mitchell; Nuss, Emily E; Bishop, Christopher

2016-09-21

Long-term treatment of Parkinson's disease with l-DOPA almost always leads to the development of involuntary movements termed l-DOPA-induced dyskinesia. Whereas hyperdopaminergic signaling in the basal ganglia is thought to cause dyskinesia, alterations in primary motor cortex (M1) activity are also prominent during dyskinesia, suggesting that the cortex may represent a therapeutic target. The present study used the rat unilateral 6-hydroxydopamine lesion model of Parkinson's disease to characterize in vivo changes in GABA and glutamate neurotransmission within M1 and determine their contribution to behavioral output. 6-Hydroxydopamine lesion led to parkinsonian motor impairment that was partially reversed by l-DOPA. Among sham-lesioned rats, l-DOPA did not change glutamate or GABA efflux. Likewise, 6-hydroxydopamine lesion did not impact GABA or glutamate among rats chronically treated with saline. However, we observed an interaction of lesion and treatment whereby, among lesioned rats, l-DOPA given acutely (1 d) or chronically (14-16 d) reduced glutamate efflux and enhanced GABA efflux. Site-specific microinjections into M1 demonstrated that l-DOPA-induced dyskinesia was reduced by M1 infusion of a D1 antagonist, an AMPA antagonist, or a GABAA agonist. Overall, the present study demonstrates that l-DOPA-induced dyskinesia is associated with increased M1 inhibition and that exogenously enhancing M1 inhibition may attenuate dyskinesia, findings that are in agreement with functional imaging and transcranial magnetic stimulation studies in human Parkinson's disease patients. Together, our study suggests that increasing M1 inhibitory tone is an endogenous compensatory response designed to limit dyskinesia severity and that potentiating this response is a viable therapeutic strategy. Most Parkinson's disease patients will receive l-DOPA and eventually develop hyperkinetic involuntary movements termed dyskinesia. Such symptoms can be as debilitating as the disease

Global actions of nicotine on the striatal microcircuit.

Science.gov (United States)

Plata, Víctor; Duhne, Mariana; Pérez-Ortega, Jesús; Hernández-Martinez, Ricardo; Rueda-Orozco, Pavel; Galarraga, Elvira; Drucker-Colín, René; Bargas, José

2013-01-01

what is the predominant action induced by the activation of cholinergic-nicotinic receptors (nAChrs) in the striatal network given that nAChrs are expressed by several elements of the circuit: cortical terminals, dopamine terminals, and various striatal GABAergic interneurons. To answer this question some type of multicellular recording has to be used without losing single cell resolution. Here, we used calcium imaging and nicotine. It is known that in the presence of low micromolar N-Methyl-D-aspartate (NMDA), the striatal microcircuit exhibits neuronal activity consisting in the spontaneous synchronization of different neuron pools that interchange their activity following determined sequences. The striatal circuit also exhibits profuse spontaneous activity in pathological states (without NMDA) such as dopamine depletion. However, in this case, most pathological activity is mostly generated by the same neuron pool. Here, we show that both types of activity are inhibited during the application of nicotine. Nicotine actions were blocked by mecamylamine, a non-specific antagonist of nAChrs. Interestingly, inhibitory actions of nicotine were also blocked by the GABAA-receptor antagonist bicuculline, in which case, the actions of nicotine on the circuit became excitatory and facilitated neuronal synchronization. We conclude that the predominant action of nicotine in the striatal microcircuit is indirect, via the activation of networks of inhibitory interneurons. This action inhibits striatal pathological activity in early Parkinsonian animals almost as potently as L-DOPA.

Striatal output markers do not alter in response to circling behaviour in 6-OHDA lesioned rats produced by acute or chronic administration of the monoamine uptake inhibitor BTS 74 398.

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Lane, E L; Cheetham, S; Jenner, P

2008-01-01

The monoamine uptake inhibitor BTS 74 398 induces ipsilateral circling in 6-hydroxydopamine (6-OHDA) lesioned rats without induction of abnormal motor behaviours associated with L-dopa administration. We examined whether this was reflected in the expression of peptide mRNA in the direct and indirect striatal output pathways.6-OHDA lesioning of the nigrostriatal pathway increased striatal expression of PPE-A mRNA and decreased levels of PPT mRNA with PPE-B mRNA expression remaining unchanged. Acute L-dopa administration normalised PPE-A mRNA and elevated PPT mRNA while PPE-B mRNA expression remained unchanged. Acute administration of BTS 74 398 did not alter striatal peptide mRNA levels. Following chronic treatment with L-dopa, PPE-A mRNA expression in the lesioned striatum continued to be normalised and PPT mRNA was increased compared to the intact side. PPE-B mRNA expression was also markedly increased relative to the non-lesioned striatum. Chronic BTS 74 398 administration did not alter mRNA expression in the 6-OHDA lesioned striatum although small increases in PPT mRNA expression in the intact and sham lesioned striatum were observed. The failure of BTS 74 398 to induce changes in striatal neuropeptide mRNA correlated with its failure to induce abnormal motor behaviours or behavioural sensitisation but does not explain how it produces a reversal of motor deficits. An action in another area of the brain appears likely and may explain the subsequent failure of BTS 74 398 and related compounds to exert anti-parkinsonian actions in man.

Estimation of L-dopa from Mucuna pruriens LINN and formulations containing M. pruriens by HPTLC method.

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Modi, Ketan Pravinbhai; Patel, Natvarlal Manilal; Goyal, Ramesh Kishorilal

2008-03-01

A selective, precise, and accurate high-performance thin-layer chromatographic (HPTLC) method has been developed for the analysis of L-dopa in Mucuna pruriens seed extract and its formulations. The method involves densitometric evaluation of L-dopa after resolving it by HPTLC on silica gel plates with n-butanol-acetic acid-water (4.0+1.0+1.0, v/v) as the mobile phase. Densitometric analysis of L-dopa was carried out in the absorbance mode at 280 nm. The relationship between the concentration of L-dopa and corresponding peak areas was found to be linear in the range of 100 to 1200 ng/spot. The method was validated for precision (inter and intraday), repeatability, and accuracy. Mean recovery was 100.30%. The relative standard deviation (RSD) values of the precision were found to be in the range 0.64-1.52%. In conclusion, the proposed TLC method was found to be precise, specific and accurate and can be used for identification and quantitative determination of L-dopa in herbal extract and its formulations.

Tratamento da síndrome parkinsoniana pelo L-dopa

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Roberto Melaragno

1971-12-01

Full Text Available O trabalho refere o tratamento com L-Dopa de 33 pacientes internados, sendo 19 homens e 14 mulheres. Os casos foram agrupados, segundo uma classificação esquemática, em leves, moderados, intensos e severos. As idades dos pacientes, previamente operados ou não, variaram de 42 a 78 anos. O esquema de medicação constou de administração de L-Dopa na dose inicial de 500 mg associado a um inibidor da MAO. A dose de L-Dopa era elevada de 500 mg cada 3 ou 4 dias, segundo a tolerância de cada paciente. Todos os sintomas dependentes, direta ou indiretamente, da rigidez tiveram melhoras mais nítidas em relação aos tremores. Durante a administração do medicamento os teores sangüíneos de ácido úrico e uréia, mostraram tendência para se elevar; a reserva alcalina, pelo contrário, tendeu para a diminuição; o hemograma revelou muitas vezes eosinofilia por vezes intensa. Os efeitos colaterais foram catalogados em dois tipos — efeitos adrenérgicos e efeitos dopaminérgicos — correspondentes a duas fases: uma primeira, de pequena duração, na qual foram usados concomitantemente o L-Dopa e um inibidor da MAO, surgindo cefaléia hipertensão arterial paroxística, rubor facial, sudorese, tenesmo vesical e angina pectoris; numa segunda fase surgiram os efeitos colaterais ditos dopaminérgicos, proporcionais à gravidade clínica do caso, cujas manifestações principais foram hipotensão arterial, sudorese fria, arritmia cardíaca e lipotimia. As complicações clínicas gerais eram representados habitualmente por anorexia, obstipação intestinal, náuseas, vômitos, discretas alterações do estado psíquico com depressão e euforia. Dentre as complicações neurológicas foram assinalados o estado parkinsonóide, discinesias e acatisia.

Cue-induced striatal dopamine release in Parkinson's disease-associated impulsive-compulsive behaviours.

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O'Sullivan, Sean S; Wu, Kit; Politis, Marios; Lawrence, Andrew D; Evans, Andrew H; Bose, Subrata K; Djamshidian, Atbin; Lees, Andrew J; Piccini, Paola

2011-04-01

Impulsive-compulsive behaviours are a significant source of morbidity for patients with Parkinson's disease receiving dopaminergic therapy. The development of these behaviours may reflect sensitization of the neural response to non-drug rewards, similar to that proposed for sensitization to drug rewards in addiction. Here, by using (11)C-raclopride positron emission tomography imaging, we investigated the effects of reward-related cues and L-dopa challenge in patients with Parkinson's disease with and without impulsive-compulsive behaviours on striatal levels of synaptic dopamine. Eighteen patients (11 with and seven without impulsive-compulsive behaviours) underwent three (11)C-raclopride positron emission tomography scans. The impulsive-compulsive behaviours included hypersexuality, binge eating, punding, compulsive use of dopamine replacement therapy, compulsive buying and pathological gambling, with eight patients exhibiting more than one impulsive-compulsive behaviour. There were no significant differences in baseline dopamine D2 receptor availability between the Parkinson's disease groups. No differences were found when comparing the percentage change of raclopride binding potential between the two Parkinson's disease groups following L-dopa challenge with neutral cues. The group with Parkinson's disease with impulsive-compulsive behaviours had a greater reduction of ventral striatum (11)C-raclopride binding potential following reward-related cue exposure, relative to neutral cue exposure, following L-dopa challenge (16.3% compared with 5.8% in Parkinson's disease controls, P = 0.016). The heightened response of striatal reward circuitry to heterogeneous reward-related visual cues among a group of patients with different impulsive-compulsive behaviours is consistent with a global sensitization to appetitive behaviours with dopaminergic therapy in vulnerable individuals. Our findings are relevant for the broader debate on the relation between impulsive

In silico screening of potent natural inhibitor compounds against Human DOPA Decarboxylase for management of Parkinson’s Disease

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Surya Narayan Rath

2017-12-01

Full Text Available Loss of dopaminergic neurons of the substantia nigra of the mid brain is a well studied pathophysiology of Parkinson’s disease (PD, is the second most common neurodegenerative disorder. To compensate dopamine levels at the Central Nervous System (CNS exogenous L-Dopa is generally administered. But the major part of the L-Dopa is metabolized by Dopa decarboxylase (DDC, E.C. 4.1.1.28, a pyridoxal 5’ –phosphate (PLP enzyme, which is abundant in CNS and hence, only 1-5% of L-Dopa reaches to dopaminergic neurons. In this context, co-administration of peripheral DDC inhibitors (carbidopa or benserazide has been successfully used for the symptomatic treatment of PD patients. But, due to use of synthetic drugs many adverse effects have been reported during treatment. Therefore, the current study is planned to discover some plant based potent natural inhibitors against human DDC as an alternative way for the management of PD. This study was conducted through virtual screening and molecular docking of DDC enzyme with phytochemicals like withania somnifera (ashwagandha, glycine max (soybean, vicia faba (broad bean, and marsilea quadrifolia (sunsunia etc to evaluate their inhibition properties. In silico study results shown a good binding affinity and predicted some of the phytochemicals as potent natural inhibitors against human DDC. This work could be validated further through experimental procedures.

Blood-brain transfer and metabolism of 6-[18F]fluoro-L-dopa in rat

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Reith, J.; Dyve, S.; Kuwabara, H.; Guttman, M.; Diksic, M.; Gjedde, A.

1990-01-01

In a study designed to reveal the rates of blood-brain transfer and decarboxylation of fluoro-L-3,4-dihydroxyphenylalanine (FDOPA), we discovered a major discrepancy between the DOPA decarboxylase activity reported in the literature and the rate of FDOPA decarboxylation measured in the study. Donor rats received intravenous injections of 6 mCi fluorine-18-labeled FDOPA. The donor rats synthesized methyl-FDOPA. Arterial plasma, containing both FDOPA and methyl-FDOPA, was sampled from the donor rats at different times and reinjected into recipient rats in which it circulated for 20 s. The blood-brain clearance of the mixture of labeled tracers in the plasma was determined by an integral method. The individual permeabilities were determined by linear regression analysis, according to which the average methyl-FDOPA permeability in the blood-brain barrier was twice that of FDOPA, which averaged 0.037 ml g-1 min-1. The permeability ratio was used to determine the fractional clearance from the brain of FDOPA (and hence of methyl-FDOPA), which averaged 0.081 min-1. In the striatum, the measured average FDOPA decarboxylation rate constant (kD3) was 0.010 min-1, or no more than 1% of the rate of striatal decarboxylation of DOPA measured in vitro and in vivo. We interpreted this finding as further evidence in favor of the hypothesis that striatum has two dopamine (DA) pools, of which only DA in the large pool is protected from metabolism. Hence, no more than 1% of the quantity of fluoro-DA theoretically synthesized was actually retained in striatum

LC-MSdetermination of L-DOPA concentration in the leaf and flower tissues of six faba bean (Vicia fabaL. lines with common and rare flowercolors

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Jinguo Hu

2015-07-01

Full Text Available Background: Parkinson’s disease (PD is the second most common neurodegenerative disorder characterized by the loss of muscle control, which causes trembling of the limbs and head as well as impaired balance. L-DOPA (L-3,4-dihydroxy phenylalanine is the major ingredient of several prescription drugs used to treat PD. Faba bean (Vicia faba L. is one of the few plant species that is known to produce L-DOPA and has the potential to be developed as a functional food crop for people suffering with PD. Objective: Aimed to provide needed information for people who want to use faba bean as a natural remedy or functional food to relieve PD symptoms, this study analyzed the variation of L-DOPA concentration in the leaf and flower tissues of six faba bean lines with common and rare flower colors. Methods: Leaf and flower samples were taken from field grown plants with different flower colors, namely, pink with purple lines and black dots, pure white, brown, and crimson. Samples were freeze-dried and L-DOPA was quantified by a LC-MS system consisting of an ACQUITY UPLC in line with a Synapt G2 HDMS quadrupole time-of-flight mass spectrometer. This experiment was carried out in two consecutive years (2012 and 2013 and the plants used in the second year were grown from the seeds harvested from the plants used in the first year. Results and Discussion: Our two-year study revealed a high level of variation in L-DOPA concentration for leaf and flower tissues among the six faba bean lines studied. The average L-DOPA concentration based on dry weight (DW in flowers ranged from 27.8 to 63.5 mg/g and 18.2 to 48.7 mg/g for leaf tissues. There was no significant correlation between L-DOPA concentrations in flowers and leaves. The L-DOPA concentration in flowers and in leaves of the same line varied but were not statistically significant between the two years. Ideally, the genotype with the highest average L-DOPA concentration in both flowers and leaves would be grown

l-Dopa responsiveness is associated with distinctive connectivity patterns in advanced Parkinson's disease.

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Akram, Harith; Wu, Chengyuan; Hyam, Jonathan; Foltynie, Thomas; Limousin, Patricia; De Vita, Enrico; Yousry, Tarek; Jahanshahi, Marjan; Hariz, Marwan; Behrens, Timothy; Ashburner, John; Zrinzo, Ludvic

2017-06-01

Neuronal loss and dopamine depletion alter motor signal processing between cortical motor areas, basal ganglia, and the thalamus, resulting in the motor manifestations of Parkinson's disease. Dopamine replacement therapy can reverse these manifestations with varying degrees of improvement. To evaluate functional connectivity in patients with advanced Parkinson's disease and changes in functional connectivity in relation to the degree of response to l-dopa, 19 patients with advanced Parkinson's disease underwent resting-state functional magnetic resonance imaging in the on-medication state. Scans were obtained on a 3-Tesla scanner in 3 × 3 × 2.5 mm 3 voxels. Seed-based bivariate regression analyses were carried out with atlas-defined basal ganglia regions as seeds, to explore relationships between functional connectivity and improvement in the motor section of the UPDRS-III following an l-dopa challenge. False discovery rate-corrected P was set at basal ganglia resting-state functional connectivity patterns associated with different degrees of l-dopa responsiveness in patients with advanced Parkinson's disease. l-Dopa exerts a graduated influence on remapping connectivity in distinct motor control networks, potentially explaining some of the variance in treatment response. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

Global actions of nicotine on the striatal microcircuit

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Victor E Plata

2013-11-01

Full Text Available The question to solve in the present work is: what is the predominant action induced by the activation of cholinergic-nicotinic receptors (nAChrs in the striatal network given that nAChrs are expressed by several elements of the circuit: cortical terminals, dopamine terminals, and various striatal GABAergic interneurons. To answer this question some type of multicellular recording has to be used without losing single cell resolution. Here, we used calcium imaging and nicotine. It is known that in the presence of low micromolar N-Methyl-D-aspartate (NMDA, the striatal microcircuit exhibits neuronal activity consisting in the spontaneous synchronization of different neuron pools that interchange their activity following determined sequences. The striatal circuit also exhibits profuse spontaneous activity in pathological states (without NMDA such as dopamine depletion. However, in this case, most pathological activity is mostly generated by the same neuron pool. Here, we show that both types of activity are inhibited during the application of nicotine. Nicotine actions were blocked by mecamylamine, a non specific antagonist of nAChrs. Interestingly, inhibitory actions of nicotine were also blocked by the GABAA-receptor antagonist bicuculline, in which case, the actions of nicotine on the circuit became excitatory and facilitated neuronal synchronization. We conclude that the predominant action of nicotine in the striatal microcircuit is indirect, via the activation of networks of inhibitory interneurons. This action inhibits striatal pathological activity in early Parkinsonian animals almost as potently as L-DOPA.

Quantitative Determination of L-DOPA in Seeds of Mucuna Pruriens Germplasm by High Performance Thin Layer Chromatography.

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Raina, Archana P; Khatri, Renu

2011-07-01

Mucuna pruriens Linn. is an important medicinal plant used for treatment of Parkinson's disease and many others in ancient Indian medical system. L-DOPA extracted from seeds of Mucuna is a constituent of more than 200 indigenous drug formulations and is more effective as drug than the synthetic counterpart. A densitometric high performance thin-layer chromatographic (HPTLC) method was developed for quantification of L-DOPA content present in the seeds extract. The method involves separation of L-DOPA on precoated silica gel 60 GF(254) HPTLC plates using a solvent system of n-butanol-acetic-acid-water (4:1:1, v/v) as the mobile phase. Quantification was done at 280 nm using absorbance reflectance mode. Linearity was found in the concentration range of 100 to 1000 ng/spot with the correlation coefficient value of 0.9980. The method was validated for accuracy, precision and repeatability. Mean recovery was 100.89%. The LOD and LOQ for L-DOPA determination were found to be 3.41 ng/spot and 10.35 ng/spot respectively. The proposed HPTLC method was found to be precise, specific and accurate for quantitative determination of L-DOPA. It can be used for rapid screening of large germplasm collections of Mucuna pruriens for L-DOPA content. The method was used to study variation in fifteen accessions of Mucuna germplasm collected from different geographical regions.

Novel L-Dopa and dopamine prodrugs containing a 2-phenyl-imidazopyridine moiety.

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Denora, Nunzio; Laquintana, Valentino; Lopedota, Angela; Serra, Mariangela; Dazzi, Laura; Biggio, Giovanni; Pal, Dhananjay; Mitra, Ashim K; Latrofa, Andrea; Trapani, Giuseppe; Liso, Gaetano

2007-07-01

The aim of this study was to gain insight into the feasibility of enhancing the delivery of L-Dopa and dopamine to the brain by linking these neurotransmitters and L-Dopa ethyl ester to 2-phenyl-3-carboxymethyl-imidazopyridine compounds giving rise to the so-called Dopimid compounds. A number of Dopimid compounds were synthesized and both stability and binding studies to dopaminergic and benzodiazepine receptors were performed. To evaluate whether Dopimid compounds are P-gp substrates, [(3)H]ritonavir uptake experiments and bi-directional transport studies on confluent MDCKII-MDR1 monolayers were carried out. The brain penetration properties of Dopimid compounds were estimated by the Clark's computational model and evaluated by investigation of their transport across BBMECs monolayers. The dopamine levels following the intraperitoneal administration of the selected Dopimid compounds were measured in vivo by using brain microdialysis in rat. Tested compounds were adequately stable in solution buffered at pH 7.4 but undergo faster cleavage in dilute rat serum at 37 degrees C. Receptor binding studies showed that Dopimid compounds are essentially devoid of affinity for dopaminergic and benzodiazepine receptors. [(3)H]ritonavir uptake experiments indicated that selected Dopimid compounds, like L-Dopa and dopamine hydrochloride, are not substrates of P-gp and it was also confirmed by bi-directional transport experiments across MDCKII-MDR1 monolayers. By Clark's model a significant brain penetration was deduced for L-Dopa ethyl ester and dopamine derivatives. Transport studies involving BBMECs monolayers indicated that some of these compounds should be able to cross the BBB. Interestingly, the rank order of apparent permeability (P (app)) values observed in these assays parallels that calculated by the computational approach. Brain microdialysis experiments in rat showed that intraperitoneal acute administration of some Dopimid compounds induced a dose-dependent increase

Gypenosides ameliorate memory deficits in MPTP-lesioned mouse model of Parkinson's disease treated with L-DOPA.

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Zhao, Ting Ting; Kim, Kyung Sook; Shin, Keon Sung; Park, Hyun Jin; Kim, Hyun Jeong; Lee, Kyung Eun; Lee, Myung Koo

2017-09-06

Previous studies have revealed that gypenosides (GPS) improve the symptoms of anxiety disorders in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned rat model of Parkinson's disease (PD). The present study aimed to investigate the effects of GPS on memory deficits in an MPTP-lesioned mouse model of PD treated with L-3,4-dihydroxyphenylalanine (L-DOPA). MPTP (30 mg/kg/day, 5 days)-lesioned mice were treated with GPS (50 mg/kg) and/or L-DOPA (10 and 25 mg/kg) for 21 days. After the final treatments, behavioral changes were assessed in all mice using passive avoidance and elevated plus-maze tests. We then evaluated the biochemical influences of GPS treatment on levels of tyrosine hydroxylase (TH), dopamine, N-methyl-D-aspartate (NMDA) receptors, extracellular signal-regulated kinase (ERK1/2), and cyclic AMP-response element binding protein (CREB) phosphorylation. MPTP-lesioned mice exhibited deficits associated with habit learning and spatial memory, which were further aggravated by treatment with L-DOPA (25 mg/kg). However, treatment with GPS (50 mg/kg) ameliorated memory deficits. Treatment with GPS (50 mg/kg) also improved L-DOPA (25 mg/kg)-treated MPTP lesion-induced decreases in retention latency on the passive avoidance test, as well as levels of TH-immunopositive cells and dopamine in the substantia nigra and striatum. GPS treatment also attenuated increases in retention transfer latency on the elevated plus-maze test and in NMDA receptor expression, as well as decreases in the phosphorylation of ERK1/2 and CREB in the hippocampus. Treatment with L-DOPA (10 mg/kg) also ameliorated deficits in habit learning and spatial memory in MPTP-lesioned mice, and this effect was further enhanced by treatment with GPS (50 mg/kg). GPS ameliorate deficits in habit learning and spatial memory by modulating the dopaminergic neuronal and N-methyl-D-aspartate receptor-mediated signaling systems in MPTP-lesioned mice treated with L-DOPA. GPS may serve as an adjuvant

Effects of L-DOPA on aggressive behavior and central monoaminergic activity in the lizard Anolis carolinensis, using a new method for drug delivery.

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Höglund, Erik; Korzan, Wayne J; Watt, Michael J; Forster, Gina L; Summers, Tangi R; Johannessen, Helga Falch; Renner, Kenneth J; Summers, Cliff H

2005-01-06

The dopamine (DA) precursor, L-DOPA (500 microg), was injected into living crickets, which were ingested (one each) by adult male Anolis carolinensis. This method of delivery elevated plasma L-DOPA and DA concentrations by approximately 1000-fold. In contrast, plasma epinephrine (Epi) and norepinephrine (NE) were not influenced by L-DOPA treatment, although they were elevated following the consumption of the cricket. Lizards that ingested L-DOPA treated crickets had elevated L-DOPA in all brain regions measured, with DA and/or DOPAC also increased significantly in most brain regions studied. Despite increased DA levels in the striatum and nucleus accumbens as a response to L-DOPA, the treatment had no influence on general motor activity. Central serotonin, NE, and Epi systems were not affected in any brain region by oral L-DOPA treatment. In addition, aggression was inhibited by this dose of L-DOPA, even though there was no effect on serotonergic systems. This is surprising because controlling aggressive behavior is usually considered the province of serotonergic activity. Aggression was measured before and after treatment, and while saline-treated lizards retained the full vigor of aggressive activity, those fed a cricket injected with L-DOPA were only one-third as aggressive after treatment. As L-DOPA treatment did not affect general motor activity, the effect appears to be directly associated with aggression. This is supported by the observation that L-DOPA treatment delayed latency to eyespot darkening, which predicts the latency to aggression.

Impact of L-DOPA treatment on regional cerebral blood flow and metabolism in the basal ganglia in a rat model of Parkinson's disease.

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Ohlin, K Elisabet; Sebastianutto, Irene; Adkins, Chris E; Lundblad, Cornelia; Lockman, Paul R; Cenci, M Angela

2012-05-15

Large increases in regional cerebral blood flow (rCBF) have been measured in patients with Parkinson's disease (PD) following the administration of L-DOPA, but the underlying mechanisms have remained unknown. In this study, rats with unilateral 6-hydroxydopamine (6-OHDA) lesions were used to compare patterns of rCBF and regional cerebral glucose utilisation (rCGU) in chronically L-DOPA-treated subjects following a final injection of L-DOPA or saline. The same animal model was used to the leakage of a blood-brain barrier (BBB) tracer molecule at 60 min vs. 24h following the last L-DOPA injection of a chronic treatment. All the parameters under investigation were examined with brain autoradiography following intravenous injections of specific radiotracers in awake animals ([14C]-iodoantipyrine for rCBF, [14C]-2-deoxyglucose for rCGU, and [14C]-α-aminoisobutyric acid for BBB leakage). Significant changes in rCBF and rCGU on the side ipsilateral to the 6-OHDA lesion relative to the non-lesioned side were seen at 60 min ("ON") but not 24h ("OFF") following L-DOPA administration. These changes were not seen in sham-operated rats. In the output nuclei of the basal ganglia (the entopeduncular nucleus and the substantia nigra pars reticulata) both rCBF and rCGU were elevated both in acutely L-DOPA-treated rats and chronically L-DOPA-treated rats displaying dyskinesia, but did not change significantly in chronically L-DOPA-treated non-dyskinetic cases. Acutely and chronically L-DOPA-treated rats with dyskinesia exhibited increases in rCBF "ON L-DOPA" also in the motor cortex, the striatum, and the globus pallidus, but the corresponding changes in rCGU did not show the same direction, magnitude, and/or relative group differences. The uptake of a BBB tracer (studied in the striatum and the substantia nigra reticulata in chronically L-DOPA treated rats) was significantly higher ON vs. OFF L-DOPA. The present results are the first to show that the administration of L-DOPA is

Inducing mutations through γ-irradiation in seeds of Mucuna pruriens for developing high L-DOPA-yielding genotypes.

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Singh, Susheel Kumar; Yadav, Deepti; Lal, Raj Kishori; Gupta, Madan M; Dhawan, Sunita Singh

2017-04-01

To develop elite genotypes in Mucuna pruriens (L.) DC with high L-DOPA (L-3, 4 dihydroxyphenylalanine) yields, with non-itching characteristics and better adaptability by applying γ-irradiation. Molecular and chemical analysis was performed for screening based on specific characteristics desired for developing suitable genotypes. Developed, mutant populations were analyzed for L-DOPA % in seeds through TLC (thin layer chromatography), and the results obtained were validated with the HPLC (High performance liquid chromatography). The DNA (Deoxyribonucleic acid) was isolated from the leaf at the initial stage and used for DNA polymorphism. RNA (Ribonucleic acid) was isolated from the leaf during maturity and used for expression analysis. The selected mutant T-I-7 showed 5.7% L-DOPA content compared to 3.18% of parent CIM-Ajar. The total polymorphism obtained was 57% with the molecular marker analysis. The gene expression analysis showed higher fold change expression of the dopadecarboxylase gene (DDC) in control compared to selected mutants (T-I-7, T-II-23, T-IV-9, T-VI-1). DNA polymorphism was used for the screening of mutants for efficient screening at an early stage. TLC was found suitable for the large-scale comparative chemical analysis of L-DOPA. The expression profile of DDC clearly demonstrated the higher yields of L-DOPA in selected mutants developed by γ-irradiation in the seeds of the control.

Presynaptic mechanisms of L-DOPA-induced dyskinesia: the findings, the debate, the therapeutic implications.

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M Angela eCenci

2014-12-01

Full Text Available The dopamine precursor L-DOPA has been the most effective treatment for Parkinson´s disease (PD for over 40 years. However, the response to this treatment changes during the progression of PD, and most patients develop dyskinesias (abnormal involuntary movements and motor fluctuations within a few years of L-DOPA therapy. There is wide consensus that these motor complications depend on both pre- and post-synaptic disturbances of nigrostriatal dopamine transmission. Several presynaptic mechanisms converge to generate large dopamine swings in the brain concomitant with the peaks-and-troughs of plasma L-DOPA levels, while post-synaptic changes engender abnormal functional responses in dopaminoceptive neurons. While this general picture is well-accepted, the relative contribution of different factors remains a matter of debate. A particularly animated debate has been growing around putative players on the presynaptic side of the cascade. To what extent do presynaptic disturbances in dopamine transmission depend on deficiency/dysfunction of the dopamine transporter, aberrant release of dopamine from serotonin neurons, or gliovascular mechanisms? And does noradrenaline (which is synthetized from dopamine play a role? This review article will summarize key findings, controversies, and pending questions regarding the presynaptic mechanisms of L-DOPA-induced dyskinesia. Intriguingly, the debate around these mechanisms has spurred research into previously unexplored facets of brain plasticity that have far-reaching implications to the treatment of neuropsychiatric disease.

Gypenosides attenuate the development of L-DOPA-induced dyskinesia in 6-hydroxydopamine-lesioned rat model of Parkinson's disease.

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Shin, Keon Sung; Zhao, Ting Ting; Park, Keun Hong; Park, Hyun Jin; Hwang, Bang Yeon; Lee, Chong Kil; Lee, Myung Koo

2015-04-21

Gypenosides (GPS) and ethanol extract of Gynostemma pentaphyllum (GP-EX) show anxiolytic effects on affective disorders in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse model of Parkinson's disease (PD). Long-term administration of L-3,4-dihydroxyphenylalanine (L-DOPA) leads to the development of severe motor side effects such as L-DOPA-induced-dyskinesia (LID) in PD. The present study investigated the effects of GPS and GP-EX on LID in a 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD. Daily administration of L-DOPA (25 mg/kg) in the 6-OHDA-lesioned rat model of PD for 22 days induced expression of LID, which was determined by the body and locomotive AIMs scores and contralateral rotational behaviors. However, co-treatments of GPS (25 and 50 mg/kg) or GP-EX (50 mg/kg) with L-DOPA significantly attenuated the development of LID without compromising the anti-parkinsonian effects of L-DOPA. In addition, the increases in ∆FosB expression and ERK1/2 phosphorylation in 6-OHDA-lesioned rats induced by L-DOPA administration were significantly reduced by co-treatment with GPS (25 and 50 mg/kg) or GP-EX (50 mg/kg). These results suggest that GPS (25 and 50 mg/kg) and GP-EX (50 mg/kg) effectively attenuate the development of LID by modulating the biomarker activities of ∆FosB expression and ERK1/2 phosphorylation in the 6-OHDA-lesioned rat model of PD. GPS and GP-EX will be useful adjuvant therapeutics for LID in PD.

Tratamento do parkinsonismo com L-Dopa

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Nilton Luís Latuf

1972-06-01

Full Text Available São apresentados os resultados obtidos no tratamento de 54 pacientes parkinsonianos com L-Dopa. A intensidade dos sintomas foi avaliada mediante a escala NUDS (Northwestern University Disability Scales antes e após o tratamento. Os autores ressaltam a obtenção de melhores resultados no que respeita à rigidez e à discinesia, em comparação com o tremor. São apontados os efeitos colaterais, quase sempre de pequena intensidade e corrigíveis com a diminuição ou suspensão da administração medicamentosa.

L-DOPA Preloading Increases the Uptake of Borophenylalanine in C6 Glioma Rat Model: A New Strategy to Improve BNCT Efficacy

International Nuclear Information System (INIS)

Capuani, Silvia; Gili, Tommaso; Bozzali, Marco; Russo, Salvatore; Porcari, Paola; Cametti, Cesare; D'Amore, Emanuela; Colasanti, Marco; Venturini, Giorgio; Maraviglia, Bruno; Lazzarino, Giuseppe; Pastore, Francesco S.

2008-01-01

Purpose: Boron neutron capture therapy (BNCT) is a radiotherapeutic modality based on 10 B(n,α) 7 Li reaction, for the treatment of malignant gliomas. One of the main limitations for BNCT effectiveness is the insufficient intake of 10 B nuclei in the tumor cells. This work was aimed at investigating the use of L-DOPA as a putative enhancer for 10 B-drug 4-dihydroxy-borylphenylalanine (BPA) uptake in the C6-glioma model. The investigation was first performed in vitro and then extended to the animal model. Methods and Materials: BPA accumulation in C6-glioma cells was assessed using radiowave dielectric spectroscopy, with and without L-DOPA preloading. Two L-DOPA incubation times (2 and 4 hours) were investigated, and the corresponding effects on BPA accumulation were quantified. C6-glioma cells were also implanted in the brain of 32 rats, and tumor growth was monitored by magnetic resonance imaging. Rats were assigned to two experimental branches: (1) BPA administration; (2) BPA administration after pretreatment with L-DOPA. All animals were sacrificed, and assessments of BPA concentrations in tumor tissue, normal brain, and blood samples were performed using high-performance liquid chromatography. Results: L-DOPA preloading induced a massive increase of BPA concentration in C6-glioma cells only after a 4-hour incubation. In the animal model, L-DOPA pretreatment produced a significantly higher accumulation of BPA in tumor tissue but not in normal brain and blood samples. Conclusions: This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT. L-DOPA preloading effect is discussed in terms of membrane transport mechanisms

The effect of L-dopa in Parkinson's disease as revealed by neurophysiological studies of motor and sensory functions.

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Suppa, Antonio; Bologna, Matteo; Conte, Antonella; Berardelli, Alfredo; Fabbrini, Giovanni

2017-02-01

This review will first discuss evidence of motor and sensory abnormalities as yielded by neurophysiological techniques in patients with PD. It will then go on to describe the effects of L-dopa replacement on motor and sensory abnormalities in PD as assessed by neurophysiological studies. Areas covered: We analyzed papers in English using Pubmed with the following keywords: L-dopa, dopamine, bradykinesia, basal ganglia, kinematic analysis, TMS, motor cortex plasticity, motor cortex excitability, somatosensory discrimination threshold, pain Expert commentary: L-dopa improves the amplitude and speed of upper limb voluntary movements, but it does not restore abnormalities in the sequence effect or voluntary facial movements. L-dopa only partially normalizes changes in motor cortex excitability and plasticity and has also contrasting effects on the sensory system and on sensory-motor integration. The neurophysiological studies reviewed here show that PD is more than a hypo-dopaminergic disease, and non-dopaminergic mechanisms should also be considered.

Direct comparison of FP-CIT SPECT and F-DOPA PET in patients with Parkinson's disease and healthy controls

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Eshuis, S.A.; Maguire, R.P.; Leenders, K.L.; Jager, P.L.; Jonkman, S.; Dierckx, R.A.

2009-01-01

Diagnosing Parkinson's disease (PD) on clinical grounds may be difficult, especially in the early stages of the disease. F-DOPA PET and FP-CIT SPECT scans are able to determine presynaptic dopaminergic activity in different ways. The aim of this study was to determine and compare the sensitivity and specificity of the two methods in the detection of striatal dopaminergic deficits in the same cohort of PD patients and healthy controls. Movement disorder specialists recruited 11 patients with early-stage PD and 17 patients with advanced PD. The patients underwent both an FP-CIT SPECT scan and an F-DOPA PET scan. In addition, 10 FP-CIT SPECT scans or 10 F-DOPA PET scans were performed in 20 healthy controls. A template with regions of interest was used to sample tracer activity of the caudate, putamen and a reference region in the brain. The outcome parameter was the striatooccipital ratio (SOR). Normal SOR values were determined in the controls. The sensitivity and specificity of both scanning methods were calculated. FP-CIT SPECT and F-DOPA PET scans were both able to discriminate PD patients from healthy controls. For the early phases of the disease, sensitivity and specificity of the contralateral striatal and putaminal uptake of FP-CIT and F-DOPA was 100%. When only caudate uptake was considered, the specificities were 100% and 90% for FP-CIT and F-DOPA, respectively, while the sensitivity was 91% for both scanning techniques. FP-CIT SPECT and F-DOPA PET scans are both able to diagnose presynaptic dopaminergic deficits in early phases of PD with excellent sensitivity and specificity. (orig.)

Presynaptic Mechanisms of l-DOPA-Induced Dyskinesia: The Findings, the Debate, and the Therapeutic Implications.

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Cenci, M Angela

2014-01-01

The dopamine (DA) precursor l-DOPA has been the most effective treatment for Parkinson's disease (PD) for over 40 years. However, the response to this treatment changes with disease progression, and most patients develop dyskinesias (abnormal involuntary movements) and motor fluctuations within a few years of l-DOPA therapy. There is wide consensus that these motor complications depend on both pre- and post-synaptic disturbances of nigrostriatal DA transmission. Several presynaptic mechanisms converge to generate large DA swings in the brain concomitant with the peaks-and-troughs of plasma l-DOPA levels, while post-synaptic changes engender abnormal functional responses in dopaminoceptive neurons. While this general picture is well-accepted, the relative contribution of different factors remains a matter of debate. A particularly animated debate has been growing around putative players on the presynaptic side of the cascade. To what extent do presynaptic disturbances in DA transmission depend on deficiency/dysfunction of the DA transporter, aberrant release of DA from serotonin neurons, or gliovascular mechanisms? And does noradrenaline (which is synthetized from DA) play a role? This review article will summarize key findings, controversies, and pending questions regarding the presynaptic mechanisms of l-DOPA-induced dyskinesia. Intriguingly, the debate around these mechanisms has spurred research into previously unexplored facets of brain plasticity that have far-reaching implications to the treatment of neuropsychiatric disease.

Biodistribution and human dosimetry estimation of fluoro-L-DOPA as PET imaging agent of dopaminergic nerve transmitter systems

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Tang Ganghua; Wang Mingfang; Luo Lei; Gan Manquan; Tang Xiaolan; Zhang Lan; Wang Yongxian

2002-01-01

Objective: To investigate the biodistribution and human dosimetry estimation of 6-[ 18 F] Fluoro-L-DOPA (FDOPA). Methods: Biodistribution of FDOPA in normal rats and brain of hemi-Parkinsonism rats were determined. Human dosimetry estimation was performed by MIRD method based on the rats biodistribution data. Results: Biodistributions in normal rats showed high uptake in kidney, blood, striatum and hippocampi, fast clearance of radioactivity from kidney and blood, longer retain time in striatum and hippocampi, and higher striatum to cerebellum and striatum to cortex ratio. FDOPA uptake, striatum to cerebellum and striatum to cortex ratio in the lesioned side of hemi-Parkinsonism rats (P 2 to 2.3 x 10 -2 mGy/MBq and the effective dose in humans was estimated to be 2.05 x 10 -2 mSv/MBq after injection of FDOPA based on rats biodistribution data, which were consistent with those reported by literature on the whole. Conclusion: Human radiation dosimetry of FDOPA and other PET tracers can be estimated based on animals biodistribution data. The synthetic FDOPA is safe and efficient and can be used in animals, human and PD patients PET studies

Plasma dihydroxyphenylalanine (DOPA) is independent of sympathetic activity in humans

DEFF Research Database (Denmark)

Eldrup, E; Christensen, N J; Andreasen, J

1989-01-01

in diabetic patients with autonomic neuropathy compared to diabetics without neuropathy, whereas baseline plasma DOPA concentrations were similar in the three groups investigated: 6.55 (5.03-7.26, median [interquartile range], n = 8) nmol l-1 in diabetics with neuropathy, 7.41 (5.79-7.97, n = 8) nmol l-1...

Radioenzymatic assay of DOPA (3,4-dihydroxyphenylalanine)

International Nuclear Information System (INIS)

Johnson, G.A.; Gren, J.M.; Kupiecki, R.

1978-01-01

We modified the single-isotope radioenzymatic assay for catecholamines [Life Sci. 21, 625(1977)] to assay 3,4-dihydroxyphenylalanine (DOPA). DOPA decarboxylase is used to convert DOPA to dopamine, which concurrently is converted to [ 3 H]-3-O-methyldopamine in the presence of catechol-O-methyltransferase and [methyl- 3 H]-S-adenosylmethionine and assayed radioenzymatically. For assay of plasma DOPA, 50 μl of untreated plasma is added directly into the incubation mixture. A duplicate mixture containing an internal standard requires a second 50-μl aliquot of plasma. Because the assay measures both DOPA and endogenous dopamine, two additional aliquots of plasma must be assayed for dopamine in the absence of the decarboxylase by the differential assay; DOPA is estimated by difference. The assay is sensitive to 25 pg (500 ng/liter of plasma). Analysis of DOPA (DOPA plus dopamine) and the concurrent differential assay of catecholamines in at least 10 samples can be done in a single working day. Plasma DOPA concentrations for 42 normotensive adults were 1430 +- 19 ng/liter (mean +- SEM). In contrast, dopamine concentrations for these same subjects averaged 23 +- 20 ng/liter. Values for the 24 women subjects (1510 +- 62 ng/liter) significantly (P = 0.04) exceeded those for the men

Effect of l-DOPA on local field potential relationship between the pedunculopontine nucleus and primary motor cortex in a rat model of Parkinson's disease.

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Geng, Xiwen; Wang, Xuenan; Xie, Jinlu; Zhang, Xiao; Wang, Xiusong; Hou, Yabing; Lei, Chengdong; Li, Min; Han, Hongyu; Yao, Xiaomeng; Zhang, Qun; Wang, Min

2016-12-15

Levodopa (l-DOPA) has been proved to reverse the pathologic neuron activities in many brain regions related to Parkinson's disease (PD). But little is known about the effect of l-DOPA on the altered electrophysiological coherent activities between pedunculopontine nucleus (PPN) and motor cortex. To investigate this, local field potentials (LFPs) of PPN and primary motor cortex (M1) were recorded simultaneously in control, 6-hydroxydopamine lesioned and lesioned rats with l-DOPA chronic treatment. The results revealed that in resting state, chronic l-DOPA treatment could correct the suppressed power of LFPs in PPN and M1 in low-frequency band (1-7Hz) and the enhanced power in high-frequency band (7-70Hz in PPN and 12-70Hz in M1) of lesioned rats. In locomotor state, l-DOPA treatment could correct the alterations in most of frequency bands except the δ band in PPN and α band in M1. Moreover, l-DOPA could also reverse the altered coherent relationships caused by dopamine depletion in resting state between PPN and M1 in β band. And in locomotor state, l-DOPA had therapeutic effect on the alterations in δ and β bands but not in the α band. These findings provide evidence that l-DOPA can reverse the altered LFP activities in PPN and M1 and their relationships in a rat model of PD, which contributes to better understanding the electrophysiological mechanisms of the pathophysiology and therapy of PD. Copyright © 2016. Published by Elsevier B.V.

L-DOPA concentration variation in the leaf and flower tissues of six faba bean lines with common and rare flower colors

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Faba bean is one of the a few plant species that can produce the medicinally important molecule, L-3,4-dihydroxy phenylalanine (L-DOPA), the major ingredient of several prescription drugs used to treat Parkinson’s disease. L-DOPA can cross the blood-brain barrier, where it is converted to dopamine, ...

Enhanced permeability and antifouling performance of cellulose acetate ultrafiltration membrane assisted by l-DOPA functionalized halloysite nanotubes.

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Mu, Keguang; Zhang, Dalun; Shao, Ziqiang; Qin, Dujian; Wang, Yalong; Wang, Shuo

2017-10-15

l-Dopa functionalized halloysite nanotubes (HNTs) were prepared by the self-polymerization of l-dopa in the weak alkaline condition. Then different contents of l-dopa coated HNTs (LPDHNTs) were blended into cellulose acetate to prepare enhanced performance ultrafiltration membranes via the phase inversion method. The HNTs and LPDHNTs were characterized by FTIR, XPS, and TEM anysis. And the membranes morphologies, separation performance, antifouling performance, mechanical properties and hydrophilicity were also investigated. It was found that the composite membranes exhibited excellent antifouling performance. The pure water flux of 3.0wt% LPDHNTs/CA membrane increased from 11.4Lm -2 h -1 to 92.9Lm -2 h -1 , while the EA rejection ratio of the membrane was about 91.2%. In addition, the mechanical properties of the resultant membranes were strengthened compared with the CA ultrafiltration membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a microchip-pulsed electrochemical method for rapid determination of L-DOPA and tyrosine in Mucuna pruriens.

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Li, Xinchun; Chen, Zuanguang; Yang, Fan; Pan, Jianbin; Li, Yinbao

2013-05-01

L-3,4-dihydroxyphenylalanine (L-DOPA) is a well-recognized therapeutic compound to Parkinson's disease. Tyrosine is a precursor for the biosynthesis of L-DOPA, both of which are widely found in traditional medicinal material, Mucuna pruriens. In this paper, we described a validated novel analytical method based on microchip capillary electrophoresis with pulsed electrochemical detection for the simultaneous measurement of L-DOPA and tyrosine in M. pruriens. This protocol adopted end-channel amperometric detection using platinum disk electrode on a homemade glass/polydimethylsiloxane electrophoresis microchip. The background buffer consisted of 10 mM borate (pH 9.5) and 0.02 mM cetyltrimethylammonium bromide, which can produce an effective resolution for the two analytes. In the optimal condition, sufficient electrophoretic separation and sensitive detection for the target analytes can be realized within 60 s. Both tyrosine and L-DOPA yielded linear response in the concentration range of 5.0-400 μM (R(2) > 0.99), and the LOD were 0.79 and 1.1 μM, respectively. The accuracy and precision of the established method were favorable. The present method shows several merits such as facile apparatus, high speed, low cost and minimal pollution, and provides a means for the pharmacologically active ingredients assay in M. pruriens. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Singlet oxygen generation during the oxidation of L-tyrosine and L-dopa with mushroom tyrosinase

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Miyaji, Akimitsu [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259-G1-14, Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kohno, Masahiro [Department of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-G1-25 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Inoue, Yoshihiro [Showa Pharmaceutical University, 3-3165 Higashi-tamagawagakuen, Machida, Tokyo 194-8543 (Japan); Baba, Toshihide, E-mail: tbaba@chemenv.titech.ac.jp [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259-G1-14, Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

2016-03-18

The generation of singlet oxygen during the oxidation of tyrosine and L-dopa using mushroom tyrosinase in a phosphate buffer (pH 7.4), the model of melanin synthesis in melanocytes, was examined. The reaction was performed in the presence of 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP), an acceptor of singlet oxygen and the electron spin resonance (ESR) of the spin adduct, 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy (4-oxo-TEMPO), was measured. An increase in the ESR signal attributable to 4-oxo-TEMPO was observed during the oxidation of tyrosine and L-dopa with tyrosinase, indicating the generation of singlet oxygen. The results suggest that {sup 1}O{sub 2} generation via tyrosinase-catalyzed melanin synthesis occurs in melanocyte. - Highlights: • Generation of singlet oxygen was observed during tyrosinase-catalyzed tyrosine oxidation. • The singlet oxygen generated when tyrosine was converted into dopachrome. • The amount of singlet oxygen is not sufficient for cell toxicity. • It decreased when the hydroxyl radicals and/or superoxide anions were trapped.

On the use of [18F]DOPA as an imaging biomarker for transplanted islet mass

International Nuclear Information System (INIS)

Eriksson, Olof; Mintz, Akiva; Liu, Chengyang; Yu, Ming; Naji, Ali; Alavi, Abass

2014-01-01

Islet transplantation is being developed as a potential cure for patients with type 1 diabetes. There is a need for non-invasive imaging techniques for the quantification of transplanted islets, as current transplantation sites are associated with a substantial loss of islet viability. The dopaminergic metabolic pathway is present in the islets; therefore, we propose Fluorine-18 labeled L-3,4-dihydroxyphenylalanine ([ 18 F]DOPA) as a biomarker for transplanted islet mass. The expression of enzymes involved in the dopaminergic metabolic pathway was investigated in both native and transplanted human islets. The specific uptake of [ 18 F]DOPA in islets and immortalized beta cells was studied in vitro by selective blocking of dopa decarboxylase (DDC). Initial in vivo positron emission tomography (PET) imaging of viable subcutaneous human islets was performed using [ 18 F]DOPA. DDC and vesicular monoamine transporter 2 are co-localized with insulin in the native human pancreas, and the expression is retained after transplantation. Islet uptake of the [ 18 F]DOPA could be modulated by inhibiting DDC, indicating that the uptake followed the normal dopaminergic metabolic pathway. In vivo imaging revealed [ 18 F]DOPA uptake at the site of the functional islet graft. Based on the in vitro and in vivo results presented in this study, we propose to further validate [ 18 F]DOPA-PET as a sensitive imaging modality for imaging extrahepatically transplanted islets. (author)

The Design and Evaluation of an l-Dopa–Lazabemide Prodrug for the Treatment of Parkinson’s Disease

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Monique Hoon

2017-11-01

Full Text Available l-Dopa, the metabolic precursor of dopamine, is the treatment of choice for the symptomatic relief of the advanced stages of Parkinson’s disease. The oral bioavailability of l-dopa, however, is only about 10% to 30%, and less than 1% of the oral dose is estimated to reach the brain unchanged. l-Dopa’s physicochemical properties are responsible for its poor bioavailability, short half-life and the wide range of inter- and intrapatient variations of plasma levels. An l-dopa–lazabemide prodrug is proposed to overcome the problems associated with l-dopa absorption. Lazabemide is a monoamine oxidase (MAO-B inhibitor, a class of compounds that slows the depletion of dopamine stores in Parkinson’s disease and elevates dopamine levels produced by exogenously administered l-dopa. l-Dopa was linked at the carboxylate with the primary aminyl functional group of lazabemide via an amide, a strategy which is anticipated to protect l-dopa against peripheral decarboxylation and possibly also enhance the membrane permeability of the prodrug. Selected physicochemical and biochemical properties of the prodrug were determined and included lipophilicity (logD, solubility, passive diffusion permeability, pKa, chemical and metabolic stability as well as cytotoxicity. Although oral and i.p. treatment of mice with the prodrug did not result in enhanced striatal dopamine levels, 3,4-dihydroxyphenylacetic acid (DOPAC levels were significantly depressed compared to saline, l-dopa and carbidopa/l-dopa treatment. Based on the results, further preclinical evaluation of the l-dopa–lazabemide prodrug should be undertaken with the aim of discovering prodrugs that may be advanced to the clinical stages of development.

Stronger Dopamine D1 Receptor-Mediated Neurotransmission in Dyskinesia.

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Farré, Daniel; Muñoz, Ana; Moreno, Estefanía; Reyes-Resina, Irene; Canet-Pons, Júlia; Dopeso-Reyes, Iria G; Rico, Alberto J; Lluís, Carme; Mallol, Josefa; Navarro, Gemma; Canela, Enric I; Cortés, Antonio; Labandeira-García, José L; Casadó, Vicent; Lanciego, José L; Franco, Rafael

2015-12-01

Radioligand binding assays to rat striatal dopamine D1 receptors showed that brain lateralization of the dopaminergic system were not due to changes in expression but in agonist affinity. D1 receptor-mediated striatal imbalance resulted from a significantly higher agonist affinity in the left striatum. D1 receptors heteromerize with dopamine D3 receptors, which are considered therapeutic targets for dyskinesia in parkinsonian patients. Expression of both D3 and D1-D3 receptor heteromers were increased in samples from 6-hydroxy-dopamine-hemilesioned rats rendered dyskinetic by treatment with 3, 4-dihydroxyphenyl-L-alanine (L-DOPA). Similar findings were obtained using striatal samples from primates. Radioligand binding studies in the presence of a D3 agonist led in dyskinetic, but not in lesioned or L-DOPA-treated rats, to a higher dopamine sensitivity. Upon D3-receptor activation, the affinity of agonists for binding to the right striatal D1 receptor increased. Excess dopamine coming from L-DOPA medication likely activates D3 receptors thus making right and left striatal D1 receptors equally responsive to dopamine. These results show that dyskinesia occurs concurrently with a right/left striatal balance in D1 receptor-mediated neurotransmission.

The influence of L-DOPA on the accumulation of lipid peroxidation products in some brain structures affected by radiation

International Nuclear Information System (INIS)

Babaev, R.A.; Kocharli, R.Kh.; Akhmedova, G.Sh.; Gasanova, A.A.; Babaev, Kh.F.

1990-01-01

A study was made of the effect of L-DOPA on the dynamics of changes in lipid peroxidation products (LPP) and the content of various types of SH-groups in certain brain structures (oblongata, cerebellum, visual and sensorimotor cortex) and their synaptosomal fractions upon irradiation. The preadministration of L-DOPA to irradiated rats inhibited LPP accumulation, prevented the decrease in the content of various types of thiols and thus exerted an antioxidant effect

Development of a sensor for L-Dopa based on Co(DMG)(2)ClPy/multi-walled carbon nanotubes composite immobilized on basal plane pyrolytic graphite electrode.

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Leite, Fernando Roberto Figueirêdo; Maroneze, Camila Marchetti; de Oliveira, Adriano Bof; dos Santos, Wallans Torres Pio; Damos, Flavio Santos; Silva Luz, Rita de Cássia

2012-08-01

L-Dopa is the immediate precursor of the neurotransmitter dopamine, being the most widely prescribed drug in the treatment of Parkinson's disease. A sensitive and selective method is presented for the voltammetric determination of L-Dopa in pharmaceutical formulations using a basal plane pyrolytic graphite (BPPG) electrode modified with chloro(pyridine)bis(dimethylglyoximato)cobalt(III) (Co(DMG)(2)ClPy) absorbed in a multi-walled carbon nanotube (MWCNT). Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy were used to characterize the materials. The electrocatalytical oxidation of L-Dopa using the Co(DMG)(2)ClPy/MWCNT/BPPG electrode was investigated by cyclic voltammetry and square wave voltammetry. The parameters that influence the electrode response (the amount of Co(DMG)(2)ClPy and of MWCNT, buffer solution, buffer concentration, buffer pH, frequency and potential pulse amplitude) were investigated. Voltammetric peak currents showed a linear response for L-Dopa concentration in the range of 3 to 100 μM, with a sensitivity of 4.43 μAcm(-2)/μM and a detection limit of 0.86 μM. The related standard deviation for 10 determinations of 50 μM L-Dopa was 1.6%. The results obtained for L-Dopa determination in pharmaceutical formulations (tablets) were in agreement with the compared official method. The sensor was successfully applied for L-Dopa selective determination in pharmaceutical formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

Clinical Investigation of the Dopaminergic System with PET and FLUORINE-18-FLUORO-L-DOPA.

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Oakes, Terrence Rayford

1995-01-01

Positron Emission Tomography (PET) is a tool that provides quantitative physiological information. It is valuable both in a clinical environment, where information is sought for an individual, and in a research environment, to answer more fundamental questions about physiology and disease states. PET is particularly attractive compared to other nuclear medicine imaging techniques in cases where the anatomical regions of interest are small or when true metabolic rate constants are required. One example with both of these requirements is the investigation of Parkinson's Disease, which is characterized as a presynaptic motor function deficit affecting the striatum. As dopaminergic neurons die, the ability of the striatum to affect motor function decreases. The extent of functional neuronal damage in the small sub-structures may be ascertained by measuring the ability of the caudate and putamen to trap and store dopamine, a neurotransmitter. PET is able to utilize a tracer of dopamine activity, ^ {18}F- scL-DOPA, to quantitate the viability of the striatum. This thesis work deals with implementing and optimizing the many different elements that compose a PET study of the dopaminergic system, including: radioisotope production; conversion of aqueous ^{18}F ^-into [^ {18}F]-F2; synthesis of ^{18}F- scL -DOPA; details of the PET scan itself; measurements to estimate the radiation dosimetry; accurate measurement of a plasma input function; and the quantitation of dopaminergic activity in normal human subjects as well as in Parkinson's Disease patients.

Physical Exercise Modulates L-DOPA-Regulated Molecular Pathways in the MPTP Mouse Model of Parkinson's Disease.

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Klemann, Cornelius J H M; Xicoy, Helena; Poelmans, Geert; Bloem, Bas R; Martens, Gerard J M; Visser, Jasper E

2018-07-01

Parkinson's disease (PD) is characterized by the degeneration of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc), resulting in motor and non-motor dysfunction. Physical exercise improves these symptoms in PD patients. To explore the molecular mechanisms underlying the beneficial effects of physical exercise, we exposed 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrimidine (MPTP)-treated mice to a four-week physical exercise regimen, and subsequently explored their motor performance and the transcriptome of multiple PD-linked brain areas. MPTP reduced the number of DA neurons in the SNpc, whereas physical exercise improved beam walking, rotarod performance, and motor behavior in the open field. Further, enrichment analyses of the RNA-sequencing data revealed that in the MPTP-treated mice physical exercise predominantly modulated signaling cascades that are regulated by the top upstream regulators L-DOPA, RICTOR, CREB1, or bicuculline/dalfampridine, associated with movement disorders, mitochondrial dysfunction, and epilepsy-related processes. To elucidate the molecular pathways underlying these cascades, we integrated the proteins encoded by the exercise-induced differentially expressed mRNAs for each of the upstream regulators into a molecular landscape, for multiple key brain areas. Most notable was the opposite effect of physical exercise compared to previously reported effects of L-DOPA on the expression of mRNAs in the SN and the ventromedial striatum that are involved in-among other processes-circadian rhythm and signaling involving DA, neuropeptides, and endocannabinoids. Altogether, our findings suggest that physical exercise can improve motor function in PD and may, at the same time, counteract L-DOPA-mediated molecular mechanisms. Further, we hypothesize that physical exercise has the potential to improve non-motor symptoms of PD, some of which may be the result of (chronic) L-DOPA use.

Dysphagia Causes Symptom Fluctuations after Oral L-DOPA Treatment in a Patient with Parkinson Disease.

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Sato, Hiromasa; Yamamoto, Toshiyuki; Sato, Masako; Furusawa, Yoshihiko; Murata, Miho

2018-01-01

The causes of "delayed-on" and "no-on" phenomena in Parkinson disease (PD) are thought to have some impact on the progress of L-DOPA from the time of ingestion until it reaches the brain and is converted to dopamine. Dysphagia can cause fluctuating symptom expression in L-DOPA therapy for PD. A 69-year-old man with PD presented with "delayed-on" and "no-on" phenomena. The patient developed a gait disorder at age 60 years, and he began coughing on his food during breakfast at age 64 years. Even though he was independent in daily life, he could not eat because of dysphagia in an "off" state. Videofluoroscopic examination of swallowing in an "off" state revealed bradykinesia of the tongue and the retention of tablets in the epiglottic vallecula. We trained him to keep his tongue in strong contact with the upper incisors before swallowing. After rehabilitation of dysphagia, the frequency of "delayed-on" and "no-on" phenomena decreased, and his peak L-DOPA plasma concentration was elevated. Additionally, transdermal rotigotine (RTG) was initiated at a maintenance dose of 9.0 mg. The patient reported improvement in swallowing, and the frequency of "no-on" phenomena decreased. In PD patients, the "no-on" phenomenon can be caused by posterior contractile dysfunction of the tongue, and it can be improved with training of the tongue and transdermal RTG administration.

Work and power reduced in L-dopa naïve patients in the early-stages of Parkinson’s disease

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Lidiane Oliveira Lima

2016-04-01

Full Text Available ABSTRACT Studies which have investigated muscular performance during the initial stages of Parkinson´s disease (PD without L-dopa treatments were not found. Objective to assess whether muscular performance, work and power, of the trunk and lower limbs in L-dopa naïve patients in the early stages of PD was lower than those of healthy subjects and to compare muscular performance between the lower limbs. Method Ten subjects with PD, Hoehn and Yahr (HY I-II, L-dopa naïve and 10 subjects in the control group were assessed with the isokinetic dynamometer. Results ANOVAs revealed that work and power measures of the trunk, hip, knee, and ankle muscular groups were lower in PD compared with the control group (p < 0.05. There were no significant differences in muscular performance between the lower limbs. Conclusion The results suggested the use of specific exercises, as rehabilitation strategies, to improve the ability to produce work and power with this population.

Rapid screening for cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L. using liquid chromatography/tandem mass spectrometry.

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Xing, Jie; Yang, Zijuan; Lv, Beibei; Xiang, Lan

2008-05-01

A simple and rapid qualitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for screening cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L. at sub-ppm levels. An electrospray ionization orbitrap mass spectrometer, which provides accurate full scan MS and MS/MS data, was used in this study. After simple extraction with ethanol and purification by AB-8 resin, the extracts were subjected to LC/MS/MS analysis. A high mass tolerance (10 ppm) was used in the initial screening to filter the full scan MS data. The cyclo-dopa and diketopiperazine alkaloid standards gave limits of detection (LODs) at or below 5 ng/mL. The results also indicated that the method had an acceptable precision for day-to-day use in the identification of compounds. The alkaloids could be identified based on their MS/MS data, elemental compositions, and retention behavior. This system was used to assay trace amounts of cyclo-dopa and diketopiperazine alkaloids in crude extracts of Portulaca oleracea L., leading to the identification of 5/2 confirmed/unconfirmed cyclo-dopa and 7/6 confirmed/unconfirmed diketopiperazine alkaloids, respectively. The screening method considerably reduces the time and cost involved in the identification of cyclo-dopa and diketopiperazine alkaloids in Portulaca oleracea L., as well as being a simple and convenient approach to the identification of other structural families of natural products. Copyright (c) 2008 John Wiley & Sons, Ltd.

On the synthesis of radiofluorinated amino acids by isotope exchange based on the example of 6-[{sup 18}F]Fluor-L-DOPA; Zur Synthese radiofluorierter aromatischer Aminosaeuren mittels Isotopenaustausch am Beispiel von 6-[{sup 18}F]Fluor-L-DOPA

Energy Technology Data Exchange (ETDEWEB)

Wagner, F M

2008-06-15

In nuclear medical diagnosis, 6-[{sup 18}F]fluoro-L-3,4-dihydroxyphenylalanine (6-[{sup 18}F]fluoro-LDOPA), an analogue of L-DOPA, is one of the few established radiopharmaceuticals used for the in vivo investigation of the presynaptic dopaminergic metabolism and of some kind of tumours via Positron Emission Tomography (PET). The presently used method of preparation of the radiotracer by electrophilic labelling is limited to low amounts of activity at high costs. Known nucleophilic syntheses, however, result either in insufficient enantiomeric purity or the known multi-step syntheses are hard to automate, due to their complexity. During this work a novel, easy to automate alternative for the preparation of 6-[{sup 18}F]fluoro-L-DOPA, was developed and evaluated, using a direct nucleophilic {sup 18}F-fluorination of a protected amino acid derivative. The resulting product has a very high enantiomeric purity. At first, the general suitability of the (S)-BOC-BMI-derivatives for the synthesis of {sup 18}F-labelled amino acids, used in this work, was investigated using a less complex precursor, which resulted in the amino acid 6-[{sup 18}F]fluoro-L-m-tyrosin via acidic hydrolysis. The preparation of a useful precursor for the nucleophilic {sup 18}F-isotope substitution, namely the (2S,5S)-tert.-butyl- 5-(2-fluoro-5-formylbenzyl)-2-tert.-butyl-3-methyl-4-oxoimidazolidine-1-carboxylate, was investigated in three general different ways. At first it was tried to obtain this product via formylation after coupling with the BOC-BMI, secondly via {alpha},{beta}-dehydro amino acid derivatives and finally via a systematic multi-step synthesis. Only the last mentioned way resulted in a precursor with sufficient purity that could be labelled. The radiochemical yield of the isotopic exchange was about 60 %. In the next step, the presented concept was modified to synthesize a precursor for the preparation of 6-[{sup 18}F]fluoro-L-DOPA. Only a combination of the protecting groups

Preliminary Study on Purification and Identification of Aromatic Acid Amino L-Dopa From Malaysia Freshwater Green Mussel Byssus

International Nuclear Information System (INIS)

Saiful Irwan Zubairi; Wan Rosmaryana Wan Musa; Syed Anuar Faua'ad Syed Mohammad

2014-01-01

L-DOPA (L-3, 4-dihydroxyphenylalanine) is a type of aromatic amino acid which can be detected by using acidic extraction and purification method involving adhesive byssus green mussel protein. The main objective of this study is to identify and purify the aromatic amino acid L-DOPA via the utilization of gel Sephadex G-200 filtration chromatography based on two types of acidic and basic mobile phase solution. The crushing and homogenizing for adhesive byssus green mussel were conducted using a mortar and a pestle with the aid of liquid nitrogen. The samples that had been crushed were then mixed and dissolved in perchloric acid 0.7 %, 1.0 % and 1.5 % (v/ v) (pre-treatment) prior to the extraction process. The extraction was carried out by centrifuging the extracts at 11,000 rpm for about 10 mins and at a temperature of 10 degree Celsius to obtain supernatant S1. The supernatant was mixed with acetone and sulphuric acid and centrifuged for the second time to produce a pellet and then it was dissolved in the respective mobile phase solutions prior to purification process. Purification was later performed using two mobile phase solutions which were acetic acid 5 % (v/ v) and NaOH 1 M. The absorbance (abs) value of each purified protein extract fractions was collected and analysed at 214 nm to 400 nm with the help of UV-spectrophotometer. The highest abs value was selected for identification and verification of amino acid L-DOPA in the purified solution. Verification was carried out by utilizing high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). The results showed that the use of 0.7 % (v/ v) perchloric acid and 5 % (v/ v) acetic acid for pre-treatment process and mobile phase solution of purification process respectively, yielded the highest effluent abs profile at a wavelength of 260 nm. TLC analysis proved the existence of several important amino acids besides L-DOPA which were tyrosine and phenylalanine after 78 hrs of collection of

Effects of (-)-sesamin on motor and memory deficits in an MPTP-lesioned mouse model of Parkinson's disease treated with l-DOPA.

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Zhao, T T; Shin, K S; Kim, K S; Park, H J; Kim, H J; Lee, K E; Lee, M K

2016-12-17

The present study investigated the effects of (-)-sesamin on motor and memory deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) with l-3,4-dihydroxyphenylalanine (l-DOPA). MPTP-lesioned (30mg/kg/day, 5days) mice showed deficits in memory including habit learning memory and spatial memory, which were further aggravated by daily treatment with 25mg/kg l-DOPA for 21days. However, daily treatment with (-)-sesamin (25 and 50mg/kg) for 21days ameliorated memory deficits in an MPTP-lesioned mouse model of PD treated with l-DOPA (25mg/kg). Both (-)-sesamin doses reduced decreases in the retention latency time in the passive avoidance test, latency to fall of rotarod test and distance traveled in the open field test, and attenuated decreases in tyrosine hydroxylase (TH)-immunopositive cells, dopamine, and its metabolites in the substantia nigra-striatum. (-)-Sesamin reduced increases in the retention transfer latency time in the elevated plus-maze test and N-methyl-d-aspartate receptor (NMDAR) expression and reduced decreases in the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus. In contrast, daily treatment with 10mg/kg l-DOPA for 21days ameliorated memory deficits in MPTP-lesioned mice, and this effect was further improved by treatment with (-)-sesamin (25 and 50mg/kg). These results suggest that (-)-sesamin protects against habit learning memory deficits by activating the dopamine neuronal system, while spatial memory deficits are decreased by its modulatory effects on the NMDAR-ERK1/2-CREB system. Accordingly, (-)-sesamin may act as an adjuvant phytonutrient for motor and memory deficits in patients with PD receiving l-DOPA. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Dysphagia Causes Symptom Fluctuations after Oral L-DOPA Treatment in a Patient with Parkinson Disease

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Hiromasa Sato

2018-03-01

Full Text Available Objective: The causes of “delayed-on” and “no-on” phenomena in Parkinson disease (PD are thought to have some impact on the progress of L-DOPA from the time of ingestion until it reaches the brain and is converted to dopamine. Dysphagia can cause fluctuating symptom expression in L-DOPA therapy for PD. Case Description: A 69-year-old man with PD presented with “delayed-on” and “no-on” phenomena. The patient developed a gait disorder at age 60 years, and he began coughing on his food during breakfast at age 64 years. Even though he was independent in daily life, he could not eat because of dysphagia in an “off” state. Videofluoroscopic examination of swallowing in an “off” state revealed bradykinesia of the tongue and the retention of tablets in the epiglottic vallecula. We trained him to keep his tongue in strong contact with the upper incisors before swallowing. After rehabilitation of dysphagia, the frequency of “delayed-on” and “no-on” phenomena decreased, and his peak L-DOPA plasma concentration was elevated. Additionally, transdermal rotigotine (RTG was initiated at a maintenance dose of 9.0 mg. The patient reported improvement in swallowing, and the frequency of “no-on” phenomena decreased. Conclusion: In PD patients, the “no-on” phenomenon can be caused by posterior contractile dysfunction of the tongue, and it can be improved with training of the tongue and transdermal RTG administration.

Single or combined treatment with L-DOPA and quinpirole differentially modulate expression and phosphorylation of key regulatory kinases in neuroblastoma cells.

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Fuzzati-Armentero, Marie Therese; Ghezzi, Cristina; Nisticò, Robert; Oda, Adriano; Blandini, Fabio

2013-09-27

In the past decades, the clinical use of dopamine agonists has expanded from adjunct therapy in patients with a deteriorating response to L-3,4-dihydroxyphenylalanine (L-DOPA) to monotherapy for the treatment of early PD. Dopamine agonists provide their antiparkinsonian benefit through stimulation of brain postsynaptic type 2 dopamine receptors that exert their effect through classical cAMP-dependent mechanisms, as well as cAMP-independent cellular signaling cascades, including the Akt/glycogen synthase kinase 3 (GSK3) pathway. Alterations of Akt/GSK3 have been observed and may contribute to the neurodegenerative processes and the development of L-DOPA-induced dyskinesia. The effects L-DOPA and quinpirole, a dopamine agonist, on the two key regulatory kinases, Akt and GSK3, were evaluated in neuroblastoma cell line. L-DOPA and dopamine agonist dose-dependently and differentially modulated Akt and GSK3 expression and phosphorylation when added alone or combined. The combined treatment inverted or potentiated the modulatory properties of the single compound. The drug- and concentration-dependent balance of dopamine receptor stimulation over auto-oxidation may distinctively modulate GSK3 isoforms and Akt. Our results indicate that particular attention must be given to drug concentration and combination when multiple therapies are applied for the clinical treatment of PD patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Untangling cortico-striatal connectivity and cross-frequency coupling in L-DOPA-induced dyskinesia

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Jovana eBelic

2016-03-01

Full Text Available We simultaneously recorded local field potentials in the primary motor cortex and sensorimotor striatum in awake, freely behaving, 6-OHDA lesioned hemi-parkinsonian rats in order to study the features directly related to pathological states such as parkinsonian state and levodopa-induced dyskinesia. We analysed the spectral characteristics of the obtained signals and observed that during dyskinesia the most prominent feature was a relative power increase in the high gamma frequency range at around 80 Hz, while for the parkinsonian state it was in the beta frequency range. Here we show that during both pathological states effective connectivity in terms of Granger causality is bidirectional with an accent on the striatal influence on the cortex. In the case of dyskinesia, we also found a high increase in effective connectivity at 80 Hz. In order to further understand the 80- Hz phenomenon, we performed cross-frequency analysis and observed characteristic patterns in the case of dyskinesia but not in the case of the parkinsonian state or the healthy state. We noted a large decrease in the modulation of the amplitude at 80 Hz by the phase of low frequency oscillations (up to ~10 Hz across both structures in the case of dyskinesia. This may suggest a lack of coupling between the low frequency activity of the recorded network and the group of neurons active at ~80 Hz.

PET imaging of dopamine transporters with [18F]FE-PE2I: Effects of anti-Parkinsonian drugs

International Nuclear Information System (INIS)

Bang, Ji-In; Jung, In Soon; Song, Yoo Sung; Park, Hyun Soo; Moon, Byung Seok; Lee, Byung Chul; Kim, Sang Eun

2016-01-01

Purpose: This study aimed to assess the striatal [ 18 F]FE-PE2I binding and the immunohistochemical stain of tyrosine hydroxylase (TH) in the striatum, and to evaluate the effects of therapeutic drugs on [ 18 F]FE-PE2I binding. Methods: Dynamic PET/CT of [ 18 F]FE-PE2I was performed in Parkinson’s disease (PD) rat models, induced by the unilateral injection of 6-OHDA into the striatum. A simplified reference tissue model method was used to calculate the striatal binding potential (striatal BP ND ). Each of the four normal rats was pretreated with pramipexole, amantadine, and escitalopram 30 min before [ 18 F]FE-PE2I injection. The effect of L-DOPA combined with benserazide was assessed in the normal and PD rats. Results: The BP ND was significantly lower in the lesioned striatum than in the striatum of the normal rats. After the pretreatment with pramipexole, amantadine, and escitalopram, the values of the striatal BP ND did not differ from those of the controls. The pretreatment with L-DOPA/benserazide, however, significantly reduced the striatal BP ND . The striatal BP ND of the PD rats with L-DOPA/benserazide pretreatment was not different from that of the same PD rats with placebo treatment. Conclusion: [ 18 F]FE-PE2I may be used as a radioligand for the in-vivo imaging of the DAT. In the normal rats, [ 18 F]FE-PE2I binding is unaffected by pramipexole, amantadine, and escitalopram. L-DOPA/benserazide does not affect the striatal [ 18 F]FE-PE2I binding in PD rats

Complementary PET studies of striatal neuronal function in the differential diagnosis between multiple system atrophy and Parkinson's disease

NARCIS (Netherlands)

Antonini, A; Leenders, KL; Vontobel, P; Maguire, RP; Missimer, J; Psylla, M; Gunther, [No Value

1997-01-01

We used PET with the tracers [F-18]fluorodeoxyglucose (FDG), [F-18]fluorodopa (FDOPA) and [C-11]raclopride (RACLO) to study striatal glucose and dopa metabolism, and dopamine D-2 receptor binding, respectively, in nine patients with multiple system atrophy. Ten patients with classical Parkinson's

The added value of [{sup 18}F]fluoro-L-DOPA PET in the diagnosis of hyperinsulinism of infancy: a retrospective study involving 49 children

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Ribeiro, Maria-Joao; Bourgeois, Sandrine; Delzescaux, Thierry [Frederic Joliot Hospital, Biomedical Imaging Institute, Life Sciences Division, CEA, Orsay (France); Boddaert, Nathalie; Brunelle, Francis [Necker-Enfants Malades Hospital, AP-HP, Department of Radiology, Paris (France); Bellanne-Chantelot, Christine [Saint-Antoine Hospital, AP-HP, Department of Cytogenetics, Paris (France); Valayannopoulos, Vassili; Lonlay, Pascale de [Necker-Enfants Malades Hospital, AP-HP, Department of Pediatrics, Paris (France); Jaubert, Francis [Necker-Enfants Malades Hospital, AP-HP, Department of Pathology, Paris (France); Nihoul-Fekete, Claire [Necker-Enfants Malades Hospital, AP-HP, Department of Surgery, Paris (France)

2007-12-15

Neuroendocrine diseases are a heterogeneous group of entities with the ability to take up amine precursors, such as L-DOPA, and convert them into biogenic amines, such as dopamine. Congenital hyperinsulinism of infancy (HI) is a neuroendocrine disease secondary to either focal adenomatous hyperplasia or a diffuse abnormal pancreatic insulin secretion. While focal hyperinsulinism may be reversed by selective surgical resection, diffuse forms require near-total pancreatectomy when resistant to medical treatment. Here, we report the diagnostic value of PET with [{sup 18}F]fluoro-L-DOPA in distinguishing focal from diffuse HI. Forty-nine children were studied with [{sup 18}F]fluoro-L-DOPA. A thoraco-abdominal scan was acquired 45-65 min after the injection of 4.2 {+-} 1.0 MBq/kg of [{sup 18}F]fluoro-L-DOPA. Additionally, 12 of the 49 children were submitted to pancreatic venous catheterisation for blood samples (PVS) and 31 were also investigated using MRI. We identified abnormal focal pancreatic uptake of [{sup 18}F]fluoro-L-DOPA in 15 children, whereas diffuse radiotracer uptake was observed in the pancreatic area in the other 34 patients. In children studied with both PET and PVS, the results were concordant in 11/12 cases. All patients with focal radiotracer uptake and nine of the patients with diffuse pancreatic radiotracer accumulation, unresponsive to medical treatment, were submitted to surgery. In 21 of these 24 patients, the histopathological results confirmed the PET findings. In focal forms, selective surgery was followed by clinical remission without carbohydrate intolerance. These data demonstrate that PET with [{sup 18}F]fluoro-L-DOPA is an accurate non-invasive technique allowing differential diagnosis between focal and diffuse forms of HI. (orig.)

Synthesis of no-carrier-added L- and D-[1-11C]-DOPA

International Nuclear Information System (INIS)

Bolster, J.M.; Vaalburg, W.; Veen, W. van; Dijk, Th. van; Molen, H.D. van der; Wynberg, H.; Woldring, M.G.; Rijksuniversiteit Groningen

1983-01-01

No-carrier-added DL-[1- 11 C]-DOPA has been synthesized by carboxylation of an α-lithioisocyanide with a radiochemical yield of up to 15% without correction for decay. The total synthesis time is 30 min. The resolution of the D- and L-isomers was accomplished within 16 min by HPLC using a chiral stationary phase and a phosphate buffer of pH 4.5 as eluent. (author)

Carbidopa-based modulation of the functional effect of the AAV2-hAADC gene therapy in 6-OHDA lesioned rats.

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Agnieszka Ciesielska

Full Text Available Progressively blunted response to L-DOPA in Parkinson's disease (PD is a critical factor that complicates long-term pharmacotherapy in view of the central importance of this drug in management of the PD-related motor disturbance. This phenomenon is likely due to progressive loss of one of the key enzymes involved in the biosynthetic pathway for dopamine in the basal ganglia: aromatic L-amino acid decarboxylase (AADC. We have developed a gene therapy based on an adeno-associated virus encoding human AADC (AAV2-hAADC infused into the Parkinsonian striatum. Although no adverse clinical effects of the AAV2-hAADC gene therapy have been observed so far, the ability to more precisely regulate transgene expression or transgene product activity could be an important long-term safety feature. The present study was designed to define pharmacological regulation of the functional activity of AAV2-hAADC transgene product by manipulating L-DOPA and carbidopa (AADC inhibitor administration in hemi-parkinsonian rats. Thirty days after unilateral striatal infusion of AAV2-hAADC, animals displayed circling behavior and acceleration of dopamine metabolism in the lesioned striatum after administration of a low dose of L-DOPA (5 mg/kg co-administered with 1.25 mg/kg of carbidopa. This phenomenon was not observed in control AAV2-GFP-treated rats. Withdrawal of carbidopa from a daily L-DOPA regimen decreased the peripheral L-DOPA pool, resulting in almost total loss of L-DOPA-induced behavioral response in AAV2-hAADC rats and a significant decline in striatal dopamine turnover. The serum L-DOPA level correlated with the magnitude of circling behavior in AAV2-hAADC rats. Additionally, AADC activity in homogenates of lesioned striata transduced by AAV2-AADC was 10-fold higher when compared with AAV2-GFP-treated control striata, confirming functional transduction. Our data suggests that the pharmacological regulation of circulating L-DOPA might be effective in the

OCCURRENCE OF L-DOPA AND DOPAMINE IN PLANTS AND CELL-CULTURES OF MUCUNA-PRURIENS AND EFFECTS OF 2,4-D AND NACL ON THESE COMPOUNDS

NARCIS (Netherlands)

WICHERS, HJ; VISSER, JF; HUIZING, HJ; PRAS, N

The development of the L-DOPA-content of roots, stems and leaves of Mucuna pruriens during growth of the plants is described. Besides L-DOPA, the leaves, but not the stems and the roots, also contain the related catechol dopamine. The time course of dopamine accumulation is compared to that of

Identification by virtual screening and in vitro testing of human DOPA decarboxylase inhibitors.

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Frederick Daidone

Full Text Available Dopa decarboxylase (DDC, a pyridoxal 5'-phosphate (PLP enzyme responsible for the biosynthesis of dopamine and serotonin, is involved in Parkinson's disease (PD. PD is a neurodegenerative disease mainly due to a progressive loss of dopamine-producing cells in the midbrain. Co-administration of L-Dopa with peripheral DDC inhibitors (carbidopa or benserazide is the most effective symptomatic treatment for PD. Although carbidopa and trihydroxybenzylhydrazine (the in vivo hydrolysis product of benserazide are both powerful irreversible DDC inhibitors, they are not selective because they irreversibly bind to free PLP and PLP-enzymes, thus inducing diverse side effects. Therefore, the main goals of this study were (a to use virtual screening to identify potential human DDC inhibitors and (b to evaluate the reliability of our virtual-screening (VS protocol by experimentally testing the "in vitro" activity of selected molecules. Starting from the crystal structure of the DDC-carbidopa complex, a new VS protocol, integrating pharmacophore searches and molecular docking, was developed. Analysis of 15 selected compounds, obtained by filtering the public ZINC database, yielded two molecules that bind to the active site of human DDC and behave as competitive inhibitors with K(i values ≥10 µM. By performing in silico similarity search on the latter compounds followed by a substructure search using the core of the most active compound we identified several competitive inhibitors of human DDC with K(i values in the low micromolar range, unable to bind free PLP, and predicted to not cross the blood-brain barrier. The most potent inhibitor with a K(i value of 500 nM represents a new lead compound, targeting human DDC, that may be the basis for lead optimization in the development of new DDC inhibitors. To our knowledge, a similar approach has not been reported yet in the field of DDC inhibitors discovery.

MUCUNA PRURIENS - IMPROVEMENT OF THE BIOTECHNOLOGICAL PRODUCTION OF THE ANTI-PARKINSON DRUG L-DOPA BY PLANT-CELL SELECTION

NARCIS (Netherlands)

PRAS, N; WOERDENBAG, HJ; BATTERMAN, S; VISSER, JF; VANUDEN, W

1993-01-01

Routinely grown cell suspension cultures of Mucuna pruriens L. (Fabaceae) were able to endogenously accumulate the anti-Parkinson drug L-dihydroxyphenylalanine (L-dopa) in the range between 0.2 and 2% on a dry weight (DW) basis. The green colour that developed in light-exposed cultures, appeared to

Differential effects of gaseous versus injectable anesthetics on changes in regional cerebral blood flow and metabolism induced by l-DOPA in a rat model of Parkinson's disease.

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Bimpisidis, Zisis; Öberg, Carl M; Maslava, Natallia; Cenci, M Angela; Lundblad, Cornelia

2017-06-01

Preclinical imaging of brain activity requires the use of anesthesia. In this study, we have compared the effects of two widely used anesthetics, inhaled isoflurane and ketamine/xylazine cocktail, on cerebral blood flow and metabolism in a rat model of Parkinson's disease and l-DOPA-induced dyskinesia. Specific tracers were used to estimate regional cerebral blood flow (rCBF - [ 14 C]-iodoantipyrine) and regional cerebral metabolic rate (rCMR - [ 14 C]-2-deoxyglucose) with a highly sensitive autoradiographic method. The two types of anesthetics had quite distinct effects on l-DOPA-induced changes in rCBF and rCMR. Isoflurane did not affect either the absolute rCBF values or the increases in rCBF in the basal ganglia after l-DOPA administration. On the contrary, rats anesthetized with ketamine/xylazine showed lower absolute rCBF values, and the rCBF increases induced by l-DOPA were masked. We developed a novel improved model to calculate rCMR, and found lower metabolic activities in rats anesthetized with isoflurane compared to animals anesthetized with ketamine/xylazine. Both anesthetics prevented changes in rCMR upon l-DOPA administration. Pharmacological challenges in isoflurane-anesthetized rats indicated that drugs mimicking the actions of ketamine/xylazine on adrenergic or glutamate receptors reproduced distinct effects of the injectable anesthetics on rCBF and rCMR. Our results highlight the importance of anesthesia in studies of cerebral flow and metabolism, and provide novel insights into mechanisms mediating abnormal neurovascular responses to l-DOPA in Parkinson's disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Excessive sensitivity to uncertain visual input in L-dopa induced dyskinesias in Parkinson’s disease: further implications for cerebellar involvement

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James eStevenson

2014-02-01

Full Text Available When faced with visual uncertainty during motor performance, humans rely more on predictive forward models and proprioception and attribute lesser importance to the ambiguous visual feedback. Though disrupted predictive control is typical of patients with cerebellar disease, sensorimotor deficits associated with the involuntary and often unconscious nature of L-dopa-induced dyskinesias in Parkinson’s disease (PD suggests dyskinetic subjects may also demonstrate impaired predictive motor control. Methods: We investigated the motor performance of 9 dyskinetic and 10 non-dyskinetic PD subjects on and off L-dopa, and of 10 age-matched control subjects, during a large-amplitude, overlearned, visually-guided tracking task. Ambiguous visual feedback was introduced by adding ‘jitter’ to a moving target that followed a Lissajous pattern. Root mean square (RMS tracking error was calculated, and ANOVA, robust multivariate linear regression and linear dynamical system analyses were used to determine the contribution of speed and ambiguity to tracking performance. Results: Increasing target ambiguity and speed contributed significantly more to the RMS error of dyskinetic subjects off medication. L-dopa improved the RMS tracking performance of both PD groups. At higher speeds, controls and PDs without dyskinesia were able to effectively de-weight ambiguous visual information. Conclusions: PDs’ visually-guided motor performance degrades with visual jitter and speed of movement to a greater degree compared to age-matched controls. However, there are fundamental differences in PDs with and without dyskinesia: subjects without dyskinesia are generally slow, and less responsive to dynamic changes in motor task requirements but, PDs with dyskinesia there was a trade-off between overall performance and inappropriate reliance on ambiguous visual feedback. This is likely associated with functional changes in posterior parietal-ponto-cerebellar pathways.

Enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens by liquid chromatography/mass spectrometry.

Science.gov (United States)

Hasegawa, Takashi; Takahashi, Kazunaga; Fukiwake, Tomohide; Saijo, Masaaki; Motoki, Yuji

2013-01-01

We developed a simple and rapid liquid chromatography/mass spectrometry (LC/MS) method for the enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens. L- and D-DOPA were ultrasonically extracted with 1% formic acid aqueous solution. The isolated extracts were analyzed by LC/MS using a Crownpak CR (-) column at 30℃. The mass spectrometer was operated in the positive mode of electrospray ionization, and the mobile phase was aqueous formic acid (pH 2.0). L-DOPA-ring-d3 was used as an internal standard. The method was validated for a dietary supplement spiked with L- and D-DOPA at 50 and 500 μg/g, respectively, and the recoveries of the DOPA enantiomers were between 97.5% and 101.3%. Relative standard deviation values of repeatability and intermediate precision were less than 7%. The method was applied to 14 dietary supplements. L-DOPA was detected in these supplements in the range of 0.88-12.8 mg/unit. D-DOPA was not detected.

Gynostemma pentaphyllum Ethanolic Extract Protects Against Memory Deficits in an MPTP-Lesioned Mouse Model of Parkinson's Disease Treated with L-DOPA.

Science.gov (United States)

Kim, Kyung Sook; Zhao, Ting Ting; Shin, Keon Sung; Park, Hyun Jin; Cho, Yoon Jeong; Lee, Kyung Eun; Kim, Seung Hwan; Lee, Myung Koo

2017-01-01

This study investigated the effects of ethanol extract from Gynostemma pentaphyllum (GP-EX) on memory deficits in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) (MPTP-lesioned mice). MPTP (30 mg/kg/day, 5 days)-lesioned mice showed deficits of habit learning memory and spatial memory, which were further aggravated by treatment with L-3,4-dihydroxyphenylalanine (L-DOPA) (25 mg/kg, 21 days). However, treatment with GP-EX (50 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice treated with L-DOPA (25 mg/kg): GP-EX prevented the decreases in retention latency time in the passive avoidance test and tyrosine hydroxylase-immunopositive cells and dopamine levels in the nigrostriatum. GP-EX also reduced increases in retention transfer latency time of the elevated plus-maze test and expression of N-methyl-D-aspartate (NMDA) receptor and improved decreases in phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus in the same models. By contrast, L-DOPA treatment (10 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice, which were further improved by GP-EX treatment. These results suggest that GP-EX ameliorates habit learning memory deficits by activating dopaminergic neurons and spatial memory deficits by modulating NMDA receptor-ERK1/2-CREB system in MPTP-lesioned mice treated with L-DOPA. GP-EX may serve as an adjuvant phytonutrient for memory deficits in PD.

Imaging mass spectrometry reveals elevated nigral levels of dynorphin neuropeptides in L-DOPA-induced dyskinesia in rat model of Parkinson's disease.

Directory of Open Access Journals (Sweden)

Anna Ljungdahl

Full Text Available L-DOPA-induced dyskinesia is a troublesome complication of L-DOPA pharmacotherapy of Parkinson's disease and has been associated with disturbed brain opioid transmission. However, so far the results of clinical and preclinical studies on the effects of opioids agonists and antagonists have been contradictory at best. Prodynorphin mRNA levels correlate well with the severity of dyskinesia in animal models of Parkinson's disease; however the identities of the actual neuroactive opioid effectors in their target basal ganglia output structures have not yet been determined. For the first time MALDI-TOF imaging mass spectrometry (IMS was used for unbiased assessment and topographical elucidation of prodynorphin-derived peptides in the substantia nigra of a unilateral rat model of Parkinson's disease and L-DOPA induced dyskinesia. Nigral levels of dynorphin B and alpha-neoendorphin strongly correlated with the severity of dyskinesia. Even if dynorphin peptide levels were elevated in both the medial and lateral part of the substantia nigra, MALDI IMS analysis revealed that the most prominent changes were localized to the lateral part of the substantia nigra. MALDI IMS is advantageous compared with traditional molecular methods, such as radioimmunoassay, in that neither the molecular identity analyzed, nor the specific localization needs to be predetermined. Indeed, MALDI IMS revealed that the bioconverted metabolite leu-enkephalin-arg also correlated positively with severity of dyskinesia. Multiplexing DynB and leu-enkephalin-arg ion images revealed small (0.25 by 0.5 mm nigral subregions with complementing ion intensities, indicating localized peptide release followed by bioconversion. The nigral dynorphins associated with L-DOPA-induced dyskinesia were not those with high affinity to kappa opioid receptors, but consisted of shorter peptides, mainly dynorphin B and alpha-neoendorphin that are known to bind and activate mu and delta opioid receptors

A Role for Mitogen- and Stress-Activated Kinase 1 in L-DOPA-Induced Dyskinesia and ∆FosB Expression

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Feyder, Michael; Södersten, Erik; Santini, Emanuela

2014-01-01

BACKGROUND: Abnormal regulation of extracellular signal-regulated kinases 1 and 2 has been implicated in 3,4-dihydroxy-l-phenylalanine (L-DOPA)-induced dyskinesia (LID), a motor complication affecting Parkinson's disease patients subjected to standard pharmacotherapy. We examined the involvement...... of mitogen- and stress-activated kinase 1 (MSK1), a downstream target of extracellular signal-regulated kinases 1 and 2, and an important regulator of transcription in LID. METHODS: 6-Hydroxydopamine was used to produce a model of Parkinson's disease in MSK1 knockout mice and in ∆FosB- or ∆c......Jun-overexpressing transgenic mice, which were assessed for LID following long-term L-DOPA administration. Biochemical processes were evaluated by Western blotting or immunofluorescence. Histone H3 phosphorylation was analyzed by chromatin immunoprecipitation followed by promotor-specific quantitative polymerase chain reaction...

Mapping of central dopamine synthesis in man, using positron emission tomography with L-[β-11C]DOPA

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Ito, Hiroshi; Shidahara, Miho; Takano, Harumasa; Takahashi, Hidehiko; Nozaki, Shoko; Suhara, Tetsuya

2007-01-01

The objective of this study was to estimate the presynaptic function of the central dopaminergic system, positron emission tomography measurement of the endogenous dopamine synthesis rate was performed with L-[β- 11 C]dihydroxyphenylanine (DOPA). In the present study, we developed a simple method for calculating an indicator of the dopamine synthesis rate with L-[β- 11 C]DOPA on a voxel-by-voxel basis for parametric mapping. After intravenous injection of L-[β- 11 C]DOPA, dynamic scanning was performed on ten healthy men for 89 min. The dopamine synthesis ratio was calculated on a voxel-by-voxel basis as the ratio of the area under the time-activity curves of brain regions to the reference brain region, that is, occipital cortex. The overall uptake rate constant as an indicator of dopamine synthesis was also calculated by kinetic and graphical analyses. The dopamine synthesis ratio calculated by the present method was in good agreement with the indicators of dopamine synthesis calculated by kinetic and graphical analyses, although a systemic underestimation was observed, especially when the integration interval was set in the early phase of the scan duration. In particular, underestimations were prominent in brain regions with relatively lower influx rate constant K 1 . By this method, regional dopamine synthesis could be estimated on a voxel-by-voxel basis. This method does not need an arterial input function and should prove to be useful for clinical research. (author)

[Deep brain stimulation in parkinsonian patients with dopa intolerance].

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García-Ruiz, Pedro J; Feliz-Feliz, Cici; Ayerbe Gracia, Joaquín; Matías Arbelo, José; Salvador, Carlos; Val Fernández, Javier Del; García-Caldentey, Juan

2017-10-28

Deep brain stimulation (DBS) is at present, a useful treatment for patients with advanced Parkinson's disease and motor complications. The crucial step toward consistent DBS outcomes remains careful patient selection; several conditions must be fulfilled including excellent levo dopa response. We report two cases of early onset Parkinson's disease with severe intolerance to levo dopa but excellent and sustained response to DBS. DBS can be a useful alternative for parkinsonian patients with severe intolerance to levo dopa, provided a positive acute response to levo dopa or apomorphine is obtained. Copyright © 2017 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

Involuntary expiratory phonation as a dose-related consequence of L-dopa therapy in a patient with Parkinson's disease.

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Ishii, Kosuke; Kumada, Masanobu; Ueki, Akira; Yamamoto, Masanori; Hirose, Hajime

2003-12-01

We report a case of involuntary phonation caused by abnormal vocal cord movements during expiration in a patient with Parkinson's disease. A 60-year-old woman had been treated for parkinsonism at the outpatient clinic of the Department of Neurology since August 1999. She began to groan involuntarily in the daytime in September 2001. She could not eat well while groaning. Stridor was not noted during sleep at night. Endoscopic examination of the larynx revealed insufficient abduction of the bilateral vocal cords, although the glottis was not so small as to cause stridor during inspiration. During expiration, however, the vocal cords adducted, resulting in the involuntary production of voice. Electromyography showed an increase in the activity of the thyroarytenoid and lateral cricoarytenoid muscles. This muscle activity was further enhanced during inspiration. The involuntary phonation disappeared when the patient's dose of L-dopa was decreased, although she had a decrease in her systemic mobility as well. When the dose of L-dopa was increased to the therapeutic level, involuntary phonation recurred, and her voluntary systemic activity improved. In the present case, it was considered that excessive dopaminergic denervation occurred in the nerve innervating the laryngeal adductors. Involuntary voice appeared to be produced by hypertonus of the laryngeal adductors because of a lowering in the threshold level for L-dopa, even though the drug was administered at the usual dose.

Variation of L-DOPA in the leaf and flower tissues of seven faba bean accessions with different flower colors

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Faba bean (Vicia faba L.) has been selected to adapt to a wide range of environments worldwide and is grown for different end-uses such as food, feed, forage and green manure. Particularly noteworthy in faba bean is the medicinally important component L-3,4-dihydroxy phenylalanine (L-DOPA), the majo...

D2 receptor genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans.

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Fazio, Leonardo; Blasi, Giuseppe; Taurisano, Paolo; Papazacharias, Apostolos; Romano, Raffaella; Gelao, Barbara; Ursini, Gianluca; Quarto, Tiziana; Lo Bianco, Luciana; Di Giorgio, Annabella; Mancini, Marina; Popolizio, Teresa; Rubini, Giuseppe; Bertolino, Alessandro

2011-02-14

Pre-synaptic D2 receptors regulate striatal dopamine release and DAT activity, key factors for modulation of motor pathways. A functional SNP of DRD2 (rs1076560 G>T) is associated with alternative splicing such that the relative expression of D2S (mainly pre-synaptic) vs. D2L (mainly post-synaptic) receptor isoforms is decreased in subjects with the T allele with a putative increase of striatal dopamine levels. To evaluate how DRD2 genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans, we have investigated the association of rs1076560 with BOLD fMRI activity during a motor task. To further evaluate the relationship of this circuitry with dopamine signaling, we also explored the correlation between genotype based differences in motor brain activity and pre-synaptic striatal DAT binding measured with [(123)I] FP-CIT SPECT. Fifty healthy subjects, genotyped for DRD2 rs1076560 were studied with BOLD-fMRI at 3T while performing a visually paced motor task with their right hand; eleven of these subjects also underwent [(123)I]FP-CIT SPECT. SPM5 random-effects models were used for statistical analyses. Subjects carrying the T allele had greater BOLD responses in left basal ganglia, thalamus, supplementary motor area, and primary motor cortex, whose activity was also negatively correlated with reaction time at the task. Moreover, left striatal DAT binding and activity of left supplementary motor area were negatively correlated. The present results suggest that DRD2 genetic variation was associated with focusing of responses in the whole motor network, in which activity of predictable nodes was correlated with reaction time and with striatal pre-synaptic dopamine signaling. Our results in humans may help shed light on genetic risk for neurobiological mechanisms involved in the pathophysiology of disorders with dysregulation of striatal dopamine like Parkinson's disease. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of trihexyphenidyl and L-dopa on brain muscarinic cholinergic receptor binding measured by positron emission tomography

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Shinotoh, H; Asahina, M; Hirayama, K [Dept. of Neurology, School of Medicine, Chiba Univ., Chiba (Japan); Inoue, O; Suhara, T; Tateno, Y [Division of Clinical Research, National Inst. of Radiological Sciences, Chiba (Japan)

1994-01-01

The effects of pharmacological intervention on brain muscarinic cholinergic receptor (mAChR) binding were assessed in seven patients with Parkinson's disease by positron emission tomography and carbon-11 labelled N-methyl-4-piperidyl benzilate ([[sup 11]C]NMPB). [[sup 11]C]NMPB was injected twice, approximately 2 hours apart, in each patient, to assess the effect of single doses of 4 mg of trihexyphenidyl (n=5) or 400 mg of L-dopa with 57 mg of benserazide (n=2) on the binding parameter of mAChRs (K[sub 3]). There was a mean 28% inhibition of K[sub 3] values in the brain in the presence of trihexyphenidyl, which was assumed to reflect mAChR occupancy. No significant change in K[sub 3] was observed in the presence of L-dopa. This study demonstrates the feasibility of measuring mAChR occupancy by an anticholinergic medication with PET.

On the synthesis of radiofluorinated amino acids by isotope exchange based on the example of 6-[18F]Fluor-L-DOPA

International Nuclear Information System (INIS)

Wagner, F.M.

2008-06-01

In nuclear medical diagnosis, 6-[ 18 F]fluoro-L-3,4-dihydroxyphenylalanine (6-[ 18 F]fluoro-LDOPA), an analogue of L-DOPA, is one of the few established radiopharmaceuticals used for the in vivo investigation of the presynaptic dopaminergic metabolism and of some kind of tumours via Positron Emission Tomography (PET). The presently used method of preparation of the radiotracer by electrophilic labelling is limited to low amounts of activity at high costs. Known nucleophilic syntheses, however, result either in insufficient enantiomeric purity or the known multi-step syntheses are hard to automate, due to their complexity. During this work a novel, easy to automate alternative for the preparation of 6-[ 18 F]fluoro-L-DOPA, was developed and evaluated, using a direct nucleophilic 18 F-fluorination of a protected amino acid derivative. The resulting product has a very high enantiomeric purity. At first, the general suitability of the (S)-BOC-BMI-derivatives for the synthesis of 18 F-labelled amino acids, used in this work, was investigated using a less complex precursor, which resulted in the amino acid 6-[ 18 F]fluoro-L-m-tyrosin via acidic hydrolysis. The preparation of a useful precursor for the nucleophilic 18 F-isotope substitution, namely the (2S,5S)-tert.-butyl- 5-(2-fluoro-5-formylbenzyl)-2-tert. -butyl-3-methyl-4-oxoimidazolidine-1-carbox= yl ate, was investigated in three general different ways. At first it was tried to obtain this product via formylation after coupling with the BOC-BMI, secondly via α,β-dehydro amino acid derivatives and finally via a systematic multi-step synthesis. Only the last mentioned way resulted in a precursor with sufficient purity that could be labelled. The radiochemical yield of the isotopic exchange was about 60 %. In the next step, the presented concept was modified to synthesize a precursor for the preparation of 6-[ 18 F]fluoro-L-DOPA. Only a combination of the protecting groups benzyl and THP resulted in the useful

Protective effect of two essential oils isolated from Rosa damascena Mill. and Lavandula angustifolia Mill, and two classic antioxidants against L-dopa oxidative toxicity induced in healthy mice.

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Nikolova, Galina; Karamalakova, Yanka; Kovacheva, Natasha; Stanev, Stanko; Zheleva, Antoaneta; Gadjeva, Veselina

2016-11-01

Levodopa (L-dopa) is a "gold standard" and most effective symptomatic agent in the Parkinson's disease (PD) treatment. The several treatments have been developed in an attempt to improve PD treatment, but most patients were still levodopa dependent. The issue of toxicity was raised in vitro studies, and suggests that L-dopa can be toxic to dopaminergic neurons, but it is not yet entirely proven. L-dopa prolonged treatment is associated with motor complications and some limitations. Combining the L-dopa therapy with antioxidants can reduce related sideeffects and provide symptomatic relief. The natural antioxidants can be isolated from any plant parts such as seeds, leaves, roots, bark, etc., and their extracts riched in phenols can retard the oxidative degradation of the lipids, proteins and DNA. Thus, study suggests that combination of essential oils (Rose oil and Lavender oil), Vitamin C and Trolox with Ldopa can reduce oxidative toxicity, and may play a key role in ROS/RNS disarm. Copyright © 2016 Elsevier Inc. All rights reserved.

Overexpression of blood microRNAs 103a, 30b, and 29a in L-dopa-treated patients with PD.

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Serafin, Alice; Foco, Luisa; Zanigni, Stefano; Blankenburg, Hagen; Picard, Anne; Zanon, Alessandra; Giannini, Giulia; Pichler, Irene; Facheris, Maurizio F; Cortelli, Pietro; Pramstaller, Peter P; Hicks, Andrew A; Domingues, Francisco S; Schwienbacher, Christine

2015-02-17

The aims of the present study were to profile the expression of several candidate microRNAs (miRNAs) in blood from L-dopa-treated and drug-naive patients with Parkinson disease (PD) vs unaffected controls and to interpret the miRNA expression data in a biological context. We analyzed RNAs from peripheral blood of 36 L-dopa-treated, 10 drug-naive patients with PD and unaffected controls matched 1:1 by sex and age. We evaluated expression by reverse transcription-quantitative real-time PCR, and we analyzed data using a 2-tailed paired t test. To detect miRNA targets, several miRNA resources were combined to generate an overall score for each candidate gene using weighted rank aggregation. Significant overexpression of miR-103a-3p (p < 0.0001), miR-30b-5p (p = 0.002), and miR-29a-3p (p = 0.005) in treated patients with PD was observed, and promising candidate target genes for these were revealed by an integrated in silico analysis. We revealed 3 candidate biomarkers for PD. miRNAs 30b-5p and 29a-3p replicated a documented deregulation in PD albeit opposite to published data, while for miR-103a-3p, we demonstrated for the first time an overexpression in treated patients with PD. Expression studies in patients and/or in isolated peripheral blood mononuclear cells before and after L-dopa administration are necessary to define the involvement of L-dopa treatment in the observed overexpression. Our in silico analysis to prioritize targets of deregulated miRNAs identified candidate target genes, including genes related to neurodegeneration and PD. Despite the preliminary character of our study, the results provide a rationale for further clarifying the role of the identified miRNAs in the pathogenesis of PD and for validating their diagnostic potential. © 2015 American Academy of Neurology.

In vivo detection of cranial dopaminergic processes: studies with L-1-C-11-Dopa and C-11-labelled ADTN derivatives

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Werf, J.F.v.d.; Kuilman, T.; Molen, H.D.v.d.; Paans, A.M.J.; Wiegman, T.; Korf, J.; Vaalburg, W.

1982-01-01

In this article, probably the first in literature, some results are presented of in vivo studies of carbon-11-labelled dopamine agonists in cats and dogs with positron emission tomography. Recently a method for the separation of D- and L-dopa enantiomers from the DL-dopa mixture was developed. These three compounds were injected intravenously and with PET cold spots in the striatium of dog's brains could be obtained, independently of pretreatment with carbidopa. The synthesis of carbon-11-labelled ADTN derivatives and their uses is discussed. (Auth.)

Influence of basal ganglia on upper limb locomotor synergies. Evidence from deep brain stimulation and L-DOPA treatment in Parkinson's disease.

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Crenna, P; Carpinella, I; Lopiano, L; Marzegan, A; Rabuffetti, M; Rizzone, M; Lanotte, M; Ferrarin, M

2008-12-01

Clinical evidence of impaired arm swing while walking in patients with Parkinson's disease suggests that basal ganglia and related systems play an important part in the control of upper limb locomotor automatism. To gain more information on this supraspinal influence, we measured arm and thigh kinematics during walking in 10 Parkinson's disease patients, under four conditions: (i) baseline (no treatment), (ii) therapeutic stimulation of the subthalamic nucleus (STN), (iii)L-DOPA medication and (iv) combined STN stimulation and L-DOPA. Ten age-matched controls provided reference data. Under baseline conditions the range of patients' arm motion was severely restricted, with no correlation with the excursion of the thigh. In addition, the arm swing was abnormally coupled in time with oscillation of the ipsilateral thigh. STN stimulation significantly increased the gait speed and improved the spatio-temporal parameters of arm and thigh motion. The kinematic changes as a function of gait speed changes, however, were significantly smaller for the upper than the lower limb, in contrast to healthy controls. Arm motion was also less responsive after L-DOPA. Simultaneous deep brain stimulation and L-DOPA had additive effects on thigh motion, but not on arm motion and arm-thigh coupling. The evidence that locomotor automatisms of the upper and lower limbs display uncorrelated impairment upon dysfunction of the basal ganglia, as well as different susceptibility to electrophysiological and pharmacological interventions, points to the presence of heterogeneously distributed, possibly partially independent, supraspinal control channels, whereby STN and dopaminergic systems have relatively weaker influence on the executive structures involved in the arm swing and preferential action on those for lower limb movements. These findings might be considered in the light of phylogenetic changes in supraspinal control of limb motion related to primate bipedalism.

Basal ganglia disorders associated with imbalances in the striatal striosome and matrix compartments

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Jill R. Crittenden

2011-09-01

Full Text Available The striatum is composed principally of GABAergic, medium spiny projection neurons (MSNs that can be categorized based on their gene expression, electrophysiological profiles and input-output circuits. Major subdivisions of MSN populations include 1 those in ventromedial and dorsolateral striatal regions, 2 those giving rise to the direct and indirect pathways, and 3 those that lie in the striosome and matrix compartments. The first two classificatory schemes have enabled advances in understanding of how basal ganglia circuits contribute to disease. However, despite the large number of molecules that are differentially expressed in the striosomes or the extra-striosomal matrix, and the evidence that these compartments have different input-output connections, our understanding of how this compartmentalization contributes to striatal function is still not clear. A broad view is that the matrix contains the direct and indirect pathway MSNs that form parts of sensorimotor and associative circuits, whereas striosomes contain MSNs that receive input from parts of limbic cortex and project directly or indirectly to the dopamine-containing neurons of the substantia nigra, pars compacta. Striosomes are widely distributed within the striatum and are thought to exert global, as well as local, influences on striatal processing by exchanging information with the surrounding matrix, including through interneurons that send processes into both compartments. It has been suggested that striosomes exert and maintain limbic control over behaviors driven by surrounding sensorimotor and associative parts of the striatal matrix. Consistent with this possibility, imbalances between striosome and matrix functions have been reported in relation to neurological disorders, including Huntington’s disease, L-DOPA-induced dyskinesias, dystonia and drug addiction. Here, we consider how signaling imbalances between the striosomes and matrix might relate to symptomatology in

Enkephalin and dynorphin neuropeptides are differently correlated with locomotor hypersensitivity and levodopa-induced dyskinesia in parkinsonian rats.

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Sgroi, Stefania; Capper-Loup, Christine; Paganetti, Paolo; Kaelin-Lang, Alain

2016-06-01

The opioidergic neuropeptides dynorphin (DYN) and enkephalin (ENK) and the D1 and D2 dopaminergic receptors (D1R, D2R) are involved in the striatal control of motor and behavioral function. In Parkinson's disease, motor disturbances such as "on-off" motor fluctuations and involuntary movements (dyskinesia) are severe complications that often arise after chronic l-dihydroxyphenylalanine (l-DOPA) treatment. Changes in the striatal expression of preproENK (PPENK), proDYN (PDYN), D1R, and D2R mRNA have been observed in parkinsonian animals treated with l-DOPA. Enhanced opioidergic transmission has been found in association with l-DOPA-induced dyskinesia, but the connection of PPENK, PDYN, D1R, and D2R mRNA expression with locomotor activity remains unclear. In this study, we measured PPENK, PDYN, D1R and D2R mRNA levels by in situ hybridization in the striatum of 6-OHDA hemi-parkinsonian rats treated with l-DOPA (PD+l-DOPA group), along with two control groups (PD+saline and naive+l-DOPA). We found different levels of expression of PPENK, PDYN, D1R and D2R mRNA across the experimental groups and correlated the changes in mRNA expression with dyskinesia and locomotor variables assessed by open field test during several phases of l-DOPA treatment. Both PDYN and PPENK mRNA levels were correlated with the severity of dyskinesia, while PPENK mRNA levels were also correlated with the frequency of contralateral rotational movements and with locomotor variables. Moreover, a strong correlation was found between D1R mRNA expression and D2R mRNA expression in the PD+l-DOPA group. These findings suggest that, in parkinsonian animals treated with l-DOPA, high levels of PPENK are a prerequisite for a locomotor sensitization to l-DOPA treatment, while PDYN overexpression is responsible only for the development of dyskinesia. Copyright © 2016 Elsevier Inc. All rights reserved.

Adversity in childhood linked to elevated striatal dopamine function in adulthood.

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Egerton, Alice; Valmaggia, Lucia R; Howes, Oliver D; Day, Fern; Chaddock, Christopher A; Allen, Paul; Winton-Brown, Toby T; Bloomfield, Michael A P; Bhattacharyya, Sagnik; Chilcott, Jack; Lappin, Julia M; Murray, Robin M; McGuire, Philip

2016-10-01

Childhood adversity increases the risk of psychosis in adulthood. Theoretical and animal models suggest that this effect may be mediated by increased striatal dopamine neurotransmission. The primary objective of this study was to examine the relationship between adversity in childhood and striatal dopamine function in early adulthood. Secondary objectives were to compare exposure to childhood adversity and striatal dopamine function in young people at ultra high risk (UHR) of psychosis and healthy volunteers. Sixty-seven young adults, comprising 47 individuals at UHR for psychosis and 20 healthy volunteers were recruited from the same geographic area and were matched for age, gender and substance use. Presynaptic dopamine function in the associative striatum was assessed using 18F-DOPA positron emission tomography. Childhood adversity was assessed using the Childhood Experience of Care and Abuse questionnaire. Within the sample as a whole, both severe physical or sexual abuse (T63=2.92; P=0.005), and unstable family arrangements (T57=2.80; P=0.007) in childhood were associated with elevated dopamine function in the associative striatum in adulthood. Comparison of the UHR and volunteer subgroups revealed similar incidence of childhood adverse experiences, and there was no significant group difference in dopamine function. This study provides evidence that childhood adversity is linked to elevated striatal dopamine function in adulthood. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Oxidation of DNA, proteins and lipids by DOPA, protein-bound DOPA, and related catechol(amine)s

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Pattison, David I; Dean, Roger T; Davies, Michael Jonathan

2002-01-01

Incubation of free 3,4-dihydroxyphenylalanine (DOPA), protein-bound DOPA (PB-DOPA) and related catechols with DNA, proteins and lipids has been shown to result in oxidative damage to the target molecule. This article reviews these reactions with particular emphasis on those that occur in the pres......Incubation of free 3,4-dihydroxyphenylalanine (DOPA), protein-bound DOPA (PB-DOPA) and related catechols with DNA, proteins and lipids has been shown to result in oxidative damage to the target molecule. This article reviews these reactions with particular emphasis on those that occur...... in the presence of molecular O(2) and redox-active metal ions (e.g. Fe(3+), Cu(2+), Cr(6+)), which are known to increase the rate of DOPA oxidation. The majority of oxidative damage appears to be mediated by reactive oxygen species (ROS) such as superoxide and HO(.) radicals, though other DOPA oxidation products...

From L-dopa to dihydroxyphenylacetaldehyde: a toxic biochemical pathway plays a vital physiological function in insects.

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Christopher Vavricka

2011-01-01

Full Text Available One protein in Aedes aegypti, classified into the aromatic amino acid decarboxylase (AAAD family based on extremely high sequence homology (∼70% with dopa decarboxylase (Ddc, was biochemically investigated. Our data revealed that this predicted AAAD protein use L-dopa as a substrate, as does Ddc, but it catalyzes the production of 3,4-dihydroxylphenylacetaldehyde (DHPAA directly from L-dopa and apparently has nothing to do with the production of any aromatic amine. The protein is therefore named DHPAA synthase. This subsequently led to the identification of the same enzyme in Drosophila melanogaster, Anopheles gambiae and Culex quinquefasciatus by an initial prediction of putative DHPAA synthase based on sequence homology and subsequent verification of DHPAA synthase identity through protein expression and activity assays. DHPAA is highly toxic because its aldehyde group readily reacts with the primary amino groups of proteins, leading to protein crosslinking and inactivation. It has previously been demonstrated by several research groups that Drosophila DHPAA synthase was expressed in tissues that produce cuticle materials and apparent defects in regions of colorless, flexible cuticular structures have been observed in its gene mutants. The presence of free amino groups in proteins, the high reactivity of DHPAA with the free amino groups, and the genetically ascertained function of the Drosophila DHPAA synthase in the formation of colorless, flexible cuticle, when taken together, suggest that mosquito and Drosophila DHPAA synthases are involved in the formation of flexible cuticle through their reactive DHPAA-mediated protein crosslinking reactions. Our data illustrate how a seemingly highly toxic pathway can serve for an important physiological function in insects.

Basal ganglia disorders studied by positron emission tomography

International Nuclear Information System (INIS)

Shinotoh, Hitoshi

1994-01-01

Recent development of positron emitting radioligands has made it possible to investigate the alterations of neurotransmitter systems associated with basal ganglia disorders in vivo. The functional integrity of nigro-striatal dopaminergic terminals may be studied with [ 18 F]6-fluoro-L-dopa ([ 18 F]dopa), and striatal dopamine receptor density with suitable PET ligands. [ 18 F]dopa uptake in the striatum (putamen) is markedly reduced in patients with Parkinson's disease (PD). [ 18 F]dopa-PET is capable of detecting sub-clinical nigral dysfunction in asymptomatic patients with familial PD and those who become Parkinsonian on conventional doses of dopamine receptor antagonists. While putamen [ 18 F]dopa uptake is reduced to a similar level in patients with multiple system atrophy (MSA) and PD, caudate [ 18 F] dopa uptake is lower in MSA than PD. However, [ 18 F]dopa PET cannot consistently distinguish MSA from PD because individual ranges of caudate [ 18 F]dopa uptake overlap. D 1 and D 2 receptor binding is markedly reduced in the striatum (posterior putamen) of MSA patients. Therefore, dopamine receptor imaging is useful for the differential diagnosis of MSA and PD. Similar marked reductions in putamen and caudate [ 18 F]dopa uptake have been observed in patients with progressive supranuclear palsy (PSP). Moderate reductions in D 2 receptor binding have been reported in the striatum of PSP patients. The reduction in D 2 receptor binding is more prominent in the caudate than putamen. Striatal [ 18 F]dopa uptake is normal or only mildly reduced in patients with dopa responsive dystonia (DRD). D 2 receptor binding is markedly reduced in patients with Huntington's disease, while striatal [ 18 F]dopa uptake is normal or mildly reduced. In summary, PET can demonstrate characteristic patterns of disruption of dopaminergic systems associated with basal ganglia disorders. These PET findings are useful in the differential diagnosis of basal ganglia disorders. (J.P.N.) 55 refs

Basal ganglia disorders studied by positron emission tomography

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Shinotoh, Hitoshi [Chiba Univ. (Japan). School of Medicine

1994-04-01

Recent development of positron emitting radioligands has made it possible to investigate the alterations of neurotransmitter systems associated with basal ganglia disorders in vivo. The functional integrity of nigro-striatal dopaminergic terminals may be studied with [[sup 18]F]6-fluoro-L-dopa ([[sup 18]F]dopa), and striatal dopamine receptor density with suitable PET ligands. [[sup 18]F]dopa uptake in the striatum (putamen) is markedly reduced in patients with Parkinson's disease (PD). [[sup 18]F]dopa-PET is capable of detecting sub-clinical nigral dysfunction in asymptomatic patients with familial PD and those who become Parkinsonian on conventional doses of dopamine receptor antagonists. While putamen [[sup 18]F]dopa uptake is reduced to a similar level in patients with multiple system atrophy (MSA) and PD, caudate [[sup 18]F] dopa uptake is lower in MSA than PD. However, [[sup 18]F]dopa PET cannot consistently distinguish MSA from PD because individual ranges of caudate [[sup 18]F]dopa uptake overlap. D[sub 1] and D[sub 2] receptor binding is markedly reduced in the striatum (posterior putamen) of MSA patients. Therefore, dopamine receptor imaging is useful for the differential diagnosis of MSA and PD. Similar marked reductions in putamen and caudate [[sup 18]F]dopa uptake have been observed in patients with progressive supranuclear palsy (PSP). Moderate reductions in D[sub 2] receptor binding have been reported in the striatum of PSP patients. The reduction in D[sub 2] receptor binding is more prominent in the caudate than putamen. Striatal [[sup 18]F]dopa uptake is normal or only mildly reduced in patients with dopa responsive dystonia (DRD). D[sub 2] receptor binding is markedly reduced in patients with Huntington's disease, while striatal [[sup 18]F]dopa uptake is normal or mildly reduced. In summary, PET can demonstrate characteristic patterns of disruption of dopaminergic systems associated with basal ganglia disorders. (J.P.N.) 55 refs.

Comparative assessment of 6-[18 F]fluoro-L-m-tyrosine and 6-[18 F]fluoro-L-dopa to evaluate dopaminergic presynaptic integrity in a Parkinson's disease rat model.

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Becker, Guillaume; Bahri, Mohamed Ali; Michel, Anne; Hustadt, Fabian; Garraux, Gaëtan; Luxen, André; Lemaire, Christian; Plenevaux, Alain

2017-05-01

Because of the progressive loss of nigro-striatal dopaminergic terminals in Parkinson's disease (PD), in vivo quantitative imaging of dopamine (DA) containing neurons in animal models of PD is of critical importance in the preclinical evaluation of highly awaited disease-modifying therapies. Among existing methods, the high sensitivity of positron emission tomography (PET) is attractive to achieve that goal. The aim of this study was to perform a quantitative comparison of brain images obtained in 6-hydroxydopamine (6-OHDA) lesioned rats using two dopaminergic PET radiotracers, namely [ 18 F]fluoro-3,4-dihydroxyphenyl-L-alanine ([ 18 F]FDOPA) and 6-[ 18 F]fluoro-L-m-tyrosine ([ 18 F]FMT). Because the imaging signal is theoretically less contaminated by metabolites, we hypothesized that the latter would show stronger relationship with behavioural and post-mortem measures of striatal dopaminergic deficiency. We used a within-subject design to measure striatal [ 18 F]FMT and [ 18 F]FDOPA uptake in eight partially lesioned, eight fully lesioned and ten sham-treated rats. Animals were pretreated with an L-aromatic amino acid decarboxylase inhibitor. A catechol-O-methyl transferase inhibitor was also given before [ 18 F]FDOPA PET. Quantitative estimates of striatal uptake were computed using conventional graphical Patlak method. Striatal dopaminergic deficiencies were measured with apomorphine-induced rotations and post-mortem striatal DA content. We observed a strong relationship between [ 18 F]FMT and [ 18 F]FDOPA estimates of decreased uptake in the denervated striatum using the tissue-derived uptake rate constant K c . However, only [ 18 F]FMT K c succeeded to discriminate between the partial and the full 6-OHDA lesion and correlated well with the post-mortem striatal DA content. This study indicates that the [ 18 F]FMT could be more sensitive, with respect of [ 18 F]FDOPA, to investigate DA terminals loss in 6-OHDA rats, and open the way to in vivo L

Colorimetric detection of manganese(II) ions using gold/dopa nanoparticles.

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Narayanan, Kannan Badri; Park, Hyun Ho

2014-10-15

We report here a one-pot, greener, eco-friendly strategy for the synthesis of gold nanoparticles using L-dopa. The as-prepared dopa-functionalized gold nanoparticles (AuNPs/dopa) can detect low concentrations of manganese(II) metal ions in aqueous solution. The binding forces between dopa and Mn(2+) ions cause dopa-functionalized gold nanoparticles to come closer together, decreasing the interparticle distance and aggregating it with a change in color of colloidal solution from red to purplish-blue. Dynamic light scattering (DLS) analysis showed a decreased surface charge on the surface of gold nanoparticles when exposed to Mn(2+) ions, which caused cross-linking aggregation. Transmission electron microscopic (TEM) images also revealed the aggregation of gold nanoparticles with the addition of Mn(2+) ions. The extinction ratio of absorbance at 700-550nm (A700/A550) was linear against the concentration of [Mn(2+)] ions. Thus, the optical absorption spectra of gold colloidal solution before and after the addition of Mn(2+) ions reveal the concentration of Mn(2+) ions in solution. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of chronic fructose overload on renal dopaminergic system: alteration of urinary L-dopa/dopamine index correlates to hypertension and precedes kidney structural damage.

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Rukavina Mikusic, Natalia L; Kouyoumdzian, Nicolás M; Del Mauro, Julieta S; Cao, Gabriel; Trida, Verónica; Gironacci, Mariela M; Puyó, Ana M; Toblli, Jorge E; Fernández, Belisario E; Choi, Marcelo R

2018-01-01

Insulin resistance induced by a high-fructose diet has been associated to hypertension and renal damage. The aim of this work was to assess alterations in the urinary L-dopa/dopamine ratio over three time periods in rats with insulin resistance induced by fructose overload and its correlation with blood pressure levels and the presence of microalbuminuria and reduced nephrin expression as markers of renal structural damage. Male Sprague-Dawley rats were randomly divided into six groups: control (C) (C4, C8 and C12) with tap water to drink and fructose-overloaded (FO) rats (FO4, FO8 and FO12) with a fructose solution (10% w/v) to drink for 4, 8 and 12 weeks. A significant increase of the urinary L-dopa/dopamine ratio was found in FO rats since week 4, which positively correlated to the development of hypertension and preceded in time the onset of microalbuminuria and reduced nephrin expression observed on week 12 of treatment. The alteration of this ratio was associated to an impairment of the renal dopaminergic system, evidenced by a reduction in renal dopamine transporters and dopamine D1 receptor expression, leading to an overexpression and overactivation of the enzyme Na + , K + -ATPase with sodium retention. In conclusion, urinary L-dopa/dopamine ratio alteration in rats with fructose overload positively correlated to the development of hypertension and preceded in time the onset of renal structural damage. This is the first study to propose the use of the urinary L-dopa/dopamine index as marker of renal dysfunction that temporarily precedes kidney structural damage induced by fructose overload. Copyright © 2017 Elsevier Inc. All rights reserved.

New PET tracers for cerebral dopamine: Should 6-[18f]fluoro-dopa be replaced?

International Nuclear Information System (INIS)

Firnau, G.; Chirakal, R.; Chen, J.J.; Murthy, D.; Nahmias, C.; Garnett, E.S.

1993-01-01

The visualization with PET of dopaminergic terminals in the human brain has been accomplished by a variety of approaches using β + -labelled substrates 1. for Aromatic L-Amino acid Decarboxylase, AADC, (6-[ 18 F]fluoro-L-dopa, FD; 6-[ 18 F]fluoro-L-meta-tyrosine, FmT; L-[ 11 C]Dopa); and β + -labelled inhibitors 2. for reuptake transporter ([ 11 C]Cocain, [ 11 C]WIN 35,428); 3. for Monoamine Oxidase-B ([ 11 C]deprenyl); 4. for the Vesicular uptake site ([ 11 C]tetrabenzamine). The enzyme approach with FD has been particularly successful in providing important insights into Parkinson's disease and dystonias. The extraction of quantitative data from FD/PET studies in humans is complicated by the formation of O-methylFD in the periphery, which, like FD, also enters the brain. Following the suggestion by deJesus (1988) to use a labelled meta-tyrosine (substrate for AADC but not COMT) the authors have synthesized FmT, developed it into a radiopharmaceutical (toxicology and radiation dose in humans) and studied the intracerebral distribution in man and the metabolites in monkeys. They found that FmT's peripheral metabolite does not enter the brain. Unlike FD, FmT delineates with greater clarity the dopaminergic terminals and cells including those in the substantia nigra that, so far, could not be investigated with any other PET tracer. Thus, FmT appears to be superior to FD

Human striatal recordings reveal abnormal discharge of projection neurons in Parkinson's disease.

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Singh, Arun; Mewes, Klaus; Gross, Robert E; DeLong, Mahlon R; Obeso, José A; Papa, Stella M

2016-08-23

Circuitry models of Parkinson's disease (PD) are based on striatal dopamine loss and aberrant striatal inputs into the basal ganglia network. However, extrastriatal mechanisms have increasingly been the focus of attention, whereas the status of striatal discharges in the parkinsonian human brain remains conjectural. We now report the activity pattern of striatal projection neurons (SPNs) in patients with PD undergoing deep brain stimulation surgery, compared with patients with essential tremor (ET) and isolated dystonia (ID). The SPN activity in ET was very low (2.1 ± 0.1 Hz) and reminiscent of that found in normal animals. In contrast, SPNs in PD fired at much higher frequency (30.2 ± 1.2 Hz) and with abundant spike bursts. The difference between PD and ET was reproduced between 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated and normal nonhuman primates. The SPN activity was also increased in ID, but to a lower level compared with the hyperactivity observed in PD. These results provide direct evidence that the striatum contributes significantly altered signals to the network in patients with PD.

Further human evidence for striatal dopamine release induced by administration of ∆9-tetrahydrocannabinol (THC): selectivity to limbic striatum.

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Bossong, Matthijs G; Mehta, Mitul A; van Berckel, Bart N M; Howes, Oliver D; Kahn, René S; Stokes, Paul R A

2015-08-01

Elevated dopamine function is thought to play a key role in both the rewarding effects of addictive drugs and the pathophysiology of schizophrenia. Accumulating epidemiological evidence indicates that cannabis use is a risk factor for the development of schizophrenia. However, human neurochemical imaging studies that examined the impact of ∆9-tetrahydrocannabinol (THC), the main psychoactive component in cannabis, on striatal dopamine release have provided inconsistent results. The objective of this study is to assess the effect of a THC challenge on human striatal dopamine release in a large sample of healthy participants. We combined human neurochemical imaging data from two previous studies that used [(11)C]raclopride positron emission tomography (PET) (n = 7 and n = 13, respectively) to examine the effect of THC on striatal dopamine neurotransmission in humans. PET images were re-analysed to overcome differences in PET data analysis. THC administration induced a significant reduction in [(11)C]raclopride binding in the limbic striatum (-3.65 %, from 2.39 ± 0.26 to 2.30 ± 0.23, p = 0.023). This is consistent with increased dopamine levels in this region. No significant differences between THC and placebo were found in other striatal subdivisions. In the largest data set of healthy participants so far, we provide evidence for a modest increase in human striatal dopamine transmission after administration of THC compared to other drugs of abuse. This finding suggests limited involvement of the endocannabinoid system in regulating human striatal dopamine release and thereby challenges the hypothesis that an increase in striatal dopamine levels after cannabis use is the primary biological mechanism underlying the associated higher risk of schizophrenia.

Efficacy and safety of extended- versus immediate-release pramipexole in Japanese patients with advanced and L-dopa-undertreated Parkinson disease: a double-blind, randomized trial.

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Mizuno, Yoshikuni; Yamamoto, Mitsutoshi; Kuno, Sadako; Hasegawa, Kazuko; Hattori, Nobutaka; Kagimura, Tatsuro; Sarashina, Akiko; Rascol, Olivier; Schapira, Anthony H V; Barone, Paolo; Hauser, Robert A; Poewe, Werner

2012-01-01

To compare the efficacy, safety, tolerability, and trough plasma levels of pramipexole extended-release (ER) and pramipexole immediate-release (IR), and to assess the effects of overnight switching from an IR to an ER formulation, in L-dopa-treated patients with Parkinson disease (PD). After a 1- to 4-week screening/enrollment, 112 patients who had exhibited L-dopa-related problems or were receiving suboptimal L-dopa dosage were randomized in double-blind, double-dummy, 1:1 fashion to pramipexole ER once daily or pramipexole IR 2 to 3 times daily for 12 weeks, both titrated to a maximum daily dose of 4.5 mg. Successful completers of double-blind treatment were switched to open-label pramipexole ER, beginning with a 4-week dose-adjustment phase. Among the double-blind treatment patients (n = 56 in each group), Unified Parkinson's Disease Rating Scale Parts II+III total scores decreased significantly from baseline and to a similar degree with pramipexole ER and IR formulations. In each group, 47 double-blind patients (83.9%) reported adverse events (AEs), requiring withdrawal of 3 ER patients (5.4%) and 2 IR patients (3.6%). Trough plasma levels at steady state (at the same doses and dose-normalized concentrations) were also similar with both formulations. Among open-label treatment patients (n = 53 from IR to ER), 83% were successfully switched (no worsening of PD symptoms) to pramipexole ER. In L-dopa-treated patients, pramipexole ER and pramipexole IR demonstrated similar efficacy, safety, tolerability, and trough plasma levels. Patients can be safely switched overnight from pramipexole IR to pramipexole ER with no impact on efficacy.

18F-DOPA PET/CT in the diagnosis and localization of persistent medullary thyroid carcinoma

International Nuclear Information System (INIS)

Archier, Aurelien; Mundler, Olivier; Heimburger, Celine; Guerin, Carole; Palazzo, Fausto F.; Henry, Jean-Francois; Sebag, Frederic; Morange, Isabelle; Schneegans, Olivier; Abdullah, Ahmad Esmaeel; Imperiale, Alessio; Taieb, David

2016-01-01

To evaluate the performance of 18 F-l-dihydroxyphenylalanine ( 18 F-DOPA) PET/CT in the detection of locoregional and distant medullary thyroid carcinoma (MTC) metastases and to compare imaging findings with histological data. We retrospectively evaluated 86 MTC patients with persistently high serum calcitonin levels after initial surgery who had undergone 18 F-DOPA PET/CT between January 2007 and December 2014 in two referral centres. They were followed up for at least 6 months after the PET/CT assessment. The results were compared with histological data or with the findings obtained during follow-up using a complementary imaging modality. 18 F-DOPA PET/CT was positive in 65 of the 86 patients, corresponding to a patient-based sensitivity of 75.6 %. Distant metastatic disease (M1) was seen in 29 patients including 11 with previously unknown metastases revealed only by PET/CT. Among the 36 patients without distant metastatic spread, 25 had nodal involvement limited to the neck, and 10 of these 25 patients underwent reoperation. The lymph node compartment-based sensitivity of 18 F-DOPA PET/CT was 100 % in the two institutions but lesion-based sensitivity was only 24 %. Preoperative and postoperative median calcitonin levels were 405 pg/mL (range 128 - 1,960 pg/mL) and 259 pg/mL (range 33 - 1,516 pg/mL), respectively. None of the patients achieved normalization of serum calcitonin after reoperation. 18 F-DOPA PET/CT enables early diagnosis of a significant number of patients with distant metastasis. It has a limited sensitivity in the detection of residual disease but provides high performance for regional analysis. A surgical compartment-oriented approach could be the approach of choice whatever the number of nodes revealed by 18 F-DOPA PET/CT. (orig.)

Automated striatal uptake analysis of 18F-FDOPA PET images applied to Parkinson's disease patients

International Nuclear Information System (INIS)

Chang Icheng; Lue Kunhan; Hsieh Hungjen; Liu Shuhsin; Kao, Chinhao K.

2011-01-01

6-[ 18 F]Fluoro-L-DOPA (FDOPA) is a radiopharmaceutical valuable for assessing the presynaptic dopaminergic function when used with positron emission tomography (PET). More specifically, the striatal-to-occipital ratio (SOR) of FDOPA uptake images has been extensively used as a quantitative parameter in these PET studies. Our aim was to develop an easy, automated method capable of performing objective analysis of SOR in FDOPA PET images of Parkinson's disease (PD) patients. Brain images from FDOPA PET studies of 21 patients with PD and 6 healthy subjects were included in our automated striatal analyses. Images of each individual were spatially normalized into an FDOPA template. Subsequently, the image slice with the highest level of basal ganglia activity was chosen among the series of normalized images. Also, the immediate preceding and following slices of the chosen image were then selected. Finally, the summation of these three images was used to quantify and calculate the SOR values. The results obtained by automated analysis were compared with manual analysis by a trained and experienced image processing technologist. The SOR values obtained from the automated analysis had a good agreement and high correlation with manual analysis. The differences in caudate, putamen, and striatum were -0.023, -0.029, and -0.025, respectively; correlation coefficients 0.961, 0.957, and 0.972, respectively. We have successfully developed a method for automated striatal uptake analysis of FDOPA PET images. There was no significant difference between the SOR values obtained from this method and using manual analysis. Yet it is an unbiased time-saving and cost-effective program and easy to implement on a personal computer. (author)

Discriminative sensing of DOPA enantiomers by cyclodextrin anchored graphene nanohybrids.

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Ates, Salih; Zor, Erhan; Akin, Ilker; Bingol, Haluk; Alpaydin, Sabri; Akgemci, Emine G

2017-06-01

Discriminative sensing of chiral species with a convenient and robust system is a challenge in chemistry, pharmaceutics and particularly in biomedical science. Advanced nanohybrid materials for discrimination of these biologically active molecules can be developed by combination of individual obvious advantages of different molecular scaffolds. Herein, we report on the comparison of the performance of cyclodextrin functionalized graphene derivatives (x-CD/rGO, x: α-, β-, γ-) for discrimination of DOPA enantiomers. Within this respect, electrochemical measurements were conducted and the experimental results were compared to molecular docking method. Thanks to cavity size of γ-CD and the unique properties of graphene, rGO/γ-CD nanohybrid is capable of selective recognition of DOPA enantiomers. Limit of detection (LOD) value and sensitivity were determined as 15.9 μM and 0.2525 μA μM -1 for D-DOPA, and 14.9 μM and 0.6894 μA μM -1 for L-DOPA. Copyright © 2017 Elsevier B.V. All rights reserved.

{sup 18}F-DOPA PET/CT in the diagnosis and localization of persistent medullary thyroid carcinoma

Energy Technology Data Exchange (ETDEWEB)

Archier, Aurelien; Mundler, Olivier [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Aix-Marseille University, European Center for Research in Medical Imaging, Marseille (France); Heimburger, Celine [University Hospitals of Strasbourg, Department of Biophysics and Nuclear Medicine, Strasbourg (France); Guerin, Carole; Palazzo, Fausto F.; Henry, Jean-Francois; Sebag, Frederic [Aix-Marseille University, Department of Endocrine Surgery, Conception Hospital, Marseille (France); Morange, Isabelle [Aix-Marseille University, Department of Endocrinology, Conception Hospital, Marseille (France); Schneegans, Olivier [Paul Strauss Cancer Center, Department of Nuclear Medicine, Strasbourg (France); Abdullah, Ahmad Esmaeel [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Imperiale, Alessio [University Hospitals of Strasbourg, Department of Biophysics and Nuclear Medicine, Strasbourg (France); ICube, UMR 7357 University of Strasbourg/CNRS and FMTS, Faculty of Medicine, Strasbourg (France); Taieb, David [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Aix-Marseille University, European Center for Research in Medical Imaging, Marseille (France); Institut Paoli-Calmettes, Inserm UMR1068 Marseille Cancerology Research Center, Marseille (France)

2016-06-15

To evaluate the performance of {sup 18}F-l-dihydroxyphenylalanine ({sup 18}F-DOPA) PET/CT in the detection of locoregional and distant medullary thyroid carcinoma (MTC) metastases and to compare imaging findings with histological data. We retrospectively evaluated 86 MTC patients with persistently high serum calcitonin levels after initial surgery who had undergone {sup 18}F-DOPA PET/CT between January 2007 and December 2014 in two referral centres. They were followed up for at least 6 months after the PET/CT assessment. The results were compared with histological data or with the findings obtained during follow-up using a complementary imaging modality. {sup 18}F-DOPA PET/CT was positive in 65 of the 86 patients, corresponding to a patient-based sensitivity of 75.6 %. Distant metastatic disease (M1) was seen in 29 patients including 11 with previously unknown metastases revealed only by PET/CT. Among the 36 patients without distant metastatic spread, 25 had nodal involvement limited to the neck, and 10 of these 25 patients underwent reoperation. The lymph node compartment-based sensitivity of {sup 18}F-DOPA PET/CT was 100 % in the two institutions but lesion-based sensitivity was only 24 %. Preoperative and postoperative median calcitonin levels were 405 pg/mL (range 128 - 1,960 pg/mL) and 259 pg/mL (range 33 - 1,516 pg/mL), respectively. None of the patients achieved normalization of serum calcitonin after reoperation. {sup 18}F-DOPA PET/CT enables early diagnosis of a significant number of patients with distant metastasis. It has a limited sensitivity in the detection of residual disease but provides high performance for regional analysis. A surgical compartment-oriented approach could be the approach of choice whatever the number of nodes revealed by {sup 18}F-DOPA PET/CT. (orig.)

Speech-induced striatal dopamine release is left lateralized and coupled to functional striatal circuits in healthy humans: A combined PET, fMRI and DTI study

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Simonyan, Kristina; Herscovitch, Peter; Horwitz, Barry

2013-01-01

Considerable progress has been recently made in understanding the brain mechanisms underlying speech and language control. However, the neurochemical underpinnings of normal speech production remain largely unknown. We investigated the extent of striatal endogenous dopamine release and its influences on the organization of functional striatal speech networks during production of meaningful English sentences using a combination of positron emission tomography (PET) with the dopamine D2/D3 receptor radioligand [11C]raclopride and functional MRI (fMRI). In addition, we used diffusion tensor tractography (DTI) to examine the extent of dopaminergic modulatory influences on striatal structural network organization. We found that, during sentence production, endogenous dopamine was released in the ventromedial portion of the dorsal striatum, in its both associative and sensorimotor functional divisions. In the associative striatum, speech-induced dopamine release established a significant relationship with neural activity and influenced the left-hemispheric lateralization of striatal functional networks. In contrast, there were no significant effects of endogenous dopamine release on the lateralization of striatal structural networks. Our data provide the first evidence for endogenous dopamine release in the dorsal striatum during normal speaking and point to the possible mechanisms behind the modulatory influences of dopamine on the organization of functional brain circuits controlling normal human speech. PMID:23277111

Repeated administration of the monoamine reuptake inhibitor BTS 74 398 induces ipsilateral circling in the 6-hydroxydopamine lesioned rat without sensitizing motor behaviours.

Science.gov (United States)

Lane, E L; Cheetham, S C; Jenner, P

2005-01-01

BTS 74 398 (1-[1-(3,4-dichlorophenyl)cyclobutyl]-2-(3-diaminethylaminopropylthio)ethanone monocitrate) is a monoamine reuptake inhibitor that reverses motor deficits in MPTP-treated (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) common marmosets without provoking established dyskinesia. However, it is not known whether BTS 74 398 primes the basal ganglia for dyskinesia induction. In this study, the ability of BTS 74 398 to sensitize 6-hydroxydopamine (6-OHDA)-lesioned rats for the production of abnormal motor behaviours and the induction of striatal DeltaFosB were determined in comparison with l-3,4-dihydroxyphenylalanine methyl ester (L-dopa). Acute administration of BTS 74 398 induced a dose-dependent ipsilateral circling response in unilaterally 6-OHDA-lesioned rats whereas L-dopa produced dose-dependent contraversive rotation. The ipsilateral circling response to BTS 74 398 did not alter during 21 days of administration. In contrast, L-dopa treatment for 21 days caused a marked increase in rotational response. Repeated administration of both L-dopa and BTS 74 398 increased general motor activity and stereotypic behaviour. In L-dopa-treated rats, orolingual, locomotive, forelimb and axial abnormal movements developed whereas BTS 74 398 produced only locomotion with a side bias but no other abnormal movements. Sensitization of circling responses and the development of abnormal movements in 6-OHDA-lesioned rats have been associated with the potential of dopaminergic drugs to induce dyskinesia. Furthermore, striatal DeltaFosB immunoreactivity, shown to correlate with dyskinesia induction, was increased by L-dopa but was unaffected by repeated BTS 74 398 administration. The lack of such changes following repeated BTS 74 398 treatment suggests that it may be an effective antiparkinsonian therapy that is unlikely to produce involuntary movements.

Overeating Behavior and Striatal Dopamine with 6-[18F]-Fluoro-L--Tyrosine PET

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Claire E. Wilcox

2010-01-01

Full Text Available Eating behavior may be affected by dopamine synthesis capacity. In this study, 6-[18F]-fluoro-L--tyrosine (FMT positron emission tomography (PET uptake in striatal subregions was correlated with BMI (kg/m2 and an estimate of the frequency of prior weight loss attempts in 15 healthy subjects. BMI was negatively correlated with FMT uptake in the dorsal caudate. Although the association between BMI and FMT uptake in the dorsal caudate was not significant upon correction for age and sex, the association fell within the range of a statistical trend. Weight loss attempts divided by years trying was also negatively correlated with FMT uptake in the dorsal putamen (=.05. These results suggest an association between low dorsal striatal presynaptic dopamine synthesis capacity and overeating behavior.

Targeting the D1-N-methyl-D-aspartate receptor complex reduces L-dopa-induced dyskinesia in 6-hydroxydopamine-lesioned Parkinson’s rats

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Song L

2016-02-01

Full Text Available Lu Song,1,* Zhanzhao Zhang,2,* Rongguo Hu,1 Jie Cheng,1 Lin Li,1 Qinyi Fan,1 Na Wu,1 Jing Gan,1 Mingzhu Zhou,1 Zhenguo Liu11Department of Neurology, Xinhua Hospital, 2Department of Plastic and Reconstructive Surgery, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China*These authors contributed equally to this workAbstract: L-3,4-dihydroxyphenylalanine (L-dopa remains the most effective therapy for Parkinson’s disease (PD, but its long-term administration is associated with the development of debilitating motor complications known as L-dopa-induced dyskinesia (LID. Enhanced function of dopamine D1 receptor (D1R and N-methyl-d-aspartate receptor (NMDAR is believed to participate in the pathogenesis of LID. Given the existence of physical and functional interactions between D1R and NMDAR, we explored the effects of uncoupling D1R and NMDA GluN1 (GluN1 interaction on LID by using the Tat-conjugated interfering peptide (Tat-D1-t2. In this study, we demonstrated in 6-hydroxydopamine (6-OHDA-lesioned PD rat model that intrastriatal injection of Tat-D1-t2 alleviated dyskinetic behaviors and downregulated the phosphorylation of DARPP-32 at Thr34 induced by levodopa. Moreover, we also showed intrastriatal administration of Tat-D1-t2 elicited alterations in membranous GluN1 and D1R expression. These findings indicate that D1R/GluN1 complexes may be a molecular target with therapeutic potential for the treatment of dyskinesia in Parkinson’s patients.Keywords: 6-hydroxydopamine, Parkinson’s disease, dyskinesia, L-dopa, D1 receptor, NMDA, protein–protein interaction

Striatal dopamine transmission is subtly modified in human A53Tα-synuclein overexpressing mice.

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Nicola J Platt

Full Text Available Mutations in, or elevated dosage of, SNCA, the gene for α-synuclein (α-syn, cause familial Parkinson's disease (PD. Mouse lines overexpressing the mutant human A53Tα-syn may represent a model of early PD. They display progressive motor deficits, abnormal cellular accumulation of α-syn, and deficits in dopamine-dependent corticostriatal plasticity, which, in the absence of overt nigrostriatal degeneration, suggest there are age-related deficits in striatal dopamine (DA signalling. In addition A53Tα-syn overexpression in cultured rodent neurons has been reported to inhibit transmitter release. Therefore here we have characterized for the first time DA release in the striatum of mice overexpressing human A53Tα-syn, and explored whether A53Tα-syn overexpression causes deficits in the release of DA. We used fast-scan cyclic voltammetry to detect DA release at carbon-fibre microelectrodes in acute striatal slices from two different lines of A53Tα-syn-overexpressing mice, at up to 24 months. In A53Tα-syn overexpressors, mean DA release evoked by a single stimulus pulse was not different from wild-types, in either dorsal striatum or nucleus accumbens. However the frequency responsiveness of DA release was slightly modified in A53Tα-syn overexpressors, and in particular showed slight deficiency when the confounding effects of striatal ACh acting at presynaptic nicotinic receptors (nAChRs were antagonized. The re-release of DA was unmodified after single-pulse stimuli, but after prolonged stimulation trains, A53Tα-syn overexpressors showed enhanced recovery of DA release at old age, in keeping with elevated striatal DA content. In summary, A53Tα-syn overexpression in mice causes subtle changes in the regulation of DA release in the striatum. While modest, these modifications may indicate or contribute to striatal dysfunction.

Motivational Disturbances and Effects of L-dopa Administration in Neurofibromatosis-1 Model Mice

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Wozniak, David F.; Diggs-Andrews, Kelly A.; Conyers, Sara; Yuede, Carla M.; Dearborn, Joshua T.; Brown, Jacquelyn A.; Tokuda, Kazuhiro; Izumi, Yukitoshi; Zorumski, Charles F.; Gutmann, David H.

2013-01-01

Children with neurofibromatosis type 1 (NF1) frequently have cognitive and behavioral deficits. Some of these deficits have been successfully modeled in Nf1 genetically-engineered mice that develop optic gliomas (Nf1 OPG mice). In the current study, we show that abnormal motivational influences affect the behavior of Nf1 OPG mice, particularly with regard to their response to novel environmental stimuli. For example, Nf1 OPG mice made fewer spontaneous alternations in a Y-maze and fewer arm entries relative to WT controls. However, analysis of normalized alternation data demonstrated that these differences were not due to a spatial working memory deficit. Other reported behavioral results (e.g., open-field test, below) suggest that differential responses to novelty and/or other motivational influences may be more important determinants of these kinds of behavior than simple differences in locomotor activity/spontaneous movements. Importantly, normal long-term depression was observed in hippocampal slices from Nf1 OPG mice. Results from elevated plus maze testing showed that differences in exploratory activity between Nf1 OPG and WT control mice may be dependent on the environmental context (e.g., threatening or non-threatening) under which exploration is being measured. Nf1 OPG mice also exhibited decreased exploratory hole poking in a novel holeboard and showed abnormal olfactory preferences, although L-dopa (50 mg/kg) administration resolved the abnormal olfactory preference behaviors. Nf1 OPG mice displayed an attenuated response to a novel open field in terms of decreased ambulatory activity and rearing but only during the first 10 min of the session. Importantly, Nf1 OPG mice demonstrated investigative rearing deficits with regard to a novel hanging object suspended on one side of the field which were not rescued by L-dopa administration. Collectively, our results provide new data important for evaluating therapeutic treatments aimed at ameliorating NF1

Motivational disturbances and effects of L-dopa administration in neurofibromatosis-1 model mice.

Directory of Open Access Journals (Sweden)

David F Wozniak

Full Text Available Children with neurofibromatosis type 1 (NF1 frequently have cognitive and behavioral deficits. Some of these deficits have been successfully modeled in Nf1 genetically-engineered mice that develop optic gliomas (Nf1 OPG mice. In the current study, we show that abnormal motivational influences affect the behavior of Nf1 OPG mice, particularly with regard to their response to novel environmental stimuli. For example, Nf1 OPG mice made fewer spontaneous alternations in a Y-maze and fewer arm entries relative to WT controls. However, analysis of normalized alternation data demonstrated that these differences were not due to a spatial working memory deficit. Other reported behavioral results (e.g., open-field test, below suggest that differential responses to novelty and/or other motivational influences may be more important determinants of these kinds of behavior than simple differences in locomotor activity/spontaneous movements. Importantly, normal long-term depression was observed in hippocampal slices from Nf1 OPG mice. Results from elevated plus maze testing showed that differences in exploratory activity between Nf1 OPG and WT control mice may be dependent on the environmental context (e.g., threatening or non-threatening under which exploration is being measured. Nf1 OPG mice also exhibited decreased exploratory hole poking in a novel holeboard and showed abnormal olfactory preferences, although L-dopa (50 mg/kg administration resolved the abnormal olfactory preference behaviors. Nf1 OPG mice displayed an attenuated response to a novel open field in terms of decreased ambulatory activity and rearing but only during the first 10 min of the session. Importantly, Nf1 OPG mice demonstrated investigative rearing deficits with regard to a novel hanging object suspended on one side of the field which were not rescued by L-dopa administration. Collectively, our results provide new data important for evaluating therapeutic treatments aimed at

Prevention of iron- and copper-mediated DNA damage by catecholamine and amino acid neurotransmitters, L-DOPA, and curcumin: metal binding as a general antioxidant mechanism.

Science.gov (United States)

García, Carla R; Angelé-Martínez, Carlos; Wilkes, Jenna A; Wang, Hsiao C; Battin, Erin E; Brumaghim, Julia L

2012-06-07

Concentrations of labile iron and copper are elevated in patients with neurological disorders, causing interest in metal-neurotransmitter interactions. Catecholamine (dopamine, epinephrine, and norepinephrine) and amino acid (glycine, glutamate, and 4-aminobutyrate) neurotransmitters are antioxidants also known to bind metal ions. To investigate the role of metal binding as an antioxidant mechanism for these neurotransmitters, L-dihydroxyphenylalanine (L-DOPA), and curcumin, their abilities to prevent iron- and copper-mediated DNA damage were quantified, cyclic voltammetry was used to determine the relationship between their redox potentials and DNA damage prevention, and UV-vis studies were conducted to determine iron and copper binding as well as iron oxidation rates. In contrast to amino acid neurotransmitters, catecholamine neurotransmitters, L-DOPA, and curcumin prevent significant iron-mediated DNA damage (IC(50) values of 3.2 to 18 μM) and are electrochemically active. However, glycine and glutamate are more effective at preventing copper-mediated DNA damage (IC(50) values of 35 and 12.9 μM, respectively) than L-DOPA, the only catecholamine to prevent this damage (IC(50) = 73 μM). This metal-mediated DNA damage prevention is directly related to the metal-binding behaviour of these compounds. When bound to iron or copper, the catecholamines, amino acids, and curcumin significantly shift iron oxidation potentials and stabilize Fe(3+) over Fe(2+) and Cu(2+) over Cu(+), a factor that may prevent metal redox cycling in vivo. These results highlight the disparate antioxidant activities of neurotransmitters, drugs, and supplements and highlight the importance of considering metal binding when identifying antioxidants to treat and prevent neurodegenerative disorders.

Continuous cerebroventricular administration of dopamine: A new treatment for severe dyskinesia in Parkinson's disease?

Science.gov (United States)

Laloux, C; Gouel, F; Lachaud, C; Timmerman, K; Do Van, B; Jonneaux, A; Petrault, M; Garcon, G; Rouaix, N; Moreau, C; Bordet, R; Duce, J A; Devedjian, J C; Devos, D

2017-07-01

In Parkinson's disease (PD) depletion of dopamine in the nigro-striatal pathway is a main pathological hallmark that requires continuous and focal restoration. Current predominant treatment with intermittent oral administration of its precursor, Levodopa (l-dopa), remains the gold standard but pharmacological drawbacks trigger motor fluctuations and dyskinesia. Continuous intracerebroventricular (i.c.v.) administration of dopamine previously failed as a therapy because of an inability to resolve the accelerated dopamine oxidation and tachyphylaxia. We aim to overcome prior challenges by demonstrating treatment feasibility and efficacy of continuous i.c.v. of dopamine close to the striatum. Dopamine prepared either anaerobically (A-dopamine) or aerobically (O-dopamine) in the presence or absence of a conservator (sodium metabisulfite, SMBS) was assessed upon acute MPTP and chronic 6-OHDA lesioning and compared to peripheral l-dopa treatment. A-dopamine restored motor function and induced a dose dependent increase of nigro-striatal tyrosine hydroxylase positive neurons in mice after 7days of MPTP insult that was not evident with either O-dopamine or l-dopa. In the 6-OHDA rat model, continuous circadian i.c.v. injection of A-dopamine over 30days also improved motor activity without occurrence of tachyphylaxia. This safety profile was highly favorable as A-dopamine did not induce dyskinesia or behavioral sensitization as observed with peripheral l-dopa treatment. Indicative of a new therapeutic strategy for patients suffering from l-dopa related complications with dyskinesia, continuous i.c.v. of A-dopamine has greater efficacy in mediating motor impairment over a large therapeutic index without inducing dyskinesia and tachyphylaxia. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Tracking the formation of eumelanin from L-Dopa using coupled measurements

Science.gov (United States)

Yip, Philip; Sutter, Jens U.

2018-04-01

Melanin plays a crucial role as a pigment all through the animal kingdom. Being a macromolecule just on the divide between an ordered crystalline or a purely amorphous form melanin has proven a challenge to structure-function analysis. Melanin assembles from small molecules much like a jigsaw and much like in a jigsaw the fine detail quickly vanishes in the overall picture. With melanin being first and foremost a photo-active molecule we focus on spectral properties for the characterisation of its structure. We use absorption measurements to illustrate the complex nature of the formation process. To gain a better hold on the formation pathway we use coupled measurements of excitation and emission to identify ‘areas of interest’ in the excitation-emission matrix (EEM). We then probe one area for characteristic fluorescence lifetimes to track one melanin building block through the formation process. Comparison of the EEMs of L-Dopa derived melanin with natural Sepia melanin shows characteristic differences. We show how the presence of copper ions creates a melanin closer to its natural form.

Carbidopa and physiological distribution of the 6-L-[{sup 18}F]-fluoro-dihydroxy-phenylalanine ({sup 18}F-DOPA); Carbidopa et biodistribution physiologique de la 6-L-[{sup 18}F]-fluorodihydroxyphenylalanine ({sup 18}F-DOPA)

Energy Technology Data Exchange (ETDEWEB)

Detour, J.; Hammer, C.; Lucas, A. [Hopitaux universitaires de Strasbourg, Service de radiopharmacie, 67 (France); Imperiale, A.; Constantinesco, A. [Hopitaux universitaires de Strasbourg, Service de biophysique et medecine nucleaire, 67 (France); Beretz, L. [Hopitaux universitaires de Strasbourg, pole de pharmacie-pharmacologie, 67 (France)

2010-07-01

Purpose: The administration of carbidopa, an peripheral inhibitor of decarboxylase DOPA, may be performed prior to a full body PET scan {sup 18}F-DOPA. There is currently no consensus regarding the routine use of this metabolic preparation (200 mg, 100 mg, 2 mg / kg, no pre-medication). Conclusions: The absence of pre-medication clearly increases pancreatic uptake of {sup 18}F-D.O.P.A.. These results suggest to reconsider the metabolic preparation based on carbidopa, particularly in cases of suspected clinico biological forms of diffuse hyper-insulinism (nesidioblastosis). Pre-medication in cases of digestive neuroendocrine tumors should be reconsidered. The dose-dependent effect of pre-medication on the tumor uptake remains to be explored. (N.C.)

Synthetic improvement and animal experiment of 6-18F-DOPA

International Nuclear Information System (INIS)

Tang Ganghua; Tang Xiaolan; Wang Mingfang; Luo Lei; Li Zhi; Huang Zuhan; Zhang Lan; Wang Yongxian

2002-01-01

Objective: To study synthetic improvement and biodistribution of 6- 18 F-DOPA in normal rats and hemi-Parkinsonism rats. Methods: 6- 18 F-DOPA was synthesized from the starting material 6-nitropiperonal via multi-step reaction including the nucleophilic fluorination, reductive iodination with diiodosilane on Sep-Pak column, chiral catalytic phase-transfer alkylation, and hydrolysis reaction. Biodistribution of 6- 18 F-DOPA in normal rats and the brain of hemi-Parkinsonism rats was determined. Results: The total time of synthesis was less than 110 min, the total uncorrected radiochemical yield from potassium 6- 18 F-DOPA was 5%-18%, and the enantiomeric purity and radiochemical purity were above 97% and 98%, respectively. High uptake in the kidney, blood, striatum, and hippocampus, rapid blood clearance in the kidney and blood, long retaining time and high striatum/cerebellum and striatum/cortex 6- 18 F-DOPA uptake ratio were found in normal rats. Compared with the intact side of hemi-Parkinsonism rats and pseudo-operated group, 6- 18 F-DOPA uptake and striatum/cerebellum and striatum/cortex 6- 18 F-DOPA uptake ratio reduced significantly in the lesioned side of hemi-Parkinsonism rats (P 18 F-DOPA. The synthetic 6- 18 F-DOPA is allowed to be used to study the animal and Parkinson's disease with PET imaging

Ageing effect on 18F-DOPA and 123I-MIBG uptake: a cross-sectional study.

Science.gov (United States)

Chiaravalloti, Agostino; Barbagallo, Gaetano; Ricci, Maria; Sannino, Pasqualina; Karalis, Georgios; Ursini, Francesco; Schillaci, Orazio

2018-06-01

The aim of this study was to investigate the relationship between age and uptake of fluorine-18-L-dihydroxyphenylalanine (F-DOPA) in the brain and myocardial uptake of iodine-123-metaiodobenzylguanidine (I-MIBG) in normal adult participants. To this end, a total of 72 healthy participants were enroled. Of these, 37 individuals (male, 21; female, 16; mean age: 60±12 years; age range: 38-85 years) underwent F-DOPA PET/CT, whereas 35 individuals (male, 19; female, 16; mean age: 61±17 years; age range: 17-87 years) underwent I-MIBG scintigraphy. For F-DOPA PET/CT, regions of interest were placed on the caudate nucleus, globus pallidus and putamen by means of the WFU Pickatlas tool implemented in SPM8 and further analysed after a normalization process. For I-MIBG scintigraphy, regions of interest were set over the upper mediastinum and a heart-to-mediastinum count ratio was calculated. The relation between age and normalized F-DOPA values or heart-to-mediastinum ratio values was examined using correlation analysis of variance and Pearson's correlation coefficient. We did not find any significant relationship between age and F-DOPA and I-MIBG uptake, respectively. Our findings suggest that both brain F-DOPA PET/CT and cardiac I-MIBG scintigraphy represent age-independent biomarkers whose analyses of quantitative uptake may not require adjustment for patients' age.

The effects of dopamine on regional cerebral blood flow in patients with Parkinson's disease before and after L-dopa. Measurement by Xe-enhanced CT

International Nuclear Information System (INIS)

Aiba, Ikuko; Indo, Toshikatsu; Takahashi, Akira.

1994-01-01

Regional cerebral blood flow (rCBF) was measured using the stable xenon enhanced CT method in previously untreated 13 patients with Parkinson's disease to evaluate CBF abnormality related to dysfunction of the nigrostriatal dopaminergic neurons. The patients comprised 5 men and 8 women with Hoehn-Yahr stage II-III. Age at onset ranged from 51 to 73 years (mean±SD, 61.8±8.9) and the duration of illness ranged from 1 to 96 months (15.1±24.1 months). In this series, there was no clinical evidence of hypertension, diabetes mellitus and cognitive impairment. rCBF was measured during 4-5-minutes inhalation, of 33% stable xenon gas-67% oxygen. The first measurement of rCBF was performed in all of the patients before L-dopa treatment. After initiation of L-dopa treatment (333.3±47.1 mg/day), the second measurement was carried out in 6 patients (1 man and 5 women) who had shown symptomatic improvement. The interval between both measurements was 57.7±16.9 days. The following results were obtained. 1) No significant CBF asymmetry was noted in any of the striatum, pallidum, thalamus, cerebrum, cerebellum and frontal lobe in untreated patients with Parkinson's disease. 2) After L-dopa treatment, rCBF was significantly increased only in the striatum as compared with the pretreatment level (51.9±9.3→63.1±9.9 ml/100g/min, p<0.01). 3) This increase was significantly greater on the more severely affected side (contralateral to the predominantly symptomatic limb) (p<0.05). These results suggest that the increase of rCBF in the striatum is closely related to functional improvement of the nigrostriatal dopaminergic neurons. (author)

Dysregulation of striatal projection neurons in Parkinson's disease.

Science.gov (United States)

Beck, Goichi; Singh, Arun; Papa, Stella M

2018-03-01

The loss of nigrostriatal dopamine (DA) is the primary cause of motor dysfunction in Parkinson's disease (PD), but the underlying striatal mechanisms remain unclear. In spite of abundant literature portraying structural, biochemical and plasticity changes of striatal projection neurons (SPNs), in the past there has been a data vacuum from the natural human disease and its close model in non-human primates. Recently, single-cell recordings in advanced parkinsonian primates have generated new insights into the altered function of SPNs. Currently, there are also human data that provide direct evidence of profoundly dysregulated SPN activity in PD. Here, we review primate recordings that are impacting our understanding of the striatal dysfunction after DA loss, particularly through the analysis of physiologic correlates of parkinsonian motor behaviors. In contrast to recordings in rodents, data obtained in primates and patients demonstrate similar major abnormalities of the spontaneous SPN firing in the alert parkinsonian state. Furthermore, these studies also show altered SPN responses to DA replacement in the advanced parkinsonian state. Clearly, there is yet much to learn about the striatal discharges in PD, but studies using primate models are contributing unique information to advance our understanding of pathophysiologic mechanisms.

Kandungan L-3, 4-dihydroxyphenylalanine Suatu Bahan Neuroprotektif pada Biji Koro Benguk (Mucuna pruriens Segar, Rebus, dan Tempe (L-3,4-DIHYDROXYPHENYLALANINE CONTENT AS A NEUROPROTECTIVE MATERIAL ON FRESH, COOKED AND FERMENTED OF KORO BENGUK (MUCUNA PR

Directory of Open Access Journals (Sweden)

Tri Wahyu Pangestiningsih

2017-04-01

Full Text Available Indonesia is rich in flora potentially used for herbal medication. One of the potential herbal is koro benguk (Mucuna pruriens beans, where in Central Java and Yogyakarta is proccessed into tempe (fermented mucuna beans for daily human consumption. Koro benguk has high level of L-3,4-dihydroxyphenylalanine (L-DOPA which has a potential neuroprotective effect on Parkinson’s disease. The aim of this study was to investigate the L-DOPA content in fresh beans, cooked and fermented of koro benguk beans. The investigation were done in fresh mucuna beans, white color (BR D and black color (BR A beans originated from Wonogiri, Central Java, and fresh, white color (KP C, cooked, and fermented beans collected from Kulon Progo, Yogyakarta. The samples were extracted using ethanol and n-propanol solutions and were analyzed using high-performance liquid chromatography (HPLC technique. The results show that the highest L-DOPA level (8,56% was found in fresh white koro benguk beans from Wonogiri extracted using ethanol. The lowest L-DOPA level (0,016% was found in fermented beans that extracted using n-propanol. Extraction using ethanol yield a higher L-DOPA level as compared to that of using n-propanol. In brief, all of the samples starting from fresh bean, cooked, and fermented koro benguk beans contain L-DOPA, with highest L-DOPA level was found in the white fresh koro benguk beans, from Wonogiri, Central Java. The lowest ingredient L-DOPA level was found in the fermented beans from Kulon Progo, Yogyakarta. ABSTRAK Indonesia sangat kaya dengan keanekaragaman flora yang potensial untuk terapi herbal, salah satunya tanaman koro benguk (Mucuna pruriens yang bijinya bisa diolah menjadi tempe sebagai konsumsi harian masyarakat di sekitar Yogyakarta dan Jawa Tengah. Biji koro benguk diketahui mengandung L-3,4-dihydroxyphenylalanine (L-DOPA tinggi dan berpotensi menjadi agen neuroprotektor pada penyakit Parkinson. Penelitian ini bertujuan untuk menguji

Volumetric assessment of recurrent or progressive gliomas: comparison between F-DOPA PET and perfusion-weighted MRI

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Cicone, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Filss, Christian P.; Langen, Karl-Josef [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; RWTH Aachen Univ. Hospital (Germany). Dept. of Nuclear Medicine; Minniti, Giuseppe; Scaringi, Claudia [Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Rossi-Espagnet, Camilla; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Sapienza Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.); Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Galldiks, Norbert [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Cologne Univ. (Germany). Dept. of Neurology; Shah, N. Jon [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine

2015-05-01

To compare the diagnostic information obtained with 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET and relative cerebral blood volume (rCBV) maps in recurrent or progressive glioma. All patients with recurrent or progressive glioma referred for F-DOPA imaging at our institution between May 2010 and May 2014 were retrospectively included, provided that macroscopic disease was visible on conventional MRI images and that rCBV maps were available for comparison. The final analysis included 50 paired studies (44 patients). After image registration, automatic tumour segmentation of both sets of images was performed using the average signal in a large reference VOI including grey and white matter multiplied by 1.6. Tumour volumes identified by both modalities were compared and their spatial congruence calculated. The distances between F-DOPA uptake and rCBV hot spots, tumour-to-brain ratios (TBRs) and normalized histograms were also computed. On visual inspection, 49 of the 50 F-DOPA and 45 of the 50 rCBV studies were classified as positive. The tumour volume delineated using F-DOPA (F-DOPA{sub vol} {sub 1.6}) greatly exceeded that of rCBV maps (rCBV{sub vol} {sub 1.6}). The median F-DOPA{sub vol} {sub 1.6} and rCBV{sub vol} {sub 1.6} were 11.44 ml (range 0 - 220.95 ml) and 1.04 ml (range 0 - 26.30 ml), respectively (p < 0.00001). Overall, the median overlapping volume was 0.27 ml, resulting in a spatial congruence of 1.38 % (range 0 - 39.22 %). The mean hot spot distance was 27.17 mm (±16.92 mm). F-DOPA uptake TBR was significantly higher than rCBV TBR (1.76 ± 0.60 vs. 1.15 ± 0.52, respectively; p < 0.0001). The histogram analysis showed that F-DOPA provided better separation of tumour from background. In 6 of the 50 studies (12 %), however, physiological uptake in the striatum interfered with tumour delineation. The information provided by F-DOPA PET and rCBV maps are substantially different. Image interpretation is easier and a larger tumour extent

l-3,4-Dihydroxyphenylalanine induces ptosis through a GPR143-independent mechanism in mice

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Suguru Ueda

2016-09-01

Full Text Available Through its conversion to dopamine by aromatic l-amino acid decarboxylase (AADC, l-3,4-dihydroxyphenylalanine (l-DOPA replenishes depleted brain dopamine in Parkinson's disease patients. We recently identified GPR143 as a candidate receptor for l-DOPA. In this study, we investigated the behavioral actions of l-DOPA in wild type (wt and Gpr143-deficient mice. l-DOPA dose-dependently (10–100 mg/kg, i.p. induced ptosis under treatment with 3-hydroxybenzylhydrazine, a centrally acting AADC inhibitor. This effect was not mimicked by 3-O-methyldopa. l-DOPA-induced ptosis in Gpr143-deficient mice to a similar extent as in wt mice. These results suggest that l-DOPA induces ptosis in a GPR143-independent fashion in mice.

Usefulness of [18F]-DA and [18F]-DOPA for PET imaging in a mouse model of pheochromocytoma

International Nuclear Information System (INIS)

Martiniova, Lucia; Cleary, Susannah; Lai, Edwin W.; Kiesewetter, Dale O.; Seidel, Jurgen; Dawson, Linda F.; Phillips, Jacqueline K.; Thomasson, David; Chen Xiaoyuan; Eisenhofer, Graeme; Powers, James F.; Kvetnansky, Richard

2012-01-01

Purpose: To evaluate the usefulness of [ 18 F]-6-fluorodopamine ([ 18 F]-DA) and [ 18 F]-L-6-fluoro-3,4-dihydroxyphenylalanine ([ 18 F]-DOPA) positron emission tomography (PET) in the detection of subcutaneous (s.c.) and metastatic pheochromocytoma in mice; to assess the expression of the norepinephrine transporter (NET) and vesicular monoamine transporters 1 and 2 (VMAT1 and VMAT2), all important for [ 18 F]-DA and [ 18 F]-DOPA uptake. Furthermore, to compare tumor detection by micro-computed tomography (microCT) to magnetic resonance imaging (MRI) in individual mouse. Methods: SUV max values were calculated from [ 18 F]-DA and [ 18 F]-DOPA PET, tumor-to-liver ratios (TLR) were obtained and expression of NET, VMAT1 and VMAT2 was evaluated. Results: [ 18 F]-DA detected less metastatic lesions compared to [ 18 F]-DOPA. TLR values for liver metastases were 2.26–2.71 for [ 18 F]-DOPA and 1.83–2.83 for [ 18 F]-DA. A limited uptake of [ 18 F]-DA was found in s.c. tumors (TLR=0.22-0.27) compared to [ 18 F]-DOPA (TLR=1.56-2.24). Overall, NET and VMAT2 were expressed in all organ and s.c. tumors. However, s.c. tumors lacked expression of VMAT1. We confirmed [ 18 F]-DA's high affinity for the NET for its uptake and VMAT1 and VMAT2 for its storage and retention in pheochromocytoma cell vesicles. In contrast, [ 18 F]-DOPA was found to utilize only VMAT2. Conclusion: MRI was superior in the detection of all organ tumors compared to microCT and PET. [ 18 F]-DOPA had overall better sensitivity than [ 18 F]-DA for the detection of metastases. Subcutaneous tumors were localized only with [ 18 F]-DOPA, a finding that may reflect differences in expression of VMAT1 and VMAT2, perhaps similar to some patients with pheochromocytoma where [ 18 F]-DOPA provides better visualization of lesions than [ 18 F]-DA.

Diagnostic utility of PET/CT with {sup 18}F-DOPA and {sup 18}F-FDG in persistent or recurrent medullary thyroid carcinoma: the importance of calcitonin and carcinoembryonic antigen cutoff

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Romero-Lluch, Ana Reyes; Guerrero-Vazquez, Raquel; Martinez-Ortega, Antonio Jesus; Navarro-Gonzalez, Elena [Hospital Universitario Virgen del Rocio, Unidad de Gestion Clinica de Endocrinologia y Nutricion, Seville (Spain); Cuenca-Cuenca, Juan Ignacio; Tirado-Hospital, Juan Luis; Borrego-Dorado, Isabel [Hospital Universitario Virgen del Rocio, Unidad de Medicina Nuclear, Seville (Spain)

2017-11-15

This study sought to evaluate and compare the utility of 18-F-fluorodihydroxyphenylalanine ({sup 18}F-DOPA) and 18-F-fluorodeoxyglucose ({sup 18}F-FDG) positron emission tomography/computed tomography (PET/CT) for identification of lesions in patients with recurrent medullary thyroid carcinoma (MTC). In addition, we analyzed the correlation between the calcitonin (Ct), carcinoembryonic antigen (CEA) levels, each doubling time (DT), and PET positivity. We evaluated the reliability of the 150 pg/mL Ct cutoff set by the American Thyroid Association guidelines for further imaging (including {sup 18}F-DOPA PET/CT). We prospectively recruited 18 patients with recurrent MTC, identified by elevation of Ct or CEA. Each patient underwent a {sup 18}F-FDG PET/CT and a {sup 18}F-DOPA PET/CT. Abnormal uptakes were detected with {sup 18}F-DOPA (n=12) and {sup 18}F-FDG (n=9), (sensitivity of 66.7% vs. 50%; p<0.01). Twenty-eight lesions were detected with {sup 18}F-DOPA vs. 16 lesions with {sup 18}F-FDG (1.56±1.5 vs. 0.89±1.18 lesions per patient; p=0.01). None of our patients showed additional lesions with {sup 18}F-FDG in comparison to {sup 18}F-DOPA. Patient-based detection rate increased significantly with Ct levels ≥150 pg/mL vs. Ct<150 pg/mL for both {sup 18}F-DOPA (sensitivity 90.9% vs. 28.6%; p=0.013) and {sup 18}F-FDG PET/CT (sensitivity 72.7% vs. 14.3%; p=0.025). Using a CEA cutoff of ≥5 ng/mL, detection rates of {sup 18}F-DOPA and {sup 18}F-FDG PET/CT were 81.1% and 72.7%, respectively. No correlation between Ct-DT or CEA-DT and PET positivity was found. Histological confirmation was obtained in eight patients. {sup 18}F-DOPA PET/CT appears to be superior to {sup 18}F-FDG PET/CT in detecting and locating lesions in patients with recurrent MTC. This technique tends to be especially useful in patients with negative results in other imaging modalities and Ct≥150 pg/mL or CEA≥5 ng/mL. (orig.)

Striatal μ-opioid receptor availability predicts cold pressor pain threshold in healthy human subjects

DEFF Research Database (Denmark)

Hagelberg, Nora; Aalto, Sargo; Tuominen, Lauri

2012-01-01

the potential associations between μ-opioid receptor BP(ND) and psychophysical measures. The results show that striatal μ-opioid receptor BP(ND) predicts cold pressor pain threshold, but not cold pressor pain tolerance or tactile sensitivity. This finding suggests that striatal μ-opioid receptor density......Previous PET studies in healthy humans have shown that brain μ-opioid receptor activation during experimental pain is associated with reductions in the sensory and affective ratings of the individual pain experience. The aim of this study was to find out whether brain μ-opioid receptor binding...... at the resting state, in absence of painful stimulation, can be a long-term predictor of experimental pain sensitivity. We measured μ-opioid receptor binding potential (BP(ND)) with μ-opioid receptor selective radiotracer [(11)C]carfentanil and positron emission tomography (PET) in 12 healthy male subjects...

Striatal dopamine release induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex: effect of aging

International Nuclear Information System (INIS)

Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun

2007-01-01

We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging

Striatal dopamine release induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex: effect of aging

Energy Technology Data Exchange (ETDEWEB)

Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

2007-07-01

We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging.

Levodopa delivery systems: advancements in delivery of the gold standard.

Science.gov (United States)

Ngwuluka, Ndidi; Pillay, Viness; Du Toit, Lisa C; Ndesendo, Valence; Choonara, Yahya; Modi, Girish; Naidoo, Dinesh

2010-02-01

Despite the fact that Parkinson's disease (PD) was discovered almost 200 years ago, its treatment and management remain immense challenges because progressive loss of dopaminergic nigral neurons, motor complications experienced by the patients as the disease progresses and drawbacks of pharmacotherapeutic management still persist. Various therapeutic agents have been used in the management of PD, including levodopa (l-DOPA), selegiline, amantadine, bromocriptine, entacapone, pramipexole dihydrochloride and more recently istradefylline and rasagiline. Of all agents, l-DOPA although the oldest, remains the most effective. l-DOPA is easier to administer, better tolerated, less expensive and is required by almost all PD patients. However, l-DOPA's efficacy in advanced PD is significantly reduced due to metabolism, subsequent low bioavailability and irregular fluctuations in its plasma levels. Significant strides have been made to improve the delivery of l-DOPA in order to enhance its bioavailability and reduce plasma fluctuations as well as motor complications experienced by patients purportedly resulting from pulsatile stimulation of the striatal dopamine receptors. Drug delivery systems that have been instituted for the delivery of l-DOPA include immediate release formulations, liquid formulations, dispersible tablets, controlled release formulations, dual-release formulations, microspheres, infusion and transdermal delivery, among others. In this review, the l-DOPA-loaded drug delivery systems developed over the past three decades are elaborated. The ultimate aim was to assess critically the attempts made thus far directed at improving l-DOPA absorption, bioavailability and maintenance of constant plasma concentrations, including the drug delivery technologies implicated. This review highlights the fact that neuropharmaceutics is at a precipice, which is expected to spur investigators to take that leap to enable the generation of innovative delivery systems for the

A six-month multicentre, double-blind, bromocriptine-controlled study of the safety and efficacy of ropinirole in the treatment of patients with Parkinson's disease not optimally controlled by L-dopa

NARCIS (Netherlands)

Brunt, ER; Brooks, DJ; Korczyn, AD; Montastruc, JL; Stocchi, F

2002-01-01

Objectives. To compare the safety and efficacy of ropinirole and bromocriptine as adjunct therapy in patients with Parkinson's disease (PD) not optimally controlled by L-dopa. Methods. A randomised, double-blind trial in which 555 patients were assigned to three treatment groups according to the

Genetically determined measures of striatal D2 signaling predict prefrontal activity during working memory performance.

Science.gov (United States)

Bertolino, Alessandro; Taurisano, Paolo; Pisciotta, Nicola Marco; Blasi, Giuseppe; Fazio, Leonardo; Romano, Raffaella; Gelao, Barbara; Lo Bianco, Luciana; Lozupone, Madia; Di Giorgio, Annabella; Caforio, Grazia; Sambataro, Fabio; Niccoli-Asabella, Artor; Papp, Audrey; Ursini, Gianluca; Sinibaldi, Lorenzo; Popolizio, Teresa; Sadee, Wolfgang; Rubini, Giuseppe

2010-02-22

Variation of the gene coding for D2 receptors (DRD2) has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560) predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic) and D2L (mainly post-synaptic). However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known. Thirty-seven healthy subjects were genotyped for rs1076560 (G>T) and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors) and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors), as well as BOLD fMRI during N-Back working memory. Subjects carrying the T allele (previously associated with reduced D2S expression) had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers) and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT. Our results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway.

Genetically determined measures of striatal D2 signaling predict prefrontal activity during working memory performance.

Directory of Open Access Journals (Sweden)

Alessandro Bertolino

2010-02-01

Full Text Available Variation of the gene coding for D2 receptors (DRD2 has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560 predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic and D2L (mainly post-synaptic. However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known.Thirty-seven healthy subjects were genotyped for rs1076560 (G>T and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors, as well as BOLD fMRI during N-Back working memory.Subjects carrying the T allele (previously associated with reduced D2S expression had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT.Our results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway.

Exploring personality traits related to dopamine D2/3 receptor availability in striatal subregions of humans.

Science.gov (United States)

Caravaggio, Fernando; Fervaha, Gagan; Chung, Jun Ku; Gerretsen, Philip; Nakajima, Shinichiro; Plitman, Eric; Iwata, Yusuke; Wilson, Alan; Graff-Guerrero, Ariel

2016-04-01

While several studies have examined how particular personality traits are related to dopamine D2/3 receptor (D2/3R) availability in the striatum of humans, few studies have reported how multiple traits measured in the same persons are differentially related to D2/3R availability in different striatal sub-regions. We examined how personality traits measured with the Karolinska Scales of Personality are related to striatal D2/3R availability measured with [(11)C]-raclopride in 30 healthy humans. Based on previous the literature, five personality traits were hypothesized to be most likely related to D2/3R availability: impulsiveness, monotony avoidance, detachment, social desirability, and socialization. We found self-reported impulsiveness was negatively correlated with D2/3R availability in the ventral striatum and globus pallidus. After controlling for age and gender, monotony avoidance was also negatively correlated with D2/3R availability in the ventral striatum and globus pallidus. Socialization was positively correlated with D2/3R availability in the ventral striatum and putamen. After controlling for age and gender, the relationship between socialization and D2/3R availability in these regions survived correction for multiple comparisons (p-threshold=.003). Thus, within the same persons, different personality traits are differentially related to in vivo D2/3R availability in different striatal sub-regions. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

L-dopa decarboxylase (DDC) gene expression is related to outcome in patients with prostate cancer.

Science.gov (United States)

Koutalellis, Georgios; Stravodimos, Konstantinos; Avgeris, Margaritis; Mavridis, Konstantinos; Scorilas, Andreas; Lazaris, Andreas; Constantinides, Constantinos

2012-09-01

What's known on the subject? and What does the study add? L-dopa decarboxylase (DDC) has been documented as a novel co-activator of androgen receptor transcriptional activity. Recently, it was shown that DDC gene expression is significantly higher in patients with PCa than in those with BPH. In the present study, there was a significant association between the DDC gene expression levels and the pathological stage and Gleason score of patients with prostate cancer (PCa). Moreover, DDC expression was shown to be an unfavourable prognostic marker of biochemical recurrence and disease-free survival in patients with PCa treated by radical prostatectomy. To determine whether L-dopa decarboxylase gene (DDC) expression levels in patients with prostate cancer (PCa) correlate to biochemical recurrence and disease prognosis after radical prostatectomy (RP). The present study consisted of 56 samples with confirmed malignancy from patients with PCa who had undergone RP at a single tertiary academic centre. Total RNA was isolated from tissue specimens and a SYBR Green fluorescence-based quantitative real-time polymerase chain reaction methodology was developed for the determination of DDC mRNA expression levels of the tested tissues. Follow-up time ranged between 1.0 and 62.0 months (mean ± SE, 28.6 ± 2.1 month; median, 31.5 months). Time to biochemical recurrence was defined as the interval between the surgery and the measurement of two consecutive values of prostate-specific antigen (PSA) ≥0.2 ng/mL. DDC expression levels were found to be positively correlated with the tumour-node-metastasis stage (P = 0.021) and Gleason score (P = 0.036) of the patients with PCa. Patients with PCa with raised DDC expression levels run a significantly higher risk of biochemical recurrence after RP, as indicated by Cox proportional regression analysis (P = 0.021). Multivariate Cox proportional regression models revealed the preoperative PSA-, age- and digital rectal examination

Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase.

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Małgorzata Cieńska

Full Text Available Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA by immobilized tyrosinase in the presence of ascorbic acid (AH2, which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native to 30% (immobilized enzyme. To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme and 70% (immobilized. A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity.

Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase.

Science.gov (United States)

Cieńska, Małgorzata; Labus, Karolina; Lewańczuk, Marcin; Koźlecki, Tomasz; Liesiene, Jolanta; Bryjak, Jolanta

2016-01-01

Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by immobilized tyrosinase in the presence of ascorbic acid (AH2), which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native) to 30% (immobilized enzyme). To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme) and 70% (immobilized). A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity.

Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase

Science.gov (United States)

Lewańczuk, Marcin; Koźlecki, Tomasz; Liesiene, Jolanta; Bryjak, Jolanta

2016-01-01

Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by immobilized tyrosinase in the presence of ascorbic acid (AH2), which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native) to 30% (immobilized enzyme). To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme) and 70% (immobilized). A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity. PMID:27711193

L-Dopa decarboxylase (DDC) constitutes an emerging biomarker in predicting patients' survival with stomach adenocarcinomas.

Science.gov (United States)

Florou, Dimitra; Papadopoulos, Iordanis N; Fragoulis, Emmanuel G; Scorilas, Andreas

2013-02-01

Stomach adenocarcinoma represents a major health problem and is regarded as the second commonest cause of cancer-associated mortality, universally, since it is still difficult to be perceived at a curable stage. Several lines of evidence have pointed out that the expression of L-Dopa decarboxylase (DDC) gene and/or protein becomes distinctively modulated in several human neuroendocrine neoplasms as well as adenocarcinomas. In order to elucidate the clinical role of DDC on primary gastric adenocarcinomas, we determined qualitatively and quantitatively the mRNA levels of the gene with regular PCR and real-time PCR by using the comparative threshold cycle method, correspondingly, and detected the expression of DDC protein by immunoblotting in cancerous and normal stomach tissue specimens. A statistically significant association was disclosed between DDC expression and gastric intestinal histotype as well as tumor localization at the distal third part of the stomach (p = 0.025 and p = 0.029, respectively). Univariate and multivariate analyses highlighted the powerful prognostic importance of DDC in relation to disease-free survival and overall survival of gastric cancer patients. According to Kaplan-Meier curves, the relative risk of relapse was found to be decreased in DDC-positive (p = 0.031) patients who, also, exhibited higher overall survival rates (p = 0.016) than those with DDC-negative tumors. This work is the first to shed light on the potential clinical usefulness of DDC, as an efficient tumor biomarker in gastric cancer. The provided evidence underlines the propitious predictive value of DDC expression in the survival of stomach adenocarcinoma patients.

Total {sup 18}F-dopa PET tumour uptake reflects metabolic endocrine tumour activity in patients with a carcinoid tumour

Energy Technology Data Exchange (ETDEWEB)

Fiebrich, Helle-Brit; Walenkamp, Annemiek M.; Vries, Elisabeth G.E. de [University Medical Centre Groningen, Department of Medical Oncology, Groningen (Netherlands); Jong, Johan R. de; Koopmans, Klaas Pieter; Dierckx, Rudi A.J.O.; Brouwers, Adrienne H. [University Medical Centre Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Kema, Ido P. [University Medical Centre Groningen, Department of Laboratory Medicine, Groningen (Netherlands); Sluiter, Wim; Links, Thera P. [University Medical Centre Groningen, Department of Endocrinology, Groningen (Netherlands)

2011-10-15

Positron emission tomography (PET) using 6-[{sup 18}F]fluoro-L-dihydroxyphenylalanine ({sup 18}F-dopa) has an excellent sensitivity to detect carcinoid tumour lesions. {sup 18}F-dopa tumour uptake and the levels of biochemical tumour markers are mediated by tumour endocrine metabolic activity. We evaluated whether total {sup 18}F-dopa tumour uptake on PET, defined as whole-body metabolic tumour burden (WBMTB), reflects tumour load per patient, as measured with tumour markers. Seventy-seven consecutive carcinoid patients who underwent an {sup 18}F-dopa PET scan in two previously published studies were analysed. For all tumour lesions mean standardised uptake values (SUVs) at 40% of the maximal SUV and tumour volume on {sup 18}F-dopa PET were determined and multiplied to calculate a metabolic burden per lesion. WBMTB was the sum of the metabolic burden of all individual lesions per patient. The 24-h urinary serotonin, urine and plasma 5-hydroxindoleacetic acid (5-HIAA), catecholamines (nor)epinephrine, dopamine and their metabolites, measured in urine and plasma, and serum chromogranin A served as tumour markers. All but 1 were evaluable for WBMTB; 74 patients had metastatic disease. {sup 18}F-dopa PET detected 979 lesions. SUV{sub max} on {sup 18}F-dopa PET varied up to 29-fold between individual lesions within the same patients. WBMTB correlated with urinary serotonin (r = 0.51) and urinary and plasma 5-HIAA (r = 0.78 and 0.66). WBMTB also correlated with urinary norepinephrine, epinephrine, dopamine and plasma dopamine, but not with serum chromogranin A. Tumour load per patient measured with {sup 18}F-dopa PET correlates with tumour markers of the serotonin and catecholamine pathway in urine and plasma in carcinoid patients, reflecting metabolic tumour activity. (orig.)

Motor cortex plasticity can indicate vulnerability to motor fluctuation and high L-DOPA need in drug-naïve Parkinson's disease.

Science.gov (United States)

Kishore, Asha; James, Praveen; Krishnan, Syam; Yahia-Cherif, Lydia; Meunier, Sabine; Popa, Traian

2017-02-01

Motor cortex plasticity is reported to be decreased in Parkinson's disease in studies which pooled patients in various stages of the disease. Whether the early decrease in plasticity is related to the motor signs or is linked to the future development of motor complications of treatment is unclear. The aim of the study was to test if motor cortex plasticity and its cerebellar modulation are impaired in treatment-naïve Parkinson's disease, are related to the motor signs of the disease and predict occurrence of motor complications of treatment. Twenty-nine denovo patients with Parkinson's disease were longitudinally assessed for motor complications for four years. Using transcranial magnetic stimulation, the plasticity of the motor cortex and its cerebellar modulation were measured (response to paired-associative stimulation alone or preceded by 2 active cerebellar stimulation protocols), both in the untreated state and after a single dose of L-DOPA. Twenty-six matched, healthy volunteers were tested, only without L-DOPA. Patients and healthy controls had similar proportions of responders and non-responders to plasticity induction. In the untreated state, the more efficient was the cerebellar modulation of motor cortex plasticity, the lower were the bradykinesia and rigidity scores. The extent of the individual plastic response to paired associative stimulation could indicate a vulnerability to develop early motor fluctuation but not dyskinesia. Measuring motor cortex plasticity in denovo Parkinson's disease could be a neurophysiological parameter that may help identify patients with greater propensity for early motor fluctuations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Long-term Levodopa Treatment Accelerates the Circadian Rhythm Dysfunction in a 6-hydroxydopamine Rat Model of Parkinson's Disease

Institute of Scientific and Technical Information of China (English)

Si-Yue Li; Ya-Li Wang; Wen-Wen Liu; Dong-Jun Lyu; Fen Wang; Cheng-Jie Mao; Ya-Ping Yang; Li-Fang Hu; Chun-Feng Liu

2017-01-01

Background:Parkinson's disease (PD) patients with long-term levodopa (L-DOPA) treatment are suffering from severe circadian dysfunction.However,it is hard to distinguish that the circadian disturbance in patients is due to the disease progression itself,or is affected by L-DOPA replacement therapy.This study was to investigate the role of L-DOPA on the circadian dysfunction in a rat model of PD.Methods:The rat model of PD was constructed by a bilateral striatal injection with 6-hydroxydopamine (6-OHDA),followed by administration of saline or 25 mg/kg L-DOPA for 21 consecutive days.Rotarod test,footprint test,and open-field test were carried out to evaluate the motor function.Striatum,suprachiasmatic nucleus (SCN),liver,and plasma were collected at 6:00,12:00,18:00,and 24:00.Quantitative real-time polymerase chain reaction was used to examine the expression of clock genes.Enzyme-linked immunosorbent assay was used to determine the secretion level of cortisol and melatonin.High-performance liquid chromatography was used to measure the neurotransmitters.Analysis of variance was used for data analysis.Results:L-DOPA alleviated the motor deficits induced by 6-OHDA lesions in the footprint and open-field test (P ＜ 0.01,P ＜ 0.001,respectively).After L-DOPA treatment,Bmal1 decreased in the SCN compared with 6-OHDA group at 12:00 (P ＜ 0.01) and 24:00 (P ＜ 0.001).In the striatum,the expression ofBmal1,Rorα was lower than that in the 6-OHDA group at 18:00 (P ＜ 0.05) and L-DOPA seemed to delay the peak of Per2 to 24:00.In liver,L-DOPA did not affect the rhythmicity and expression of these clock genes (P ＞ 0.05).In addition,the cortisol secretion was increased (P ＞ 0.05),but melatonin was further inhibited after L-DOPA treatment at 6:00 (P ＜ 0.01).Conclusions:In the circadian system of advanced PD rat models,circadian dysfunction is not only contributed by the degeneration of the disease itself but also long-term L-DOPA therapy may further aggravate it.

The Parkinsonian Subthalamic Network: Measures of Power, Linear, and Non-linear Synchronization and their Relationship to L-DOPA Treatment and OFF State Motor Severity.

Science.gov (United States)

West, Timothy; Farmer, Simon; Berthouze, Luc; Jha, Ashwani; Beudel, Martijn; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Brown, Peter; Litvak, Vladimir

2016-01-01

In this paper we investigated the dopaminergic modulation of neuronal interactions occurring in the subthalamic nucleus (STN) during Parkinson's disease (PD). We utilized linear measures of local and long range synchrony such as power and coherence, as well as Detrended Fluctuation Analysis for Phase Synchrony (DFA-PS)- a recently developed non-linear method that computes the extent of long tailed autocorrelations present in the phase interactions between two coupled signals. Through analysis of local field potentials (LFPs) taken from the STN we seek to determine changes in the neurodynamics that may underpin the pathophysiology of PD in a group of 12 patients who had undergone surgery for deep brain stimulation. We demonstrate up modulation of alpha-theta (5-12 Hz) band power in response to L-DOPA treatment, whilst low beta band power (15-20 Hz) band-power is suppressed. We also find evidence for significant local connectivity within the region surrounding STN although there was evidence for its modulation via administration of L-DOPA. Further to this we present evidence for a positive correlation between the phase ordering of bilateral STN interactions and the severity of bradykinetic and rigidity symptoms in PD. Although, the ability of non-linear measures to predict clinical state did not exceed standard measures such as beta power, these measures may help identify the connections which play a role in pathological dynamics.

Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

Science.gov (United States)

Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

2012-11-01

The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Levodopa-induced dyskinesia is associated with increased thyrotropin releasing hormone in the dorsal striatum of hemi-parkinsonian rats.

Directory of Open Access Journals (Sweden)

Ippolita Cantuti-Castelvetri

2010-11-01

Full Text Available Dyskinesias associated with involuntary movements and painful muscle contractions are a common and severe complication of standard levodopa (L-DOPA, L-3,4-dihydroxyphenylalanine therapy for Parkinson's disease. Pathologic neuroplasticity leading to hyper-responsive dopamine receptor signaling in the sensorimotor striatum is thought to underlie this currently untreatable condition.Quantitative real-time polymerase chain reaction (PCR was employed to evaluate the molecular changes associated with L-DOPA-induced dyskinesias in Parkinson's disease. With this technique, we determined that thyrotropin releasing hormone (TRH was greatly increased in the dopamine-depleted striatum of hemi-parkinsonian rats that developed abnormal movements in response to L-DOPA therapy, relative to the levels measured in the contralateral non-dopamine-depleted striatum, and in the striatum of non-dyskinetic control rats. ProTRH immunostaining suggested that TRH peptide levels were almost absent in the dopamine-depleted striatum of control rats that did not develop dyskinesias, but in the dyskinetic rats, proTRH immunostaining was dramatically up-regulated in the striatum, particularly in the sensorimotor striatum. This up-regulation of TRH peptide affected striatal medium spiny neurons of both the direct and indirect pathways, as well as neurons in striosomes.TRH is not known to be a key striatal neuromodulator, but intrastriatal injection of TRH in experimental animals can induce abnormal movements, apparently through increasing dopamine release. Our finding of a dramatic and selective up-regulation of TRH expression in the sensorimotor striatum of dyskinetic rat models suggests a TRH-mediated regulatory mechanism that may underlie the pathologic neuroplasticity driving dopamine hyper-responsivity in Parkinson's disease.

Expression analysis and clinical utility of L-Dopa decarboxylase (DDC) in prostate cancer.

Science.gov (United States)

Avgeris, Margaritis; Koutalellis, Georgios; Fragoulis, Emmanuel G; Scorilas, Andreas

2008-10-01

L-Dopa decarboxylase (DDC) is a pyridoxal 5'-phosphate-dependent enzyme that was found to be involved in many malignancies. The aim of this study was to investigate the mRNA expression levels of DDC in prostate tissues and to evaluate its clinical utility in prostate cancer (CaP). Total RNA was isolated from 118 tissue specimens from benign prostate hyperplasia (BPH) and CaP patients and a highly sensitive quantitative real-time RT-PCR (qRT-PCR) method for DDC mRNA quantification has been developed using the SYBR Green chemistry. LNCaP prostate cancer cell line was used as a calibrator and GAPDH as a housekeeping gene. DDC was found to be overexpressed, at the mRNA level, in the specimens from prostate cancer patients, in comparison to those from benign prostate hyperplasia patients (pDDC expression has significant discriminatory value between CaP and BPH (pDDC expression status was compared with other established prognostic factors, in prostate cancer. High expression levels of DDC were found more frequently in high Gleason's score tumors (p=0.022) as well as in advanced stage patients (p=0.032). Our data reveal the potential of DDC expression, at the mRNA level, as a novel biomarker in prostate cancer.

7-[3-(4-[2,3-dimethylphenyl]piperazinyl)propoxy]-2 (1H)-quinolinone (OPC-4392), a presynaptic dopamine autoreceptor agonist and postsynaptic D2 receptor antagonist

International Nuclear Information System (INIS)

Yasuda, Y.; Kikuchi, T.; Suzuki, S.; Tsutsui, M.; Yamada, K.; Hiyama, T.

1988-01-01

The assertion that OPC-4392 acts as an agonist at presynaptic dopamine autoreceptors is supported by the following behavioral and biochemical observations: OPC-4392, 3-PPP and apomorphine inhibited the reserpine-induced increase in DOPA accumulation in the forebrain of mice and in the frontal cortex, limbic forebrain and striatum of rats. In addition, the gamma-butyrolactone (GBL)-induced increase in DOPA accumulation in the mouse forebrain was also inhibited by OPC-4392, 3-PPP and apomorphine. The inhibitory effect of OPC-4392 on GBL-induced DOPA accumulation lasted for at least 8 hours after oral administration to mice, while that of 3-PPP and apomorphine disappeared in 4 hours after subcutaneous injection. OPC-4392 failed to increase spontaneous motor activity in reserpinized mice, enhance spontaneous ipsilateral rotation in rats with unilateral striatal kainic acid (KA) lesions, induce contralateral rotation in rats with unilateral striatal 6-hydroxydopamine (6-OHDA) lesions and inhibit 14 C-acetylcholine (Ach) release stimulated by 20 mM KCl in rat striatal slices

Positron emission tomography in degenerative disorders of the dopaminergic system

Energy Technology Data Exchange (ETDEWEB)

Karbe, H; Holthoff, V; Huber, M; Herholz, K; Wienhard, K; Wagner, R; Heiss, W D [Universitaetsklinik fuer Neurologie und Max-Planck-Institut fuer neurologische Forschung, Koeln (Germany)

1992-01-01

21 patients who had Parkinson's disease (PD), PD plus dementia of Alzheimer type (PDAT) or progressive supranuclear palsy (PSP), were studied with positron emission tomography (PET) using ({sup 18}F)-2-fluoro-2-deoxy-D-glucose (FDG). In one patient with strictly unilateral PD side differences in striatal dopa uptake were studied with 6-({sup 18}F)fluoro-L-dopa (F-dopa). In patients with PD PET with FDG did not show any significant change in regional cerebral metabolic rates for glucose (rCMR(Glu)). In PDAT glucose metabolism was generally reduced, the most severe decrease was found in parietal cortex. The metabolic pattern was similar to that typically found in patients with Alzheimer's disease (AD). In the patient with strictly unilateral PD rCMR(Glu) was normal, F-dopa PET, however, revealed a distinct reduction of dopa uptake in the contralateral putamen. In PSP glucose metabolism was significantly decreased in subcortical regions (caudatum, putamen and brainstem) and in frontal cortex. Thus PET demonstrated a clear difference of metabolic pattern between PDAT and PSP. (authors).

Mucuna pruriens and its major constituent L-DOPA recover spermatogenic loss by combating ROS, loss of mitochondrial membrane potential and apoptosis.

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Singh, Akhand Pratap; Sarkar, Saumya; Tripathi, Muktanand; Rajender, Singh

2013-01-01

The Ayurvedic medicinal system claims Mucuna pruriens (MP) to possess pro-male fertility, aphrodisiac and adaptogenic properties. Some scientific evidence also supports its pro-male fertility properties; however, the mechanism of its action is not yet clear. The present study aimed at demonstrating spermatogenic restorative efficacy of MP and its major constituent L-DOPA (LD), and finding the possible mechanism of action thereof in a rat model. Ethinyl estradiol (EE) was administered at a rate of 3 mg/kg body weight (BW)/day for a period of 14 days to generate a rat model with compromised spermatogenesis. MP and LD were administered in two separate groups of these animals starting 15(th) day for a period of 56 days, and the results were compared with an auto-recovery (AR) group. Sperm count and motility, testis histo-architecture, level of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis, peripheral hormone levels and testicular germ cell populations were analysed, in all experimental groups. We observed efficient and quick recovery of spermatogenesis in MP and LD groups in comparison to the auto-recovery group. The treatment regulated ROS level, apoptosis, and mitochondrial membrane potential (MMP), recovered the hypothalamic-pituitary-gonadal axis and the number of testicular germ cells, ultimately leading to increased sperm count and motility. M. pruriens efficiently recovers the spermatogenic loss induced due to EE administration. The recovery is mediated by reduction in ROS level, restoration of MMP, regulation of apoptosis and eventual increase in the number of germ cells and regulation of apoptosis. The present study simplified the complexity of mechanism involved and provided meaningful insights into MP/LD mediated correction of spermatogenic impairment caused by estrogens exposure. This is the first study demonstrating that L-DOPA largely accounts for pro-spermatogenic properties of M. pruriens. The manuscript bears CDRI

No-carrier-added (NCA) synthesis of 6-[18F]fluoro-L-DOPA using 3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[6S-(6α, 8α, 8αβ)]-6,8-methano-2H-1,4-benzoxazin-2-one

International Nuclear Information System (INIS)

Horti, A.; Yale Univ., West Haven, CT; Redmond, D.E. Jr.; Soufer, R.

1995-01-01

3,5,6,7,8,8a-Hexahydro-7,7,8a-trimethyl-[6S-(6α,8α , 8αβ)]-6,8-methano-2H-1,4-benzoxazino-2-one (2) was investigated as chiral auxiliary for asymmetric NCA nucleophilic synthesis of 6-[ 18 F]Fluoro-L-DOPA. Direct condensation of 3,4-dimethoxy-2-[ 18 F]fluorobenzaldehyde (1a) or 6-[ 18 F]fluoro-piperonal (1b) in the presence of NaH with 2 gave the corresponding [ 18 F]-3-[(2-fluorophenyl)methylene]-3,5,6,7,8,8a-hexahydro-7,7,8 a-trimethyl-[6S-(3Z,3α,6α,8α,8αβ)]-6, 8-methano-2H-1,4-benzoxazin-2-one derivative 3a or 3b as a single stereoisomer. L-Selectride promoted hydrogenation of the olefinic double bond of these derivatives, in presence of tertbutyl alcohol, afforded the corresponding [ 18 F]-3-[(2-fluorophenyl) methyl]-3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[3S-(3α, 6α, 8α8αβ)]-6,8-methano-2H-1,4-benzoxazin-2-one derivatives (4a,b) without affecting the orientation of diasterofacial discrimination. Deprotection of the derivatives 4a,b yielded 6-[ 18 F]fluoro-L-DOPA (e.e. >90%, 3% radiochemical yield (EOB), total synthesis time 125 min, specific activity >2000 mCi/μmol). Direct deprotection/reduction of the compounds 3a,b provides the enantiomeric mixture of 6-[ 18 F]fluoro-D,L-DOPA (10-12% radiochemical yield) and, after chiral separation, 6-[ 18 F]fluoro-L-DOPA (e.e. 98%, 4-5% radiochemical yield). (author)

Refractory epilepsy and basal ganglia: the role of seizure frequency

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Bouilleret, V.; Trebossen, R.; Mantzerides, M.; Semah, F.; Ribeiro, M.J. [Service Hospitalier Frederic Joliot, I2BM/DSV, CEA, 91 - Orsay (France); Bouilleret, V. [CHU Bicetre, Unite de Neurophysiologie et d' Epileptologie, AP-HP, 75 - Paris (France); Chassoux, F. [Hopital Saint Anne, Service de Neurochirurgie, 75 - Paris (France); Biraben, A. [CHU, Service de Neurologie, Hopital Pontchaillou, 35 - Rennes (France)

2008-02-15

Objectives. - A decrease of [{sup 18}F]Fluoro-L-DOPA uptake in basal ganglia (B.G.) was recently reported in medically refractory epilepsy. The purpose of this study was to assess the involvement of dopaminergic neurotransmission in refractory Temporal Lobe Epilepsy (T.L.E.) and its relationship to glucose metabolism and morphological changes. Methods. - Twelve T.L.E. patients were studied using [{sup 18}F]FDG PET, [{sup 18}F]Fluoro-L-DOPA PET and MRI and compared with healthy control volunteers. Morphological cerebral changes were assessed using Voxel-Based Morphometry (V.B.M.). Student t test statistical maps of functional and morphological differences between patients and controls were obtained using a general linear model. Results. - In T.L.E. patients, [{sup 18}F]Fluoro-L-DOPA uptake was reduced to the same extent in caudate and putamen in both cerebral hemispheres as well as in the substantia nigra (S.N.). These dopaminergic functional alterations occurred without any glucose metabolism changes in these areas. The only mild morphological abnormality was found in striatal regions without any changes in the S.N.. Conclusion. - The present study provides support for dopaminergic neurotransmission involvement in T.L.E.. The discrepancies between G.M.V. atrophy and the pattern of [{sup 18}F]Fluoro-L-DOPA suggest that B.G. involvement is not related to structural subcortical abnormalities. A functional decrease can be ruled out as there was no change of the glycolytic pathway metabolism in these areas. (authors)

Mitochondrial DNA depletion by ethidium bromide decreases neuronal mitochondrial creatine kinase: Implications for striatal energy metabolism.

Science.gov (United States)

Warren, Emily Booth; Aicher, Aidan Edward; Fessel, Joshua Patrick; Konradi, Christine

2017-01-01

Mitochondrial DNA (mtDNA), the discrete genome which encodes subunits of the mitochondrial respiratory chain, is present at highly variable copy numbers across cell types. Though severe mtDNA depletion dramatically reduces mitochondrial function, the impact of tissue-specific mtDNA reduction remains debated. Previously, our lab identified reduced mtDNA quantity in the putamen of Parkinson's Disease (PD) patients who had developed L-DOPA Induced Dyskinesia (LID), compared to PD patients who had not developed LID and healthy subjects. Here, we present the consequences of mtDNA depletion by ethidium bromide (EtBr) treatment on the bioenergetic function of primary cultured neurons, astrocytes and neuron-enriched cocultures from rat striatum. We report that EtBr inhibition of mtDNA replication and transcription consistently reduces mitochondrial oxygen consumption, and that neurons are significantly more sensitive to EtBr than astrocytes. EtBr also increases glycolytic activity in astrocytes, whereas in neurons it reduces the expression of mitochondrial creatine kinase mRNA and levels of phosphocreatine. Further, we show that mitochondrial creatine kinase mRNA is similarly downregulated in dyskinetic PD patients, compared to both non-dyskinetic PD patients and healthy subjects. Our data support a hypothesis that reduced striatal mtDNA contributes to energetic dysregulation in the dyskinetic striatum by destabilizing the energy buffering system of the phosphocreatine/creatine shuttle.

Mitochondrial DNA depletion by ethidium bromide decreases neuronal mitochondrial creatine kinase: Implications for striatal energy metabolism.

Directory of Open Access Journals (Sweden)

Emily Booth Warren

Full Text Available Mitochondrial DNA (mtDNA, the discrete genome which encodes subunits of the mitochondrial respiratory chain, is present at highly variable copy numbers across cell types. Though severe mtDNA depletion dramatically reduces mitochondrial function, the impact of tissue-specific mtDNA reduction remains debated. Previously, our lab identified reduced mtDNA quantity in the putamen of Parkinson's Disease (PD patients who had developed L-DOPA Induced Dyskinesia (LID, compared to PD patients who had not developed LID and healthy subjects. Here, we present the consequences of mtDNA depletion by ethidium bromide (EtBr treatment on the bioenergetic function of primary cultured neurons, astrocytes and neuron-enriched cocultures from rat striatum. We report that EtBr inhibition of mtDNA replication and transcription consistently reduces mitochondrial oxygen consumption, and that neurons are significantly more sensitive to EtBr than astrocytes. EtBr also increases glycolytic activity in astrocytes, whereas in neurons it reduces the expression of mitochondrial creatine kinase mRNA and levels of phosphocreatine. Further, we show that mitochondrial creatine kinase mRNA is similarly downregulated in dyskinetic PD patients, compared to both non-dyskinetic PD patients and healthy subjects. Our data support a hypothesis that reduced striatal mtDNA contributes to energetic dysregulation in the dyskinetic striatum by destabilizing the energy buffering system of the phosphocreatine/creatine shuttle.

Case Reports Showing a Long-Term Effect of Subanesthetic Ketamine Infusion in Reducing L-DOPA-Induced Dyskinesias

Directory of Open Access Journals (Sweden)

Scott J. Sherman

2016-02-01

Full Text Available Ketamine is an FDA-approved drug with a known safety profile. Low-dose subanesthetic intravenous ketamine infusion treatment has led to long-term reduction of treatment-resistant depression and of chronic pain states. We report on low-dose subanesthetic intravenous ketamine infusion treatment in Parkinson's disease (PD patients by 5 case studies and show a long-lasting therapeutic benefit to reduce L-DOPA-induced dyskinesia (LID, improve on time, and reduce depression. Based on the literature we hypothesize that low-dose ketamine may act as a ‘chemical deep brain stimulation', by desynchronizing hypersynchronous oscillatory brain activity, including in the basal ganglia and the motor cortex. The presented PD case reports indicate tolerability, safety and long-term beneficial effects of low-dose ketamine infusion that should be further investigated in a properly controlled prospective clinical trial for treatment of LID, as well as the prevalent nonmotor features pain and depression in PD patients.

A Dopa Decarboxylase Modulating the Immune Response of Scallop Chlamys farreri

Science.gov (United States)

Zhou, Zhi; Yang, Jialong; Wang, Lingling; Zhang, Huan; Gao, Yang; Shi, Xiaowei; Wang, Mengqiang; Kong, Pengfei; Qiu, Limei; Song, Linsheng

2011-01-01

Background Dopa decarboxylase (DDC) is a pyridoxal 5-phosphate (PLP)-dependent enzyme that catalyzes the decarboxylation of L-Dopa to dopamine, and involved in complex neuroendocrine-immune regulatory network. The function for DDC in the immunomodulation remains unclear in invertebrate. Methodology The full-length cDNA encoding DDC (designated CfDDC) was cloned from mollusc scallop Chlamys farreri. It contained an open reading frame encoding a polypeptide of 560 amino acids. The CfDDC mRNA transcripts could be detected in all the tested tissues, including the immune tissues haemocytes and hepatopancreas. After scallops were treated with LPS stimulation, the mRNA expression level of CfDDC in haemocytes increased significantly (5.5-fold, PDDC inhibitor methyldopa, the ROS level in haemocytes of scallops was decreased significantly to 0.41-fold (PDDC in scallop, modulated the immune responses such as haemocytes encapsulation as well as the ROS level through its catalytic activity, functioning as an indispensable immunomodulating enzyme in the neuroendocrine-immune regulatory network of mollusc. PMID:21533240

Rasd2 Modulates Prefronto-Striatal Phenotypes in Humans and 'Schizophrenia-Like Behaviors' in Mice.

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Vitucci, Daniela; Di Giorgio, Annabella; Napolitano, Francesco; Pelosi, Barbara; Blasi, Giuseppe; Errico, Francesco; Attrotto, Maria Teresa; Gelao, Barbara; Fazio, Leonardo; Taurisano, Paolo; Di Maio, Anna; Marsili, Valentina; Pasqualetti, Massimo; Bertolino, Alessandro; Usiello, Alessandro

2016-02-01

Rasd2 is a thyroid hormone target gene, which encodes for a GTP-binding protein enriched in the striatum where, among other functions, it modulates dopaminergic neurotransmission. Here we report that human RASD2 mRNA is abundant in putamen, but it also occurs in the cerebral cortex, with a distinctive expression pattern that differs from that present in rodents. Consistent with its localization, we found that a genetic variation in RASD2 (rs6518956) affects postmortem prefrontal mRNA expression in healthy humans and is associated with phenotypes of relevance to schizophrenia, including prefrontal and striatal grey matter volume and physiology during working memory, as measured with magnetic resonance imaging. Interestingly, quantitative real-time PCR analysis indicated that RASD2 mRNA is slightly reduced in postmortem prefrontal cortex of patients with schizophrenia. In the attempt to uncover the neurobiological substrates associated with Rasd2 activity, we used knockout mice to analyze the in vivo influence of this G-protein on the prepulse inhibition of the startle response and psychotomimetic drug-related behavioral response. Data showed that Rasd2 mutants display deficits in basal prepulse inhibition that, in turn, exacerbate gating disruption under psychotomimetic drug challenge. Furthermore, we documented that lack of Rasd2 strikingly enhances the behavioral sensitivity to motor stimulation elicited by amphetamine and phencyclidine. Based on animal model data, along with the finding that RASD2 influences prefronto-striatal phenotypes in healthy humans, we suggest that genetic mutation or reduced levels of this G-protein might have a role in cerebral circuitry dysfunction underpinning exaggerated psychotomimetic drugs responses and development of specific biological phenotypes linked to schizophrenia.

Differential regulation of striatal motor behavior and related cellular responses by dopamine D2L and D2S isoforms.

Science.gov (United States)

Radl, Daniela; Chiacchiaretta, Martina; Lewis, Robert G; Brami-Cherrier, Karen; Arcuri, Ludovico; Borrelli, Emiliana

2018-01-02

The dopamine D2 receptor (D2R) is a major component of the dopamine system. D2R-mediated signaling in dopamine neurons is involved in the presynaptic regulation of dopamine levels. Postsynaptically, i.e., in striatal neurons, D2R signaling controls complex functions such as motor activity through regulation of cell firing and heterologous neurotransmitter release. The presence of two isoforms, D2L and D2S, which are generated by a mechanism of alternative splicing of the Drd2 gene, raises the question of whether both isoforms may equally control presynaptic and postsynaptic events. Here, we addressed this question by comparing behavioral and cellular responses of mice with the selective ablation of either D2L or D2S isoform. We establish that the presence of either D2L or D2S can support postsynaptic functions related to the control of motor activity in basal conditions. On the contrary, absence of D2S but not D2L prevents the inhibition of tyrosine hydroxylase phosphorylation and, thereby, of dopamine synthesis, supporting a major presynaptic role for D2S. Interestingly, boosting dopamine signaling in the striatum by acute cocaine administration reveals that absence of D2L, but not of D2S, strongly impairs the motor and cellular response to the drug, in a manner similar to the ablation of both isoforms. These results suggest that when the dopamine system is challenged, D2L signaling is required for the control of striatal circuits regulating motor activity. Thus, our findings show that D2L and D2S share similar functions in basal conditions but not in response to stimulation of the dopamine system.

EFFECT OF CADMIUM(II) ON FREE RADICALS IN DOPA-MELANIN TESTED BY EPR SPECTROSCOPY.

Science.gov (United States)

Zdybel, Magdalena; Pilawa, Barbara; Chodurek, Ewa

2015-01-01

Electron paramagnetic resonance (EPR) spectroscopy may be applied to examine interactions of melanin with metal ions and drugs. In this work EPR method was used to examination of changes in free radical system of DOPA-melanin--the model eumelanin after complexing with diamagnetic cadmium(II) ions. Cadmium(II) may affect free radicals in melanin and drugs binding by this polymer, so the knowledge of modification of properties and free radical concentration in melanin is important to pharmacy. The effect of cadmium(II) in different concentrations on free radicals in DOPA-melanin was determined. EPR spectra of DOPA-melanin, and DOPA-melanin complexes with cadmium(II) were measured by an X-band (9.3 GHz) EPR spectrometer produced by Radiopan (Poznań, Poland) and the Rapid Scan Unit from Jagmar (Krak6w, Poland). The DOPA (3,4-dihydroxyphenylalanine) to metal ions molar ratios in the reaction mixtures were 2:1, 1:1, and 1: 2. High concentrations of o-semiquinone (g ~2.0040) free radicals (~10(21)-10(22) spin/g) characterize DOPA-melanin and its complexes with cadmium(II). Formation of melanin complexes with cadmium(II) increase free radical concentration in DOPA-melanin. The highest free radical concentration was obtained for DOPA-melanin-cadmium(II) (1:1) complexes. Broad EPR lines with linewidths: 0.37-0.73 mT, were measured. Linewidths increase after binding of cadmium(II) to melanin. Changes of integral intensities and linewidths with increasing microwave power indicate the homogeneous broadening of EPR lines, independently on the metal ion concentration. Slow spin-lattice relaxation processes existed in all the tested samples, their EPR lines saturated at low microwave powers. Cadmium(II) causes fastening of spin-lattice relaxation processes in DOPA-melanin. The EPR results bring to light the effect of cadmium(II) on free radicals in melanin, and probably as the consequence on drug binding to eumelanin.

Accuracy of F-DOPA PET and perfusion-MRI for differentiating radionecrotic from progressive brain metastases after radiosurgery

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Cicone, Francesco; Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; ' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Minniti, Giuseppe; Scaringi, Claudia; Maurizi Enrici, Riccardo [' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Romano, Andrea; Tavanti, Francesca; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.)

2015-01-15

We assessed the performance of 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET for differentiating radionecrosis (RN) from tumour progression (PD) in a population of patients with brain metastases, treated with stereotactic radiosurgery. The accuracy of F-DOPA PET was compared with that of perfusion-weighted magnetic resonance (perfusion-MR). In 42 patients with a total of 50 brain metastases from various primaries F-DOPA PET/CT was performed because of suspected radiological progression at the site of previously irradiated brain metastasis. Several semiquantitative PET parameters were recorded, and their diagnostic accuracy was compared by receiver operating characteristic curve analyses. The diagnosis was established by either surgery or follow-up. A comparison was made between F-DOPA PET and perfusion-MR sequences acquired no more than 3 weeks apart. Definitive outcome was available in 46 of the 50 lesions (20 PD, 26 RN). Of the 46 lesions, 11 were surgically excised while in the remaining 35 lesions the diagnosis was established by radiological and clinical criteria. The best diagnostic performance was obtained using the semiquantitative PET parameter maximum lesion to maximum background uptake ratio (SUVL{sub max}/Bkgr{sub max}). With a cut-off value of 1.59, a sensitivity of 90 % and a specificity of 92.3 % were achieved in differentiating RN from PD lesions (accuracy 91.3 %). Relative cerebral blood volume (rCBV) derived from perfusion-MR was available for comparison in 37 of the 46 metastases. Overall accuracy of rCBV was lower than that of all semiquantitative PET parameters under study. The best differentiating rCBV cut-off value was 2.14; this yielded a sensitivity of 86.7 % and a specificity of 68.2 % (accuracy 75.6 %). F-DOPA PET is a highly accurate tool for differentiating RN from PD brain metastases after stereotactic radiosurgery. In this specific setting, F-DOPA PET seems to perform better than perfusion-MR. (orig.)

Sequential analysis: manganese, catecholamines, and L-dopa induced dyskinesia. [Cat's brain

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Papavasiliou, P S; Miller, S T; Cotzias, G C; Kraner, H W; Hsieh, R S

1975-01-01

The paper specifies methodology for the sequential determination of manganese and catecholamines in selfsame brain samples and shows correlations between them. Small samples were obtained from five regions of brain of cats that had received either saline or levodopa. The doses of levodopa were varied so that although all animals reacted, some developed dyskinesia while others did not. Each sample was first analyzed nondestructively for manganese and then destructively for dopa and dopamine; thus errors inherent in analyzing separate samples, due to the structural heterogeneity of the brain, were avoided. Statistically significant correlations were found (1) between levodopa-induced dyskinesia and the concentrations of dopamine and manganese in some of the regions analysed, and (2) between the concentrations of dopamine and of manganese in the caudates of the cats receiving the highest doses of levodopa. (auth)

No-carrier-added (NCA) synthesis of 6-[{sup 18}F]fluoro-L-DOPA using 3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[6S-(6{alpha}, 8{alpha}, 8{alpha}{beta})]-6,8-methano-2H-1,4-benzoxazin-2-one

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Horti, A. [Yale Univ., New Haven, CT (United States). School of Medicine]|[Yale Univ., West Haven, CT (United States). PET Center; Redmond, D.E. Jr. [Yale Univ., New Haven, CT (United States). School of Medicine; Soufer, R. [Yale Univ., West Haven, CT (United States). PET Center

1995-12-31

3,5,6,7,8,8a-Hexahydro-7,7,8a-trimethyl-[6S-(6{alpha},8{alpha} , 8{alpha}{beta})]-6,8-methano-2H-1,4-benzoxazino-2-one (2) was investigated as chiral auxiliary for asymmetric NCA nucleophilic synthesis of 6-[{sup 18}F]Fluoro-L-DOPA. Direct condensation of 3,4-dimethoxy-2-[{sup 18}F]fluorobenzaldehyde (1a) or 6-[{sup 18}F]fluoro-piperonal (1b) in the presence of NaH with 2 gave the corresponding [{sup 18}F]-3-[(2-fluorophenyl)methylene]-3,5,6,7,8,8a-hexahydro-7,7,8 a-trimethyl-[6S-(3Z,3{alpha},6{alpha},8{alpha},8{alpha}{beta})]-6, 8-methano-2H-1,4-benzoxazin-2-one derivative 3a or 3b as a single stereoisomer. L-Selectride promoted hydrogenation of the olefinic double bond of these derivatives, in presence of tertbutyl alcohol, afforded the corresponding [{sup 18}F]-3-[(2-fluorophenyl) methyl]-3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[3S-(3{alpha}, 6{alpha}, 8{alpha}8{alpha}{beta})]-6,8-methano-2H-1,4-benzoxazin-2-one derivatives (4a,b) without affecting the orientation of diasterofacial discrimination. Deprotection of the derivatives 4a,b yielded 6-[{sup 18}F]fluoro-L-DOPA (e.e. >90%, 3% radiochemical yield (EOB), total synthesis time 125 min, specific activity >2000 mCi/{mu}mol). Direct deprotection/reduction of the compounds 3a,b provides the enantiomeric mixture of 6-[{sup 18}F]fluoro-D,L-DOPA (10-12% radiochemical yield) and, after chiral separation, 6-[{sup 18}F]fluoro-L-DOPA (e.e. 98%, 4-5% radiochemical yield). (author).

A retrospective comparison between 68Ga-DOTA-TOC PET/CT and 18F-DOPA PET/CT in patients with extra-adrenal paraganglioma.

Science.gov (United States)

Kroiss, Alexander; Putzer, Daniel; Frech, Andreas; Decristoforo, Clemens; Uprimny, Christian; Gasser, Rudolf Wolfgang; Shulkin, Barry Lynn; Url, Christoph; Widmann, Gerlig; Prommegger, Rupert; Sprinzl, Georg Mathias; Fraedrich, Gustav; Virgolini, Irene Johanna

2013-12-01

(18)F-Fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by (68)Ga-DOTA-Tyr(3)-octreotide ((68)Ga-DOTA-TOC) PET. Therefore, we compared (68)Ga-DOTA-TOC and (18)F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with (68)Ga-DOTA-TOC PET and (18)F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUVmax) of each functional imaging modality in concordant tumour lesions was measured. Compared with anatomical imaging, (68)Ga-DOTA-TOC PET and (18)F-DOPA PET each had a per-patient and per-lesion detection rate of 100% in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of (68)Ga-DOTA-TOC was 100% and that of (18)F-DOPA PET was 56.0%. Overall, (68)Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and (18)F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of (68)Ga-DOTA-TOC PET was 100% (McNemar, P TOC PET and 11.8 ± 7.9 for (18)F-DOPA PET (Mann-Whitney U test, P TOC PET may be superior to (18)F-DOPA PET and diagnostic CT in providing valuable information for pretherapeutic staging of extra-adrenal PGL, particularly in surgically inoperable tumours and metastatic or multifocal disease.

Selective 3,4-Dihydroxyphenylalanine Analysis in Human Urine as Ethoxycarbonyltert- butyldimethylsilyl Derivatives by Gas Chromatography-Mass Spectrometry

International Nuclear Information System (INIS)

Paik, Man Jeong; Nguyen, Duc Toan; Cho, In Seon; Kim, Kyoung Rae; Cho, Ki Hong; Choi, Sang Dun; Lee, Gwang; Yoon, Jae Hwan; Shim, Woo Young

2011-01-01

A new analytical method for measurement of 3,4-dihydroxyphenylalanine (DOPA) in human urine was developed. DOPA from an aqueous solution was converted into an ethoxycarbonyl (EOC) derivative. A tertbutyldimethylsilyl (TBDMS) reaction under anhydrous conditions was then attempted for analysis by gas chromatography-mass spectrometry in selected ion monitoring mode. A new mass spectral data on DOPA as a tri-EOC/mono-TBDMS derivative was built. This method showed good linearity (r ≥ 0.999), precision (% relative standard deviation = 3.1-9.2), and accuracy (% relative error = .7.2-8.8), with a detection limit of 0.05 ng/mL. This selective and accurate method of DOPA analysis will be useful for biochemical monitoring of various neurological disorders including Parkinson's disease in biological fluids

A retrospective comparison between 68Ga-DOTA-TOC PET/CT and 18F-DOPA PET/CT in patients with extra-adrenal paraganglioma

International Nuclear Information System (INIS)

Kroiss, Alexander; Putzer, Daniel; Decristoforo, Clemens; Uprimny, Christian; Virgolini, Irene Johanna; Frech, Andreas; Fraedrich, Gustav; Gasser, Rudolf Wolfgang; Shulkin, Barry Lynn; Url, Christoph; Widmann, Gerlig; Prommegger, Rupert; Sprinzl, Georg Mathias

2013-01-01

18 F-Fluoro-l-dihydroxyphenylalanine ( 18 F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by 68 Ga-DOTA-Tyr 3 -octreotide ( 68 Ga-DOTA-TOC) PET. Therefore, we compared 68 Ga-DOTA-TOC and 18 F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with 68 Ga-DOTA-TOC PET and 18 F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUV max ) of each functional imaging modality in concordant tumour lesions was measured. Compared with anatomical imaging, 68 Ga-DOTA-TOC PET and 18 F-DOPA PET each had a per-patient and per-lesion detection rate of 100 % in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of 68 Ga-DOTA-TOC was 100 % and that of 18 F-DOPA PET was 56.0 %. Overall, 68 Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and 18 F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of 68 Ga-DOTA-TOC PET was 100 % (McNemar, P 18 F-DOPA PET was 71.1 % (McNemar, P max (mean ± SD) of all 32 concordant lesions was 67.9 ± 61.5 for 68 Ga-DOTA-TOC PET and 11.8 ± 7.9 for 18 F-DOPA PET (Mann-Whitney U test, P 68 Ga-DOTA-TOC PET may be superior to 18 F-DOPA PET and diagnostic CT in providing valuable information for pretherapeutic staging of extra-adrenal PGL, particularly in surgically

18F-DOPA PET and enhanced CT imaging for congenital hyperinsulinism: initial UK experience from a technologist's perspective.

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Meintjes, Marguerite; Endozo, Raymond; Dickson, John; Erlandsson, Kjel; Hussain, Khalid; Townsend, Caroline; Menezes, Leon; Bomanji, Jamshed

2013-06-01

Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycaemia in infants and children. Histologically, there are two subgroups, diffuse and focal. The aim of this study was to evaluate the accuracy of (18)F-fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) PET/computed tomography (CT) and contrast-enhanced CT in distinguishing between focal and diffuse lesions in infants with CHI who are unresponsive to medical therapy. In addition, this paper describes the detailed protocol used for imaging and analysis of (18)F-DOPA PET/CT images in our clinical practice. Twenty-two (18)F-DOPA PET/CT and contrast-enhanced CT imaging studies were carried out on 18 consecutive patients (nine boys and nine girls) with CHI (median age, 2 years and 1 month; range, 1-84 months) who had positive dominant ABCC8 mutation genetic results or negative ABCC8/t results but did not respond to first-line medical therapy with high-dose diazoxide. (18)F-DOPA was produced by the cyclotron unit of Woolfson Molecular Imaging Centre, Manchester, and transported to our centre in central London after synthesis and implementation of quality control measures. (18)F-DOPA was administered intravenously at a dose of 4 MBq/kg, and iodine contrast medium was injected intravenously at a dose of 1.5 ml/kg. Single bed position PET/CT images of the pancreas were acquired under light sedation with oral chloral hydrate. Four PET dynamic data acquisition scans were taken 20, 40, 50 and 60 min after injection for a duration of 10 min each. The results were assessed by visual interpretation and quantitative measurements of standardized uptake values (SUVs) in the head, body, and tail of the pancreas. Of the 18 patients, 13 showed diffuse and five showed focal (18)F-DOPA PET pancreatic uptake. Three regions of interest were drawn over the head, body and tail of the pancreas to calculate the SUV(max). Using the formula - highest SUV(max)/next highest SUV(max) - a ratio was calculated. Five patients had

Rasd2 Modulates Prefronto-Striatal Phenotypes in Humans and ‘Schizophrenia-Like Behaviors' in Mice

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Vitucci, Daniela; Di Giorgio, Annabella; Napolitano, Francesco; Pelosi, Barbara; Blasi, Giuseppe; Errico, Francesco; Attrotto, Maria Teresa; Gelao, Barbara; Fazio, Leonardo; Taurisano, Paolo; Di Maio, Anna; Marsili, Valentina; Pasqualetti, Massimo; Bertolino, Alessandro; Usiello, Alessandro

2016-01-01

Rasd2 is a thyroid hormone target gene, which encodes for a GTP-binding protein enriched in the striatum where, among other functions, it modulates dopaminergic neurotransmission. Here we report that human RASD2 mRNA is abundant in putamen, but it also occurs in the cerebral cortex, with a distinctive expression pattern that differs from that present in rodents. Consistent with its localization, we found that a genetic variation in RASD2 (rs6518956) affects postmortem prefrontal mRNA expression in healthy humans and is associated with phenotypes of relevance to schizophrenia, including prefrontal and striatal grey matter volume and physiology during working memory, as measured with magnetic resonance imaging. Interestingly, quantitative real-time PCR analysis indicated that RASD2 mRNA is slightly reduced in postmortem prefrontal cortex of patients with schizophrenia. In the attempt to uncover the neurobiological substrates associated with Rasd2 activity, we used knockout mice to analyze the in vivo influence of this G-protein on the prepulse inhibition of the startle response and psychotomimetic drug-related behavioral response. Data showed that Rasd2 mutants display deficits in basal prepulse inhibition that, in turn, exacerbate gating disruption under psychotomimetic drug challenge. Furthermore, we documented that lack of Rasd2 strikingly enhances the behavioral sensitivity to motor stimulation elicited by amphetamine and phencyclidine. Based on animal model data, along with the finding that RASD2 influences prefronto-striatal phenotypes in healthy humans, we suggest that genetic mutation or reduced levels of this G-protein might have a role in cerebral circuitry dysfunction underpinning exaggerated psychotomimetic drugs responses and development of specific biological phenotypes linked to schizophrenia. PMID:26228524

Dopaminergic differentiation of human neural stem cells mediated by co-cultured rat striatal brain slices

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Anwar, Mohammad Raffaqat; Andreasen, Christian Maaløv; Lippert, Solvej Kølvraa

2008-01-01

differentiation, we co-cultured cells from a human neural forebrain-derived stem cell line (hNS1) with rat striatal brain slices. In brief, coronal slices of neonatal rat striatum were cultured on semiporous membrane inserts placed in six-well trays overlying monolayers of hNS1 cells. After 12 days of co......Properly committed neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. To establish a setting for identification of secreted neural compounds promoting dopaminergic...

L-DOPA decarboxylase mRNA expression is associated with tumor stage and size in head and neck squamous cell carcinoma: a retrospective cohort study

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Geomela Panagiota-Aikaterini

2012-10-01

Full Text Available Abstract Background Head and neck squamous cell carcinoma (HNSCC represents one of the most commonly diagnosed malignancies worldwide. The DDC gene encodes L-DOPA decarboxylase, an enzyme catalyzing the decarboxylation of L-DOPA to dopamine. We have recently shown that DDC mRNA is a significant predictor of patients’ prognosis in colorectal adenocarcinoma and prostate cancer. The aim of the current study was to analyze the DDC mRNA expression in HNSCC patients. Methods 53 malignant tumors were resected from the larynx, pharynx, tongue, buccal mucosa, parotid glands, and nasal cavity, as well as from 34 adjacent non-cancerous tissues of HNSCC patients, and were homogenized. Total RNA was isolated and converted into first-strand cDNA. An ultrasensitive real-time PCR method based on the SYBR Green chemistry was used for DDC mRNA quantification in head and neck tissue specimens. Relative quantification was performed using the comparative Ct (2-ddCt method. Results DDC mRNA levels were lower in squamous cell carcinomas (SCCs of the larynx and tongue than in adjacent non-cancerous tissue specimens. Furthermore, low DDC mRNA expression was noticed in laryngeal and tongue tumors of advanced TNM stage or bigger size, compared to early-stage or smaller tumors, respectively. No statistically significant differences were observed between SCCs resected from pharynx, buccal mucosa, or nasal cavity, and their normal counterparts. Conclusion This is the first study examining the DDC mRNA expression in HNSCC. According to our results, DDC mRNA expression may constitute a potential prognostic biomarker in tongue and/or larynx SCCs, which principally represent the overwhelming majority of HNSCC cases.

L-DOPA decarboxylase mRNA expression is associated with tumor stage and size in head and neck squamous cell carcinoma: a retrospective cohort study

International Nuclear Information System (INIS)

Geomela, Panagiota-Aikaterini; Kontos, Christos K; Yiotakis, Ioannis; Fragoulis, Emmanuel G; Scorilas, Andreas

2012-01-01

Head and neck squamous cell carcinoma (HNSCC) represents one of the most commonly diagnosed malignancies worldwide. The DDC gene encodes L-DOPA decarboxylase, an enzyme catalyzing the decarboxylation of L-DOPA to dopamine. We have recently shown that DDC mRNA is a significant predictor of patients’ prognosis in colorectal adenocarcinoma and prostate cancer. The aim of the current study was to analyze the DDC mRNA expression in HNSCC patients. 53 malignant tumors were resected from the larynx, pharynx, tongue, buccal mucosa, parotid glands, and nasal cavity, as well as from 34 adjacent non-cancerous tissues of HNSCC patients, and were homogenized. Total RNA was isolated and converted into first-strand cDNA. An ultrasensitive real-time PCR method based on the SYBR Green chemistry was used for DDC mRNA quantification in head and neck tissue specimens. Relative quantification was performed using the comparative Ct (2 -ddCt ) method. DDC mRNA levels were lower in squamous cell carcinomas (SCCs) of the larynx and tongue than in adjacent non-cancerous tissue specimens. Furthermore, low DDC mRNA expression was noticed in laryngeal and tongue tumors of advanced TNM stage or bigger size, compared to early-stage or smaller tumors, respectively. No statistically significant differences were observed between SCCs resected from pharynx, buccal mucosa, or nasal cavity, and their normal counterparts. This is the first study examining the DDC mRNA expression in HNSCC. According to our results, DDC mRNA expression may constitute a potential prognostic biomarker in tongue and/or larynx SCCs, which principally represent the overwhelming majority of HNSCC cases

Quantitative high-throughput gene expression profiling of human striatal development to screen stem cell–derived medium spiny neurons

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Marco Straccia

Full Text Available A systematic characterization of the spatio-temporal gene expression during human neurodevelopment is essential to understand brain function in both physiological and pathological conditions. In recent years, stem cell technology has provided an in vitro tool to recapitulate human development, permitting also the generation of human models for many diseases. The correct differentiation of human pluripotent stem cell (hPSC into specific cell types should be evaluated by comparison with specific cells/tissue profiles from the equivalent adult in vivo organ. Here, we define by a quantitative high-throughput gene expression analysis the subset of specific genes of the whole ganglionic eminence (WGE and adult human striatum. Our results demonstrate that not only the number of specific genes is crucial but also their relative expression levels between brain areas. We next used these gene profiles to characterize the differentiation of hPSCs. Our findings demonstrate a temporal progression of gene expression during striatal differentiation of hPSCs from a WGE toward an adult striatum identity. Present results establish a gene expression profile to qualitatively and quantitatively evaluate the telencephalic hPSC-derived progenitors eventually used for transplantation and mature striatal neurons for disease modeling and drug-screening.

Mucuna pruriens and its major constituent L-DOPA recover spermatogenic loss by combating ROS, loss of mitochondrial membrane potential and apoptosis.

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Akhand Pratap Singh

Full Text Available BACKGROUND: The Ayurvedic medicinal system claims Mucuna pruriens (MP to possess pro-male fertility, aphrodisiac and adaptogenic properties. Some scientific evidence also supports its pro-male fertility properties; however, the mechanism of its action is not yet clear. The present study aimed at demonstrating spermatogenic restorative efficacy of MP and its major constituent L-DOPA (LD, and finding the possible mechanism of action thereof in a rat model. METHODOLOGY/FINDINGS: Ethinyl estradiol (EE was administered at a rate of 3 mg/kg body weight (BW/day for a period of 14 days to generate a rat model with compromised spermatogenesis. MP and LD were administered in two separate groups of these animals starting 15(th day for a period of 56 days, and the results were compared with an auto-recovery (AR group. Sperm count and motility, testis histo-architecture, level of reactive oxygen species (ROS, mitochondrial membrane potential (MMP, apoptosis, peripheral hormone levels and testicular germ cell populations were analysed, in all experimental groups. We observed efficient and quick recovery of spermatogenesis in MP and LD groups in comparison to the auto-recovery group. The treatment regulated ROS level, apoptosis, and mitochondrial membrane potential (MMP, recovered the hypothalamic-pituitary-gonadal axis and the number of testicular germ cells, ultimately leading to increased sperm count and motility. CONCLUSION/SIGNIFICANCE: M. pruriens efficiently recovers the spermatogenic loss induced due to EE administration. The recovery is mediated by reduction in ROS level, restoration of MMP, regulation of apoptosis and eventual increase in the number of germ cells and regulation of apoptosis. The present study simplified the complexity of mechanism involved and provided meaningful insights into MP/LD mediated correction of spermatogenic impairment caused by estrogens exposure. This is the first study demonstrating that L-DOPA largely accounts for pro

Prospective trial evaluating the sensitivity and specificity of 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (18F-DOPA) PET and MRI in patients with recurrent gliomas.

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Youland, Ryan S; Pafundi, Deanna H; Brinkmann, Debra H; Lowe, Val J; Morris, Jonathan M; Kemp, Bradley J; Hunt, Christopher H; Giannini, Caterina; Parney, Ian F; Laack, Nadia N

2018-05-01

Treatment-related changes can be difficult to differentiate from progressive glioma using MRI with contrast (CE). The purpose of this study is to compare the sensitivity and specificity of 18F-DOPA-PET and MRI in patients with recurrent glioma. Thirteen patients with MRI findings suspicious for recurrent glioma were prospectively enrolled and underwent 18F-DOPA-PET and MRI for neurosurgical planning. Stereotactic biopsies were obtained from regions of concordant and discordant PET and MRI CE, all within regions of T2/FLAIR signal hyperintensity. The sensitivity and specificity of 18F-DOPA-PET and CE were calculated based on histopathologic analysis. Receiver operating characteristic curve analysis revealed optimal tumor to normal (T/N) and SUVmax thresholds. In the 37 specimens obtained, 51% exhibited MRI contrast enhancement (M+) and 78% demonstrated 18F-DOPA-PET avidity (P+). Imaging characteristics included M-P- in 16%, M-P+ in 32%, M+P+ in 46% and M+P- in 5%. Histopathologic review of biopsies revealed grade II components in 16%, grade III in 43%, grade IV in 30% and no tumor in 11%. MRI CE sensitivity for recurrent tumor was 52% and specificity was 50%. PET sensitivity for tumor was 82% and specificity was 50%. A T/N threshold > 2.0 altered sensitivity to 76% and specificity to 100% and SUVmax > 1.36 improved sensitivity and specificity to 94 and 75%, respectively. 18F-DOPA-PET can provide increased sensitivity and specificity compared with MRI CE for visualizing the spatial distribution of recurrent gliomas. Future studies will incorporate 18F-DOPA-PET into re-irradiation target volume delineation for RT planning.

EPR studies of chromium(V) intermediates generated via reduction of chromium(VI) by DOPA and related catecholamines

DEFF Research Database (Denmark)

Pattison, D I; Lay, P A; Davies, Michael Jonathan

2000-01-01

The reductions of K2Cr2O7 by catecholamines, DOPA, DOPA-beta,beta-d2, N-acetyl-DOPA, alpha-methyl-DOPA, dopamine, adrenaline, noradrenaline, catechol, 1,2-dihydroxybenzoic acid (DHBA), and 4-tert-butylcatechol (TBC), produce a number of Cr(V) electron paramagnetic resonance (EPR) signals. These s......The reductions of K2Cr2O7 by catecholamines, DOPA, DOPA-beta,beta-d2, N-acetyl-DOPA, alpha-methyl-DOPA, dopamine, adrenaline, noradrenaline, catechol, 1,2-dihydroxybenzoic acid (DHBA), and 4-tert-butylcatechol (TBC), produce a number of Cr(V) electron paramagnetic resonance (EPR) signals...... deuteration or enrichment with 15N), and simulation of the signals, show that the superhyperfine couplings originate from the side chain protons, confirming that the catecholamine ligands are cyclized. At pH 3.5, a major short-lived EPR signal is observed for many of the substrates at g(iso) approximately 1......) species with a sixth ligand (e.g. H2O). Addition of catalase or deoxygenation of the solutions did not affect the main EPR signals. When the substrates were in excess (pH > 4.5), primary and secondary (cyclized) semiquinones were also detected. Semiquinone stabilization by Zn(II) complexation yielded...

Acute effect of intravenously applied alcohol in the human striatal and extrastriatal D2 /D3 dopamine system.

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Pfeifer, Philippe; Tüscher, Oliver; Buchholz, Hans Georg; Gründer, Gerhard; Vernaleken, Ingo; Paulzen, Michael; Zimmermann, Ulrich S; Maus, Stephan; Lieb, Klaus; Eggermann, Thomas; Fehr, Christoph; Schreckenberger, Mathias

2017-09-01

Investigations on the acute effects of alcohol in the human mesolimbic dopamine D 2 /D 3 receptor system have yielded conflicting results. With respect to the effects of alcohol on extrastriatal D 2 /D 3 dopamine receptors no investigations have been reported yet. Therefore we applied PET imaging using the postsynaptic dopamine D 2 /D 3 receptor ligand [ 18 F]fallypride addressing the question, whether intravenously applied alcohol stimulates the extrastriatal and striatal dopamine system. We measured subjective effects of alcohol and made correlation analyses with the striatal and extrastriatal D 2 /D 3 binding potential. Twenty-four healthy male μ-opioid receptor (OPRM1)118G allele carriers underwent a standardized intravenous and placebo alcohol administration. The subjective effects of alcohol were measured with a visual analogue scale. For the evaluation of the dopamine response we calculated the binding potential (BP ND ) by using the simplified reference tissue model (SRTM). In addition, we calculated distribution volumes (target and reference regions) in 10 subjects for which metabolite corrected arterial samples were available. In the alcohol condition no significant dopamine response in terms of a reduction of BP ND was observed in striatal and extrastriatal brain regions. We found a positive correlation for 'liking' alcohol and the BP ND in extrastriatal brain regions (Inferior frontal cortex (IFC) (r = 0.533, p = 0.007), orbitofrontal cortex (OFC) (r = 0.416, p = 0.043) and prefrontal cortex (PFC) (r = 0.625, p = 0.001)). The acute alcohol effects on the D 2 /D 3 dopamine receptor binding potential of the striatal and extrastriatal system in our experiment were insignificant. A positive correlation of the subjective effect of 'liking' alcohol with cortical D 2 /D 3 receptors may hint at an addiction relevant trait. © 2016 Society for the Study of Addiction.

18F-DOPA PET/CT Physiological Distribution and Pitfalls: Experience in 215 Patients.

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Calabria, Ferdinando F; Chiaravalloti, Agostino; Jaffrain-Rea, Marielise L; Zinzi, Maddalena; Sannino, Pasqualina; Minniti, Giuseppe; Rubello, Domenico; Schillaci, Orazio

2016-10-01

F-DOPA PET/CT is potentially helpful in the management of patients with low-grade brain tumors, movement disorders, and somatic neuroendocrine tumors. We describe the whole-body physiological distribution of F-DOPA uptake. We examined 215 patients with F-DOPA PET/CT. Among these, 161 had brain scans and 54 had whole-body scans. Physiological distribution was negligible in the brain, with the exception of basal ganglia, whereas greatest activity was noted in the liver, pancreas, other exocrine glands, and the urinary system. Incidental tracer uptake sites were identified in 5.5% of patients. Some of these findings were due to inflammation, whereas in most cases, uptake was seen in benign tumors of the brain or in the endocrine or exocrine glands. F-DOPA uptake may be seen in inflammatory tissue or benign tumors. Correlations with history, physical examination, laboratory examination, CT, MRI, and histology are necessary for optimal diagnosis.

Brain 18F-DOPA PET and cognition in de novo Parkinson's disease

International Nuclear Information System (INIS)

Picco, Agnese; Arnaldi, Dario; Brugnolo, Andrea; Nobili, Flavio; Morbelli, Silvia; Bossert, Irene; Piccardo, Arnoldo; Girtler, Nicola; Marinelli, Lucio; Abbruzzese, Giovanni; Castaldi, Antonio; De Carli, Fabrizio; Campus, Claudio

2015-01-01

The role of mesocortical dopaminergic pathways in the cognitive function of patients with early Parkinson's disease (PD) needs to be further clarified. The study groups comprised 15 drug-naive patients with de novo PD and 10 patients with essential tremor (controls) who underwent 18 F-DOPA PET (static acquisition, normalization on mean cerebellar counts) and an extended neuropsychological test battery. Factor analysis with varimax rotation was applied to the neuropsychological test scores, to yield five factors from 16 original scores, which explained 82 % of the total variance. Correlations between cognitive factors and 18 F-DOPA uptake were assessed with SPM8, taking age and gender as nuisance variables. 18 F-DOPA uptake was significantly lower in PD patients than in controls in the bilateral striatum, mainly in the more affected (right) hemisphere, and in a small right temporal region. Significant positive correlations were found only in PD patients between the executive factor and 18 F-DOPA uptake in the bilateral anterior cingulate cortex (ACC) and the middle frontal gyrus, between the verbal fluency factor and 18 F-DOPA uptake in left BA 46 and the bilateral striatum, and between the visuospatial factor and 18 F-DOPA uptake in the left ACC and bilateral striatum. No correlations were found between 18 F-DOPA uptake and either the verbal memory factor or the abstraction-working memory factor. These data clarify the role of the mesocortical dopaminergic pathways in cognitive function in early PD, highlighting the medial frontal lobe, anterior cingulate, and left BA 46 as the main sites of cortical correlation with executive and language functions. (orig.)

Mussel-Inspired Protein Nanoparticles Containing Iron(III)-DOPA Complexes for pH-Responsive Drug Delivery.

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Kim, Bum Jin; Cheong, Hogyun; Hwang, Byeong Hee; Cha, Hyung Joon

2015-06-15

A novel bioinspired strategy for protein nanoparticle (NP) synthesis to achieve pH-responsive drug release exploits the pH-dependent changes in the coordination stoichiometry of iron(III)-3,4-dihydroxyphenylalanine (DOPA) complexes, which play a major cross-linking role in mussel byssal threads. Doxorubicin-loaded polymeric NPs that are based on Fe(III)-DOPA complexation were thus synthesized with a DOPA-modified recombinant mussel adhesive protein through a co-electrospraying process. The release of doxorubicin was found to be predominantly governed by a change in the structure of the Fe(III)-DOPA complexes induced by an acidic pH value. It was also demonstrated that the fabricated NPs exhibited effective cytotoxicity towards cancer cells through efficient cellular uptake and cytosolic release. Therefore, it is anticipated that Fe(III)-DOPA complexation can be successfully utilized as a new design principle for pH-responsive NPs for diverse controlled drug-delivery applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOPA, norepinephrine, and dopamine in rat tissues

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Eldrup, E; Richter, Erik; Christensen, N J

1989-01-01

We studied the effect of unilateral sympathectomy on rat quadriceps and gastrocnemius muscle concentrations of endogenous dihydroxyphenylalanine (DOPA), dopamine (DA), and norepinephrine (NE) and assessed the relationships between these catecholamines in several rat tissues. Catecholamines were...

In-vivo studies by positron emission tomography of the pharmacokinetics of L-6-F-18-fluorodopa

International Nuclear Information System (INIS)

Pate, B.D.; Calne, D.B.; Hewitt, K.A.; Ruth, T.J.; Adam, M.J.

1989-01-01

Positron emission tomography has been used to study the pharmacokinetics of fluorine-18-labelled L-6-fluorodopa in the brains of cynomolgus monkey subjects. The protocol for each experiment consisted of two series of twelve 10-minutes scans, conducted one after the other with the monkey in the same position, with an inhibitor acting at a specific stage of the kinetics, administered before the second series. Subtractions of the two scan series (following correction for activity residue in the second scans) then gave a quantitative measure of the effects produced by the inhibitor. The inhibitors studied include NSD 1015 (decarboxylase inhibitor), chlorgyline (MAO-A inhibitor), deprenyl (MAO-B inhibitor), pargyline (inhibitor of both MAO-A and MAO-B), U-0521 (COMT inhibitor), and reserpine (vesicular storage inhibitor). The results show that L-6-fluorodopa is a substrate for dopa decarboxylase, while fluorodopamine is a substrate for both MAO-A and MAO-B, and for COMT. Vesicular storage (inhibited by reserpine) was shown also to be essential for concentration of the activity into striatal images

Demonstration of tyrosinase in the vitiligo skin of human beings by a sensitive fluorometric method as well as by 14C(U)-L-tyrosine incorporation into melanin

International Nuclear Information System (INIS)

Husain, I.; Vijayan, E.; Ramaiah, A.; Pasricha, J.S.; Madan, N.C.

1982-01-01

Tyrosinase activity (Monophenol, dihydroxyphenylalanine: oxygen oxidoreductase EC 1.14.18.1) in vitiligo and normal epidermal homogenates of skin from human beings was measured by estimating beta 3,4-dihydroxyphenylalanine (dopa) by a highly sensitive fluorometric method described in this paper. The tyrosine activity in the vitiligo skin was about 4 to 37% of corresponding normal skin. The activity of tyrosinase in normal human skin from different individuals and from different regions of the body was in the range of 4 to 140 picomoles of beta 3,4-dihydroxyphenylalanine formed per min/mg protein of epidermal homogenate. The enzyme from vitiligo and normal skin was severely inhibited by substance(s) of low molecular weight. The enzyme exhibits a lag of about 4 hr in the absence of added beta 3,4-dihydroxyphenylalanine and 1 hr in presence of 5 microM dopa. Tyrosinase from the normal and vitiligo skin was inhibited by excess concentration of tyrosine. The homogenates from vitiligo skin could synthesize melanin from C14(U)-L-Tyrosine. The rate of tyrosine incorporation into melanin by the epidermal homogenates is increased by 3,4-dihydroxyphenylalanine (dopa) disproportionate to its effect on tyrosinase activity. Based on the data presented in this paper it is concluded that melanocytes are present in the vitiligo skin. A tentative hypothesis is put forward to explain the lack of melanin synthesis by the vitiligo skin under in vivo conditions, although melanocytes are present

Free and conjugated dopamine in human ventricular fluid

International Nuclear Information System (INIS)

Sharpless, N.S.; Thal, L.J.; Wolfson, L.I.; Tabaddor, K.; Tyce, G.M.; Waltz, J.M.

1981-01-01

Free dopamine and an acid hydrolyzable conjugate of dopamine were measured in human ventricular fluid specimens with a radioenzymatic assay and by high performance liquid chromatography (HPLC) with electrochemical detection. Only trace amounts of free norepinephrine and dopamine were detected in ventricular fluid from patients with movement disorders. When the ventricular fluid was hydrolyzed by heating in HClO 4 or by lyophilization in dilute HClO 4 , however, a substantial amount of free dopamine was released. Values for free plus conjugated dopamine in ventricular fluid from patients who had never taken L-DOPA ranged from 139 to 340 pg/ml when determined by HPLC and from 223 to 428 pg/ml when measured radioenzymatically. The correlation coefficient for values obtained by the two methods in the same sample of CSF was 0.94 (P<0.001). Patients who had been treated with L-DOPA had higher levels of conjugated dopamine in their ventricular CSF which correlated inversely with the time between the last dose of L-DOPA and withdrawal of the ventricular fluid. Additionally, one patient with acute cerebral trauma had elevated levels of free norepinephrine and both free and conjugated dopamine in his ventricular fluid. Conjugation may be an important inactivation pathway for released dopamine in man. (Auth.)

L-dopa, biperideno e excreção sebácea na doença de Parkinson

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João C. B. Villares

1989-03-01

Full Text Available A excreção sebácea frontal de 47 parkinsonianos «de novo» antes e após tratamento com anticolinérgico (biperideno, levodopa + IDAA e bromocriptina foi avaliada pelo método do ácido ósmico. Outros 100 parkinsonianos sob terapêutica crônica com biperideno, levodopa + IDAA ou associação de ambos foram avaliados. Parkinsonianos «de novo» do sexo masculino apresentam valores de excreção sebácea significativamente mais elevados em relação às mulheres. Verificou-se que biperideno não foi eficaz em reduzir o grau de excreção sebácea. Já, em relação a L-dopa + IDAA constatou-se que a droga foi efetiva em reduzir o grau de excreção sebácea (NC e TRE tanto no sexo masculino quanto no feminino. Em relação à bromocriptina (l0mg/dia também constatou-se que houve redução da excreção sebácea no sexo masculino. Correlação significante positiva foi verificada entre o NC, tremor, bradicinesia, hipertonia, alterações da marcha e postura e incapacidade funcional, entre parkinsonianos do sexo masculino e faixa etária 50-59 anos, no período pré-tratamento. Após o período de tratamento não mais havia correlação entre excreção sebácea e as manifestações neurológicas da doença de Parkinson. Entre parkinsonianos sob terapêutica crônica verificou-se correlação positiva e significante entre excreção sebácea e bradicinesia. O grau de excreção sebácea de parkinsonianos «de novo» sem tratamento não difere do grau daqueles sob tratamento crônico, exceção feita a parkinsonianos com idade > 60 anos, em que verificou-se maior grau de excreção sebácea (NC e TRE em relação ao mesmo sexo e faixa etária, sem tratamento. L-dopa + IDAA foi eficiente em reduzir o grau de excreção sebácea de parkinsonianos «de novo», tornando-a significativamente menor em relação àqueles sob tratamento crônico. Não há diferença entre o grau de excreção sebácea de parkinsonianos «de novo» sem tratamento e

The measurement of the nigrostriatal dopaminergic function and glucose metabolism in patients with movement disorders

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Otsuka, Makoto; Ichiya, Yuichi; Kuwabara, Yasuo; Sasaki, Masayuki; Fukumura, Toshimitsu; Masuda, Kouji; Shima, Fumio; Kato, Motohiro (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

1992-12-01

The nigrostriatal dopaminergic function and glucose metabolism were evaluated in 34 patients with various movement disorders by using positron emission tomography with [sup 18]F-Dopa and [sup 18]F-FDG respectively. The [sup 18]F-Dopa uptake in the striatum (the caudate head and the putamen) decreased in patients with Parkinson's disease but was relatively unaffected in the caudate. The cerebral glucose metabolism was normal in patients with Parkinson's disease. The [sup 18]F-Dopa uptake in the striatum also decreased in cases of atypical parkinsonism and in cases of progressive supranuclear palsy, but there was no difference in the uptake between the caudate and the putamen. The glucose metabolism decreased in the cerebral hemisphere including the striatum; this finding was also different from those of Parkinson's disease. A normal [sup 18]F-Dopa uptake in the striatum with a markedly decreased striatal glucose metabolism and a mildly decreased cortical glucose metabolism was observed in cases of Huntington's disease and Wilson's disease. The [sup 18]F-Dopa uptake in the striatum increased and the glucose metabolism was normal in cases of idiopathic dystonia. Various patterns of [sup 18]F-Dopa uptake and glucose metabolism were thus observed in the various movement disorders. These results suggest that the measurements of the [sup 18]F-Dopa uptake and the cerebral glucose metabolism would be useful for the evaluation of the striatal function in various movement disorders. (author).

The measurement of the nigrostriatal dopaminergic function and glucose metabolism in patients with movement disorders

Energy Technology Data Exchange (ETDEWEB)

Otsuka, Makoto; Ichiya, Yuichi; Kuwabara, Yasuo; Sasaki, Masayuki; Fukumura, Toshimitsu; Masuda, Kouji; Shima, Fumio; Kato, Motohiro [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

1992-12-01

The nigrostriatal dopaminergic function and glucose metabolism were evaluated in 34 patients with various movement disorders by using positron emission tomography with [sup 18]F-Dopa and [sup 18]F-FDG respectively. The [sup 18]F-Dopa uptake in the striatum (the caudate head and the putamen) decreased in patients with Parkinson's disease but was relatively unaffected in the caudate. The cerebral glucose metabolism was normal in patients with Parkinson's disease. The [sup 18]F-Dopa uptake in the striatum also decreased in cases of atypical parkinsonism and in cases of progressive supranuclear palsy, but there was no difference in the uptake between the caudate and the putamen. The glucose metabolism decreased in the cerebral hemisphere including the striatum; this finding was also different from those of Parkinson's disease. A normal [sup 18]F-Dopa uptake in the striatum with a markedly decreased striatal glucose metabolism and a mildly decreased cortical glucose metabolism was observed in cases of Huntington's disease and Wilson's disease. The [sup 18]F-Dopa uptake in the striatum increased and the glucose metabolism was normal in cases of idiopathic dystonia. Various patterns of [sup 18]F-Dopa uptake and glucose metabolism were thus observed in the various movement disorders. These results suggest that the measurements of the [sup 18]F-Dopa uptake and the cerebral glucose metabolism would be useful for the evaluation of the striatal function in various movement disorders. (author).

Inflammation alters AMPA-stimulated calcium responses in dorsal striatal D2 but not D1 spiny projection neurons.

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Winland, Carissa D; Welsh, Nora; Sepulveda-Rodriguez, Alberto; Vicini, Stefano; Maguire-Zeiss, Kathleen A

2017-11-01

Neuroinflammation precedes neuronal loss in striatal neurodegenerative diseases and can be exacerbated by the release of proinflammatory molecules by microglia. These molecules can affect trafficking of AMPARs. The preferential trafficking of calcium-permeable versus impermeable AMPARs can result in disruptions of [Ca 2+ ] i and alter cellular functions. In striatal neurodegenerative diseases, changes in [Ca 2+ ] i and L-type voltage-gated calcium channels (VGCCs) have been reported. Therefore, this study sought to determine whether a proinflammatory environment alters AMPA-stimulated [Ca 2+ ] i through calcium-permeable AMPARs and/or L-type VGCCs in dopamine-2- and dopamine-1-expressing striatal spiny projection neurons (D2 and D1 SPNs) in the dorsal striatum. Mice expressing the calcium indicator protein, GCaMP in D2 or D1 SPNs, were utilized for calcium imaging. Microglial activation was assessed by morphology analyses. To induce inflammation, acute mouse striatal slices were incubated with lipopolysaccharide (LPS). Here we report that LPS treatment potentiated AMPA responses only in D2 SPNs. When a nonspecific VGCC blocker was included, we observed a decrease of AMPA-stimulated calcium fluorescence in D2 but not D1 SPNs. The remaining agonist-induced [Ca 2+ ] i was mediated by calcium-permeable AMPARs because the responses were completely blocked by a selective calcium-permeable AMPAR antagonist. We used isradipine, the highly selective L-type VGCC antagonist to determine the role of L-type VGCCs in SPNs treated with LPS. Isradipine decreased AMPA-stimulated responses selectively in D2 SPNs after LPS treatment. Our findings suggest that dorsal striatal D2 SPNs are specifically targeted in proinflammatory conditions and that L-type VGCCs and calcium-permeable AMPARs are important mediators of this effect. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Brain {sup 18}F-DOPA PET and cognition in de novo Parkinson's disease

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Picco, Agnese; Arnaldi, Dario; Brugnolo, Andrea; Nobili, Flavio [University of Genoa and IRCCS AOU San Martino-IST, Clinical Neurology, Department of Neuroscience (DINOGMI), Genoa (Italy); Morbelli, Silvia; Bossert, Irene [University of Genoa and IRCCS AOU San Martino-IST, Nuclear Medicine, Department of Health Sciences (DISSAL), Genoa (Italy); Piccardo, Arnoldo [Ospedali Galliera, Nuclear Medicine, Department of Imaging Diagnostics, Genoa (Italy); Girtler, Nicola [University of Genoa and IRCCS AOU San Martino-IST, Clinical Neurology, Department of Neuroscience (DINOGMI), Genoa (Italy); IRCCS San Martino-IST, Clinical Psychology and Psychotherapy Unit, Genoa (Italy); Marinelli, Lucio; Abbruzzese, Giovanni [University of Genoa and IRCCS AOU San Martino-IST, Neurological Rehabilitation, Department of Neuroscience (DINOGMI), Genoa (Italy); Castaldi, Antonio [Ospedali Galliera, Radiology, Department of Imaging Diagnostics, Genoa (Italy); De Carli, Fabrizio [Consiglio Nazionale delle Ricerche (CNR), Institute of Bioimaging and Molecular Physiology, Genoa (Italy); Campus, Claudio [Istituto Italiano di Tecnologia, Genoa (Italy)

2015-03-28

The role of mesocortical dopaminergic pathways in the cognitive function of patients with early Parkinson's disease (PD) needs to be further clarified. The study groups comprised 15 drug-naive patients with de novo PD and 10 patients with essential tremor (controls) who underwent {sup 18}F-DOPA PET (static acquisition, normalization on mean cerebellar counts) and an extended neuropsychological test battery. Factor analysis with varimax rotation was applied to the neuropsychological test scores, to yield five factors from 16 original scores, which explained 82 % of the total variance. Correlations between cognitive factors and {sup 18}F-DOPA uptake were assessed with SPM8, taking age and gender as nuisance variables. {sup 18}F-DOPA uptake was significantly lower in PD patients than in controls in the bilateral striatum, mainly in the more affected (right) hemisphere, and in a small right temporal region. Significant positive correlations were found only in PD patients between the executive factor and {sup 18}F-DOPA uptake in the bilateral anterior cingulate cortex (ACC) and the middle frontal gyrus, between the verbal fluency factor and {sup 18}F-DOPA uptake in left BA 46 and the bilateral striatum, and between the visuospatial factor and {sup 18}F-DOPA uptake in the left ACC and bilateral striatum. No correlations were found between {sup 18}F-DOPA uptake and either the verbal memory factor or the abstraction-working memory factor. These data clarify the role of the mesocortical dopaminergic pathways in cognitive function in early PD, highlighting the medial frontal lobe, anterior cingulate, and left BA 46 as the main sites of cortical correlation with executive and language functions. (orig.)

Striatal dopamine in Parkinson disease: A meta-analysis of imaging studies.

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Kaasinen, Valtteri; Vahlberg, Tero

2017-12-01

A meta-analysis of 142 positron emission tomography and single photon emission computed tomography studies that have investigated striatal presynaptic dopamine function in Parkinson disease (PD) was performed. Subregional estimates of striatal dopamine metabolism are presented. The aromatic L-amino-acid decarboxylase (AADC) defect appears to be consistently smaller than the dopamine transporter and vesicular monoamine transporter 2 defects, suggesting upregulation of AADC function in PD. The correlation between disease severity and dopamine loss appears linear, but the majority of longitudinal studies point to a negative exponential progression pattern of dopamine loss in PD. Ann Neurol 2017;82:873-882. © 2017 American Neurological Association.

A retrospective comparison between {sup 68}Ga-DOTA-TOC PET/CT and {sup 18}F-DOPA PET/CT in patients with extra-adrenal paraganglioma

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Kroiss, Alexander; Putzer, Daniel; Decristoforo, Clemens; Uprimny, Christian; Virgolini, Irene Johanna [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria); Frech, Andreas; Fraedrich, Gustav [Innsbruck Medical University, Department of Vascular Surgery, Innsbruck (Austria); Gasser, Rudolf Wolfgang [Innsbruck Medical University, Department of Internal Medicine I, Innsbruck (Austria); Shulkin, Barry Lynn [St. Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); Url, Christoph [Innsbruck Medical University, Department of Otorhinolaryngology, Innsbruck (Austria); Widmann, Gerlig [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Prommegger, Rupert [Sanatorium Kettenbruecke, Department of Surgery, Innsbruck (Austria); Sprinzl, Georg Mathias [State Clinic St. Poelten, Department of Otorhinolaryngology, St. Poelten (Austria)

2013-12-15

{sup 18}F-Fluoro-l-dihydroxyphenylalanine ({sup 18}F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by {sup 68}Ga-DOTA-Tyr{sup 3}-octreotide ({sup 68}Ga-DOTA-TOC) PET. Therefore, we compared {sup 68}Ga-DOTA-TOC and {sup 18}F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with {sup 68}Ga-DOTA-TOC PET and {sup 18}F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUV{sub max}) of each functional imaging modality in concordant tumour lesions was measured. Compared with anatomical imaging, {sup 68}Ga-DOTA-TOC PET and {sup 18}F-DOPA PET each had a per-patient and per-lesion detection rate of 100 % in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of {sup 68}Ga-DOTA-TOC was 100 % and that of {sup 18}F-DOPA PET was 56.0 %. Overall, {sup 68}Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and {sup 18}F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of {sup 68}Ga-DOTA-TOC PET was 100 % (McNemar, P < 0.5), and that of {sup 18}F-DOPA PET was 71.1 % (McNemar, P < 0.001). The SUV{sub max} (mean {+-} SD) of all 32 concordant lesions was 67.9 {+-} 61.5 for {sup 68}Ga-DOTA-TOC PET and 11.8 {+-} 7.9 for {sup 18}F-DOPA PET (Mann-Whitney U test, P < 0.0001). {sup 68}Ga-DOTA-TOC PET

Rapid synthesis and purification of carbon-11 labelled DOPA: a potential agent for brain studies

International Nuclear Information System (INIS)

Reiffers, S.; Beerling-van der Molen, H.D.; Vaalburg, W.; Hoeve, W. ten; Paans, A.M.J.; Korf, J.; Woldring, M.G.; Wynberg, H.

1977-01-01

A rapid method for preparation and purification of β-(3,4-dihydroxyphenyl)-D,L-α-alanine-1- 11 C( 11 C-DOPA), using 11 CO 2 as the radioactive precursor is described. Carboxylation of an α-lithioisocyanide, containing protected hydroxylic groups, was followed by a three-step hydrolysis of the intermediate αioscyano carboxylic acid. Preliminary experiments in rats indicate that the compound is preferentially decarboxylated in brain areas rich in dopamine containing neurons. (author)

Intraindividual comparison of 68Ga-DOTA-TATE and 18F-DOPA PET in patients with well-differentiated metastatic neuroendocrine tumours

International Nuclear Information System (INIS)

Haug, Alexander; Auernhammer, Christoph J.; Goeke, Burkhard; Waengler, Bjoern; Tiling, Reinhold; Bartenstein, Peter; Poepperl, Gabriele; Schmidt, Gerwin

2009-01-01

To compare the diagnostic impact of 68 Ga-DOTA-TATE and 18 F-DOPA PET in the diagnosis of well-differentiated metastatic neuroendocrine tumours (NET). PET/CT using both 68 Ga-DOTA-TATE and 18 F-DOPA was performed in 25 patients with histologically proven metastatic NET (nine gut, five pancreas, six lung, one paranasal sinus, four with unknown primary). Analyses of PET examinations were patient-based (pathological uptake: yes/no), and based on tumour regions (primary tumour if present and metastases of liver, lung, bones and lymph nodes). The results were compared with the results of contrast enhanced CT, and with plasma serotonin levels, which were available in 24 of the 25 patients. Patient-based sensitivities were 96% for 68 Ga-DOTA-TATE PET and 56% for 18 F-DOPA PET. 68 Ga-DOTA-TATE PET delineated metastases in 54 of 55 positive metastatic tumour regions in contrast to 29 of 55 delineated by 18 F-DOPA PET. Overall, 68 Ga-DOTA-TATE was superior to 18 F-DOPA in 13 patients (two patients showed fewer positive tumour regions with 18 F-DOPA PET). The results were comparable in 12 patients. In 13 of 24 patients, plasma serotonin levels were elevated, and 11 of these 13 patients showed pathological uptake of 18 F-DOPA. Of the 11 patients with normal levels of serotonin, 3 also showed positive 18 F-DOPA uptake. In patients positive for 18 F-DOPA uptake the maximum tumour SUVs were correlated with the levels of serotonin (r=0.66, p=0.01). In this study 68 Ga-DOTA-TATE PET proved clearly superior to 18 F-DOPA PET for detection and staging of NET. 18 F-DOPA uptake tended to be increased in those patients with elevated plasma serotonin. We conclude that 18 F-DOPA PET should be employed in patients with NET with negative 68 Ga-DOTA-TATE PET and elevated plasma serotonin. (orig.)

Solvent 1H/2H isotopic effects in the reaction of the L-Tyrosine oxidation catalyzed by Tyrosinase

International Nuclear Information System (INIS)

Kozlowska, M.; Kanska, M.

2006-01-01

Tyrosinase is well known catalyst in the oxidation of L-Tyrosine to L-DOPA and following oxidation of L-DOPA to dopachinone. The aim of communication is to present the results of studies on the solvent isotopic effects (SIE) in the above reactions for the 1 H/ 2 H in the 3',5' and 2',6' substituted tyrosine. Obtained dependence of the reaction rate on the substrate concentration were applied for optimization of the kinetic parameters, k cat and k cat /K m , in the Michaelis-Menten equation. As a result - better understanding of the L-DOPA creation can be achieved

Estimation of in vitro activity of tuberoinfundibular dopaminergic neurons by measurement of DOPA synthesis in the median eminence of hypothalamic slices.

Science.gov (United States)

Arita, J; Kimura, F

1984-12-01

A new method for estimation of in vitro neurosecretory activity of tuberoinfundibular dopaminergic (TIDA) neurons was developed by measuring the rate of synthesis of dihydroxyphenylalanine (DOPA) in the median eminence of hypothalamic slices. Sagittal hypothalamic slices of ovariectomized rats were incubated in a medium containing 3-hydroxybenzylhydrazine (NSD 1015), an inhibitor of DOPA decarboxylase. DOPA accumulated in the median eminence following incubation with NSD 1015 was determined by high-performance liquid chromatography with electro-chemical detection. The amount of DOPA accumulated in vitro in the median eminence was maximal in a medium containing 10 mM NSD 1015 and linear up to 120 min at 37 degrees C. Increasing the concentration of tyrosine in medium stimulated the synthesis of DOPA in the median eminence. The synthesis of DOPA was blocked by 1 mM alpha-methyltyrosine, an inhibitor of tyrosine hydroxylase. The rate of in vitro synthesis of DOPA in the median eminence was 33% of that of in vivo synthesis. Incubation in a medium containing 50 mM K+ to depolarize neurons caused a 2.4-fold increase in DOPA synthesis in the median eminence. The high K+-induced increase in DOPA synthesis was blocked by omission of Ca2+ and addition of 1 mM EGTA into the medium, suggesting Ca2+ dependency of depolarization-activated DOPA synthesis. These results indicate that this in vitro assay is a useful means to study the regulatory mechanisms of TIDA neurons.

Striatal dopamine D2/3 receptor regulation by stress inoculation in squirrel monkeys

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Alex G. Lee

2016-06-01

Full Text Available Intermittent mildly stressful situations provide opportunities to learn, practice, and improve coping in a process called stress inoculation. Stress inoculation also enhances cognitive control and response inhibition of impulsive motivated behavior. Cognitive control and motivation have been linked to striatal dopamine D2 and/or D3 receptors (DRD2/3 in rodents, monkeys, and humans. Here, we study squirrel monkeys randomized early in life to stress inoculation with or without maternal companionship and a no-stress control treatment condition. Striatal DRD2/3 availability in adulthood was measured in vivo by [11C]raclopride binding using positron emission tomography (PET. DRD2/3 availability was greater in caudate and putamen compared to ventral striatum as reported in PET studies of humans and other non-human primates. DRD2/3 availability in ventral striatum was also consistently greater in stress inoculated squirrel monkeys compared to no-stress controls. Squirrel monkeys exposed to stress inoculation in the presence of their mother did not differ from squirrel monkeys exposed to stress inoculation without maternal companionship. Similar effects in different social contexts extend the generality of our findings and together suggest that stress inoculation increases striatal DRD2/3 availability as a correlate of cognitive control in squirrel monkeys.

Production of 3,4-dihydroxy L-phenylalanine by a newly isolated Aspergillus niger and parameter significance analysis by Plackett-Burman design

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Haq I

2010-12-01

Full Text Available Abstract Background The amino acid derivative 3,4-dihydroxy L-phenylalanine (L-dopa is gaining interest as a drug of choice for Parkinson's disease. Aspergillus oryzae is commonly used for L-dopa production; however, a slower growth rate and relatively lower tyrosinase activity of mycelia have led to an increasing interest in exploiting alternative fungal cultures. In the present investigation, we report on the microbiological transformation of L-tyrosine to L-dopa accomplished by a newly isolated filamentous fungus Aspergillus niger. Results The culture A. niger (isolate GCBT-8 was propagated in 500 ml Erlenmeyer flasks and the pre-grown mycelia (48 h old were used in the reaction mixture as a source of enzyme tyrosinase. Grinded mycelia gave 1.26 fold higher L-dopa production compared to the intact at 6% glucose (pH 5.5. The rate of L-tyrosine consumption was improved from 0.198 to 0.281 mg/ml. Among the various nitrogen sources, 1.5% peptone, 1% yeast extract and 0.2% ammonium chloride were optimized. The maximal L-dopa was produced (0.365 mg/ml at 0.3% potassium dihydrogen phosphate with L-tyrosine consumption of 0.403 mg/ml. Conclusion Over ~73% yield was achieved (degree of freedom 3 when the process parameters were identified using 2k-Plackett-Burman experimental design. The results are highly significant (p ≤ 0.05 and mark the commercial utility (LSD 0.016 of the mould culture which is perhaps the first ever report on L-dopa production from A. niger.

Enhanced striatal sensitivity to aversive reinforcement in adolescents versus adults.

Science.gov (United States)

Galván, Adriana; McGlennen, Kristine M

2013-02-01

Neurodevelopmental changes in mesolimbic regions are associated with adolescent risk-taking behavior. Numerous studies have shown exaggerated activation in the striatum in adolescents compared with children and adults during reward processing. However, striatal sensitivity to aversion remains elusive. Given the important role of the striatum in tracking both appetitive and aversive events, addressing this question is critical to understanding adolescent decision-making, as both positive and negative factors contribute to this behavior. In this study, human adult and adolescent participants performed a task in which they received squirts of appetitive or aversive liquid while undergoing fMRI, a novel approach in human adolescents. Compared with adults, adolescents showed greater behavioral and striatal sensitivity to both appetitive and aversive stimuli, an effect that was exaggerated in response to delivery of the aversive stimulus. Collectively, these findings contribute to understanding how neural responses to positive and negative outcomes differ between adolescents and adults and how they may influence adolescent behavior.

Dopa-responsive dystonia

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Đurić Gordana

2009-01-01

Full Text Available Backgrround/Aim. Dystonia is considered to be a prolonged involuntary contractions of the muscles leading to twisting, repetitive movements or irregular postures. Etiologically, it could be classified as primary and secondary dystonia. Dopa-responsive dystonia (DRD belongs to a group of primary dystonia. The aim of this study was to detect the presence of gene GCH-I mutation in our population in patients with dopa-responsive dystonic dyskinesia and to analyze clinical specificity of the affected. Methods. Out of the group of patients with dystonia of different distribution four patients were separated whose clinical picture indicated the diagnosis of DRD. Two patients had a positive family anamnesis while the other two were sporadic. Genetic analysis was performed by the use of a standard protocol, which included PCR amplification and DNK sequencing according to the method of Senger and autoradiografy. Results. In the patients from the family DRD-1 new hetaerazygote point mutation 520G→A in 4-m exson gene GCH-I was revealed. First symptoms of the disease showed in the age of seven by the torsion of the left foot, progressively advanced and got into the evolution of numbness in the legs, aggravated gait, tending to worsen in the evening, and the therapy with levodopa (500 mg produced a dramatic effect. The second mutation in the female patient from the family DRD-2 was homozygote deletion in1-m intron gene GCH-I (IVS1-85delA. Unwilling torsion of the foot, feeling of weakness in the lower extremities (that caused falling without loss of the consciousness were clinical demonstrations of the disease. The application of levodopa (300 mg caused regression of the symptoms of the disease. Hetaerazygote deletion of adenine in the position 209 in the first exon (209del A was identificated in the patient DRD-3 with negative family anamnesis, in who in the age of ten the torsion of the foot inside occurred for the first time following by trembling of

[18F]DOPA PET/ceCT in diagnosis and staging of primary medullary thyroid carcinoma prior to surgery.

Science.gov (United States)

Rasul, Sazan; Hartenbach, Sabrina; Rebhan, Katharina; Göllner, Adelina; Karanikas, Georgios; Mayerhoefer, Marius; Mazal, Peter; Hacker, Marcus; Hartenbach, Markus

2018-05-15

Medullary thyroid carcinoma (MTC) is characterized by a high rate of metastasis. In this study we evaluated the ability of [ 18 F]DOPA PET/ceCT to stage MTC in patients with suspicious thyroid nodules and pathologically elevated serum calcitonin (Ctn) levels prior to total thyroidectomy and lymph node (LN) dissection. A group of 32 patients with sonographically suspicious thyroid nodules and pathologically elevated basal Ctn (bCtn) and stimulated Ctn (sCtn) levels underwent DOPA PET/ceCT prior to surgery. Postoperative histology served as the standard of reference for ultrasonography and DOPA PET/ceCT region-based LN staging. Univariate and multivariate regression analyses as well as receiver operating characteristic analysis were used to evaluate the correlations between preoperative and histological parameters and postoperative tumour persistence or relapse. Primary MTC was histologically verified in all patients. Of the 32 patients, 28 showed increased DOPA decarboxylase activity in the primary tumour (sensitivity 88%, mean SUVmax 10.5). Undetected tumours were exclusively staged pT1a. The sensitivities of DOPA PET in the detection of central and lateral metastatic neck LN were 53% and 73%, in contrast to 20% and 39%, respectively, for neck ultrasonography. Preoperative bCtn and carcinoembryonic antigen levels as well as cN1b status and the number of involved neck regions on DOPA PET/ceCT were predictive of postoperative tumour persistence/relapse in the univariate regression analysis (P PET/ceCT cN1b status remained significant in the multivariate analysis (P = 0.016, relative risk 4.02). This study revealed that DOPA PET/ceCT has high sensitivity in the detection of primary MTC and superior sensitivity in the detection of LN metastases compared to ultrasonography. DOPA PET/ceCT identification of N1b status predicts postoperative tumour persistence. Thus, implementation of a DOPA-guided LN dissection might improve surgical success.

Parsing Heterogeneous Striatal Activity

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Kae Nakamura

2017-05-01

Full Text Available The striatum is an input channel of the basal ganglia and is well known to be involved in reward-based decision making and learning. At the macroscopic level, the striatum has been postulated to contain parallel functional modules, each of which includes neurons that perform similar computations to support selection of appropriate actions for different task contexts. At the single-neuron level, however, recent studies in monkeys and rodents have revealed heterogeneity in neuronal activity even within restricted modules of the striatum. Looking for generality in the complex striatal activity patterns, here we briefly survey several types of striatal activity, focusing on their usefulness for mediating behaviors. In particular, we focus on two types of behavioral tasks: reward-based tasks that use salient sensory cues and manipulate outcomes associated with the cues; and perceptual decision tasks that manipulate the quality of noisy sensory cues and associate all correct decisions with the same outcome. Guided by previous insights on the modular organization and general selection-related functions of the basal ganglia, we relate striatal activity patterns on these tasks to two types of computations: implementation of selection and evaluation. We suggest that a parsing with the selection/evaluation categories encourages a focus on the functional commonalities revealed by studies with different animal models and behavioral tasks, instead of a focus on aspects of striatal activity that may be specific to a particular task setting. We then highlight several questions in the selection-evaluation framework for future explorations.

Fronto-striatal atrophy in behavioural variant frontotemporal dementia & Alzheimer’s disease

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Maxime eBertoux

2015-07-01

Full Text Available Behavioural variant frontotemporal dementia (bvFTD has only recently been associated with significant striatal atrophy, whereas the striatum appears to be relatively preserved in Alzheimer’s disease (AD. Considering the critical role the striatum has in cognition and behaviour, striatal degeneration, together with frontal atrophy, could be responsible of some characteristic symptoms in bvFTD and emerges therefore as promising novel diagnostic biomarker to distinguish bvFTD and AD. Previous studies have, however, only taken either cortical or striatal atrophy into account when comparing the two diseases. In this study, we establish for the first time a profile of fronto-striatal atrophy in 23 bvFTD and 29 AD patients at presentation, based on the structural connectivity of striatal and cortical regions. Patients are compared to 50 healthy controls by using a novel probabilistic connectivity atlas, which defines striatal regions by their cortical white matter connectivity, allowing us to explore the degeneration of the frontal and striatal regions that are functionally linked. Comparisons with controls revealed that bvFTD showed substantial fronto-striatal atrophy affecting the ventral as well as anterior and posterior dorso-lateral prefrontal cortices and the related striatal subregions. By contrast, AD showed few fronto-striatal atrophy, despite having significant posterior dorso-lateral prefrontal degeneration. Direct comparison between bvFTD and AD revealed significantly more atrophy in the ventral striatal-ventromedial prefrontal cortex regions in bvFTD. Consequently, deficits in ventral fronto-striatal regions emerge as promising novel and efficient diagnosis biomarker for bvFTD. Future investigations into the contributions of these fronto-striatal loops on bvFTD symptomology are needed to develop simple diagnostic and disease tracking algorithms.

The value of 18F-DOPA PET-CT in patients with medullary thyroid carcinoma: comparison with 18F-FDG PET-CT

International Nuclear Information System (INIS)

Beheshti, Mohsen; Poecher, Sigrid; Vali, Reza; Nader, Michael; Langsteger, Werner; Waldenberger, Peter; Broinger, Gabriele; Kohlfuerst, Susanne; Pirich, Christian; Dralle, Henning

2009-01-01

The purpose of this prospective study was to compare the value of DOPA PET-CT with FDG PET-CT in the detection of malignant lesions in patients with medullary thyroid carcinoma (MTC). Twenty-six consecutive patients (10 men, 16 women, mean age 59 ± 14 years) with elevated calcitonin levels were evaluated in this prospective study. DOPA and FDG PET-CT modalities were performed within a maximum of 4 weeks (median 7 days) in all patients. The data were evaluated on a patient- and lesion-based analysis. The final diagnosis of positive PET lesions was based on histopathological findings and/or imaging follow-up studies (i.e., DOPA and/or FDG PET-CT) for at least 6 months (range 6-24 months). In 21 (21/26) patients at least one malignant lesion was detected by DOPA PET, while only 15 (15/26) patients showed abnormal FDG uptake. DOPA PET provided important additional information in the follow-up assessment in seven (27%) patients which changed the therapeutic management. The patient-based analysis of our data demonstrated a sensitivity of 81% for DOPA PET versus 58% for FDG PET, respectively. In four (4/26) postoperative patients DOPA and FDG PET-CT studies were negative in spite of elevated serum calcitonin and CEA levels as well as abnormal pentagastrin tests. Overall 59 pathological lesions with abnormal tracer uptake were seen on DOPA and/or FDG PET studies. In the final diagnosis 53 lesions proved to be malignant. DOPA PET correctly detected 94% (50/53) of malignant lesions, whereas only 62% (33/53) of malignant lesions were detected with FDG PET. DOPA PET-CT showed superior results to FDG PET-CT in the preoperative and follow-up assessment of MTC patients. Therefore, we recommend DOPA PET-CT as a one-stop diagnostic procedure to provide both functional and morphological data in order to select those patients who may benefit from (re-)operation with curative intent as well as guiding further surgical procedures. (orig.)

Transgenic mice expressing a Huntington s disease mutation are resistant to quinolinic acid-induced striatal excitotoxicity

OpenAIRE

Hansson, Oskar; Petersén, Åsa; Leist, Marcel; Nicotera, Pierluigi; Castilho, Roger F.; Brundin, Patrik

1999-01-01

Huntington’s disease (HD) is a hereditary neurodegenerative disorder presenting with chorea, dementia, and extensive striatal neuronal death. The mechanism through which the widely expressed mutant HD gene mediates a slowly progressing striatal neurotoxicity is unknown. Glutamate receptor-mediated excitotoxicity has been hypothesized to contribute to the pathogenesis of HD. Here we show that transgenic HD mice expressing exon 1 of a human HD gene with an expanded number of CAG repeats (line R...

Striatal D1- and D2-type dopamine receptors are linked to motor response inhibition in human subjects.

Science.gov (United States)

Robertson, Chelsea L; Ishibashi, Kenji; Mandelkern, Mark A; Brown, Amira K; Ghahremani, Dara G; Sabb, Fred; Bilder, Robert; Cannon, Tyrone; Borg, Jacqueline; London, Edythe D

2015-04-15

Motor response inhibition is mediated by neural circuits involving dopaminergic transmission; however, the relative contributions of dopaminergic signaling via D1- and D2-type receptors are unclear. Although evidence supports dissociable contributions of D1- and D2-type receptors to response inhibition in rats and associations of D2-type receptors to response inhibition in humans, the relationship between D1-type receptors and response inhibition has not been evaluated in humans. Here, we tested whether individual differences in striatal D1- and D2-type receptors are related to response inhibition in human subjects, possibly in opposing ways. Thirty-one volunteers participated. Response inhibition was indexed by stop-signal reaction time on the stop-signal task and commission errors on the continuous performance task, and tested for association with striatal D1- and D2-type receptor availability [binding potential referred to nondisplaceable uptake (BPND)], measured using positron emission tomography with [(11)C]NNC-112 and [(18)F]fallypride, respectively. Stop-signal reaction time was negatively correlated with D1- and D2-type BPND in whole striatum, with significant relationships involving the dorsal striatum, but not the ventral striatum, and no significant correlations involving the continuous performance task. The results indicate that dopamine D1- and D2-type receptors are associated with response inhibition, and identify the dorsal striatum as an important locus of dopaminergic control in stopping. Moreover, the similar contribution of both receptor subtypes suggests the importance of a relative balance between phasic and tonic dopaminergic activity subserved by D1- and D2-type receptors, respectively, in support of response inhibition. The results also suggest that the stop-signal task and the continuous performance task use different neurochemical mechanisms subserving motor response inhibition. Copyright © 2015 the authors 0270-6474/15/355990-08$15.00/0.

Positron emission tomography suggests that the rate of progression of idiopathic parkinsonism is slow

International Nuclear Information System (INIS)

Bhatt, M.H.; Snow, B.J.; Martin, W.R.; Pate, B.D.; Ruth, T.J.; Calne, D.B.

1991-01-01

The authors performed sequential positron emission tomography scans with 6-[18F]fluoro-L-dopa in 9 patients with idiopathic parkinsonism and 7 age-matched normal control subjects to compare changes in the nigrostriatal dopaminergic pathway over time. The mean interval between the scans was 3.3 years for the group with idiopathic parkinsonism and 3.9 years for the control subjects. The scans were analyzed by calculating the ratio of striatal to background radioactivity. Both groups showed statistically significant reductions of striatal uptake over the interval. The rate of decrease was almost identical in each group (p = 0.6). They infer that the usual rate of loss of integrity of the dopaminergic nigrostriatal pathway in patients with idiopathic parkinsonism is slow and the rate of change between the two groups was comparable

DISC1 and striatal volume: a potential risk phenotype for mental illness

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M. Mallar eChakravarty

2012-06-01

Full Text Available Disrupted-in-schizophrenia 1 was originally discovered in a large Scottish family with abnormally high rates of severe mental illness, including schizophrenia, bipolar disorder, and depression. An accumulating body of evidence from genetic, postmortem, and animal data supports a role for DISC1 in different forms of mental illness. DISC1 may play an important role in determining structure and function of several brain regions. One brain region of particular importance for several mental disorders is the striatum, and DISC1 mutant mice have demonstrated an increase in dopamine (D2 receptors in this structure. However, association between DISC1 functional polymorphisms and striatal structure have not been examined in humans to our knowledge. We, therefore hypothesized that there would be a relationship between human striatal volume and DISC1 genotype, specifically in the Leu607Phe (rs6675281 and Ser704Cys (rs821618 single nucleotide polymorphisms. We tested our hypothesis by automatically identifying the striatum in fifty-four healthy volunteers recruited for this study. We also performed an exploratory analysis of cortical thickness, cortical surface area, and structure volume. Our results demonstrate that Phe allele carriers have larger striatal volume bilaterally (left striatum: p=0.017; right striatum: p=0.016. From the exploratory analyses we found that Phe carriers also had larger right hemisphere volumes and right occipital lobe surface area (p=0.014 compared to LeuLeu homozygotes (p=0.0074. However, these exploratory findings do not survive a conservative correction for multiple comparisons. Our findings demonstrate that a functional DISC1 variant influences striatal volumes. Taken together with animal data that this gene influences D2 receptor levels in striatum, a key risk pathway for mental illnesses such as schizophrenia and bipolar disorder may be conferred via DISC1’s effects on the striatum .

A novel missense mutation pattern of the GCH1 gene in dopa-responsive dystonia Novo padrão de mutação missense no gene GCH1 na distonia dopa-responsiva

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Rosana H. Scola

2007-12-01

Full Text Available Dopa-responsive dystonia (DRD is an inherited metabolic disorder now classified as DYT5 with two different biochemical defects: autosomal dominant GTP cyclohydrolase 1 (GCH1 deficiency or autosomal recessive tyrosine hydroxylase deficiency. We report the case of a 10-years-old girl with progressive generalized dystonia and gait disorder who presented dramatic response to levodopa. The phenylalanine to tyrosine ratio was significantly higher after phenylalanine loading test. This condition had two different heterozygous mutations in the GCH1 gene: the previously reported P23L mutation and a new Q182E mutation. The characteristics of the DRD and the molecular genetic findings are discussed.Distonia dopa-responsiva (DRD, classificada como DYT5, é um erro inato do metabolismo que pode ser causado por dois diferentes tipos de defeito bioquímico: deficiência de GTP ciclo-hidrolase 1 (GCH1 (autossômica dominante ou de tirosina hidroxilase (autossômica recessiva. Descrevemos o caso de menina de 10 anos com distonia generalizada progressiva e alteração da marcha com importante melhora após uso de levodopa. A relação fenilalanina/tirosina estava aumentada após teste de sobrecarga com fenilalanina. O estudo molecular mostrou que o paciente apresenta uma combinação hererozigótica de mutação no gene GCH1: a já conhecida mutação P23L e uma nova mutação Q182E. Discutem-se as características da DRD e as alterações genéticas possíveis.

[Rapid and prolonged facilitation of stereotyped motor behavior (verticalization) induced by apomorphine in mice previously submitted to stimulation of dopaminergic receptors].

Science.gov (United States)

Costentin, J; Marçais, H; Protais, P; Schwartz, J C

1976-03-01

The climbing behaviour, a stereotyped motor behaviour, is elicited in mice by stimulation of striatal dopamine receptor by low doses of apomorphine. The action of apomorphine is unexpectedly enhanced in animals pretreated with a single dose of this agent (5 mg/kg). This enhancement occurs as early as 2 h following the first administration and persists for at least 3 days. It is also observed after pretreatments with a combination of L-DOPA and dexamphetamine. This effect seems independent from the desensitization of the dopaminergic receptors involved in thermoregulation that we have previously reported.

Nitric oxide-soluble guanylyl cyclase-cyclic GMP signaling in the striatum: New targets for the treatment of Parkinson's disease?

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Anthony R West

2011-06-01

Full Text Available Striatal nitric oxide (NO-producing interneurons play an important role in the regulation of corticostriatal synaptic transmission and motor behavior. Striatal NO synthesis is driven by concurrent activation of NMDA and dopamine (DA D1 receptors. NO diffuses into the dendrites of medium-sized spiny neurons (MSNs which contain high levels of NO receptors called soluble guanylyl cyclases (sGC. NO-mediated activation of sGC leads to the synthesis of the second messenger cGMP. In the intact striatum, transient elevations in intracellular cGMP primarily act to increase neuronal excitability and to facilitate glutamatergic corticostriatal transmission. NO-cGMP signaling also functionally opposes the inhibitory effects of DA D2 receptor activation on corticostriatal transmission. Not surprisingly, abnormal striatal NO-sGC-cGMP signaling becomes apparent following striatal DA depletion, an alteration thought to contribute to pathophysiological changes observed in basal ganglia circuits in Parkinson’s disease (PD. Here, we discuss recent developments in the field which have shed light on the role of NO-sGC-cGMP signaling pathways in basal ganglia dysfunction and motor symptoms associated with PD and L-DOPA-induced dyskinesias.

Selective updating of working memory content modulates meso-cortico-striatal activity.

Science.gov (United States)

Murty, Vishnu P; Sambataro, Fabio; Radulescu, Eugenia; Altamura, Mario; Iudicello, Jennifer; Zoltick, Bradley; Weinberger, Daniel R; Goldberg, Terry E; Mattay, Venkata S

2011-08-01

Accumulating evidence from non-human primates and computational modeling suggests that dopaminergic signals arising from the midbrain (substantia nigra/ventral tegmental area) mediate striatal gating of the prefrontal cortex during the selective updating of working memory. Using event-related functional magnetic resonance imaging, we explored the neural mechanisms underlying the selective updating of information stored in working memory. Participants were scanned during a novel working memory task that parses the neurophysiology underlying working memory maintenance, overwriting, and selective updating. Analyses revealed a functionally coupled network consisting of a midbrain region encompassing the substantia nigra/ventral tegmental area, caudate, and dorsolateral prefrontal cortex that was selectively engaged during working memory updating compared to the overwriting and maintenance of working memory content. Further analysis revealed differential midbrain-dorsolateral prefrontal interactions during selective updating between low-performing and high-performing individuals. These findings highlight the role of this meso-cortico-striatal circuitry during the selective updating of working memory in humans, which complements previous research in behavioral neuroscience and computational modeling. Published by Elsevier Inc.

Prolonged striatal disinhibition as a chronic animal model of tic disorders.

Science.gov (United States)

Vinner, Esther; Israelashvili, Michal; Bar-Gad, Izhar

2017-12-01

Experimental findings and theoretical models have associated Tourette syndrome with abnormal striatal inhibition. The expression of tics, the hallmark symptom of this disorder, has been transiently induced in non-human primates and rodents by the injection of GABA A antagonists into the striatum, leading to temporary disinhibition. The novel chronic model of tic expression utilizes mini-osmotic pumps implanted subcutaneously in the rat's back for prolonged infusion of bicuculline into the dorsolateral striatum. Tics were expressed on the contralateral side to the infusion over a period of multiple days. Tic expression was stable, and maintained similar properties throughout the infusion period. Electrophysiological recordings revealed the existence of tic-related local field potential spikes and individual neuron activity changes that remained stable throughout the infusion period. The striatal disinhibition model provides a unique combination of face validity (tic expression) and construct validity (abnormal striatal inhibition) but is limited to sub-hour periods. The new chronic model extends the period of tic expression to multiple days and thus enables the study of tic dynamics and the effects of behavior and pharmacological agents on tic expression. The chronic model provides similar behavioral and neuronal correlates of tics as the acute striatal disinhibition model but over prolonged periods of time, thus providing a unique, basal ganglia initiated model of tic expression. Chronic expression of symptoms is the key to studying the time varying properties of Tourette syndrome and the effects of multiple internal and external factors on this disorder. Copyright © 2017 Elsevier B.V. All rights reserved.

Striatal dysfunction in attention deficit and hyperkinetic disorder

International Nuclear Information System (INIS)

Lou, H.C.; Henriksen, L.; Bruhn, P.; Borner, H.; Nielsen, J.B.

1989-01-01

We have previously reported that periventricular structures are hypoperfused in attention deficit and hyperactivity disorder (ADHD). This study has expanded the number of patients, who were divided into two groups: six patients with pure ADHD, and 13 patients with ADHD in combination with other neurologic symptoms. By using xenon 133 inhalation and emission tomography, the regional cerebral blood flow distribution was determined and compared with a control group. Striatal regions were found to be hypoperfused and, by inference, hypofunctional in both groups. This hypoperfusion was statistically significant in the right striatum in ADHD, and in both striatal regions in ADHD with other neuropsychologic and neurologic symptoms. The primary sensory and sensorimotor cortical regions were highly perfused. Methylphenidate increased flow to striatal and posterior periventricular regions, and tended to decrease flow to primary sensory regions. Low striatal activity, partially reversible with methylphenidate, appears to be a cardinal feature in ADHD

Striatal dysfunction in attention deficit and hyperkinetic disorder

Energy Technology Data Exchange (ETDEWEB)

Lou, H.C.; Henriksen, L.; Bruhn, P.; Borner, H.; Nielsen, J.B.

1989-01-01

We have previously reported that periventricular structures are hypoperfused in attention deficit and hyperactivity disorder (ADHD). This study has expanded the number of patients, who were divided into two groups: six patients with pure ADHD, and 13 patients with ADHD in combination with other neurologic symptoms. By using xenon 133 inhalation and emission tomography, the regional cerebral blood flow distribution was determined and compared with a control group. Striatal regions were found to be hypoperfused and, by inference, hypofunctional in both groups. This hypoperfusion was statistically significant in the right striatum in ADHD, and in both striatal regions in ADHD with other neuropsychologic and neurologic symptoms. The primary sensory and sensorimotor cortical regions were highly perfused. Methylphenidate increased flow to striatal and posterior periventricular regions, and tended to decrease flow to primary sensory regions. Low striatal activity, partially reversible with methylphenidate, appears to be a cardinal feature in ADHD.

Clinical value of 18F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography (18F-DOPA PET/CT) for detecting pheochromocytoma

International Nuclear Information System (INIS)

Luster, Markus; Zeich, Katrin; Glatting, Gerhard; Buck, Andreas K.; Solbach, Christoph; Reske, Sven N.; Karges, Wolfram; Pauls, Sandra; Verburg, Frederik A.; Dralle, Henning; Neumaier, Bernd; Mottaghy, Felix M.

2010-01-01

In detecting pheochromocytoma (PHEO), positron emission tomography (PET) with the radiolabelled amine precursor 18 F-fluorodihydroxyphenylalanine ( 18 F-DOPA) offers excellent specificity, while computed tomography (CT) provides high sensitivity and ability to localize lesions; therefore, the combination of these modalities could be advantageous in this setting. The aim of this study was to investigate whether combined 18 F-DOPA PET/CT more accurately detects and localizes PHEO lesions than does each modality alone. 18 F-DOPA PET, CT and 18 F-DOPA PET/CT images of 25 consecutive patients undergoing diagnostic scanning of suspected sporadic or multiple endocrine neoplasia type 2 syndrome-associated PHEO were reviewed retrospectively in randomized sequence. Two blinded observers scored the images regarding the likelihood of PHEO being present and localizable. Results were correlated with subsequent clinical history and, when available, histology. Of the 19 lesions detected by all three modalities, PET identified each as positive for PHEO, but was unable to definitively localize 15 of 19 (79%). CT could definitively localize all 19 lesions, but could not definitively diagnose or exclude PHEO in 18 of 19 (95%) lesions. Furthermore, CT falsely identified as negative for PHEO one lesion which was judged to be positive for this tumor by both PET and PET/CT. Only in PET/CT scans were all 19 lesions accurately characterized and localized. On a per-patient basis, the sensitivity of 18 F-DOPA PET/CT for PHEO was 100% and the specificity 88%, with a 100% positive predictive value and an 88% negative predictive value. 18 F-DOPA PET/CT more accurately diagnoses and localizes adrenal and extra-adrenal masses suspicious for PHEO than do 18 F-DOPA PET or CT alone. (orig.)

Radiosynthesis and biological evaluation of N-(2-[18F]fluoropropionyl)-3,4-dihydroxy-l-phenylalanine as a PET tracer for oncologic imaging.

Science.gov (United States)

Tang, Caihua; Nie, Dahong; Tang, Ganghua; Gao, Siyuan; Liu, Shaoyu; Wen, Fuhua; Tang, Xiaolan

2017-07-01

Several 11 C and 18 F labeled 3,4-dihydroxy-l-phenylalanine (l-DOPA) analogues have been used for neurologic and oncologic diseases, especially for brain tumors and neuroendocrine tumors PET imaging. However, 18 F-labeled N-substituted l-DOPA analogues have not been reported so far. In the current study, radiosynthesis and biological evaluation of a new 18 F-labeled l-DOPA analogue, N-(2-[ 18 F]fluoropropionyl)-3,4-dihydroxy-l-phenylalanine ([ 18 F]FPDOPA) for tumor PET imaging are performed. The synthesis of [ 18 F]FPDOPA was via a two-step reaction sequence from 4-nitrophenyl-2-[ 18 F]fluoropropionate ([ 18 F]NFP). The biodistribution of [ 18 F]FPDOPA was determined in normal Kunming mice. In vitro competitive inhibition and protein incorporation experiments were performed with SPC-A-1 lung adenocarcinoma cell lines. PET/CT studies of [ 18 F]FPDOPA were conducted in C6 rat glioma and SPC-A-1 human lung adenocarcinoma and H460 human large cell lung cancer-bearing nude mice. [ 18 F]FPDOPA was prepared with a decay-corrected radiochemical yield of 28±5% and a specific activity of 50±15GBq/μmol (n=10) within 125min. In vitro cell experiments showed that [ 18 F]FPDOPA uptake in SPC-A-1 cells was primarily transported through Na + -independent system L, with Na + -dependent system B 0,+ and system ASC partly involved in it. Biodistribution data in mice showed that renal-bladder route was the main excretory system of [ 18 F]FPDOPA. PET imaging demonstrated intense accumulation of [ 18 F]FPDOPA in several tumor xenografts, with (8.50±0.40)%ID/g in C6 glioma, (6.30±0.12)%ID/g in SPC-A-1 lung adenocarcinoma, and (6.50±0.10)%ID/g in H460 large cell lung cancer, respectively. A novel N-substituted 18 F-labeled L-DOPA analogue [ 18 F]FPDOPA is synthesized and evaluated in vitro and in vivo. The results support that [ 18 F]FPDOPA seems to be a potential PET tracer for tumor imaging, especially be a better potential PET tracer than [ 18 F]fluoro-2-deoxy-d-glucose ([ 18 F

Fraksi Etanol 96% Biji Koro Benguk (Mucuna Pruriens L.) Sebagai Peningkat Kualitas Spermatozoa Mencit (Mus Musculus)

OpenAIRE

Winarni, Sri; Judiwati, Rina; Prajogo, Bambang; Hayati, Alfiah

2011-01-01

Background: The examination of sperm quality is the main priority for infertility diagnosis. Based on previous study with mice, active ingredient of Mucuna pruriens L. or koro benguk (Papilionaceae), the L-dopa, may affect the quality of spermatozoa.Objective: Research was to study the effect of 96% ethanol fraction Mucuna pruriens seed on spermatozoaquality of mice exposed to 2-Methoxy ethanol. L-dopa in 96% ethanol fraction of M. pruriens seed was 14.7%.Methode: This was an experimental stu...

Prognostic value of {sup 18}F-DOPA PET/CT at the time of recurrence in patients affected by neuroblastoma

Energy Technology Data Exchange (ETDEWEB)

Piccardo, Arnoldo [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); E.O. Ospedali Galliera, Department of Nuclear Medicine, Genoa (Italy); Puntoni, Matteo [Galliera Hospital, Clinical Trial Research Unit, Genoa (Italy); Lopci, Egesta; Fanti, Stefano [Sant' Orsola-Malpighi Hospital, Nuclear Medicine Unit, Bologna (Italy); Conte, Massimo; Sorrentino, Stefania; Garaventa, Alberto [G. Gaslini Children' s Hospital, Department of Hematology-Oncology, Genoa (Italy); Foppiani, Luca [Galliera Hospital, Internal Medicine, Genoa (Italy); Morana, Giovanni [G. Gaslini Children' s Hospital, Department of Pathology and Radiology, Genoa (Italy); Naseri, Mehrdad; Villavecchia, Giampiero [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); Cistaro, Angelina [IRMET, PET Centre, Turin (Italy)

2014-06-15

The aim of this study was to investigate the relationship between {sup 123}I-metaiodobenzylguanidine (MIBG) scan semi-quantification and a new {sup 18}F-DOPA positron emission tomography (PET)/CT score in patients with suspected or documented neuroblastoma (NB) relapse and to assess the association between these two parameters and progression-free survival (PFS)/overall survival (OS). We analysed 24 NB patients who had undergone {sup 123}I-MIBG and {sup 18}F-DOPA PET/CT scans at the time of suspected relapse, after applying a proper scoring system for each scan. In time-to-event analyses, the score distributions were regarded as continuous and were categorized in tertiles and medians. We used Kaplan-Meier curves and Cox proportional hazard models for PFS and OS in order to estimate the independent prognostic impact of {sup 123}I-MIBG and {sup 18}F-DOPA PET/CT scans. The {sup 123}I-MIBG and {sup 18}F-DOPA scores were highly and positively correlated (Spearman's rho = 0.8, p < 0.001). Over a median follow-up of 14 months (range 6-82), 12 cases of disease progression and 6 deaths occurred. Multivariate Cox models showed a higher risk of disease progression [hazard ratio (HR) 17.0, 95 % confidence interval (CI) 2.7-109] in NB patients with {sup 123}I-MIBG score > 3 (3rd tertile) and an even higher risk (HR:37.2, 95 % CI 2.4-574) in those with {sup 18}F-DOPA whole-body metabolic burden (WBMB) >7.5 (median), after adjustment for all main clinical/pathological factors considered. Kaplan-Meier analyses showed a significant association with OS (log-rank p = 0.01 and p = 0.03 for {sup 123}I-MIBG and {sup 18}F-DOPA WBMB, respectively). Our results confirm the good agreement between {sup 18}F-DOPA PET/CT and {sup 123}I-MIBG scan in patients affected by NB relapse. In time-to-event analyses, {sup 123}I-MIBG scan and {sup 18}F-DOPA PET/CT scores were independently and significantly associated with disease progression. (orig.)

Análise acústica da prosódia em mulheres com doença de Parkinson: efeito da Levodopa Acoustic analysis of prosody in females with Parkinson's disease: effect of L-dopa

Directory of Open Access Journals (Sweden)

Luciana L. Azevedo

2003-12-01

Full Text Available MOTIVO DO ESTUDO: Pacientes com doença de Parkinson (DP apresentam anormalidades da fala caracterizadas por pequena variação da frequência fundamental (Fo e maior amplitude. O papel dos sistemas dopaminérgicos na patogênese dessas alterações e o efeito terapêutico da L-dopa não se encontram claramente determinados. O objetivo desta investigação é avaliar o efeito da L-dopa nas caraterísticas da prosódia de mulheres com DP. MÉTODO: Nós estudamos 8 mulheres com DP (68,4 ± 6,4 anos e 8 mulheres controles (63,5 ± 6,8 anos. As pacientes (estágio H-Y 2, uma; estágio 2,5, quatro; estágio 3, três foram examinadas quando off e on. A frequência fundamental intensidade e duração da fala de sentenças afirmativas foram analisadas com o programa WinPitch 1.8 (Philippe Martin®. Os parâmetros Fo analisados foram: Fo usual (Fo us, Fo máxima (Fo max, Fo mínima (Fo min, Fo max da tônica prénuclear (Fo max PNT, Fo min da tônica prénuclear (Fo min PNT, Fo max da tônica nuclear (Fo max NT, Fo min da tônica nuclear (Fo min TN, velocidade da variação melódica da PNT (VPNT, velocidade da variação melódica da NT (VNT, amplitude da variação melódica da PNT (APNT, e amplitude da variação melódica da NT (ANT. Duração da sentença (D, duração da PNT (DPNT, duração da NT (DNT e número de sílabas por segundo (NSS foram os parâmetros de duração investigados. Foram estudadas as seguintes variáveis da intensidade: intensidade média (MI, intensidade máxima (I max, intensidade mínima (I min, intensidade da PNT (IPNT e intensidade da NT (INT. Diferenças foram estatisticamente significativas se pBACKGROUND: Untreated Parkinson's disease (PD patients display speech abnormalities characterized by narrow range of fundamental frequency (Fo variation and higher amplitude. The role of dopaminergic systems in the pathogenesis of these changes as well as the therapeutic effect of L-dopa have not been clearly determined. The aim

Dopa-responsive dystonia: functional analysis of single nucleotide substitutions within the 5' untranslated GCH1 region.

Directory of Open Access Journals (Sweden)

Ioanna A Armata

Full Text Available BACKGROUND: Mutations in the GCH1 gene are associated with childhood onset, dopa-responsive dystonia (DRD. Correct diagnosis of DRD is crucial, given the potential for complete recovery once treated with L-dopa. The majority of DRD associated mutations lie within the coding region of the GCH1 gene, but three additional single nucleotide sequence substitutions have been reported within the 5' untranslated (5'UTR region of the mRNA. The biologic significance of these 5'UTR GCH1 sequence substitutions has not been analyzed. METHODOLOGY/PRINCIPAL FINDINGS: Luciferase reporter assays, quantitative real time PCR and RNA decay assays, combined with bioinformatics, revealed a pathogenic 5'UTR GCH1 substitution. The +142C>T single nucleotide 5'UTR substitution that segregates with affected status in DRD patients, substantially attenuates translation without altering RNA expression levels or stability. The +142C>T substitution disrupts translation most likely by creating an upstream initiation start codon (uAUG and an upstream open reading frame (uORF. CONCLUSIONS/SIGNIFICANCE: This is the first GCH1 regulatory substitution reported to act at a post-transcriptional level, increasing the list of genetic diseases caused by abnormal translation and reaffirming the importance of investigating potential regulatory substitutions in genetic diseases.

The applications of 18F-DOPA PET in Parkinson's disease

International Nuclear Information System (INIS)

Zuo Chuantao

2000-01-01

The injury of the presynaptic nigro-striae dopaminergic projection is the important mechanism of Parkinson's disease (PD). 18 F-DOPA PET provides a measure of the structure as well as the biochemical integrity of the dopaminergic neurons, which contribute to the early diagnosis, differentiation diagnosis, prognosis evaluation of PD

Behavioral sensitivity of temporally modulated striatal neurons

Directory of Open Access Journals (Sweden)

George ePortugal

2011-07-01

Full Text Available Recent investigations into the neural mechanisms that underlie temporal perception have revealed that the striatum is an important contributor to interval timing processes, and electrophysiological recording studies have shown that the firing rates of striatal neurons are modulated by the time in a trial at which an operant response is made. However, it remains unclear whether striatal firing rate modulations are related to the passage of time alone (i.e., whether temporal information is represented in an abstract manner independent of other attributes of biological importance, or whether this temporal information is embedded within striatal activity related to co-occurring contextual information, such as motor behaviors. This study evaluated these two hypotheses by recording from striatal neurons while rats performed a temporal production task. Rats were trained to respond at different nosepoke apertures for food reward under two simultaneously active reinforcement schedules: a variable-interval (VI-15 sec schedule and a fixed-interval (FI-15 sec schedule of reinforcement. Responding during a trial occurred in a sequential manner composing 3 phases; VI responding, FI responding, VI responding. The vast majority of task-sensitive striatal neurons (95% varied their firing rates associated with equivalent behaviors (e.g., periods in which their snout was held within the nosepoke across these behavioral phases, and 96% of cells varied their firing rates for the same behavior within a phase, thereby demonstrating their sensitivity to time. However, in a direct test of the abstract timing hypothesis, 91% of temporally modulated hold cells were further modulated by the overt motor behaviors associated with transitioning between nosepokes. As such, these data are inconsistent with the striatum representing time in an abstract’ manner, but support the hypothesis that temporal information is embedded within contextual and motor functions of the

Clinical value of {sup 18}F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography ({sup 18}F-DOPA PET/CT) for detecting pheochromocytoma

Energy Technology Data Exchange (ETDEWEB)

Luster, Markus; Zeich, Katrin; Glatting, Gerhard; Buck, Andreas K.; Solbach, Christoph; Reske, Sven N. [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); Karges, Wolfram [RWTH Aachen, Division of Endocrinology and Diabetes, Aachen (Germany); Pauls, Sandra [University of Ulm, Department of Radiology, Ulm (Germany); Verburg, Frederik A. [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Dralle, Henning [University Halle-Wittenberg, Department of General, Visceral and Vascular Surgery, Halle (Germany); Neumaier, Bernd [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); Max-Planck-Institut fuer Neurologische Forschung, Section for Radiochemistry, Cologne (Germany); Mottaghy, Felix M. [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany)

2010-03-15

In detecting pheochromocytoma (PHEO), positron emission tomography (PET) with the radiolabelled amine precursor {sup 18}F-fluorodihydroxyphenylalanine ({sup 18}F-DOPA) offers excellent specificity, while computed tomography (CT) provides high sensitivity and ability to localize lesions; therefore, the combination of these modalities could be advantageous in this setting. The aim of this study was to investigate whether combined {sup 18}F-DOPA PET/CT more accurately detects and localizes PHEO lesions than does each modality alone. {sup 18}F-DOPA PET, CT and {sup 18}F-DOPA PET/CT images of 25 consecutive patients undergoing diagnostic scanning of suspected sporadic or multiple endocrine neoplasia type 2 syndrome-associated PHEO were reviewed retrospectively in randomized sequence. Two blinded observers scored the images regarding the likelihood of PHEO being present and localizable. Results were correlated with subsequent clinical history and, when available, histology. Of the 19 lesions detected by all three modalities, PET identified each as positive for PHEO, but was unable to definitively localize 15 of 19 (79%). CT could definitively localize all 19 lesions, but could not definitively diagnose or exclude PHEO in 18 of 19 (95%) lesions. Furthermore, CT falsely identified as negative for PHEO one lesion which was judged to be positive for this tumor by both PET and PET/CT. Only in PET/CT scans were all 19 lesions accurately characterized and localized. On a per-patient basis, the sensitivity of {sup 18}F-DOPA PET/CT for PHEO was 100% and the specificity 88%, with a 100% positive predictive value and an 88% negative predictive value. {sup 18}F-DOPA PET/CT more accurately diagnoses and localizes adrenal and extra-adrenal masses suspicious for PHEO than do {sup 18}F-DOPA PET or CT alone. (orig.)

Plateau potentials in alpha‐motoneurones induced by intravenous injection of L‐dopa and clonidine in the spinal cat

DEFF Research Database (Denmark)

Conway, B. A.; Hultborn, H.; Kiehn, O.

1988-01-01

1. Intracellular recordings were made from lumbar alpha‐motoneurones in unanaesthetized decerebrate acute spinal cats. The response of motoneurones to direct current pulse injection or synaptic excitation was investigated following intravenous injection of L‐beta‐3,4‐dihydroxyphenylalanine (L....... It is demonstrated that plateau potentials in the motoneurones contribute to the late long‐lasting reflexes observed in L‐DOPA‐treated spinal cats. 7. It is concluded that L‐DOPA (and clonidine) change the response properties of the motoneurones in an analogous way to 5‐hydroxy‐DL‐tryptophan (5‐HTP...

Levodopa inhibits the development of form-deprivation myopia in guinea pigs.

Science.gov (United States)

Mao, Junfeng; Liu, Shuangzhen; Qin, Wenjuan; Li, Fengyun; Wu, Xiaoying; Tan, Qian

2010-01-01

It has been shown that visual deprivation leads to a myopic refractive error and also reduces the retinal concentration of dopamine. Exogenously 3,4-dihydroxy-L-phenylalanine (levodopa, L-DOPA) can be converted into dopamine in vivo, which safely and effectively treats Parkinson disease. Moreover, L-DOPA was also used in the treatment of amblyopia in clinical studies. However, the effect of L-DOPA on the development of myopia has not been studied. The aim of this study was to investigate whether intraperitoneal injection of L-DOPA could inhibit form-deprivation myopia in guinea pigs and to explore a new strategy for drug treatment of myopia. Sixty guinea pigs, at age of 4 weeks, were randomly divided into six groups: normal control, L-DOPA group, saline group, deprived group, deprived plus L-DOPA group, and deprived plus saline group. Form deprivation was induced with translucent eye shields on the right eye and lasted for 10 days. L-DOPA was injected intraperitoneally into the guinea pig once a day. The corneal radius of curvature, refraction, and axial length were measured in all animals. Subsequently, retinal dopamine content was evaluated by high-performance liquid chromatography with electrochemical detection. Ten days of eye occlusion caused the form-deprived eyes to elongate and become myopic, and retinal dopamine content to decrease, but the corneal radius of curvature was not affected. Repeated intraperitoneal injection of L-DOPA could inhibit the myopic shift (from -3.62 +/- 0.98 D to -1.50 +/- 0.38 D; p < 0.001) due to goggles occluding and compensate retinal dopamine (from 0.65 +/- 0.10 ng to 1.33 +/- 0.23 ng; p < 0.001). Administration of L-DOPA to the unoccluded animals had no effect on its ocular refraction. There was no effect of intraperitoneal saline on the ocular refractive state and retinal dopamine. Systemic L-DOPA was partly effective in this guinea pig model and, therefore, is worth testing for effectiveness in progressing human myopes.

No association between striatal dopamine transporter binding and body mass index

DEFF Research Database (Denmark)

van de Giessen, Elsmarieke; Hesse, Swen; Caan, Matthan W A

2013-01-01

Dopamine is one among several neurotransmitters that regulate food intake and overeating. Thus, it has been linked to the pathophysiology of obesity and high body mass index (BMI). Striatal dopamine D(2) receptor availability is lower in obesity and there are indications that striatal dopamine...... transporter (DAT) availability is also decreased. In this study, we tested whether BMI and striatal DAT availability are associated....

Alterations in Striatal Circuits Underlying Addiction-Like Behaviors.

Science.gov (United States)

Kim, Hyun Jin; Lee, Joo Han; Yun, Kyunghwa; Kim, Joung-Hun

2017-06-30

Drug addiction is a severe psychiatric disorder characterized by the compulsive pursuit of drugs of abuse despite potential adverse consequences. Although several decades of studies have revealed that psychostimulant use can result in extensive alterations of neural circuits and physiology, no effective therapeutic strategies or medicines for drug addiction currently exist. Changes in neuronal connectivity and regulation occurring after repeated drug exposure contribute to addiction-like behaviors in animal models. Among the involved brain areas, including those of the reward system, the striatum is the major area of convergence for glutamate, GABA, and dopamine transmission, and this brain region potentially determines stereotyped behaviors. Although the physiological consequences of striatal neurons after drug exposure have been relatively well documented, it remains to be clarified how changes in striatal connectivity underlie and modulate the expression of addiction-like behaviors. Understanding how striatal circuits contribute to addiction-like behaviors may lead to the development of strategies that successfully attenuate drug-induced behavioral changes. In this review, we summarize the results of recent studies that have examined striatal circuitry and pathway-specific alterations leading to addiction-like behaviors to provide an updated framework for future investigations.

DOPA, a Digital Observatory for Protected Areas including Monitoring and Forecasting Services

Science.gov (United States)

Dubois, Gregoire; Hartley, Andrew; Peedell, Stephen; de Jesus, Jorge; Ó Tuama, Éamonn; Cottam, Andrew; May, Ian; Fisher, Ian; Nativi, Stefano; Bertrand, Francis

2010-05-01

The Digital Observatory for Protected Areas (DOPA) is a biodiversity information system currently developed as an interoperable web service at the Joint Research Centre of the European Commission in collaboration with other international organizations, including GBIF, UNEP-WCMC, Birdlife International and RSPB. DOPA is designed to assess the state and pressure of Protected Areas (PAs) and to prioritize them accordingly, in order to support decision making and fund allocation processes. To become an operational web service allowing the automatic monitoring of protected areas, DOPA needs to be able to capture the dynamics of spatio-temporal changes in habitats and anthropogenic pressure on PAs as well as the changes in the species distributions. Because some of the most valuable natural ecosystems and species on the planet cover large areas making field monitoring methods very difficult for a large scale assessment, the automatic collection and processing of remote sensing data are processes at the heart of the problem. To further be able to forecast changes due to climate change, DOPA has to rely on an architecture that enables it to communicate with the appropriate modeling web services. The purpose of this presentation is to present the architecture of the DOPA with special attention to e-Habitat, its web processing service designed for assessing the irreplaceability of habitats as well as for the modeling of habitats under different climate change scenarios. The use of open standards for spatial data and of open source programming languages for the development of the core functionalities of the system are expected to encourage the participation of the scientific community beyond the current partnerships and to favour the sharing of such an observatory which could be installed at any other location. Acknowledgement: Part of this work is funded under the 7th Framework Programme by the EuroGEOSS (www.eurogeoss.eu) project of the European Commission. The views

Effects of the modern food environment on striatal function, cognition and regulation of ingestive behavior.

Science.gov (United States)

Burke, Mary V; Small, Dana M

2016-06-01

Emerging evidence from human and animal studies suggest that consumption of palatable foods rich in fat and/or carbohydrates may produce deleterious influences on brain function independently of body weight or metabolic disease. Here we consider two mechanisms by which diet can impact striatal circuits to amplify food cue reactivity and impair inhibitory control. First, we review findings demonstrating that the energetic properties of foods regulate nucleus accumbens food cue reactivity, a demonstrated predictor of weight gain susceptibility, which is then sensitized by chronic consumption of an energy dense diet. Second, we consider evidence for diet-induced adaptations in dorsal striatal dopamine signaling that is associated with impaired inhibitory control and negative outcome learning.

Aspergillus niger PA2 Tyrosinase Covalently Immobilized on a Novel Eco-Friendly Bio-Composite of Chitosan-Gelatin and Its Evaluation for L-DOPA Production

Science.gov (United States)

Agarwal, Pragati; Dubey, Swati; Singh, Mukta; Singh, Rajesh P.

2016-01-01

Tyrosinase (EC 1.14.18.1) a copper-containing monooxygenase, isolated from a fungal isolate Aspergillus niger PA2 was subjected for immobilization onto a composite consisting of chitosan and gelatin biopolymers. The homogeneity of the chitosan-gelatin biocomposite film was characterized by X-ray diffraction analyses. To evaluate immobilization efficiency, chitosan-gelatin-Tyr bio-composite films were analyzed by field emission scanning electron microscopy, atomic force microscopy and UV-spectroscopy. The rough morphology of the film led to a high loading of enzyme and it could retain its bioactivity for a longer period. The enzyme adsorbed onto the film exhibited 72% of its activity after 10 days and exhibited good repeatability for up to nine times, after intermittent storage. Moreover, the immobilized enzyme exhibited broader pH and temperature profile as compared to free counterpart. Immobilized enzyme was further evaluated for the synthesis of L-DOPA (2,4-dihydroxy phenylalanine) which is a precursor of dopamine and a potent drug for the treatment of Parkinson's disease and for myocardium neurogenic injury. PMID:28066399

Adversity in childhood linked to elevated striatal dopamine function in adulthood

OpenAIRE

Egerton, A.; Valmaggia, L. R.; Howes, O. D.; Day, F.; Chaddock, C. A.; Allen, P.; Winton-Brown, T. T.; Bloomfield, M. A. P.; Bhattacharyya, S.; Chilcott, J.; Lappin, J. M.; Murray, R. M.; McGuire, P.

2016-01-01

Childhood adversity increases the risk of psychosis in adulthood. Theoretical and animal models suggest that this effect may be mediated by increased striatal dopamine neurotransmission. The primary objective of this study was to examine the relationship between adversity in childhood and striatal dopamine function in early adulthood. Secondary objectives were to compare exposure to childhood adversity and striatal dopamine function in young people at ultra high risk (UHR) of psychosis and he...

Molecular and functional definition of the developing human striatum.

Science.gov (United States)

Onorati, Marco; Castiglioni, Valentina; Biasci, Daniele; Cesana, Elisabetta; Menon, Ramesh; Vuono, Romina; Talpo, Francesca; Laguna Goya, Rocio; Lyons, Paul A; Bulfamante, Gaetano P; Muzio, Luca; Martino, Gianvito; Toselli, Mauro; Farina, Cinthia; Barker, Roger A; Biella, Gerardo; Cattaneo, Elena

2014-12-01

The complexity of the human brain derives from the intricate interplay of molecular instructions during development. Here we systematically investigated gene expression changes in the prenatal human striatum and cerebral cortex during development from post-conception weeks 2 to 20. We identified tissue-specific gene coexpression networks, differentially expressed genes and a minimal set of bimodal genes, including those encoding transcription factors, that distinguished striatal from neocortical identities. Unexpected differences from mouse striatal development were discovered. We monitored 36 determinants at the protein level, revealing regional domains of expression and their refinement, during striatal development. We electrophysiologically profiled human striatal neurons differentiated in vitro and determined their refined molecular and functional properties. These results provide a resource and opportunity to gain global understanding of how transcriptional and functional processes converge to specify human striatal and neocortical neurons during development.

Oxidative metabolism and Ca2+ handling in isolated brain mitochondria and striatal neurons from R6/2 mice, a model of Huntington's disease.

Science.gov (United States)

Hamilton, James; Pellman, Jessica J; Brustovetsky, Tatiana; Harris, Robert A; Brustovetsky, Nickolay

2016-07-01

Alterations in oxidative metabolism and defects in mitochondrial Ca 2+ handling have been implicated in the pathology of Huntington's disease (HD), but existing data are contradictory. We investigated the effect of human mHtt fragments on oxidative metabolism and Ca 2+ handling in isolated brain mitochondria and cultured striatal neurons from the R6/2 mouse model of HD. Non-synaptic and synaptic mitochondria isolated from the brains of R6/2 mice had similar respiratory rates and Ca 2+ uptake capacity compared with mitochondria from wild-type (WT) mice. Respiratory activity of cultured striatal neurons measured with Seahorse XF24 flux analyzer revealed unaltered cellular respiration in neurons derived from R6/2 mice compared with neurons from WT animals. Consistent with the lack of respiratory dysfunction, ATP content of cultured striatal neurons from R6/2 and WT mice was similar. Mitochondrial Ca 2+ accumulation was also evaluated in cultured striatal neurons from R6/2 and WT animals. Our data obtained with striatal neurons derived from R6/2 and WT mice show that both glutamate-induced increases in cytosolic Ca 2+ and subsequent carbonilcyanide p-triflouromethoxyphenylhydrazone-induced increases in cytosolic Ca 2+ were similar between WT and R6/2, suggesting that mitochondria in neurons derived from both types of animals accumulated comparable amounts of Ca 2+ Overall, our data argue against respiratory deficiency and impaired Ca 2+ handling induced by human mHtt fragments in both isolated brain mitochondria and cultured striatal neurons from transgenic R6/2 mice. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Ventral striatal activity correlates with memory confidence for old- and new-responses in a difficult recognition test.

Directory of Open Access Journals (Sweden)

Ulrike Schwarze

Full Text Available Activity in the ventral striatum has frequently been associated with retrieval success, i.e., it is higher for hits than correct rejections. Based on the prominent role of the ventral striatum in the reward circuit, its activity has been interpreted to reflect the higher subjective value of hits compared to correct rejections in standard recognition tests. This hypothesis was supported by a recent study showing that ventral striatal activity is higher for correct rejections than hits when the value of rejections is increased by external incentives. These findings imply that the striatal response during recognition is context-sensitive and modulated by the adaptive significance of "oldness" or "newness" to the current goals. The present study is based on the idea that not only external incentives, but also other deviations from standard recognition tests which affect the subjective value of specific response types should modulate striatal activity. Therefore, we explored ventral striatal activity in an unusually difficult recognition test that was characterized by low levels of confidence and accuracy. Based on the human uncertainty aversion, in such a recognition context, the subjective value of all high confident decisions is expected to be higher than usual, i.e., also rejecting items with high certainty is deemed rewarding. In an accompanying behavioural experiment, participants rated the pleasantness of each recognition response. As hypothesized, ventral striatal activity correlated in the current unusually difficult recognition test not only with retrieval success, but also with confidence. Moreover, participants indicated that they were more satisfied by higher confidence in addition to perceived oldness of an item. Taken together, the results are in line with the hypothesis that ventral striatal activity during recognition codes the subjective value of different response types that is modulated by the context of the recognition test.

Striatal dopamine release and genetic variation of the serotonin 2C receptor in humans.

Science.gov (United States)

Mickey, Brian J; Sanford, Benjamin J; Love, Tiffany M; Shen, Pei-Hong; Hodgkinson, Colin A; Stohler, Christian S; Goldman, David; Zubieta, Jon-Kar

2012-07-04

Mesoaccumbal and nigrostriatal projections are sensitive to stress, and heightened stress sensitivity is thought to confer risk for neuropsychiatric disorders. Serotonin 2C (5-HT(2C)) receptors mediate the inhibitory effects of serotonin on dopaminergic circuitry in experimental animals, and preclinical findings have implicated 5-HT(2C) receptors in motivated behaviors and psychotropic drug mechanisms. In humans, a common missense single-nucleotide change (rs6318, Cys23Ser) in the 5-HT(2C) receptor gene (HTR2C) has been associated with altered activity in vitro and with clinical mood disorders. We hypothesized that dopaminergic circuitry would be more sensitive to stress in humans carrying the Ser23 variant. To test this hypothesis, we studied 54 healthy humans using positron emission tomography and the displaceable D(2)/D(3) receptor radiotracer [(11)C]raclopride. Binding potential (BP(ND)) was quantified before and after a standardized stress challenge consisting of 20 min of moderate deep muscular pain, and reduction in BP(ND) served as an index of dopamine release. The Cys23Ser variant was genotyped on a custom array, and ancestry informative markers were used to control for population stratification. We found greater dopamine release in the nucleus accumbens, caudate nucleus, and putamen among Ser23 carriers, after controlling for sex, age, and ancestry. Genotype accounted for 12% of the variance in dopamine release in the nucleus accumbens. There was no association of Cys23Ser with baseline BP(ND). These findings indicate that a putatively functional HTR2C variant (Ser23) is associated with greater striatal dopamine release during pain in healthy humans. Mesoaccumbal stress sensitivity may mediate the effects of HTR2C variation on risk of neuropsychiatric disorders.

Inhibition of the striatal specific phosphodiesterase PDE10A ameliorates striatal and cortical pathology in R6/2 mouse model of Huntington's disease.

Directory of Open Access Journals (Sweden)

Carmela Giampà

2010-10-01

Full Text Available Huntington's disease is a devastating neurodegenerative condition for which there is no therapy to slow disease progression. The particular vulnerability of striatal medium spiny neurons to Huntington's pathology is hypothesized to result from transcriptional dysregulation within the cAMP and CREB signaling cascades in these neurons. To test this hypothesis, and a potential therapeutic approach, we investigated whether inhibition of the striatal-specific cyclic nucleotide phosphodiesterase PDE10A would alleviate neurological deficits and brain pathology in a highly utilized model system, the R6/2 mouse.R6/2 mice were treated with the highly selective PDE10A inhibitor TP-10 from 4 weeks of age until euthanasia. TP-10 treatment significantly reduced and delayed the development of the hind paw clasping response during tail suspension, deficits in rotarod performance, and decrease in locomotor activity in an open field. Treatment prolonged time to loss of righting reflex. These effects of PDE10A inhibition on neurological function were reflected in a significant amelioration in brain pathology, including reduction in striatal and cortical cell loss, the formation of striatal neuronal intranuclear inclusions, and the degree of microglial activation that occurs in response to the mutant huntingtin-induced brain damage. Striatal and cortical levels of phosphorylated CREB and BDNF were significantly elevated.Our findings provide experimental support for targeting the cAMP and CREB signaling pathways and more broadly transcriptional dysregulation as a therapeutic approach to Huntington's disease. It is noteworthy that PDE10A inhibition in the R6/2 mice reduces striatal pathology, consistent with the localization of the enzyme in medium spiny neurons, and also cortical pathology and the formation of neuronal nuclear inclusions. These latter findings suggest that striatal pathology may be a primary driver of these secondary pathological events. More

DMEM enhances tyrosinase activity in B16 mouse melanoma cells and human melanocytes

Directory of Open Access Journals (Sweden)

Panpen Diawpanich

2008-07-01

Full Text Available Media components may affect the activities of cultured cells. In this study, tyrosinase activity was evaluated by using B16-F10 mouse melanoma cell lines (B16-F10 and primary human melanocytes cultured in different media. An optical density measurement and a L-dopa reaction assay were used as the determination of the tyrosinase activity. The study of B16-F10 found the optical density to be 2010, 2246 and 2961 in cells cultured in RPMI Medium 1640 (RPMI1640,Minimum Essential Medium (MEM and Dulbecco’s Modified Eagle Medium (DMEM, respectively. Moreover, compared to RPMI 1640 and MEM, DMEM showed the darkest color of melanin formation in culture media and in cells after the L-dopa reaction assay. Addition of kojic acid showed a significant inhibitory effect on tyrosinase activity in all media.Whereas MCDB153 showed no significant effect on human melanocytes, DMEM caused a dramatic increase in tyrosinase activity after 4 days of cultivation. Addition of kojic acid showed a significant tyrosinase inhibitory effect in DMEM only. Furthermore, an active ingredient in green tea, epigallocathechin gallate (EGCG could inhibit tyrosinase activity in both B16-F10 and human melanocytes cultured in DMEM. In summary, these results suggest that DMEM is a suitable medium that provides high detection sensitivity in a tyrosinase inhibition assay.

m-DOPA addition in MAPLE immobilization of lipase for biosensor applications

Directory of Open Access Journals (Sweden)

Valeria Califano

2015-12-01

Full Text Available Matrix Assisted Pulsed Laser Evaporation (MAPLE is a thin film deposition technique which uses a pulsed laser beam impinging, inside a high vacuum chamber, on a frozen target containing the guest molecules in a volatile matrix to induce fast “evaporation” of the matrix, and ejection of the guest molecules. Lipase, an enzyme acting as a catalyst in hydrolysis of lipids, is widely used in biosensors for detection of triglycerides in blood serum. A key action to this purpose is lipase immobilization on a substrate. In a recent paper, we have shown that MAPLE technique is able to deposit lipase on a substrate in an active form. Here we show that addition to the guest/matrix target of a small amount of m-DOPA (3-(3,4-dihydroxyphenyl-2-methyl-l-alanine in order to improve adhesion and protect lipase secondary structure, also allows the lowering the laser pulse energy required for matrix evaporation and therefore the risk of damaging the enzyme.

Production of dopamine by aromatic L-amino acid decarboxylase cells after spinal cord injury

DEFF Research Database (Denmark)

Ren, Liqun; Wienecke, Jacob; Hultborn, Hans

2016-01-01

adopted as we used previously (Wienecke et al., J. Neurosci. 34, 11984, 2014). In the chronic SCI rats (> 45d), no AADC cells expressed DA if there was no exogenous L-dopa application. However, following administration of a peripheral AADC inhibitor (carbidopa) with or without a monoamine oxidase...... inhibitor (pargyline) co-application, systemic administration of L-dopa resulted in ~ 94% of AADC cells to become DA-immunopositive in the spinal cord below the lesion, whereas in normal or sham-operated rats none or very few of AADC cells became DA-immunopositive with the same treatment. Using tail...

NADPH oxidase-derived H2O2 subverts pathogen signaling by oxidative phosphotyrosine conversion to PB-DOPA

Science.gov (United States)

Alvarez, Luis A.; Kovačič, Lidija; Rodríguez, Javier; Gosemann, Jan-Hendrik; Kubica, Malgorzata; Pircalabioru, Gratiela G.; Friedmacher, Florian; Cean, Ada; Ghişe, Alina; Sărăndan, Mihai B.; Puri, Prem; Daff, Simon; Plettner, Erika; von Kriegsheim, Alex; Bourke, Billy; Knaus, Ulla G.

2016-01-01

Strengthening the host immune system to fully exploit its potential as antimicrobial defense is vital in countering antibiotic resistance. Chemical compounds released during bidirectional host–pathogen cross-talk, which follows a sensing-response paradigm, can serve as protective mediators. A potent, diffusible messenger is hydrogen peroxide (H2O2), but its consequences on extracellular pathogens are unknown. Here we show that H2O2, released by the host on pathogen contact, subverts the tyrosine signaling network of a number of bacteria accustomed to low-oxygen environments. This defense mechanism uses heme-containing bacterial enzymes with peroxidase-like activity to facilitate phosphotyrosine (p-Tyr) oxidation. An intrabacterial reaction converts p-Tyr to protein-bound dopa (PB-DOPA) via a tyrosinyl radical intermediate, thereby altering antioxidant defense and inactivating enzymes involved in polysaccharide biosynthesis and metabolism. Disruption of bacterial signaling by DOPA modification reveals an infection containment strategy that weakens bacterial fitness and could be a blueprint for antivirulence approaches. PMID:27562167

NADPH oxidase-derived H2O2 subverts pathogen signaling by oxidative phosphotyrosine conversion to PB-DOPA.

Science.gov (United States)

Alvarez, Luis A; Kovačič, Lidija; Rodríguez, Javier; Gosemann, Jan-Hendrik; Kubica, Malgorzata; Pircalabioru, Gratiela G; Friedmacher, Florian; Cean, Ada; Ghişe, Alina; Sărăndan, Mihai B; Puri, Prem; Daff, Simon; Plettner, Erika; von Kriegsheim, Alex; Bourke, Billy; Knaus, Ulla G

2016-09-13

Strengthening the host immune system to fully exploit its potential as antimicrobial defense is vital in countering antibiotic resistance. Chemical compounds released during bidirectional host-pathogen cross-talk, which follows a sensing-response paradigm, can serve as protective mediators. A potent, diffusible messenger is hydrogen peroxide (H2O2), but its consequences on extracellular pathogens are unknown. Here we show that H2O2, released by the host on pathogen contact, subverts the tyrosine signaling network of a number of bacteria accustomed to low-oxygen environments. This defense mechanism uses heme-containing bacterial enzymes with peroxidase-like activity to facilitate phosphotyrosine (p-Tyr) oxidation. An intrabacterial reaction converts p-Tyr to protein-bound dopa (PB-DOPA) via a tyrosinyl radical intermediate, thereby altering antioxidant defense and inactivating enzymes involved in polysaccharide biosynthesis and metabolism. Disruption of bacterial signaling by DOPA modification reveals an infection containment strategy that weakens bacterial fitness and could be a blueprint for antivirulence approaches.

Deep brain stimulation of the center median-parafascicular complex of the thalamus has efficient anti-parkinsonian action associated with widespread cellular responses in the basal ganglia network in a rat model of Parkinson's disease.

Science.gov (United States)

Jouve, Loréline; Salin, Pascal; Melon, Christophe; Kerkerian-Le Goff, Lydia

2010-07-21

The thalamic centromedian-parafascicular (CM/Pf) complex, mainly represented by Pf in rodents, is proposed as an interesting target for the neurosurgical treatment of movement disorders, including Parkinson's disease. In this study, we examined the functional impact of subchronic high-frequency stimulation (HFS) of Pf in the 6-hydroxydopamine-lesioned hemiparkinsonian rat model. Pf-HFS had significant anti-akinetic action, evidenced by alleviation of limb use asymmetry (cylinder test). Whereas this anti-akinetic action was moderate, Pf-HFS totally reversed lateralized neglect (corridor task), suggesting potent action on sensorimotor integration. At the cellular level, Pf-HFS partially reversed the dopamine denervation-induced increase in striatal preproenkephalin A mRNA levels, a marker of the neurons of the indirect pathway, without interfering with the markers of the direct pathway (preprotachykinin and preprodynorphin). Pf-HFS totally reversed the lesion-induced changes in the gene expression of cytochrome oxidase subunit I in the subthalamic nucleus, the globus pallidus, and the substantia nigra pars reticulata, and partially in the entopeduncular nucleus. Unlike HFS of the subthalamic nucleus, Pf-HFS did not induce per se dyskinesias and directly, although partially, alleviated L-3,4-dihydroxyphenylalanine (L-DOPA)-induced forelimb dyskinesia. Conversely, L-DOPA treatment negatively interfered with the anti-parkinsonian effect of Pf-HFS. Altogether, these data show that Pf-DBS, by recruiting a large basal ganglia circuitry, provides moderate to strong anti-parkinsonian benefits that might, however, be affected by L-DOPA. The widespread behavioral and cellular outcomes of Pf-HFS evidenced here demonstrate that CM/Pf is an important node for modulating the pathophysiological functioning of basal ganglia and related disorders.

Striatal volume predicts level of video game skill acquisition.

Science.gov (United States)

Erickson, Kirk I; Boot, Walter R; Basak, Chandramallika; Neider, Mark B; Prakash, Ruchika S; Voss, Michelle W; Graybiel, Ann M; Simons, Daniel J; Fabiani, Monica; Gratton, Gabriele; Kramer, Arthur F

2010-11-01

Video game skills transfer to other tasks, but individual differences in performance and in learning and transfer rates make it difficult to identify the source of transfer benefits. We asked whether variability in initial acquisition and of improvement in performance on a demanding video game, the Space Fortress game, could be predicted by variations in the pretraining volume of either of 2 key brain regions implicated in learning and memory: the striatum, implicated in procedural learning and cognitive flexibility, and the hippocampus, implicated in declarative memory. We found that hippocampal volumes did not predict learning improvement but that striatal volumes did. Moreover, for the striatum, the volumes of the dorsal striatum predicted improvement in performance but the volumes of the ventral striatum did not. Both ventral and dorsal striatal volumes predicted early acquisition rates. Furthermore, this early-stage correlation between striatal volumes and learning held regardless of the cognitive flexibility demands of the game versions, whereas the predictive power of the dorsal striatal volumes held selectively for performance improvements in a game version emphasizing cognitive flexibility. These findings suggest a neuroanatomical basis for the superiority of training strategies that promote cognitive flexibility and transfer to untrained tasks.

Real-time parallel processing of grammatical structure in the fronto-striatal system: a recurrent network simulation study using reservoir computing.

Science.gov (United States)

Hinaut, Xavier; Dominey, Peter Ford

2013-01-01

Sentence processing takes place in real-time. Previous words in the sentence can influence the processing of the current word in the timescale of hundreds of milliseconds. Recent neurophysiological studies in humans suggest that the fronto-striatal system (frontal cortex, and striatum--the major input locus of the basal ganglia) plays a crucial role in this process. The current research provides a possible explanation of how certain aspects of this real-time processing can occur, based on the dynamics of recurrent cortical networks, and plasticity in the cortico-striatal system. We simulate prefrontal area BA47 as a recurrent network that receives on-line input about word categories during sentence processing, with plastic connections between cortex and striatum. We exploit the homology between the cortico-striatal system and reservoir computing, where recurrent frontal cortical networks are the reservoir, and plastic cortico-striatal synapses are the readout. The system is trained on sentence-meaning pairs, where meaning is coded as activation in the striatum corresponding to the roles that different nouns and verbs play in the sentences. The model learns an extended set of grammatical constructions, and demonstrates the ability to generalize to novel constructions. It demonstrates how early in the sentence, a parallel set of predictions are made concerning the meaning, which are then confirmed or updated as the processing of the input sentence proceeds. It demonstrates how on-line responses to words are influenced by previous words in the sentence, and by previous sentences in the discourse, providing new insight into the neurophysiology of the P600 ERP scalp response to grammatical complexity. This demonstrates that a recurrent neural network can decode grammatical structure from sentences in real-time in order to generate a predictive representation of the meaning of the sentences. This can provide insight into the underlying mechanisms of human cortico-striatal

Comparison of 18F-fluoro-L-DOPA, 18F-fluoro-deoxyglucose, and 18F-fluorodopamine PET and 123I-MIBG scintigraphy in the localization of pheochromocytoma and paraganglioma.

NARCIS (Netherlands)

Timmers, H.J.L.M.; Chen, C.C.; Carrasquillo, J.A.; Whatley, M.; Ling, A.; Havekes, B.; Eisenhofer, G.; Martiniova, L.; Adams, K.T.; Pacak, K.

2009-01-01

CONTEXT: Besides (123)I-metaiodobenzylguanidine (MIBG), positron emission tomography (PET) agents are available for the localization of paraganglioma (PGL), including (18)F-3,4-dihydroxyphenylalanine (DOPA), (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG), and (18)F-fluorodopamine ((18)F-FDA). OBJECTIVE:

Utilization of fluoro dopa in nuclear medicine method for determination of radiochemical purity: study of irradiation during the manipulation; Utilisation de la FDOPA dans un service de medecine nucleaire: mise au point d'une methode de controle de purete radiochimique, etude de poste sur l'irradiation de l'operateur lors de la manipulation

Energy Technology Data Exchange (ETDEWEB)

Bizien, V

2007-10-15

As a first step is a bibliographic reminder done on the use of two main fluorine molecules, FDG and F DOPA. The objective of the work then acted to develop a chromatographic method for determining the radiochemical purity of F DOPA response to the alteration of its stability after neutralization. Finally, the optimization of a technique of TLC will determine a period of stability in order to offset the risks that may delay examinations (breakdowns of cameras). The preparation of product requires handling, a study of post will then determine radiation doses on ends of members and on the whole-body when preparing the F DOPA. (N.C.)

Optogenetic approaches to evaluate striatal function in animal models of Parkinson disease.

Science.gov (United States)

Parker, Krystal L; Kim, Youngcho; Alberico, Stephanie L; Emmons, Eric B; Narayanan, Nandakumar S

2016-03-01

Optogenetics refers to the ability to control cells that have been genetically modified to express light-sensitive ion channels. The introduction of optogenetic approaches has facilitated the dissection of neural circuits. Optogenetics allows for the precise stimulation and inhibition of specific sets of neurons and their projections with fine temporal specificity. These techniques are ideally suited to investigating neural circuitry underlying motor and cognitive dysfunction in animal models of human disease. Here, we focus on how optogenetics has been used over the last decade to probe striatal circuits that are involved in Parkinson disease, a neurodegenerative condition involving motor and cognitive abnormalities resulting from degeneration of midbrain dopaminergic neurons. The precise mechanisms underlying the striatal contribution to both cognitive and motor dysfunction in Parkinson disease are unknown. Although optogenetic approaches are somewhat removed from clinical use, insight from these studies can help identify novel therapeutic targets and may inspire new treatments for Parkinson disease. Elucidating how neuronal and behavioral functions are influenced and potentially rescued by optogenetic manipulation in animal models could prove to be translatable to humans. These insights can be used to guide future brain-stimulation approaches for motor and cognitive abnormalities in Parkinson disease and other neuropsychiatric diseases.

Temporal changes of striatal dopamine release during and after a video game with a monetary reward: a PET study with [11C]raclopride continuous infusion

International Nuclear Information System (INIS)

Kim, S. E.; Cho, S. S.; Choe, Y. S.; Lee, S. Y.; Kang, E.; Kim, B. T.

2002-01-01

In an attempt to understand the neurochemical changes associated with rewarded motor learning in human brain, we investigated the temporal changes of striatal dopamine (DA) release during and after a goal-directed psychomotor task (a video game) with a monetary incentive using [ 11 C]raclopride PET. Seven healthy, right-handed, nonsmokers were studied with PET for 120 min (50 min resting followed by 40 min video game and another 30 min resting) while receiving a bolus plus constant infusion of the DA D2 receptor radioligand [ 11 C]raclopride. During the video game (from 50 to 90 min postinjection), subjects played Tetris, which involved learning of joystick movement to fit falling jigsaw blocks, and periodically rewarded with unpredictable amount monetary incentives for improved performance. Striatal V3', calculated as striatal-cerebellar/cerebellar activity ratio, was measured under equilibrium condition, at baseline and during and after the video game. Striatal V3' was significantly reduced during the video game compared with baseline levels, indicating increased DA release in this region (caudate, -15±6%; putamen, -30±10%). During the 30 min after the game ended, striatal [ 11 C]raclopride binding was gradually increased and the V3' approached baseline levels. There was a significant correlation between the reduction in striatal V3' and the task performance during the video game. These results demonstrate DA release in the human striatum during a psychomotor task with a monetary reward and to our knowledge for the first time a gradual DA restoration to baseline levels following the offset of stimulation. They also illustrate that acute fluctuations of synaptic DA can be measured in vivo using [ 11 C]raclopride PET

Parametric imaging of the rate constant K[sub i] using 18Fluoro-L-dopa positron emission tomography in progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Cordes, M. (Neurodegenerative Disorders Centre, Univ. Hospital, Univ. of British Columbia, Vancouver, BC (Canada) Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf-Virchow, Berlin (Germany)); Snow, B.J. (Neurodegenerative Disorders Centre, Univ. Hospital, Univ. of British Columbia, Vancouver, BC (Canada)); Morrison, S. (TRIUMF, Univ. of British Columbia, Vancouver, BC (Canada)); Sossi, V. (TRIUMF, Univ. of British Columbia, Vancouver, BC (Canada)); Ruth, T.J. (TRIUMF, Univ. of British Columbia, Vancouver, BC (Canada)); Calne, D.B. (Neurodegenerative Disorders Centre, Univ. Hospital, Univ. of British Columbia, Vancouver, BC (Canada))

1993-01-01

Positron emission tomography (PET) studies using 18F-L-dopa were carried out in 9 patients with supranuclear palsy and 13 controls. For quantification of PET data a rate constant K[sub i] was calculated for the radiotracer using a graphical method. Corrections for nonspecific activity were performed in both arterial plasma and brain tissue. The purpose of this study was to test the hypothesis that parametric images of the rate constant K mapping can be obtained on a pixel-by-pixel basis using an appropriate mathematical algorithm. K[sub i] values from these parametric images and the graphical approach were compared. Both correlated closely, with y=0.013+0.947[sup *]x, r=0.992 and y=-0.052+1.048[sup *]x, r=0.965 in patients and controls, respectively. Contrast measurements were also performed and showed a striking increase in contrast on parametric images. K mapping offers several advantages over the graphical approach, since parametric images are time-independent, i.e. one image represents the quantitative result of the study. In addition, parmetric images of the rate constant are normalized to arterial plasma radioactivity and corrected for tissue metabolites. Thus, parametric images of K[sub i] in different individuals can be compared directly without further processing in order to assess the nigrostriatal integrity. (orig.)

MK-801 protection against methamphetamine-induced striatal dopamine terminal injury is associated with attenuated dopamine overflow.

Science.gov (United States)

Weihmuller, F B; O'Dell, S J; Marshall, J F

1992-06-01

Repeated administrations of methamphetamine (m-AMPH) produce high extracellular levels of dopamine (DA) and subsequent striatal DA terminal damage. Pharmacological blockade of N-methyl-D-aspartate (NMDA) receptors has been shown previously to prevent m-AMPH-induced striatal DA terminal injury, but the mechanism for this protection is unclear. In the present study, in vivo microdialysis was used to determine the effects of blockade of NMDA receptors with the noncompetitive antagonist MK-801 on m-AMPH-induced striatal DA overflow. Four injections of MK-801 (0.5 mg/kg, ip) alone did not significantly change extracellular striatal DA concentrations from pretreatment values. Four treatments with m-AMPH (4.0 mg/kg, sc at 2-hr intervals) increased striatal DA overflow, and the overflow was particularly extensive following the fourth injection. This m-AMPH regimen produced a 40% reduction in striatal DA tissue content 1 week later. Treatment with MK-801 15 min before each of the four m-AMPH injections or prior to only the last two m-AMPH administrations attenuated the m-AMPH-induced increase in striatal DA overflow and protected completely against striatal DA depletions. Other MK-801 treatment regimens less effectively reduced the m-AMPH-induced striatal DA efflux and were ineffective in protecting against striatal DA depletions. Linear regression analysis indicated that cumulative DA overflow was strongly predictive (r = -.68) of striatal DA tissue levels measured one week later. These findings suggest that the extensive DA overflow seen during a neurotoxic regimen of m-AMPH is a crucial component of the subsequent neurotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Nanomolar simultaneous determination of levodopa and serotonin at a novel carbon ionic liquid electrode modified with Co(OH)2 nanoparticles and multi-walled carbon nanotubes

International Nuclear Information System (INIS)

Babaei, Ali; Taheri, Ali Reza; Aminikhah, Majid

2013-01-01

Highlights: ► A novel modified carbon ionic liquid electrode is fabricated as Nafion/Co(OH) 2 –MWCNTs/CILE. ► The modified electrode was used as the new sensor for nanomolar simultaneous determinations of L-dopa and serotonin. ► The electrode was impermeable to uric acid and ascorbic acid and other anionic species as electroactive coexistent compounds. ► Several techniques as cyclic voltammetry, differential pulse voltammetry and chronoamperometry were used for investigations. ► The proposed sensor showed a wide linear range, low detection limit, high stability and good reproducibility. -- Abstract: A novel modified carbon ionic liquid electrode is prepared as an electrochemical sensor for simultaneous determination of levodopa (L-dopa) and serotonin (5-HT). The experimental results suggest that a carbon ionic liquid electrode modified with multi-walled carbon nanotubes and cobalt hydroxide nanoparticles, and coated with Nafion (Nafion/Co(OH) 2 –MWCNTs/CILE), accelerates the electron transfer reactions of L-dopa and 5-HT. In addition it shows no significant interferences of uric acid and ascorbic acid as electroactive coexistent compounds with L-dopa and 5-HT in biological systems. The fabricated sensor revealed some advantages such as convenient preparation, good stability and high sensitivity toward 5-HT and L-dopa determination. The DPV data showed that the obtained anodic peak currents were linearly dependent on the L-dopa and 5-HT concentrations in the range of 0.25–225 and 0.05–75 μmol L −1 , respectively. The applicability of the modified electrode was demonstrated by simultaneous determination of 5-HT and L-dopa in human serum

FRAKSI ETANOL 96% BIJI KORO BENGUK (Mucuna pruriens L. SEBAGAI PENINGKAT KUALITAS SPERMATOZOA MENCIT (Mus musculus

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Sri Winarni

2012-11-01

Full Text Available Background: The examination of sperm quality is the main priority for infertility diagnosis. Based on previous study with mice, active ingredient of Mucuna pruriens L. or koro benguk (Papilionaceae, the L-dopa, may affect the quality of spermatozoa.Objective: Research was to study the effect of 96% ethanol fraction Mucuna pruriens seed on spermatozoaquality of mice exposed to 2-Methoxy ethanol. L-dopa in 96% ethanol fraction of M. pruriens seed was 14.7%.Methode: This was an experimental study using complete randomized design. Subjects were BALB/C mice (Mus musculus. Five groups served as control, 3 groups received subcutaneos injection of 2-ME as muchas 100 mg/kg.bw/day for 12 days, followed with 96% ethanol fraction Mucuna pruriens seed starting from14 mg/kg.bw/day, 28 mg/kg.bw/day, and 56 mg/kg.bw/day for 51 days.Result: The 96% ethanol fraction of Mucuna pruriens seeds are significant increase motility (p<0,01 andthe percentage of normal spermatozoa morphology (p= 0,042.Conclusion: 96% ethanol fraction of Mucuna pruriens seeds are able to increase motility and the percentage of normal spermatozoa morphology in mice exposed to 2-ME. Keywords: Mucuna pruriens L., L-dopa, mouse spermatozoa

β1-adrenergic receptors activate two distinct signaling pathways in striatal neurons

Science.gov (United States)

Meitzen, John; Luoma, Jessie I.; Stern, Christopher M.; Mermelstein, Paul G.

2010-01-01

Monoamine action in the dorsal striatum and nucleus accumbens plays essential roles in striatal physiology. Although research often focuses on dopamine and its receptors, norepinephrine and adrenergic receptors are also crucial in regulating striatal function. While noradrenergic neurotransmission has been identified in the striatum, little is known regarding the signaling pathways activated by β-adrenergic receptors in this brain region. Using cultured striatal neurons, we characterized a novel signaling pathway by which activation of β1-adrenergic receptors leads to the rapid phosphorylation of cAMP Response Element Binding Protein (CREB), a transcription-factor implicated as a molecular switch underlying long-term changes in brain function. Norepinephrine-mediated CREB phosphorylation requires β1-adrenergic receptor stimulation of a receptor tyrosine kinase, ultimately leading to the activation of a Ras/Raf/MEK/MAPK/MSK signaling pathway. Activation of β1-adrenergic receptors also induces CRE-dependent transcription and increased c-fos expression. In addition, stimulation of β1-adrenergic receptors produces cAMP production, but surprisingly, β1-adrenergic receptor activation of adenylyl cyclase was not functionally linked to rapid CREB phosphorylation. These findings demonstrate that activation of β1-adrenergic receptors on striatal neurons can stimulate two distinct signaling pathways. These adrenergic actions can produce long-term changes in gene expression, as well as rapidly modulate cellular physiology. By elucidating the mechanisms by which norepinephrine and β1-adrenergic receptor activation affects striatal physiology, we provide the means to more fully understand the role of monoamines in modulating striatal function, specifically how norepinephrine and β1-adrenergic receptors may affect striatal physiology. PMID:21143600

Reduced striatal D2 receptor binding in myoclonus-dystonia

International Nuclear Information System (INIS)

Beukers, R.J.; Weisscher, N.; Tijssen, M.A.J.; Booij, J.; Zijlstra, F.; Amelsvoort, T.A.M.J. van

2009-01-01

To study striatal dopamine D 2 receptor availability in DYT11 mutation carriers of the autosomal dominantly inherited disorder myoclonus-dystonia (M-D). Fifteen DYT11 mutation carriers (11 clinically affected) and 15 age- and sex-matched controls were studied using 123 I-IBZM SPECT. Specific striatal binding ratios were calculated using standard templates for striatum and occipital areas. Multivariate analysis with corrections for ageing and smoking showed significantly lower specific striatal to occipital IBZM uptake ratios (SORs) both in the left and right striatum in clinically affected patients and also in all DYT11 mutation carriers compared to control subjects. Our findings are consistent with the theory of reduced dopamine D 2 receptor (D2R) availability in dystonia, although the possibility of increased endogenous dopamine, and consequently, competitive D2R occupancy cannot be ruled out. (orig.)

An inquiry into the semiquantitative parameters of striatal dopamine receptor imaging

International Nuclear Information System (INIS)

Cao Guoxiang; Tan Tianzhi; Kuang Anren; Liang Zhenglu

1998-01-01

Purpose: To inquire into the optimal striatal reference region for nonspecific IBZM uptake in brain dopamine receptor imaging. Methods: Using in vivo data from rats, the authors compared the results of 125 I-iodobenzamide ( 125 I-IBZM) striatal specific binding that were respectively obtained taking cerebellum and frontal cortex as striatal reference region of nonspecific uptake of ligand. Results: Radioiodination labelled IBZM bound stereoselectively and reversibly to striatal D2 receptors. Frontal cortex and cerebellum showed rapid uptake and rapid washout of ligand. When cerebellar uptake was used as a reference of nonspecific uptake in striatum, IBZM saturation could not be demonstrated. But when the frontal cortex was used as reference region, saturation could be demonstrated with B max = 44 pmol/g striatum tissue. The percentage of haloperidol replacement and the percentage of uptake difference between striatum and other brain regions which were derived from competitive inhibition experiments with a large does of spiperone or haloperidol, suggested that the cerebellar uptake underestimated nonspecific uptake in the striatum while frontal cortex was an appropriate reference region for nonspecific uptake of ligand in striatum. Conclusions: For the calculation of specific IBZM binding and other semiquantitative parameters of striatal dopamine D2 receptor imaging, frontal cortex would be the nonspecific reference region of choice

Quinolinic acid induces disrupts cytoskeletal homeostasis in striatal neurons. Protective role of astrocyte-neuron interaction.

Science.gov (United States)

Pierozan, Paula; Ferreira, Fernanda; de Lima, Bárbara Ortiz; Pessoa-Pureur, Regina

2015-02-01

Quinolinic acid (QUIN) is an endogenous metabolite of the kynurenine pathway involved in several neurological disorders. Among the several mechanisms involved in QUIN-mediated toxicity, disruption of the cytoskeleton has been demonstrated in striatally injected rats and in striatal slices. The present work searched for the actions of QUIN in primary striatal neurons. Neurons exposed to 10 µM QUIN presented hyperphosphorylated neurofilament (NF) subunits (NFL, NFM, and NFH). Hyperphosphorylation was abrogated in the presence of protein kinase A and protein kinase C inhibitors H89 (20 μM) and staurosporine (10 nM), respectively, as well as by specific antagonists to N-methyl-D-aspartate (50 µM DL-AP5) and metabotropic glutamate receptor 1 (100 µM MPEP). Also, intra- and extracellular Ca(2+) chelators (10 µM BAPTA-AM and 1 mM EGTA, respectively) and Ca(2+) influx through L-type voltage-dependent Ca(2+) channel (10 µM verapamil) are implicated in QUIN-mediated effects. Cells immunostained for the neuronal markers βIII-tubulin and microtubule-associated protein 2 showed altered neurite/neuron ratios and neurite outgrowth. NF hyperphosphorylation and morphological alterations were totally prevented by conditioned medium from QUIN-treated astrocytes. Cocultured astrocytes and neurons interacted with one another reciprocally, protecting them against QUIN injury. Cocultured cells preserved their cytoskeletal organization and cell morphology together with unaltered activity of the phosphorylating system associated with the cytoskeleton. This article describes cytoskeletal disruption as one of the most relevant actions of QUIN toxicity in striatal neurons in culture with soluble factors secreted by astrocytes, with neuron-astrocyte interaction playing a role in neuroprotection. © 2014 Wiley Periodicals, Inc.

Endothelial Proliferation and Increased Blood - Brain Barrier Permeability in the Basal Ganglia in a Rat Model of 3,4-Dihydrozyphenyl-L-Alanine-Induced Dyskinesia

DEFF Research Database (Denmark)

Westin, Jenny E.; Lindgren, Hanna S.; Gardi, Jonathan Eyal

2006-01-01

3,4-Dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia is associated with molecular and synaptic plasticity in the basal ganglia, but the occurrence of structural remodeling through cell genesis has not been explored. In this study, rats with 6-hydroxydopamine lesions received injections of th...... of angiogenesis and blood-brain barrier dysfunction in an experimental model of L-DOPA-induced dyskinesia. These microvascular changes are likely to affect the kinetics of L-DOPA entry into the brain, favoring the occurrence of motor complications....... dyskinesia. The vast majority (60-80%) of the newborn cells stained positively for endothelial markers. This endothelial proliferation was associated with an upregulation of immature endothelial markers (nestin) and a downregulation of endothelial barrier antigen on blood vessel walls. In addition......, dyskinetic rats exhibited a significant increase in total blood vessel length and a visible extravasation of serum albumin in the two structures in which endothelial proliferation was most pronounced (substantia nigra pars reticulata and entopeduncular nucleus). The present study provides the first evidence...

Tracers tor the investigation of cerebral presynaptic dopaminergic function with positron emission tomography

International Nuclear Information System (INIS)

Firnau, G.; Chirakal, R.; Nahmias, C.; Garnett, E.S.

1991-01-01

Two pharmacologic concepts, open-quotes metabolic precursorsclose quotes and open-quotes enzyme inhibitorsclose quotes have been applied to the design of PET tracers for the metabolic aspects of the neurotransmitter dopamine. As the result, highly useful, positron-emitting radiotracers have been developed with which to visualize and measure the cerebral distribution and metabolism of dopaminergic neurons. Positron emitter-labeled DOPA, particularly 6-[ 18 F]fluoro-L-DOPA, is being used to obtain information about the neurochemical anatomy of the dopamine system, and potentially, the rate constant of dopamine biosynthesis. 6-[ 18 F]Fluoro-L- meta-tyrosine delineates the dopaminergic structures even better than 6-[ 18 F]fluoro-L-DOPA but cannot provide kinetic information about dopamine biosynthesis. The in vivo activity of the enzyme aromatic L-aminoacid decarboxylase and that of monoamine oxidase types A and B can be measured with a-fluoro-methyl-6-[ 18 F]fluoro-L-DOPA, [ 11 C]clorgyline and L-[ 11 C]deprenyl, respectively. Thus, neuropharmacologic investigations of human presynaptic dopamine pharmacology are now possible in vivo

Comparison between 68Ga-DOTA-NOC and 18F-DOPA PET for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours

International Nuclear Information System (INIS)

Ambrosini, Valentina; Tomassetti, Paola; Castellucci, Paolo; Campana, Davide; Montini, Giancarlo; Rubello, Domenico; Nanni, Cristina; Rizzello, Anna; Franchi, Roberto; Fanti, Stefano

2008-01-01

18 F-FDG positron emission tomography (PET) value for the assessment of neuro-endocrine tumours (NET) is limited. Preliminary studies indicate that 18 F-DOPA and 68 Ga-DOTA-NOC are more accurate for disease assessment and 68 Ga-DOTA peptides provide additional data on receptor status that are crucial for targeted radionuclide therapy. At present, there are no comparative studies investigating their role in NET. The aim of this study was to compare 68 Ga-DOTA-NOC and 18 F-DOPA for the evaluation of gastro-entero-pancreatic and lung neuro-endocrine tumours. Thirteen patients with biopsy-proven NET (gastro-entero-pancreatic or pulmonary) were prospectively enrolled and scheduled for 18 F-DOPA and 68 Ga-DOTA-NOC PET. PET results obtained with both tracers were compared with each other, with other conventional diagnostic procedures (CT, ultrasound) and with follow-up (clinical, imaging). The most common primary tumour site was the pancreas (8/13) followed by the ileum (2/13), the lung (2/13) and the duodenum (1/13). The carcinoma was well differentiated in 10/13 and poorly differentiated in 3/13 cases. 68 Ga-DOTA-NOC PET was positive, showing at least one lesion, in 13/13 cases while 18 F-DOPA PET was positive in 9/13. On a lesions basis, 68 Ga-DOTA-NOC identified more lesions than 18 F-DOPA (71 vs 45), especially at liver, lung and lymph node level. 68 Ga-DOTA-NOC correctly identified the primary site in six of eight non-operated cases (in five cases, the primary was surgically removed before PET), while 18 F-DOPA identified the primary only in two of eight cases. Although the patients studied are few and heterogeneous, our data show that 68 Ga-DOTA-NOC is accurate for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours in either the primary or metastatic site and that it offers several advantages over 18 F-DOPA. (orig.)

Comparison between 68Ga-DOTA-NOC and 18F-DOPA PET for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours.

Science.gov (United States)

Ambrosini, Valentina; Tomassetti, Paola; Castellucci, Paolo; Campana, Davide; Montini, Giancarlo; Rubello, Domenico; Nanni, Cristina; Rizzello, Anna; Franchi, Roberto; Fanti, Stefano

2008-08-01

(18)F-FDG positron emission tomography (PET) value for the assessment of neuro-endocrine tumours (NET) is limited. Preliminary studies indicate that (18)F-DOPA and (68)Ga-DOTA-NOC are more accurate for disease assessment and (68)Ga-DOTA peptides provide additional data on receptor status that are crucial for targeted radionuclide therapy. At present, there are no comparative studies investigating their role in NET. The aim of this study was to compare (68)Ga-DOTA-NOC and (18)F-DOPA for the evaluation of gastro-entero-pancreatic and lung neuro-endocrine tumours. Thirteen patients with biopsy-proven NET (gastro-entero-pancreatic or pulmonary) were prospectively enrolled and scheduled for (18)F-DOPA and (68)Ga-DOTA-NOC PET. PET results obtained with both tracers were compared with each other, with other conventional diagnostic procedures (CT, ultrasound) and with follow-up (clinical, imaging). The most common primary tumour site was the pancreas (8/13) followed by the ileum (2/13), the lung (2/13) and the duodenum (1/13). The carcinoma was well differentiated in 10/13 and poorly differentiated in 3/13 cases. (68)Ga-DOTA-NOC PET was positive, showing at least one lesion, in 13/13 cases while (18)F-DOPA PET was positive in 9/13. On a lesions basis, (68)Ga-DOTA-NOC identified more lesions than (18)F-DOPA (71 vs 45), especially at liver, lung and lymph node level. (68)Ga-DOTA-NOC correctly identified the primary site in six of eight non-operated cases (in five cases, the primary was surgically removed before PET), while (18)F-DOPA identified the primary only in two of eight cases. Although the patients studied are few and heterogeneous, our data show that (68)Ga-DOTA-NOC is accurate for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumours in either the primary or metastatic site and that it offers several advantages over (18)F-DOPA.

Inhibitory effect of Dendrobium officinale polysaccharide on human gastric cancer cell xenografts in nude mice

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Liying ZHANG

2017-10-01

Full Text Available Abstract This study investigated the inhibitory effect of Dendrobium officinale polysaccharide (DOPA on human gastric cancer cell SGC-7901 xenografts in nude mice. The nude mice with SGC-7901 xenografts were randomly divided into model, 5-fluorouracil (5-Fu, low-dose DOPA, middle-dose DOPA and high-dose DOPA group. The later four groups were intragastrically administrated with 100, 200 and 400 mg·kg–1·day–1 DOPA, 400 mg·kg–1·day–1 5-Fu and normal saline, respectively. After treatment for 20 days, the tumor inhibition rate of in high-dose DOPA group was basically equivalent to 5-Fu group. Compared with 5-Fu, DOPA had no obvious toxic side effect on spleen or thymus indexes, routine blood indexes or liver and kidney functions of nude mice. Compared with model group, the serum tumor necrosis factor-α and interleukin-2 levels in middle- and high-dose DOPA group were significantly increased (P < 0.05, Bax protein expression was significantly increased (P < 0.05, and Bcl-2 protein expression was significantly decreased (P < 0.05. DOPA can inhibit the growth of SGC-7901 cell xenografts in nude mice. The mechanism may be related to its increase of serum TNF-α and IL-2 levels, up-regulation of Bax protein expression and down-regulation of Bcl-2 protein expression.

HIV Infection Is Associated with Impaired Striatal Function during Inhibition with Normal Cortical Functioning on Functional MRI

NARCIS (Netherlands)

du Plessis, Stéfan; Vink, Matthijs; Joska, John A; Koutsilieri, Eleni; Bagadia, Asif; Stein, Dan J; Emsley, Robin

2015-01-01

The aim of the present study was to investigate the effect of HIV infection on cortical and subcortical regions of the frontal-striatal system involved in the inhibition of voluntary movement. Functional MRI (fMRI) studies suggest that human immunodeficiency virus (HIV) infection is associated with

Grading and outcome prediction of pediatric diffuse astrocytic tumors with diffusion and arterial spin labeling perfusion MRI in comparison with 18F-DOPA PET

Energy Technology Data Exchange (ETDEWEB)

Morana, Giovanni; Tortora, Domenico; Severino, Mariasavina; Rossi, Andrea [Istituto Giannina Gaslini, Neuroradiology Unit, Genoa (Italy); Piccardo, Arnoldo; Cabria, Manlio [Ente Ospedaliero Ospedali Galliera, Nuclear Medicine Unit, Genoa (Italy); Puntoni, Matteo [Ente Ospedaliero Ospedali Galliera, Clinical Trial Unit, Scientific Directorate, Genoa (Italy); Nozza, Paolo [Istituto Giannina Gaslini, Pathology Unit, Genoa (Italy); Ravegnani, Marcello; Consales, Alessandro; Mascelli, Samantha; Raso, Alessandro [Istituto Giannina Gaslini, Neurosurgery Unit, Genoa (Italy); Verrico, Antonio; Milanaccio, Claudia [Istituto Giannina Gaslini, Neuro-oncology Unit, Genoa (Italy)

2017-11-15

The aim of this study was to investigate MRI-derived diffusion weighted imaging (DWI) and arterial spin labeling (ASL) perfusion imaging in comparison with {sup 18}F-dihydroxyphenylalanine (DOPA) PET with respect to diagnostic performance in tumor grading and outcome prediction in pediatric patients with diffuse astrocytic tumors (DAT). We retrospectively analyzed 26 children with histologically proven treatment naive low and high grade DAT who underwent ASL and DWI performed within 2 weeks of {sup 18}F-DOPA PET. Relative ASL-derived cerebral blood flow max (rCBF max) and DWI-derived minimum apparent diffusion coefficient (rADC min) were compared with {sup 18}F-DOPA uptake tumor/normal tissue (T/N) and tumor/striatum (T/S) ratios, and correlated with World Health Organization (WHO) tumor grade and progression-free survival (PFS). Statistics included Pearson's chi-square and Mann-Whitney U tests, Spearman's rank correlation, receiver operating characteristic (ROC) analysis, discriminant function analysis (DFA), Kaplan-Meier survival curve, and Cox analysis. A significant correlation was demonstrated between rCBF max, rADC min, and {sup 18}F-DOPA PET data (p < 0.001). Significant differences in terms of rCBF max, rADC min, and {sup 18}F-DOPA uptake were found between low- and high-grade DAT (p ≤ 0.001). ROC analysis and DFA demonstrated that T/S and T/N values were the best parameters for predicting tumor progression (AUC 0.93, p < 0.001). On univariate analysis, all diagnostic tools correlated with PFS (p ≤ 0.001); however, on multivariate analysis, only {sup 18}F-DOPA uptake remained significantly associated with outcome (p ≤ 0.03), while a trend emerged for rCBF max (p = 0.09) and rADC min (p = 0.08). The combination of MRI and PET data increased the predictive power for prognosticating tumor progression (AUC 0.97, p < 0.001). DWI, ASL and {sup 18}F-DOPA PET provide useful complementary information for pediatric DAT grading. {sup 18}F-DOPA uptake

Where attention falls: Increased risk of falls from the converging impact of cortical cholinergic and midbrain dopamine loss on striatal function

Science.gov (United States)

Sarter, Martin; Albin, Roger L.; Kucinski, Aaron; Lustig, Cindy

2015-01-01

Falls are a major source of hospitalization, long-term institutionalization, and death in older adults and patients with Parkinson’s disease (PD). Limited attentional resources are a major risk factor for falls. In this review, we specify cognitive–behavioral mechanisms that produce falls and map these mechanisms onto a model of multi-system degeneration. Results from PET studies in PD fallers and findings from a recently developed animal model support the hypothesis that falls result from interactions between loss of basal forebrain cholinergic projections to the cortex and striatal dopamine loss. Striatal dopamine loss produces inefficient, low-vigor gait, posture control, and movement. Cortical cholinergic deafferentation impairs a wide range of attentional processes, including monitoring of gait, posture and complex movements. Cholinergic cell loss reveals the full impact of striatal dopamine loss on motor performance, reflecting loss of compensatory attentional supervision of movement. Dysregulation of dorsomedial striatal circuitry is an essential, albeit not exclusive, mediator of falls in this dual-system model. Because cholinergic neuromodulatory activity influences cortical circuitry primarily via stimulation of α4β2* nicotinic acetylcholine receptors, and because agonists at these receptors are known to benefit attentional processes in animals and humans, treating PD fallers with such agonists, as an adjunct to dopaminergic treatment, is predicted to reduce falls. Falls are an informative behavioral endpoint to study attentional–motor integration by striatal circuitry. PMID:24805070

Enzymatic syntheses of some 11C-labelled analogues of L-tyrosine and L-tryptophan

International Nuclear Information System (INIS)

Bjurling, P.; Malmborg, P.; Langstroem, B.

1990-01-01

In the elucidation of biochemical processes by use of positron emission tomography (PET), the multi-tracer approach can be valuable. In previous work, the authors have been studying the dopaminergic and serotonergic neurosystems by use of 11 C-labelled L-DOPA and 5-hydroxy-L-tryptophan, respectively. They have now developed the syntheses of several analogues of tyrosine and tryptophan, labelled with 11 C in the β-position, which are of interest for use in similar applications

Temporal changes of striatal dopamine release during and after a video game with a monetary reward: a PET study with [11C] raclopride continuous infusion

International Nuclear Information System (INIS)

Sang Eun Kim; Yearn Seong Choe; Eunjoo Kang; Dong Soo Lee; June-Key Chung; Myung-Chul Lee; Sang Soo Cho

2004-01-01

Purpose: In an attempt to understand the neurochemical changes associated with rewarded motor learning in human brain, we investigated the temporal changes of striatal dopamine (DA) release during and after a goal-directed psychomotor task (a video game) with a monetary incentive using [ 11 C] raclopride PET. Methods: Seven healthy, right-handed, nonsmokers were studied with PET for 120 min (50 min resting followed by 40 min video game and another 30 min resting) while receiving a bolus plus constant infusion of the DA D2 receptor radioligand [ 11 C] raclopride. During the video game (from 50 to 90 min postinjection), subjects played Tetris, which involved learning of joystick movement to fit falling jigsaw blocks, and periodically rewarded with unpredictable amount monetary incentives for improved performance. Striatal V 3 ', calculated as striatal-cerebellar/cerebellar activity ratio, was measured under equilibrium condition, at baseline and during and after the video game. Results: Striatal V 3 ' was significantly reduced during the video game compared with baseline levels, indicating increased DA release in this region (caudate, -15±6%; putamen, -30±10%). During the 30 min after the game ended, striatal [ 11 C] raclopride binding was gradually increased and the V 3 ' approached baseline levels. There was a significant correlation between the reduction in striatal V 3 ' and the task performance during the video game. Conclusions: These results demonstrate DA release in the human striatum during a psychomotor task with a monetary reward and to our knowledge for the first time a gradual DA restoration to baseline levels following the offset of stimulation. They also illustrate that acute fluctuations of synaptic DA can be measured in vivo using [ 11 C] raclopride PET. (authors)

18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism. A blinded evaluation

International Nuclear Information System (INIS)

Dahl Christiansen, Charlotte; Helleskov Rasmussen, Annett; Petersen, Henrik; Lerberg Nielsen, Anne; Detlefsen, Soenke; Brusgaard, Klaus; Rasmussen, Lars; Hovendal, Claus; Melikyan, Maria; Ekstroem, Klas; Globa, Evgenia; Christesen, Henrik Thybo

2018-01-01

Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F-fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3 -octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV max ) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85-1); specificity of 0.96 (0.82-0.99). The optimal 18F-DOPA PET SUV max ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV max cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93-1) for 18F-DOPA PET vs. 0.71 (0.43-0.95) for 68Ga-DOTANOC PET (p < 0.03). In patients subjected to surgery, localization of the focal lesion was correct in 91%, and 100%, by 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT, respectively. 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged. (orig.)

18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism. A blinded evaluation

Energy Technology Data Exchange (ETDEWEB)

Dahl Christiansen, Charlotte; Helleskov Rasmussen, Annett [Hans Christian Andersen Children' s Hospital, Odense University Hospital, Odense (Denmark); University of Southern Denmark, Department of Clinical Research, Odense (Denmark); Petersen, Henrik; Lerberg Nielsen, Anne [Odense University Hospital, Department of Nuclear Medicine, Odense (Denmark); Detlefsen, Soenke [University of Southern Denmark, Department of Clinical Research, Odense (Denmark); Odense University Hospital, Department of Pathology, Odense (Denmark); Brusgaard, Klaus [Odense University Hospital, Department of Clinical Genetics, Odense (Denmark); Rasmussen, Lars; Hovendal, Claus [Odense University Hospital, Department of Abdominal Surgery, Odense (Denmark); Melikyan, Maria [Endocrine Research Centre, Moscow (Russian Federation); Ekstroem, Klas [Karolinska Hospital, Astrid Lindgren Children' s Hospital, Stockholm (Sweden); Globa, Evgenia [MOH of Ukraine, Ukrainian Center of Endocrine Surgery, Endocrine Organs and Tissue Transplantation, Kyiv (Ukraine); Christesen, Henrik Thybo [Hans Christian Andersen Children' s Hospital, Odense University Hospital, Odense (Denmark); University of Southern Denmark, Department of Clinical Research, Odense (Denmark); Odense University Hospital, Odense Pancreas Center (OPAC), Odense (Denmark); Odense University Hospital, Department of Paediatrics, Odense C (Denmark)

2018-02-15

Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F-fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3 -octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV{sub max}) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85-1); specificity of 0.96 (0.82-0.99). The optimal 18F-DOPA PET SUV{sub max} ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV{sub max} cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93-1) for 18F-DOPA PET vs. 0.71 (0.43-0.95) for 68Ga-DOTANOC PET (p < 0.03). In patients subjected to surgery, localization of the focal lesion was correct in 91%, and 100%, by 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT, respectively. 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged. (orig.)

Dopamine-Related Disruption of Functional Topography of Striatal Connections in Unmedicated Patients With Schizophrenia.

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Horga, Guillermo; Cassidy, Clifford M; Xu, Xiaoyan; Moore, Holly; Slifstein, Mark; Van Snellenberg, Jared X; Abi-Dargham, Anissa

2016-08-01

Despite the well-established role of striatal dopamine in psychosis, current views generally agree that cortical dysfunction is likely necessary for the emergence of psychotic symptoms. The topographic organization of striatal-cortical connections is central to gating and integration of higher-order information, so a disruption of such topography via dysregulated dopamine could lead to cortical dysfunction in schizophrenia. However, this hypothesis remains to be tested using multivariate methods ascertaining the global pattern of striatal connectivity and without the confounding effects of antidopaminergic medication. To examine whether the pattern of brain connectivity across striatal subregions is abnormal in unmedicated patients with schizophrenia and whether this abnormality relates to psychotic symptoms and extrastriatal dopaminergic transmission. In this multimodal, case-control study, we obtained resting-state functional magnetic resonance imaging data from 18 unmedicated patients with schizophrenia and 24 matched healthy controls from the New York State Psychiatric Institute. A subset of these (12 and 17, respectively) underwent positron emission tomography with the dopamine D2 receptor radiotracer carbon 11-labeled FLB457 before and after amphetamine administration. Data were acquired between June 16, 2011, and February 25, 2014. Data analysis was performed from September 1, 2014, to January 11, 2016. Group differences in the striatal connectivity pattern (assessed via multivariable logistic regression) across striatal subregions, the association between the multivariate striatal connectivity pattern and extrastriatal baseline D2 receptor binding potential and its change after amphetamine administration, and the association between the multivariate connectivity pattern and the severity of positive symptoms evaluated with the Positive and Negative Syndrome Scale. Of the patients with schizophrenia (mean [SEM] age, 35.6 [11.8] years), 9 (50%) were male and 9

Intrastriatal administration of botulinum neurotoxin A normalizes striatal D2 R binding and reduces striatal D1 R binding in male hemiparkinsonian rats.

Science.gov (United States)

Wedekind, Franziska; Oskamp, Angela; Lang, Markus; Hawlitschka, Alexander; Zilles, Karl; Wree, Andreas; Bauer, Andreas

2018-01-01

Cerebral administration of botulinum neurotoxin A (BoNT-A) has been shown to improve disease-specific motor behavior in a rat model of Parkinson disease (PD). Since the dopaminergic system of the basal ganglia fundamentally contributes to motor function, we investigated the impact of BoNT-A on striatal dopamine receptor expression using in vitro and in vivo imaging techniques (positron emission tomography and quantitative autoradiography, respectively). Seventeen male Wistar rats were unilaterally lesioned with 6-hydroxydopamine (6-OHDA) and assigned to two treatment groups 7 weeks later: 10 rats were treated ipsilaterally with an intrastriatal injection of 1 ng BoNT-A, while the others received vehicle (n = 7). All animals were tested for asymmetric motor behavior (apomorphine-induced rotations and forelimb usage) and for striatal expression of dopamine receptors and transporters (D 1 R, D 2 R, and DAT). The striatal D 2 R availability was also quantified longitudinally (1.5, 3, and 5 months after intervention) in 5 animals per treatment group. The 6-OHDA lesion alone induced a unilateral PD-like phenotype and a 13% increase of striatal D 2 R. BoNT-A treatment reduced the asymmetry in both apomorphine-induced rotational behavior and D 2 R expression, with the latter returning to normal values 5 months after intervention. D 1 R expression was significantly reduced, while DAT concentrations showed no alteration. Independent of the treatment, higher interhemispheric symmetry in raclopride binding to D 2 R was generally associated with reduced forelimb akinesia. Our findings indicate that striatal BoNT-A treatment diminishes motor impairment and induces changes in D 1 and D 2 binding site density in the 6-OHDA rat model of PD. © 2017 Wiley Periodicals, Inc.

In vitro and in vivo investigation of natural compounds from seed extract of Mucuna pruriens lacking l-DOPA for the treatment of erectile dysfunction.

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Duangnin, Natthachai; Phitak, Thanyaluck; Pothacharoen, Peraphan; Kongtawelert, Prachya

2017-03-01

To investigate the biological effects of the Mucuna pruriens (M. pruriens) seed extracts that lacked l-DOPA, which was formerly reported as the active ingredient, on erectile dysfunction (ED) both in vitro and in vivo. Seed of M. pruriens plant that cultivated in Mae Taeng District, Chiang Mai Province, Thailand, was collected. Component of its seeds were extracted and isolated into 2 fractions using methanol, polar and nonpolar. Each fraction was investigated for phytochemicals using gas chromatography and mass spectroscopy and was screened for biological activity in vitro using three different cell lines. The most biological active fraction was used to treat both streptozotocin (STZ)-induced diabetes mellitus-erectile dysfunction (DM-ED) male Wistar rats and normal rats (n = 6 per groups) to compare the effect on sexual behavior parameters, including number of intromission, mounting and ejaculation, with that of rats given Sildenafil by individually pairing with their female counterparts. Penile tissues and serums were collected to determine histological structure, related gene expression and biomolecules. The phytochemicals of the polar fraction were possibly catechol and its derivatives plus polyphenols, whereas the nonpolar fraction consisted of lipid derivatives. l-DOPA was not detected in either of the extracts. The polar fraction was able to up-regulate the expression of ED-related genes including eNOS and nNOS in vitro which subsequently promotes nitric oxide production and maintains intracellular cyclic guanosine monophosphate levels. When administrated to DM-ED rats, the polar extract significantly improved all sexual behavior parameters in DM-ED rats compared to untreated group (18.3 ± 1.8 to 10.8 ± 2.9 for intromission, 9.8 ± 2.2 to 5.7 ± 1.3 for mounting, and 1.8 ± 0.6 to 0.2 ± 0.4 for ejaculation). That effect might due to the ability of the extract to stimulate the expression of eNOS and nNOS which results in nitric oxide

Fronto-striatal atrophy correlates of neuropsychiatric dysfunction in frontotemporal dementia (FTD and Alzheimer's disease (AD

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Dong Seok Yi

Full Text Available ABSTRACT Behavioural disturbances in frontotemporal dementia (FTD are thought to reflect mainly atrophy of cortical regions. Recent studies suggest that subcortical brain regions, in particular the striatum, are also significantly affected and this pathology might play a role in the generation of behavioural symptoms. Objective: To investigate prefrontal cortical and striatal atrophy contributions to behavioural symptoms in FTD. Methods: One hundred and eighty-two participants (87 FTD patients, 39 AD patients and 56 controls were included. Behavioural profiles were established using the Cambridge Behavioural Inventory Revised (CBI-R and Frontal System Behaviour Scale (FrSBe. Atrophy in prefrontal (VMPFC, DLPFC and striatal (caudate, putamen regions was established via a 5-point visual rating scale of the MRI scans. Behavioural scores were correlated with atrophy rating scores. Results: Behavioural and atrophy ratings demonstrated that patients were significantly impaired compared to controls, with bvFTD being most severely affected. Behavioural-anatomical correlations revealed that VMPFC atrophy was closely related to abnormal behaviour and motivation disturbances. Stereotypical behaviours were associated with both VMPFC and striatal atrophy. By contrast, disturbance of eating was found to be related to striatal atrophy only. Conclusion: Frontal and striatal atrophy contributed to the behavioural disturbances seen in FTD, with some behaviours related to frontal, striatal or combined fronto-striatal pathology. Consideration of striatal contributions to the generation of behavioural disturbances should be taken into account when assessing patients with potential FTD.

The pan-Kv7 (KCNQ) Channel Opener Retigabine Inhibits Striatal Excitability by Direct Action on Striatal Neurons In Vivo

DEFF Research Database (Denmark)

Hansen, Henrik H; Weikop, Pia; Mikkelsen, Maria D

2017-01-01

Central Kv7 (KCNQ) channels are voltage-dependent potassium channels composed of different combinations of four Kv7 subunits, being differently expressed in the brain. Notably, striatal dopaminergic neurotransmission is strongly suppressed by systemic administration of the pan-Kv7 channel opener ...... by acute systemic haloperidol administration in the rat. The relative mRNA levels of Kv7 subunits in the rat striatum were found to be Kv7.2 = Kv7.3 = Kv7.5 > >Kv7.4. These data suggest that intrastriatal Kv7 channels play a direct role in regulating striatal excitability in vivo....

Temporal changes of striatal dopamine release during and after a video game with a monetary reward: a PET study with [{sup 11}C]raclopride continuous infusion

Energy Technology Data Exchange (ETDEWEB)

Kim, S. E. [Sungkyunkwon University School of Medicine, Suwon (Korea, Republic of); Cho, S. S.; Choe, Y. S.; Lee, S. Y.; Kang, E.; Kim, B. T. [Seoul National University hospital, Seoul (Korea, Republic of)

2002-07-01

In an attempt to understand the neurochemical changes associated with rewarded motor learning in human brain, we investigated the temporal changes of striatal dopamine (DA) release during and after a goal-directed psychomotor task (a video game) with a monetary incentive using [{sup 11}C]raclopride PET. Seven healthy, right-handed, nonsmokers were studied with PET for 120 min (50 min resting followed by 40 min video game and another 30 min resting) while receiving a bolus plus constant infusion of the DA D2 receptor radioligand [{sup 11}C]raclopride. During the video game (from 50 to 90 min postinjection), subjects played Tetris, which involved learning of joystick movement to fit falling jigsaw blocks, and periodically rewarded with unpredictable amount monetary incentives for improved performance. Striatal V3', calculated as striatal-cerebellar/cerebellar activity ratio, was measured under equilibrium condition, at baseline and during and after the video game. Striatal V3' was significantly reduced during the video game compared with baseline levels, indicating increased DA release in this region (caudate, -15{+-}6%; putamen, -30{+-}10%). During the 30 min after the game ended, striatal [{sup 11}C]raclopride binding was gradually increased and the V3' approached baseline levels. There was a significant correlation between the reduction in striatal V3' and the task performance during the video game. These results demonstrate DA release in the human striatum during a psychomotor task with a monetary reward and to our knowledge for the first time a gradual DA restoration to baseline levels following the offset of stimulation. They also illustrate that acute fluctuations of synaptic DA can be measured in vivo using [{sup 11}C]raclopride PET.

Striatal activation reflects urgency in perceptual decision making.

Science.gov (United States)

van Maanen, Leendert; Fontanesi, Laura; Hawkins, Guy E; Forstmann, Birte U

2016-10-01

Deciding between multiple courses of action often entails an increasing need to do something as time passes - a sense of urgency. This notion of urgency is not incorporated in standard theories of speeded decision making that assume information is accumulated until a critical fixed threshold is reached. Yet, it is hypothesized in novel theoretical models of decision making. In two experiments, we investigated the behavioral and neural evidence for an "urgency signal" in human perceptual decision making. Experiment 1 found that as the duration of the decision making process increased, participants made a choice based on less evidence for the selected option. Experiment 2 replicated this finding, and additionally found that variability in this effect across participants covaried with activation in the striatum. We conclude that individual differences in susceptibility to urgency are reflected by striatal activation. By dynamically updating a response threshold, the striatum is involved in signaling urgency in humans. Copyright © 2016 Elsevier Inc. All rights reserved.

l-DOPA Decarboxylase (DDC) Expression Status as a Novel Molecular Tumor Marker for Diagnostic and Prognostic Purposes in Laryngeal Cancer.

Science.gov (United States)

Patsis, Christos; Glyka, Vasiliki; Yiotakis, Ioannis; Fragoulis, Emmanuel G; Scorilas, Andreas

2012-08-01

l-DOPA decarboxylase (DDC) plays an essential role in the enzymatic synthesis of dopamine and alterations in its gene expression have been reported in several malignancies. Our objective was to analyze DDC messenger RNA (mRNA) and protein expression in laryngeal tissues and to evaluate the clinical implication of this molecule in laryngeal cancer. In this study, total RNA was isolated from 157 tissue samples surgically removed from 100 laryngeal cancer patients. A highly sensitive real-time polymerase chain reaction methodology based on SYBR Green I fluorescent dye was developed for the quantification of DDC mRNA levels. In addition, Western blot analysis was performed for the detection of DDC protein. DDC mRNA expression was revealed to be significantly downregulated in primary laryngeal cancer samples compared with their nonmalignant counterparts (P = .001). A significant negative association was also disclosed between DDC mRNA levels and TNM staging (P = .034). Univariate analysis showed that patients bearing DDC-positive tumors had a significantly decreased risk of death (hazard ratio = 0.23, P = .012) and local recurrence (hazard ratio = 0.32, P =.006), whereas DDC expression retained its favorable prognostic significance in the multivariate analysis. Kaplan-Meier curves further demonstrated that DDC-positive patients experienced longer overall and disease-free survival periods (P = .006 and P = .004, respectively). Moreover, DDC protein was detected in both neoplastic and noncancerous tissues. Therefore, our results suggest that DDC expression status could qualify as a promising biomarker for the future clinical management of laryngeal cancer patients.

Sensory Entrainment Mechanisms in Auditory Perception: Neural Synchronization Cortico-Striatal Activation.

Science.gov (United States)

Sameiro-Barbosa, Catia M; Geiser, Eveline

2016-01-01

The auditory system displays modulations in sensitivity that can align with the temporal structure of the acoustic environment. This sensory entrainment can facilitate sensory perception and is particularly relevant for audition. Systems neuroscience is slowly uncovering the neural mechanisms underlying the behaviorally observed sensory entrainment effects in the human sensory system. The present article summarizes the prominent behavioral effects of sensory entrainment and reviews our current understanding of the neural basis of sensory entrainment, such as synchronized neural oscillations, and potentially, neural activation in the cortico-striatal system.

Sensory Entrainment Mechanisms in Auditory Perception: Neural Synchronization Cortico-Striatal Activation

Science.gov (United States)

Sameiro-Barbosa, Catia M.; Geiser, Eveline

2016-01-01

The auditory system displays modulations in sensitivity that can align with the temporal structure of the acoustic environment. This sensory entrainment can facilitate sensory perception and is particularly relevant for audition. Systems neuroscience is slowly uncovering the neural mechanisms underlying the behaviorally observed sensory entrainment effects in the human sensory system. The present article summarizes the prominent behavioral effects of sensory entrainment and reviews our current understanding of the neural basis of sensory entrainment, such as synchronized neural oscillations, and potentially, neural activation in the cortico-striatal system. PMID:27559306

Where attention falls: Increased risk of falls from the converging impact of cortical cholinergic and midbrain dopamine loss on striatal function.

Science.gov (United States)

Sarter, Martin; Albin, Roger L; Kucinski, Aaron; Lustig, Cindy

2014-07-01

Falls are a major source of hospitalization, long-term institutionalization, and death in older adults and patients with Parkinson's disease (PD). Limited attentional resources are a major risk factor for falls. In this review, we specify cognitive-behavioral mechanisms that produce falls and map these mechanisms onto a model of multi-system degeneration. Results from PET studies in PD fallers and findings from a recently developed animal model support the hypothesis that falls result from interactions between loss of basal forebrain cholinergic projections to the cortex and striatal dopamine loss. Striatal dopamine loss produces inefficient, low-vigor gait, posture control, and movement. Cortical cholinergic deafferentation impairs a wide range of attentional processes, including monitoring of gait, posture and complex movements. Cholinergic cell loss reveals the full impact of striatal dopamine loss on motor performance, reflecting loss of compensatory attentional supervision of movement. Dysregulation of dorsomedial striatal circuitry is an essential, albeit not exclusive, mediator of falls in this dual-system model. Because cholinergic neuromodulatory activity influences cortical circuitry primarily via stimulation of α4β2* nicotinic acetylcholine receptors, and because agonists at these receptors are known to benefit attentional processes in animals and humans, treating PD fallers with such agonists, as an adjunct to dopaminergic treatment, is predicted to reduce falls. Falls are an informative behavioral endpoint to study attentional-motor integration by striatal circuitry. Copyright © 2014 Elsevier Inc. All rights reserved.

Uso precoce e tardio de dopamina após isquemia miocárdica Early and late use of dopamine after myocardial ischemia

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Ademar R. Souza

2004-09-01

Full Text Available OBJETIVO: Avaliar os efeitos na função ventricular esquerda do uso precoce e tardio de dopamina, em modelo experimental de coração isolado. MÉTODO: Foram utilizados 60 coelhos em modelo de coração isolado mantido por animal suporte. Um balão intraventricular foi locado no ventrículo esquerdo. Três grupos foram constituídos: grupo controle (GC; grupo que recebeu dopamina precoce (Dopa P e grupo que recebeu dopamina tardia (após 20 minutos (Dopa T. Foram realizadas leituras hemodinâmicas diretas e indiretas. RESULTADOS: Fluxo sangüíneo coronariano: GC(7,196 ± 1,275ml/min; Dopa P (9,477 ± 1,160ml/min; Dopa T (14,316 ± 2,308ml/min, com GC=Dopa P, GC ¹Dopa T e Dopa P¹Dopa T. Primeira derivada temporal da pressão intraventricular (dp/dt+: GC (719,61 ± 127,53ml/min; Dopa P (719,61 ± 127,53ml/min; Dopa T (1431,60 ± 230,87ml/min, p0,05, Dopa P=Dopa T=GC. Estresse sistólico desenvolvido: GC (27,273 ± 10,276g/cm²; Dopa P (55,219 ± 24,625g/cm²; Dopa T (79,152 ± 12,166g/cm², Dopa P=Dopa T, Dopa P=GC e GC ¹ Dopa T.Dialdeído Malônico (MDA: GC (4,5 ± 0,527mmol/L; Dopa P (4,7 ± 1,16mmol/L; Dopa T (4,1 ± 0,7379mmol/L, p>0,05, Dopa P=Dopa T=GC. CONCLUSÕES: Concluiu-se que, no modelo experimental delineado, o uso precoce da dopamina foi deletério, segundo algumas variáveis hemodinâmicas.OBJECTIVE: To evaluate the effect on the left ventricular function of the early and late use of dopamine in an experimental model of an isolated heart. METHOD: Were used 60 rabbits in an isolated heart model sustained by animal support. An intraventricular balloon was placed in the left ventricle. Three groups were constituted: a control group (CG; a group that received dopamine precociously (Dopa P and a group that received dopamine after 20 minutes (Dopa T. Direct and indirect hemodynamic readings were taken. RESULTS: Coronary artery flow: CG (7.196 ± 1.275 mL/min; Dopa P (9.477 ± 1.160 mL/min; Dopa T (14.316 ± 2.308 mL/min, with CG

Control of striatal signaling by G protein regulators

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Keqiang eXie

2011-08-01

Full Text Available Signaling via heterotrimeric G proteins plays a crucial role in modulating the responses of striatal neurons that ultimately shape core behaviors mediated by the basal ganglia circuitry, such as reward valuation, habit formation and movement coordination. Activation of G-protein-coupled receptors (GPCRs by extracellular signals activates heterotrimeric G proteins by promoting the binding of GTP to their α subunits. G proteins exert their effects by influencing the activity of key effector proteins in this region, including ion channels, second messenger enzymes and protein kinases. Striatal neurons express a staggering number of GPCRs whose activation results in the engagement of downstream signaling pathways and cellular responses with unique profiles but common molecular mechanisms. Studies over the last decade have revealed that the extent and duration of GPCR signaling are controlled by a conserved protein family named Regulator of G protein Signaling (RGS. RGS proteins accelerate GTP hydrolysis by the α subunits of G proteins, thus promoting deactivation of GPCR signaling. In this review, we discuss the progress made in understanding the roles of RGS proteins in controlling striatal G protein signaling and providing integration and selectivity of signal transmission. We review evidence on the formation of a macromolecular complex between RGS proteins and other components of striatal signaling pathways, their molecular regulatory mechanisms and impacts on GPCR signaling in the striatum obtained from biochemical studies and experiments involving genetic mouse models. Special emphasis is placed on RGS9-2, a member of the RGS family that is highly enriched in the striatum and plays critical roles in drug addiction and motor control.

Donor-Specific Anti-HLA Antibodies in Huntington's Disease Recipients of Human Fetal Striatal Grafts.

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Porfirio, Berardino; Paganini, Marco; Mazzanti, Benedetta; Bagnoli, Silvia; Bucciantini, Sandra; Ghelli, Elena; Nacmias, Benedetta; Putignano, Anna Laura; Rombolà, Giovanni; Saccardi, Riccardo; Lombardini, Letizia; Di Lorenzo, Nicola; Vannelli, Gabriella B; Gallina, Pasquale

2015-01-01

Fetal grafting in a human diseased brain was thought to be less immunogenic than other solid organ transplants, hence the minor impact on the efficacy of the transplant. How much prophylactic immune protection is required for neural allotransplantation is also debated. High-sensitive anti-HLA antibody screening in this field has never been reported. Sixteen patients with Huntington's disease underwent human fetal striatal transplantation in the frame of an open-label observational trial, which is being carried out at Florence University. All patients had both brain hemispheres grafted in two separate robotic-stereotactic procedures. The trial started in February 2006 with the first graft to the first patient (R1). R16 was given his second graft on March 2011. All patients received triple immunosuppressive treatment. Pre- and posttransplant sera were analyzed for the presence of anti-HLA antibodies using the multiplexed microsphere-based suspension array Luminex xMAP technology. Median follow-up was 38.5 months (range 13-85). Six patients developed anti-HLA antibodies, which turned out to be donor specific. Alloimmunization occurred in a time window of 0-49 months after the first neurosurgical procedure. The immunogenic determinants were non-self-epitopes from mismatched HLA antigens. These determinants were both public epitopes shared by two or more HLA molecules and private epitopes unique to individual HLA molecules. One patient had non-donor-specific anti-HLA antibodies in her pretransplant serum sample, possibly due to previous sensitization events. Although the clinical significance of donor-specific antibodies is far from being established, particularly in the setting of neuronal transplantation, these findings underline the need of careful pre- and posttransplant immunogenetic evaluation of patients with intracerebral grafts.

Fractal analysis of striatal dopamine re-uptake sites

International Nuclear Information System (INIS)

Kuikka, J.T.; Bergstroem, K.A.; Tiihonen, J.; Raesaenen, P.; Karhu, J.

1997-01-01

Spatial variation in regional blood flow, metabolism and receptor density within the brain and in other organs is measurable even with a low spatial resolution technique such as emission tomography. It has been previously shown that the observed variance increases with increasing number of subregions in the organ/tissue studied. This resolution-dependent variance can be described by fractal analysis. We studied striatal dopamine re-uptake sites in 39 healthy volunteers with high-resolution single-photon emission tomography using iodine-123 labelled 2β-carbomethoxy-3β-(4-iodophenyl)tropane ([ 123 I]β-CIT). The mean fractal dimension was 1.15±0.07. The results indicate that regional striatal dopamine re-uptake sites involve considerable spatial heterogeneity which is higher than the uniform density (dimension=1.00) but much lower than complete randomness (dimension=1.50). There was a gender difference, with females having a higher heterogeneity in both the left and the right striatum. In addition, we found striatal asymmetry (left-to-right heterogeneity ratio of 1.19±0.15; P<0.001), suggesting functional hemispheric lateralization consistent with the control of motor behaviour and integrative functions. (orig.). With 5 figs., 1 tab

Fractal analysis of striatal dopamine re-uptake sites

Energy Technology Data Exchange (ETDEWEB)

Kuikka, J.T.; Bergstroem, K.A. [Department of Clinical Physiology, Kuopio University Hospital, Kuopio (Finland); Tiihonen, J.; Raesaenen, P. [Department of Forensic Psychiatry, University of Kuopio and Niuvanniemi Hospital, Kuopio (Finland); Karhu, J. [Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio (Finland)

1997-09-01

Spatial variation in regional blood flow, metabolism and receptor density within the brain and in other organs is measurable even with a low spatial resolution technique such as emission tomography. It has been previously shown that the observed variance increases with increasing number of subregions in the organ/tissue studied. This resolution-dependent variance can be described by fractal analysis. We studied striatal dopamine re-uptake sites in 39 healthy volunteers with high-resolution single-photon emission tomography using iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ([{sup 123}I]{beta}-CIT). The mean fractal dimension was 1.15{+-}0.07. The results indicate that regional striatal dopamine re-uptake sites involve considerable spatial heterogeneity which is higher than the uniform density (dimension=1.00) but much lower than complete randomness (dimension=1.50). There was a gender difference, with females having a higher heterogeneity in both the left and the right striatum. In addition, we found striatal asymmetry (left-to-right heterogeneity ratio of 1.19{+-}0.15; P<0.001), suggesting functional hemispheric lateralization consistent with the control of motor behaviour and integrative functions. (orig.). With 5 figs., 1 tab.

18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism: a blinded evaluation.

Science.gov (United States)

Christiansen, Charlotte Dahl; Petersen, Henrik; Nielsen, Anne Lerberg; Detlefsen, Sönke; Brusgaard, Klaus; Rasmussen, Lars; Melikyan, Maria; Ekström, Klas; Globa, Evgenia; Rasmussen, Annett Helleskov; Hovendal, Claus; Christesen, Henrik Thybo

2018-02-01

Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F-fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3-octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV max ) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85-1); specificity of 0.96 (0.82-0.99). The optimal 18F-DOPA PET SUV max ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV max cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93-1) for 18F-DOPA PET vs. 0.71 (0.43-0.95) for 68Ga-DOTANOC PET (p PET/CT and 68Ga-DOTANOC PET/CT, respectively. 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged.

Magnetically Separable Fe3O4@DOPA-Pd: A Heterogeneous Catalyst for Aqueous Heck Reaction

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Magnetically separable Fe3O4@DOPA-Pd catalyst has been synthesized via anchoring of palladium over dopamine-coated magnetite via non-covalent interaction and the catalyst is utilized for expeditious Heck coupling in aqueous media.

Simultaneous determination of levodopa and carbidopa from fava bean, green peas and green beans by high performance liquid gas chromatography.

Science.gov (United States)

Mehran S M, Mohseni; B, Golshani

2013-06-01

According to many studies, sprouted fava beans are a rich source of levo-dihydroxy phenylalanine (L-dopa) the precursor of dopamine, and they are now being investigated for use in the management of Parkinson's disease. The addition of Carbidopa (C-dopa) can reduce the daily use of the L-dopa dosage requirements and it can also reduce the side effects which are associated with the L-dopa administration. The present research was conducted to find the levo-dihydroxy phenylalanine (L-dopa) and Carbidopa (C-dopa) in fava beans, green peas and green beans by High Performance Gas Chromatography (HPLC). Carbidopa (C-dopa) is a peripheral decarboxylase inhibitor. As a substitution therapy, it used in combination to treat Parkinson's disease. We obtained L-dopa and C-dopa from fava beans which were in the fresh and dry sprouted form, whose concentrations were 1.4,1.5 and 2.6,2.4 mg/ml respectively. The maximal stimulation of the L-DOPA content was seen on day 8 for the fava beans, which was 100% higher than that of the control level. The results of this study indicate that faba beans are a good source of natural L-dopa and C-dopa. The quantification of this capacity according to the stage and the plant part could be suitable for applications in the food industry and in plant medicine. The consumption of fava beans can increase the levels of L-dopa and C-dopa in the blood, with a marked improvement in the motor performance of the patients with parkinson disease, without any side effects.

Nutrient digestibility of Mucuna (Mucuna pruriens var. utilis) bean in guinea fowl (Numida meleagris, L): Effects of heat treatment and levels of incorporation in diets.

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Dahouda, M; Toléba, S S; Youssao, A K I; Hambuckers, A; Dangou-Sapoho, R; Martin, G B; Fillet, M; Hornick, J-L

2009-09-01

1. Mucuna pruriens var. utilis is a legume, the seeds of which are scarcely used in animal diets owing to their high content of 3,4-dihydroxy-L-phenylalanine (L-Dopa). 2. Experiments were conducted on guinea fowl to assess the effects of two types of heat processing (cooking and toasting) on chemical composition and nutrient digestibility of Mucuna seeds offered alone or incorporated at three concentrations (40, 120 or 200 g/kg) in complete diets. 3. Diets containing 200 g/kg seeds had more crude fibre and less ether extract. L-Dopa content increased with the amount of Mucuna inclusion. Cooking reduced markedly L-Dopa content while toasting had no effect. When fed alone, Mucuna seeds dramatically decreased feed intake. 4. Feed intake (FI) and body weight gain (BWG) were not influenced by the complete diets. Cooking significantly increased crude fibre digestibility. 5. It is suggested that cracked and cooked Mucuna bean can be incorporated at a safe level of 120 g/kg in complete diets for guinea fowl production.

Gender Differences in Age-Related Striatal Dopamine Depletion in Parkinson’s Disease

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Jae Jung Lee

2015-09-01

Full Text Available Objective Gender differences are a well-known clinical characteristic of Parkinson’s disease (PD. In-vivo imaging studies demonstrated that women have greater striatal dopamine transporter (DAT activity than do men, both in the normal population and in PD patients. We hypothesize that women exhibit more rapid aging-related striatal DAT reduction than do men, as the potential neuroprotective effect of estrogen wanes with age. Methods This study included 307 de novo PD patients (152 men and 155 women who underwent DAT scans for an initial diagnostic work-up. Gender differences in age-related DAT decline were assessed in striatal sub-regions using linear regression analysis. Results Female patients exhibited greater DAT activity compared with male patients in all striatal sub-regions. The linear regression analysis revealed that age-related DAT decline was greater in the anterior and posterior caudate, and the anterior putamen in women compared with men; we did not observe this difference in other sub-regions. Conclusions This study demonstrated the presence of gender differences in age-related DAT decline in striatal sub-regions, particularly in the antero-dorsal striatum, in patients with PD, presumably due to aging-related decrease in estrogen. Because this difference was not observed in the sensorimotor striatum, this finding also suggests that women may not have a greater capacity to tolerate PD pathogenesis than do men.

A dopa decarboxylase modulating the immune response of scallop Chlamys farreri.

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Zhi Zhou

Full Text Available BACKGROUND: Dopa decarboxylase (DDC is a pyridoxal 5-phosphate (PLP-dependent enzyme that catalyzes the decarboxylation of L-Dopa to dopamine, and involved in complex neuroendocrine-immune regulatory network. The function for DDC in the immunomodulation remains unclear in invertebrate. METHODOLOGY: The full-length cDNA encoding DDC (designated CfDDC was cloned from mollusc scallop Chlamys farreri. It contained an open reading frame encoding a polypeptide of 560 amino acids. The CfDDC mRNA transcripts could be detected in all the tested tissues, including the immune tissues haemocytes and hepatopancreas. After scallops were treated with LPS stimulation, the mRNA expression level of CfDDC in haemocytes increased significantly (5.5-fold, P<0.05 at 3 h and reached the peak at 12 h (9.8-fold, P<0.05, and then recovered to the baseline level. The recombinant protein of CfDDC (rCfDDC was expressed in Escherichia coli BL21 (DE3-Transetta, and 1 mg rCfDDC could catalyze the production of 1.651±0.22 ng dopamine within 1 h in vitro. When the haemocytes were incubated with rCfDDC-coated agarose beads, the haemocyte encapsulation to the beads was increased significantly from 70% at 6 h to 93% at 24 h in vitro in comparison with that in the control (23% at 6 h to 25% at 24 h, and the increased haemocyte encapsulation was repressed by the addition of rCfDDC antibody (which is acquired via immunization 6-week old rats with rCfDDC. After the injection of DDC inhibitor methyldopa, the ROS level in haemocytes of scallops was decreased significantly to 0.41-fold (P<0.05 of blank group at 12 h and 0.47-fold (P<0.05 at 24 h, respectively. CONCLUSIONS: These results collectively suggested that CfDDC, as a homologue of DDC in scallop, modulated the immune responses such as haemocytes encapsulation as well as the ROS level through its catalytic activity, functioning as an indispensable immunomodulating enzyme in the neuroendocrine-immune regulatory network of mollusc.

Functional connectivity modeling of consistent cortico-striatal degeneration in Huntington's disease

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Imis Dogan

2015-01-01

Full Text Available Huntington's disease (HD is a progressive neurodegenerative disorder characterized by a complex neuropsychiatric phenotype. In a recent meta-analysis we identified core regions of consistent neurodegeneration in premanifest HD in the striatum and middle occipital gyrus (MOG. For early manifest HD convergent evidence of atrophy was most prominent in the striatum, motor cortex (M1 and inferior frontal junction (IFJ. The aim of the present study was to functionally characterize this topography of brain atrophy and to investigate differential connectivity patterns formed by consistent cortico-striatal atrophy regions in HD. Using areas of striatal and cortical atrophy at different disease stages as seeds, we performed task-free resting-state and task-based meta-analytic connectivity modeling (MACM. MACM utilizes the large data source of the BrainMap database and identifies significant areas of above-chance co-activation with the seed-region via the activation-likelihood-estimation approach. In order to delineate functional networks formed by cortical as well as striatal atrophy regions we computed the conjunction between the co-activation profiles of striatal and cortical seeds in the premanifest and manifest stages of HD, respectively. Functional characterization of the seeds was obtained using the behavioral meta-data of BrainMap. Cortico-striatal atrophy seeds of the premanifest stage of HD showed common co-activation with a rather cognitive network including the striatum, anterior insula, lateral prefrontal, premotor, supplementary motor and parietal regions. A similar but more pronounced co-activation pattern, additionally including the medial prefrontal cortex and thalamic nuclei was found with striatal and IFJ seeds at the manifest HD stage. The striatum and M1 were functionally connected mainly to premotor and sensorimotor areas, posterior insula, putamen and thalamus. Behavioral characterization of the seeds confirmed that experiments

l-DOPA Decarboxylase (DDC) Expression Status as a Novel Molecular Tumor Marker for Diagnostic and Prognostic Purposes in Laryngeal Cancer1

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Patsis, Christos; Glyka, Vasiliki; Yiotakis, Ioannis; Fragoulis, Emmanuel G; Scorilas, Andreas

2012-01-01

l-DOPA decarboxylase (DDC) plays an essential role in the enzymatic synthesis of dopamine and alterations in its gene expression have been reported in several malignancies. Our objective was to analyze DDC messenger RNA (mRNA) and protein expression in laryngeal tissues and to evaluate the clinical implication of this molecule in laryngeal cancer. In this study, total RNA was isolated from 157 tissue samples surgically removed from 100 laryngeal cancer patients. A highly sensitive real-time polymerase chain reaction methodology based on SYBR Green I fluorescent dye was developed for the quantification of DDC mRNA levels. In addition, Western blot analysis was performed for the detection of DDC protein. DDC mRNA expression was revealed to be significantly downregulated in primary laryngeal cancer samples compared with their nonmalignant counterparts (P = .001). A significant negative association was also disclosed between DDC mRNA levels and TNM staging (P = .034). Univariate analysis showed that patients bearing DDC-positive tumors had a significantly decreased risk of death (hazard ratio = 0.23, P = .012) and local recurrence (hazard ratio = 0.32, P =.006), whereas DDC expression retained its favorable prognostic significance in the multivariate analysis. Kaplan-Meier curves further demonstrated that DDC-positive patients experienced longer overall and disease-free survival periods (P = .006 and P = .004, respectively). Moreover, DDC protein was detected in both neoplastic and noncancerous tissues. Therefore, our results suggest that DDC expression status could qualify as a promising biomarker for the future clinical management of laryngeal cancer patients. PMID:22937181

[sup 123]I-IBZM SPECT: Reconstruction methodology and results in Parkinsonism and dystonia

Energy Technology Data Exchange (ETDEWEB)

Berding, G [Abt. fuer Nuklearmedizin und Spezielle Biophysik, Medizinische Hochschule Hannover (Germany); Gratz, K F [Abt. fuer Nuklearmedizin und Spezielle Biophysik, Medizinische Hochschule Hannover (Germany); Kolbe, H [Neurologische Klinik mit Klinischer Neurophysiologie, Medizinische Hochschule Hannover (Germany); Meyer, G J [Abt. fuer Nuklearmedizin und Spezielle Biophysik, Medizinische Hochschule Hannover (Germany); Dengler, R [Neurologische Klinik mit Klinischer Neurophysiologie, Medizinische Hochschule Hannover (Germany); Knoop, B O [Abt. fuer Nuklearmesstechnik und Strahlenschutz, Medizinische Hochschule Hannover (Germany); Hundeshagen, H [Abt. fuer Nuklearmedizin und Spezielle Biophysik, Medizinische Hochschule Hannover (Germany)

1994-10-01

In 58 patients with Parkinsonism or dystonia striatal dopamine D[sub 2] receptors were investigated using [sup 123]I-iodobenzamide ([sup 123]I-IBZM) single-photon emission computed tomography (SPECT). The influence of SPECT reconstruction methodology on semiquantification and the clinical value of [sup 123]I-IBZM SPECT were evaluated. Delineation of the striatal uptake and striatum/frontal cortex (ST/FC) ratios were improved by the use of compensation procedures for scatter and attenuation as well as the choice of an adequate filter. Satisfactory results were achieved using a Metz prefilter with a comparatively high order number (i.e. high cut-off and low suppression of higher frequencies via roll-off). Regarding clinical diagnoses it was not possible to differentiate between advanced idiopathic Parkinson's disease (IP) and Parkinsonism of other aetiology (OP) on the basis of [sup 123]I-IBZM SPECT. But patients with IP and favourable response to L-Dopa showed significantly higher ST/FC ratios than those with fluctuating response. In patients with dystonia ST/FC ratios were significantly higher compared to patients with IP or OP. (orig.)

Chronic alcohol intake abolishes the relationship between dopamine synthesis capacity and learning signals in the ventral striatum

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Deserno, Lorenz; Beck, Anne; Huys, Quentin J. M.

2015-01-01

Drugs of abuse elicit dopamine release in the ventral striatum, possibly biasing dopamine-driven reinforcement learning towards drug-related reward at the expense of non-drug-related reward. Indeed, in alcohol-dependent patients, reactivity in dopaminergic target areas is shifted from non-drug......-related stimuli towards drug-related stimuli. Such ‘hijacked’ dopamine signals may impair flexible learning from non-drug-related rewards, and thus promote craving for the drug of abuse. Here, we used functional magnetic resonance imaging to measure ventral striatal activation by reward prediction errors (RPEs......) during a probabilistic reversal learning task in recently detoxified alcohol-dependent patients and healthy controls (N = 27). All participants also underwent 6-[18F]fluoro-DOPA positron emission tomography to assess ventral striatal dopamine synthesis capacity. Neither ventral striatal activation...

HIV infection results in ventral-striatal reward system hypo-activation during cue processing

NARCIS (Netherlands)

Plessis, Stéfan du; Vink, Matthijs; Joska, John A; Koutsilieri, Eleni; Bagadia, Asif; Stein, Dan J; Emsley, Robin

2015-01-01

OBJECTIVE: Functional MRI has thus far demonstrated that HIV has an impact on frontal-striatal systems involved in executive functioning. The potential impact of HIV on frontal-striatal systems involved in reward processing has yet to be examined by functional MRI. This study therefore aims to

The phosphorylation status and cytoskeletal remodeling of striatal astrocytes treated with quinolinic acid

International Nuclear Information System (INIS)

Pierozan, Paula; Ferreira, Fernanda; Ortiz de Lima, Bárbara; Gonçalves Fernandes, Carolina; Totarelli Monteforte, Priscila; Castro Medaglia, Natalia de; Bincoletto, Claudia; Soubhi Smaili, Soraya; Pessoa-Pureur, Regina

2014-01-01

Quinolinic acid (QUIN) is a glutamate agonist which markedly enhances the vulnerability of neural cells to excitotoxicity. QUIN is produced from the amino acid tryptophan through the kynurenine pathway (KP). Dysregulation of this pathway is associated with neurodegenerative conditions. In this study we treated striatal astrocytes in culture with QUIN and assayed the endogenous phosphorylating system associated with glial fibrillary acidic protein (GFAP) and vimentin as well as cytoskeletal remodeling. After 24 h incubation with 100 µM QUIN, cells were exposed to 32 P-orthophosphate and/or protein kinase A (PKA), protein kinase dependent of Ca 2+ /calmodulin II (PKCaMII) or protein kinase C (PKC) inhibitors, H89 (20 μM), KN93 (10 μM) and staurosporin (10 nM), respectively. Results showed that hyperphosphorylation was abrogated by PKA and PKC inhibitors but not by the PKCaMII inhibitor. The specific antagonists to ionotropic NMDA and non-NMDA (50 µM DL-AP5 and CNQX, respectively) glutamate receptors as well as to metabotropic glutamate receptor (mGLUR; 50 µM MCPG), mGLUR1 (100 µM MPEP) and mGLUR5 (10 µM 4C3HPG) prevented the hyperphosphorylation provoked by QUIN. Also, intra and extracellular Ca 2+ quelators (1 mM EGTA; 10 µM BAPTA-AM, respectively) prevented QUIN-mediated effect, while Ca 2+ influx through voltage-dependent Ca 2+ channel type L (L-VDCC) (blocker: 10 µM verapamil) is not implicated in this effect. Morphological analysis showed dramatically altered actin cytoskeleton with concomitant change of morphology to fusiform and/or flattened cells with retracted cytoplasm and disruption of the GFAP meshwork, supporting misregulation of actin cytoskeleton. Both hyperphosphorylation and cytoskeletal remodeling were reversed 24 h after QUIN removal. Astrocytes are highly plastic cells and the vulnerability of astrocyte cytoskeleton may have important implications for understanding the neurotoxicity of QUIN in neurodegenerative disorders. - Highlights: �

Beyond the Classic VTA: Extended Amygdala Projections to DA-Striatal Paths in the Primate.

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Fudge, Julie L; Kelly, Emily A; Pal, Ria; Bedont, Joseph L; Park, Lydia; Ho, Brian

2017-07-01

The central extended amygdala (CEA) has been conceptualized as a 'macrosystem' that regulates various stress-induced behaviors. Consistent with this, the CEA highly expresses corticotropin-releasing factor (CRF), an important modulator of stress responses. Stress alters goal-directed responses associated with striatal paths, including maladaptive responses such as drug seeking, social withdrawal, and compulsive behavior. CEA inputs to the midbrain dopamine (DA) system are positioned to influence striatal functions through mesolimbic DA-striatal pathways. However, the structure of this amygdala-CEA-DA neuron path to the striatum has been poorly characterized in primates. In primates, we combined neuronal tracer injections into various arms of the circuit through specific DA subpopulations to assess: (1) whether the circuit connecting amygdala, CEA, and DA cells follows CEA intrinsic organization, or a more direct topography involving bed nucleus vs central nucleus divisions; (2) CRF content of the CEA-DA path; and (3) striatal subregions specifically involved in CEA-DA-striatal loops. We found that the amygdala-CEA-DA path follows macrostructural subdivisions, with the majority of input/outputs converging in the medial central nucleus, the sublenticular extended amygdala, and the posterior lateral bed nucleus of the stria terminalis. The proportion of CRF+ outputs is >50%, and mainly targets the A10 parabrachial pigmented nucleus (PBP) and A8 (retrorubal field, RRF) neuronal subpopulations, with additional inputs to the dorsal A9 neurons. CRF-enriched CEA-DA projections are positioned to influence outputs to the 'limbic-associative' striatum, which is distinct from striatal regions targeted by DA cells lacking CEA input. We conclude that the concept of the CEA is supported on connectional grounds, and that CEA termination over the PBP and RRF neuronal populations can influence striatal circuits involved in associative learning.

Locally formed dopamine inhibits Na+-K+-ATPase activity in rat renal cortical tubule cells

International Nuclear Information System (INIS)

Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J.

1988-01-01

Dopamine, generated locally from L-dopa, inhibits Na + -K + -ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na + -K + -ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate (Qo 2 ) and 86 Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive Qo 2 or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive Qo 2 in a concentration-dependent manner, with half-maximal inhibition (K 0.5 ) of 5 x 10 -7 M and a maximal inhibition of 14.1 ± 1.5% at 10 -4 M. L-Dopa also blunted the nystatin-stimulated Qo 2 in a concentration-dependent manner, indicating the L-dopa directly inhibits Na + -K + -ATPase activity and not sodium entry. Ouabain-sensitive 86 Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive Qo 2 and 86 Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive Qo 2 at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na + -K + -ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner

The epidermal melanocyte system in individuals of Scandinavian origin, determined by DOPA-staining and TEM

DEFF Research Database (Denmark)

Drzewiecki, K T; Piltz-Drzewiecka, J

1979-01-01

The quantitative evaluation of DOPA-positive epidermal melanocytes in 16 patients of Scandinavian origin showed both individual and regional differences in the melanocyte count. Our data is in agreement with other published studies. The distribution in the number of melanocytes varies significant...

Motor tics evoked by striatal disinhibition in the rat

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Bronfeld, Maya; Yael, Dorin; Belelovsky, Katya; Bar-Gad, Izhar

2013-01-01

Motor tics are sudden, brief, repetitive movements that constitute the main symptom of Tourette syndrome (TS). Multiple lines of evidence suggest the involvement of the cortico-basal ganglia system, and in particular the basal ganglia input structure—the striatum in tic formation. The striatum receives somatotopically organized cortical projections and contains an internal GABAergic network of interneurons and projection neurons' collaterals. Disruption of local striatal GABAergic connectivity has been associated with TS and was found to induce abnormal movements in model animals. We have previously described the behavioral and neurophysiological characteristics of motor tics induced in monkeys by local striatal microinjections of the GABAA antagonist bicuculline. In the current study we explored the abnormal movements induced by a similar manipulation in freely moving rats. We targeted microinjections to different parts of the dorsal striatum, and examined the effects of this manipulation on the induced tic properties, such as latency, duration, and somatic localization. Tics induced by striatal disinhibition in monkeys and rats shared multiple properties: tics began within several minutes after microinjection, were expressed solely in the contralateral side, and waxed and waned around a mean inter-tic interval of 1–4 s. A clear somatotopic organization was observed only in rats, where injections to the anterior or posterior striatum led to tics in the forelimb or hindlimb areas, respectively. These results suggest that striatal disinhibition in the rat may be used to model motor tics such as observed in TS. Establishing this reliable and accessible animal model could facilitate the study of the neural mechanisms underlying motor tics, and the testing of potential therapies for tic disorders. PMID:24065893

Neuroglial plasticity at striatal glutamatergic synapses in Parkinson's disease

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Rosa M Villalba

2011-08-01

Full Text Available Striatal dopamine denervation is the pathological hallmark of Parkinson’s disease (PD. Another major pathological change described in animal models and PD patients is a significant reduction in the density of dendritic spines on medium spiny striatal projection neurons. Simultaneously, the ultrastructural features of the neuronal synaptic elements at the remaining corticostriatal and thalamostriatal glutamatergic axo-spinous synapses undergo complex ultrastructural remodeling consistent with increased synaptic activity (Villalba et al., 2011. The concept of tripartite synapses (TS was introduced a decade ago, according to which astrocytes process and exchange information with neuronal synaptic elements at glutamatergic synapses (Araque et al., 1999a. Although there has been compelling evidence that astrocytes are integral functional elements of tripartite glutamatergic synaptic complexes in the cerebral cortex and hippocampus, their exact functional role, degree of plasticity and preponderance in other CNS regions remain poorly understood. In this review, we discuss our recent findings showing that neuronal elements at cortical and thalamic glutamatergic synapses undergo significant plastic changes in the striatum of MPTP-treated parkinsonian monkeys. We also present new ultrastructural data that demonstrate a significant expansion of the astrocytic coverage of striatal TS synapses in the parkinsonian state, providing further evidence for ultrastructural compensatory changes that affect both neuronal and glial elements at TS. Together with our limited understanding of the mechanisms by which astrocytes respond to changes in neuronal activity and extracellular transmitter homeostasis, the role of both neuronal and glial components of excitatory synapses must be considered, if one hopes to take advantage of glia-neuronal communication knowledge to better understand the pathophysiology of striatal processing in parkinsonism, and develop new PD

Molecular substrates of action control in cortico-striatal circuits.

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Shiflett, Michael W; Balleine, Bernard W

2011-09-15

The purpose of this review is to describe the molecular mechanisms in the striatum that mediate reward-based learning and action control during instrumental conditioning. Experiments assessing the neural bases of instrumental conditioning have uncovered functional circuits in the striatum, including dorsal and ventral striatal sub-regions, involved in action-outcome learning, stimulus-response learning, and the motivational control of action by reward-associated cues. Integration of dopamine (DA) and glutamate neurotransmission within these striatal sub-regions is hypothesized to enable learning and action control through its role in shaping synaptic plasticity and cellular excitability. The extracellular signal regulated kinase (ERK) appears to be particularly important for reward-based learning and action control due to its sensitivity to combined DA and glutamate receptor activation and its involvement in a range of cellular functions. ERK activation in striatal neurons is proposed to have a dual role in both the learning and performance factors that contribute to instrumental conditioning through its regulation of plasticity-related transcription factors and its modulation of intrinsic cellular excitability. Furthermore, perturbation of ERK activation by drugs of abuse may give rise to behavioral disorders such as addiction. Copyright © 2011 Elsevier Ltd. All rights reserved.

The role of striatal NMDA receptors in drug addiction.

Science.gov (United States)

Ma, Yao-Ying; Cepeda, Carlos; Cui, Cai-Lian

2009-01-01

The past decade has witnessed an impressive accumulation of evidence indicating that the excitatory amino acid glutamate and its receptors, in particular the N-methyl-D-aspartate (NMDA) receptor subtype, play an important role in drug addiction. Various lines of research using animal models of drug addiction have demonstrated that drug-induced craving is accompanied by significant upregulation of NR2B subunit expression. Furthermore, selective blockade of NR2B-containing NMDA receptors in the striatum, especially in the nucleus accumbens (NAc) can inhibit drug craving and reinstatement. The purpose of this review is to examine the role of striatal NMDA receptors in drug addiction. After a brief description of glutamatergic innervation and NMDA receptor subunit distribution in the striatum, we discuss potential mechanisms to explain the role of striatal NMDA receptors in drug addiction by elucidating signaling cascades involved in the regulation of subunit expression and redistribution, phosphorylation of receptor subunits, as well as activation of intracellular signals triggered by drug experience. Understanding the mechanisms regulating striatal NMDA receptor changes in drug addiction will provide more specific and rational targets to counteract the deleterious effects of drug addiction.

In vivo evaluation of striatal dopamine reuptake sites using 11C-nomifensine and positron emission tomography

International Nuclear Information System (INIS)

Aquilonius, S.-M.; Bergstroem, K.; Eckernaes, S.-Aa.; Leenders, K.L.; Hartvig, P.; Lundquist, H.; Antoni, G.; Gee, A.; Rimland, A.; Uhlin, J.; Langstroem, B.

1987-01-01

In vitro nomifensine demonstrates high affinity and specificity for dopamine reuptake sites in the brain. In the present study 11 C-nomifensine was administered i.v. in trace amounts (10-50 μg) to ketamine anaesthetized Rhesus monkeys (6-10 kg b.w.) and the timecourse of radioactivity within different brain regions was measured by positron emission tomography (PET). Six base-line experiments lasting for 60-80 min were performed. The procedure was repeated after pretreatment with nomifensine (2-6 mg/kg i.v.), another reuptake inhibitor, mazindol (0.3 mg/kg i.v.), desipramine (0.5 mg/kg i.v.) or spiperone (0.3 mg/kg i.v.) before the administration of a second 11 C-nomifensine dose. The highest radioactivity uptake was found in the dopamine innervated striatum and the lowest in a region containing the cerebellum, known to be almost devoid of dopaminergic neurons. The difference between striatal and cerebellar uptake of 11 C-nomifensine derived radioactivity was markedly reduced after nomifensine and mazindol but not after desipramine and spiperone. These results indicate that in vivo the striatal uptake of 11 C-nomifensine, as measured with PET, involves specific binding with the dopamine reuptake sites. In the first human applications of 11 C-nomifensine and PET in a healthy volunteer, the regional uptake of radioactivity was similar to that in base-line experiments with Rhesus monkeys. In the healthy subject the striatal/cerebellar ratio was 1.6, 50 min after the injection of 11 C-nomifensine. In a hemi-parkinsonian patient this ratio was 1.1 contralaterally and 1.3 ipsilaterally to the affected side. 11 C-nomifensine and PET seems to be an auspicious method to measure the striatal dopaminergic nerve terminals of man in vivo. (author)

[3H]Dopamine accumulation and release from striatal slices in young, mature and senescent rats

International Nuclear Information System (INIS)

Thompson, J.M.

1981-01-01

Examinations of [ 3 H]dopamine ([ 3 H]DA) release following KCl or amphetamine administration in striatal slices from young (7 month), mature (12 month) and senescent (24 month) Wistar rats showed no age-related changes. Further, the amount of [ 3 H]DA accumulated in the striatal slices showed no changes with age. Thus, previously reported age-related deficits in motor behavior (i.e. rotational) are not produced by changes in striatal DA accumulation or release. (Auth.)

Lower levels of uric acid and striatal dopamine in non-tremor dominant Parkinson's disease subtype.

Directory of Open Access Journals (Sweden)

Ismael Huertas

Full Text Available Parkinson's disease (PD patients who present with tremor and maintain a predominance of tremor have a better prognosis. Similarly, PD patients with high levels of uric acid (UA, a natural neuroprotectant, have also a better disease course. Our aim was to investigate whether PD motor subtypes differ in their levels of UA, and if these differences correlate with the degree of dopamine transporter (DAT availability. We included 75 PD patients from whom we collected information about their motor symptoms, DAT imaging and UA concentration levels. Based on the predominance of their motor symptoms, patients were classified into postural instability and gait disorder (PIGD, n = 36, intermediate (I, n = 22, and tremor-dominant (TD, n = 17 subtypes. The levels of UA and striatal DAT were compared across subtypes and the correlation between these two measures was also explored. We found that PIGD patients had lower levels of UA (3.7 vs 4.5 vs 5.3 mg/dL; P<0.001 and striatal DAT than patients with an intermediate or TD phenotype. Furthermore, UA levels significantly correlated with the levels of striatal DAT. We also observed that some PIGD (25% and I (45% patients had a predominance of tremor at disease onset. We speculate that UA might be involved in the maintenance of the less damaging TD phenotype and thus also in the conversion from TD to PIGD. Low levels of this natural antioxidant could lead to a major neuronal damage and therefore influence the conversion to a more severe motor phenotype.

The monoamine reuptake inhibitor BTS 74 398 fails to evoke established dyskinesia but does not synergise with levodopa in MPTP-treated primates.

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Hansard, Matthew J; Smith, Lance A; Jackson, Michael J; Cheetham, Sharon C; Jenner, Peter

2004-01-01

Long-term treatment of Parkinson's disease (PD) with levodopa (L-dopa) induces dyskinesia that, once established, is provoked by each dose of L-dopa or a dopamine (DA) agonist. In contrast, monoamine reuptake inhibitors may reverse motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated primates without provoking established involuntary movements. We now examine whether the potent monoamine reuptake blocker BTS 74 398 induces established dyskinesia in MPTP-treated common marmosets primed previously with L-dopa and whether co-administration of BTS 74 398 with L-dopa potentiates motor behaviour and dyskinesia induced by acute L-dopa treatment. Administration of BTS 74 398 (2.5, 5.0, or 10.0 mg/kg, p.o.) in MPTP-treated common marmosets increased locomotor activity and reduced motor disability in a dose-related manner but did not provoke involuntary movements. BTS 74 398 (2.5, 5.0, or 10.0 mg/kg p.o.) co-administered with a threshold dose of L-dopa (2.5 mg/kg p.o.) did not evoke a motor response or induce dyskinesia. Similarly, concomitant administration of BTS 74 398 (5.0 mg/kg p.o.) with a submaximal L-dopa dose (12.5 mg/kg p.o.) did not potentiate the motor response produced by L-dopa alone and there was no alteration in the dyskinesia provoked by L-dopa challenge. BTS 74 398 reverses motor abnormalities in MPTP-treated marmosets without evoking established dyskinesia but no additive improvement occurs when administered in combination with L-dopa. The lack of synergy with L-dopa may suggest different sites of drug action. Copyright 2003 Movement Disorder Society

Role of contingency in striatal response to incentive in adolescents with anxiety.

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Benson, Brenda E; Guyer, Amanda E; Nelson, Eric E; Pine, Daniel S; Ernst, Monique

2015-03-01

This study examines the effect of contingency on reward function in anxiety. We define contingency as the aspect of a situation in which the outcome is determined by one's action-that is, when there is a direct link between one's action and the outcome of the action. Past findings in adolescents with anxiety or at risk for anxiety have revealed hypersensitive behavioral and neural responses to higher value rewards with correct performance. This hypersensitivity to highly valued (salient) actions suggests that the value of actions is determined not only by outcome magnitude, but also by the degree to which the outcome is contingent on correct performance. Thus, contingency and incentive value might each modulate reward responses in unique ways in anxiety. Using fMRI with a monetary reward task, striatal response to cue anticipation is compared in 18 clinically anxious and 20 healthy adolescents. This task manipulates orthogonally reward contingency and incentive value. Findings suggest that contingency modulates the neural response to incentive magnitude differently in the two groups. Specifically, during the contingent condition, right-striatal response tracks incentive value in anxious, but not healthy, adolescents. During the noncontingent condition, striatal response is bilaterally stronger to low than to high incentive in anxious adolescents, while healthy adolescents exhibit the expected opposite pattern. Both contingency and reward magnitude differentiate striatal activation in anxious versus healthy adolescents. These findings may reflect exaggerated concern about performance and/or alterations of striatal coding of reward value in anxious adolescents. Abnormalities in reward function in anxiety may have treatment implications.

Conformational reduction of DOPA in the gas phase studied by laser desorption supersonic jet laser spectroscopy.

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Ishiuchi, Shun-ichi; Mitsuda, Haruhiko; Asakawa, Toshiro; Miyazaki, Mitsuhiko; Fujii, Masaaki

2011-05-07

The conformational reduction in catecholamine neurotransmitters was studied by resonance enhanced multi photon ionization (REMPI), ultraviolet-ultraviolet (UV-UV) hole burning and infrared (IR) dip spectroscopy with applying a laser desorption supersonic jet technique to DOPA, which is one of the catecholamine neurotransmitters and has one more phenolic OH group than tyrosine. It is concluded that DOPA has a single observable conformer in the gas phase at low temperature. Quantum chemical calculations at several levels with or without the dispersion correction were also carried out to study stable conformations. From the comparison between the computational IR spectra and the experimental ones, the most stable structure was determined. It is strongly suggested that the conformational reduction is caused by electrostatic interactions, such as a dipole-dipole interaction, between the chain and OH groups. This journal is © the Owner Societies 2011

In vivo neurochemical characterization of clothianidin induced striatal dopamine release.

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Faro, L R F; Oliveira, I M; Durán, R; Alfonso, M

2012-12-16

Clothianidin (CLO) is a neonicotinoid insecticide with selective action on nicotinic acetylcholine receptors. The aim of this study was to determine the neurochemical basis for CLO-induced striatal dopamine release using the microdialysis technique in freely moving and conscious rats. Intrastriatal administration of CLO (3.5mM), produced an increase in both spontaneous (2462 ± 627% with respect to basal values) and KCl-evoked (4672 ± 706% with respect to basal values) dopamine release. This effect was attenuated in Ca(2+)-free medium, and was prevented in reserpine pre-treated animals or in presence of tetrodotoxin (TTX). To investigate the involvement of dopamine transporter (DAT), the effect of CLO was observed in presence of nomifensine. The coadministration of CLO and nomifensine produced an additive effect on striatal dopamine release. The results suggest that the effect of CLO on striatal dopamine release is predominantly mediated by an exocytotic mechanism, Ca(2+), vesicular and TTX-dependent and not by a mechanism mediated by dopamine transporter. Published by Elsevier Ireland Ltd.

Comparison of (68)Ga-DOTA-Tyr(3)-octreotide and (18)F-fluoro-L-dihydroxyphenylalanine positron emission tomography in neuroendocrine tumor patients.

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Putzer, D; Gabriel, M; Kendler, D; Henninger, B; Knoflach, M; Kroiss, A; Vonguggenberg, E; Warwitz, B; Virgolini, I J

2010-02-01

(68)Ga-DOTA-Tyr3-octreotide positron emission tomography ((68)Ga-DOTA-TOC PET) and (18)F-fluoro-L-dihydroxyphenylalanine PET ((18)F-DOPA PET) are emerging modalities for imaging of neuroendocrine tumors. This study reports our initial experiences with these two PET modalities on initial diagnosis, staging and restaging in NET patients. Fifteen patients with NET underwent both (68)Ga-DOTA-TOC and (18)F-DOPA PET as well as computed tomography (CT). Image findings were compared on a patient-basis (pathological uptake: yes/no) as well as on a lesion-basis. Contrast-enhanced CT and histological follow-up served as gold standard. Furthermore, imaging results were matched with tumor marker levels and quantitative tracer uptake by the tumor lesions. When comparing (68)Ga-DOTA-TOC and (18)F-DOPA PET, each modality showed a sensitivity of 64% and a specificity of 100% on a patient-based analysis. (68)Ga-DOTA-TOC PET and (18)F-DOPA PET showed equal findings in 7 out of 15 patients and disagreement in 8 patients. (68)Ga-DOTA-TOC revealed more metastases than (18)F-DOPA PET in 6 patients, while (18)F-DOPA PET detected more metastases than (68)Ga-DOTA-TOC in 4 patients. By (68)Ga-DOTA-TOC PET, 208 malignant lesions were detected, while by (18)F-DOPA only 86 lesions were found, and in CT 124, respectively. (68)Ga-DOTA-TOC and (18)F-DOPA PET are useful tools in the detection and staging of NET lesions. Our initial results allow the conclusion that (68)Ga-DOTA-TOC PET may have a stronger clinical impact in NET patients, as it does not only offer diagnostic information, but is decisive for the further treatment management, i. e. PRRT, as well.

Striatal dopamine release codes uncertainty in pathological gambling

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Linnet, Jakob; Mouridsen, Kim; Peterson, Ericka

2012-01-01

Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain—striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear...... function of expected reward and an inverse U-shaped function of uncertainty. In this study, we investigated the dopaminergic coding of reward and uncertainty in 18 pathological gambling sufferers and 16 healthy controls. We used positron emission tomography (PET) with the tracer [11C]raclopride to measure...... dopamine release, and we used performance on the Iowa Gambling Task (IGT) to determine overall reward and uncertainty. We hypothesized that we would find a linear function between dopamine release and IGT performance, if dopamine release coded reward in pathological gambling. If, on the other hand...

Striatal dopamine release codes uncertainty in pathological gambling

DEFF Research Database (Denmark)

Linnet, Jakob; Mouridsen, Kim; Peterson, Ericka

2012-01-01

Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain-striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear...... function of expected reward and an inverse U-shaped function of uncertainty. In this study, we investigated the dopaminergic coding of reward and uncertainty in 18 pathological gambling sufferers and 16 healthy controls. We used positron emission tomography (PET) with the tracer [(11)C......]raclopride to measure dopamine release, and we used performance on the Iowa Gambling Task (IGT) to determine overall reward and uncertainty. We hypothesized that we would find a linear function between dopamine release and IGT performance, if dopamine release coded reward in pathological gambling. If, on the other hand...

Levodopa administration modulates striatal processing of punishment-associated items in healthy participants.

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Wittmann, Bianca C; D'Esposito, Mark

2015-01-01

Appetitive and aversive processes share a number of features such as their relevance for action and learning. On a neural level, reward and its predictors are associated with increased firing of dopaminergic neurons, whereas punishment processing has been linked to the serotonergic system and to decreases in dopamine transmission. Recent data indicate, however, that the dopaminergic system also responds to aversive stimuli and associated actions. In this pharmacological functional magnetic resonance imaging study, we investigated the contribution of the dopaminergic system to reward and punishment processing in humans. Two groups of participants received either placebo or the dopamine precursor levodopa and were scanned during alternating reward and punishment anticipation blocks. Levodopa administration increased striatal activations for cues presented in punishment blocks. In an interaction with individual personality scores, levodopa also enhanced striatal activation for punishment-predictive compared with neutral cues in participants scoring higher on the novelty-seeking dimension. These data support recent indications that dopamine contributes to punishment processing and suggest that the novelty-seeking trait is a measure of susceptibility to drug effects on motivation. These findings are also consistent with the possibility of an inverted U-shaped response function of dopamine in the striatum, suggesting an optimal level of dopamine release for motivational processing.

Emotion-induced loss aversion and striatal-amygdala coupling in low-anxious individuals.

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Charpentier, Caroline J; De Martino, Benedetto; Sim, Alena L; Sharot, Tali; Roiser, Jonathan P

2016-04-01

Adapting behavior to changes in the environment is a crucial ability for survival but such adaptation varies widely across individuals. Here, we asked how humans alter their economic decision-making in response to emotional cues, and whether this is related to trait anxiety. Developing an emotional decision-making task for functional magnetic resonance imaging, in which gambling decisions were preceded by emotional and non-emotional primes, we assessed emotional influences on loss aversion, the tendency to overweigh potential monetary losses relative to gains. Our behavioral results revealed that only low-anxious individuals exhibited increased loss aversion under emotional conditions. This emotional modulation of decision-making was accompanied by a corresponding emotion-elicited increase in amygdala-striatal functional connectivity, which correlated with the behavioral effect across participants. Consistent with prior reports of 'neural loss aversion', both amygdala and ventral striatum tracked losses more strongly than gains, and amygdala loss aversion signals were exaggerated by emotion, suggesting a potential role for this structure in integrating value and emotion cues. Increased loss aversion and striatal-amygdala coupling induced by emotional cues may reflect the engagement of adaptive harm-avoidance mechanisms in low-anxious individuals, possibly promoting resilience to psychopathology. © The Author (2015). Published by Oxford University Press.

Opposite Effects of Stimulant and Antipsychotic Drugs on Striatal Fast-Spiking Interneurons

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Wiltschko, Alexander B; Pettibone, Jeffrey R; Berke, Joshua D

2010-01-01

Psychomotor stimulants and typical antipsychotic drugs have powerful but opposite effects on mood and behavior, largely through alterations in striatal dopamine signaling. Exactly how these drug actions lead to behavioral change is not well understood, as previous electrophysiological studies have found highly heterogeneous changes in striatal neuron firing. In this study, we examined whether part of this heterogeneity reflects the mixture of distinct cell types present in the striatum, by di...

Repeated cocaine administration results in supersensitivity of striatal D-2 dopamine autoreceptors to pergolide

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Dwoskin, L.P.; Peris, J.; Yasuda, R.P.; Philpott, K.; Zahniser, N.R.

1988-01-01

Groups of rats administered cocaine-HCl (10 mg/kg, i.p.) or saline either acutely or once daily for 8 or 14 days were killed 24 hrs after the last dose. In striatal slices prelabelled with [ 3 H]DA, modulation of [ 3 H]-overflow by pergolide was used to measure D-2 autoreceptor activity. Compared to the contemporaneous control group pergolide produced a greater inhibition only in striatal slices from rats treated repeatedly with cocaine. In radioligand binding studies using striatal membranes from control rats, pergolide had a 500-fold greater affinity for the D-2, as opposed to the D-1, dopamine (DA) receptor subtype. These results indicate that repeated treatment with cocaine produces supersensitive striatal D-2 release-modulating autoreceptors consistent with a compensatory change to diminish the effect of elevated synaptic concentrations of DA produced by cocaine. In contrast, supersensitivity of D-2 receptors was not detected in [ 3 H]spiperone binding assays. 31 references, 2 figures, 1 table

Locally formed dopamine inhibits Na sup + -K sup + -ATPase activity in rat renal cortical tubule cells

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Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J. (Harvard Medical School, Boston, MA (USA) Karolinska Institute, Stockholm (Sweden))

1988-10-01

Dopamine, generated locally from L-dopa, inhibits Na{sup +}-K{sup +}-ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na{sup +}-K{sup +}-ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate ({dot Q}o{sub 2}) and {sup 86}Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive {dot Q}o{sub 2} or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive {dot Q}o{sub 2} in a concentration-dependent manner, with half-maximal inhibition (K{sub 0.5}) of 5 {times} 10{sup {minus}7} M and a maximal inhibition of 14.1 {plus minus} 1.5% at 10{sup {minus}4}M. L-Dopa also blunted the nystatin-stimulated {dot Q}o{sub 2} in a concentration-dependent manner, indicating the L-dopa directly inhibits Na{sup +}-K{sup +}-ATPase activity and not sodium entry. Ouabain-sensitive {sup 86}Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} and {sup 86}Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na{sup +}-K{sup +}-ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner.

Striatal pre-enkephalin overexpression improves Huntington's disease symptoms in the R6/2 mouse model of Huntington's disease.

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Stéphanie Bissonnette

Full Text Available The reduction of pre-enkephalin (pENK mRNA expression might be an early sign of striatal neuronal dysfunction in Huntington's disease (HD, due to mutated huntingtin protein. Indeed, striatopallidal (pENK-containing neurodegeneration occurs at earlier stage of the disease, compare to the loss of striatonigral neurons. However, no data are available about the functional role of striatal pENK in HD. According to the neuroprotective properties of opioids that have been recognized recently, the objective of this study was to investigate whether striatal overexpression of pENK at early stage of HD can improve motor dysfunction, and/or reduce striatal neuronal loss in the R6/2 transgenic mouse model of HD. To achieve this goal recombinant adeno-associated-virus (rAAV2-containing green fluorescence protein (GFP-pENK was injected bilaterally in the striatum of R6/2 mice at 5 weeks old to overexpress opioid peptide pENK. Striatal injection of rAAV2-GFP was used as a control. Different behavioral tests were carried out before and/or after striatal injections of rAAV2. The animals were euthanized at 10 weeks old. Our results demonstrate that striatal overexpression of pENK had beneficial effects on behavioral symptoms of HD in R6/2 by: delaying the onset of decline in muscular force; reduction of clasping; improvement of fast motor activity, short-term memory and recognition; as well as normalization of anxiety-like behavior. The improvement of behavioral dysfunction in R6/2 mice having received rAAV2-GFP-pENK associated with upregulation of striatal pENK mRNA; the increased level of enkephalin peptide in the striatum, globus pallidus and substantia nigra; as well as the slight increase in the number of striatal neurons compared with other groups of R6/2. Accordingly, we suggest that at early stage of HD upregulation of striatal enkephalin might play a key role at attenuating illness symptoms.

Disturbed neural circuits in a subtype of chronic catatonic schizophrenia demonstrated by F-18-FDG-PET and F-18-DOPA-PET

International Nuclear Information System (INIS)

Lauer, M.; Beckmann, H.; Stoeber, G.; Schirrmeister, H.; Gerhard, A.; Ellitok, E.; Reske, S.N.

2001-01-01

Permanent verbal, visual scenic and coenaestetic hallucinations are the most prominent psychopathological symptoms aside from psychomotor disorders in speech-sluggish catatonia, a subtype of chronic catatonic schizophrenia according to Karl Leonhard. These continuous hallucinations serve as an excellent paradigm for the investigation of the assumed functional disturbances of cortical circuits in schizophrenia. Data from positron emission tomography (F-18-FDG-PET and F-18-DOPA-PET) from three patients with this rare phenotype were available (two cases of simple speech-sluggish catatonia, one case of a combined speech-prompt/speech-sluggish subtype) and were compared with a control collective. During their permanent hallucinations, all catatonic patients showed a clear bitemporal hypometabolism in the F-18-FDG-PET. Both patients with the simple speech-sluggish catatonia showed an additional bilateral thalamic hypermetabolism and an additional bilateral hypometabolism of the frontal cortex, especially on the left side. In contrast, the patient with the combined speech-prompt/speech-sluggish catatonia showed a bilateral thalamic hypo-metabolism combined with a bifrontal cortical hypermetabolism. However, the left/right ratio of the frontal cortex also showed a lateralization effect with a clear relative hypometabolism of the left frontal cortex. The F-18-DOPA-PET of both schizophrenic patients with simple speech-sluggish catatonia showed a normal F-18-DOPA storage in the striatum, whereas in the right putamen of the patient with the combined form a higher right/left ratio in F-DOPA storage was discernible, indicating an additional lateralized influence of the dopaminergic system in this subtype of chronic catatonic schizophrenia. (author)

Adrenergic receptor-mediated modulation of striatal firing patterns.

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Ohta, Hiroyuki; Kohno, Yu; Arake, Masashi; Tamura, Risa; Yukawa, Suguru; Sato, Yoshiaki; Morimoto, Yuji; Nishida, Yasuhiro; Yawo, Hiromu

2016-11-01

Although noradrenaline and adrenaline are some of the most important neurotransmitters in the central nervous system, the effects of noradrenergic/adrenergic modulation on the striatum have not been determined. In order to explore the effects of adrenergic receptor (AR) agonists on the striatal firing patterns, we used optogenetic methods which can induce continuous firings. We employed transgenic rats expressing channelrhodopsin-2 (ChR2) in neurons. The medium spiny neuron showed a slow rising depolarization during the 1-s long optogenetic striatal photostimulation and a residual potential with 8.6-s half-life decay after the photostimulation. As a result of the residual potential, five repetitive 1-sec long photostimulations with 20-s onset intervals cumulatively increased the number of spikes. This 'firing increment', possibly relating to the timing control function of the striatum, was used to evaluate the AR modulation. The β-AR agonist isoproterenol decreased the firing increment between the 1st and 5th stimulation cycles, while the α 1 -AR agonist phenylephrine enhanced the firing increment. Isoproterenol and adrenaline increased the early phase (0-0.5s of the photostimulation) firing response. This adrenergic modulation was inhibited by the β-antagonist propranolol. Conversely, phenylephrine and noradrenaline reduced the early phase response. β-ARs and α 1 -ARs work in opposition controlling the striatal firing initiation and the firing increment. Copyright © 2016 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

The relation of putamen nucleus 6-[18F]fluoro-L-m-tyrosine uptake to total Unified Parkinson's Disease Rating Scale scores

International Nuclear Information System (INIS)

Buchy, R.

2002-01-01

The contribution of dopaminergic deficiency in the striatum to the severity of locomotor disability in Parkinson's disease has been consistently shown with 6-[ 18 F]fluoro-L-DOPA in positron emission tomography. Recently, 6-[ 18 F]fluoro-L-m-tyrosine, an alternative tracer with similar distribution kinetics has been used to facilitate data analysis. Locomotor disability in Parkinson's disease can be measured using the Unified Parkinson's Disease Rating Scale. The Unified Parkinson's Disease Rating Scale was used in conjunction with 6-[ 18 F]fluoro-L-m-tyrosine -PET to clinically examine a group of five Parkinson's disease patients. An inverse relation similar to that previously demonstrated with 6-[ 18 F]fluoro-L-DOPA was found between the putamen nucleus 6-[ 18 F]fluoro-L-m-tyrosine influx constant and Unified Parkinson's Disease Rating Scale score. This finding suggests that like 6-[ 18 F]fluoro-L-m-tyrosine can be used to accurately measure the degree of locomotor disability caused by Parkinson's disease. (author)

Contributions of positron emission tomography to elucidating the pathogenesis of idiopathic Parkinsonism and dopa responsive dystonia

International Nuclear Information System (INIS)

Calne, D.B.; Fuente-Fernandez, R. de la; Kishore, A.

1996-01-01

The metabolic mapping of brain activity. using PET, confirms the conventional wisdom of neurophysiology. In studies of pathophysiology, PET has yielded evidence that has generated new hypotheses. Progression of the lesion detectable with fluorodopa, in human subjects exposed to MPTP, raises the possibility of a transient environmental event being a cause of progressive neurodegeneration. Studies with fluorodopa in Idiopathic Parkinsonism indicate that the rate of loss of neurons is faster initially, and then tends to approach the normal age-related decline. In dopa responsive dystonia, the finding of normal fluorodopa PET led to the prediction that the lesion would be functional rather than anatomical; this has been confirmed by the identification of a defect in dopamine synthesis in this disorder. Finally, new PET ligands show promise for future studies designed to unravel the pathogenesis of diseases involving the basal ganglia. (author)

The preparation and antibacterial effects of dopa-cotton/AgNPs

International Nuclear Information System (INIS)

Xu Hong; Shi Xue; Ma Hui; Lv Yihang; Zhang Linping; Mao Zhiping

2011-01-01

Silver nanoparticles (AgNPs) have been known to have powerful antibacterial activity. In this paper, in situ generation of AgNPs on the surface of dopamine modified cotton fabrics (dopa-cotton/AgNPs) in aqueous solution under room temperature is presented. X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FE-SEM) were used to analyze the surface chemical composition and the morphology of the modified cotton fabrics, respectively. The results indicated that the surface of cotton fabrics was successfully coated with polydopamine and AgNPs. The cotton fabrics with AgNPs showed durable antibacterial activity.

Attenuation of antagonist-induced impairment of dopamine receptors by L-prolyl-L-leucyl-glycinamide

International Nuclear Information System (INIS)

Saleh, M.I.M.

1988-01-01

The present study was undertaken in order to determine whether chronic,long-term postnatal challenge of rat pups per se, with specific dopamine D1 and D2 receptor antagonists, would modify the ontogeny of the respective receptor types. Since the neuropeptide L-prolyl-L-leucyl-glycinamide (PLG) attenuates the effect of haloperidol on dopamine D2 receptors in adult rats it was of interest to determine whether PLG would modulate antagonists-induced alterations in the ontogeny of striatal dopamine D1 and D2 receptors. Half of the rats were treated daily for 32 days from birth with SCH-23390, a selective dopamine D1 antagonist; or spiroperidol, a selective dopamine D2 antagonists; or both SCH-23390 and spiroperidol; or saline. The other half of the litters were treated with PLG, in combination with the other treatments. Animals were decapitated at 5, 8, and 12 weeks from birth for neurochemical analysis of the striatum. Chronic SCH-23390 treatment produced a 70-80% decrease in the binding of [ 3 H] SCH-23390 to striatal homogenates. The alteration at 5 weeks was associated with a 78% decrease in the Bmax for [ 3 H] SCH-23390 binding, and no change in the K D . Similarly, at 5, 8, and 12 weeks, chronic spiroperidol treatment reduced the binding of [ 3 H] spiroperidol to striatal homogenates by 70-80%

The phosphorylation status and cytoskeletal remodeling of striatal astrocytes treated with quinolinic acid

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Pierozan, Paula; Ferreira, Fernanda; Ortiz de Lima, Bárbara; Gonçalves Fernandes, Carolina [Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003 (Brazil); Totarelli Monteforte, Priscila; Castro Medaglia, Natalia de; Bincoletto, Claudia; Soubhi Smaili, Soraya [Departamento de Farmacologia, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP (Brazil); Pessoa-Pureur, Regina, E-mail: rpureur@ufrgs.br [Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003 (Brazil)

2014-04-01

Quinolinic acid (QUIN) is a glutamate agonist which markedly enhances the vulnerability of neural cells to excitotoxicity. QUIN is produced from the amino acid tryptophan through the kynurenine pathway (KP). Dysregulation of this pathway is associated with neurodegenerative conditions. In this study we treated striatal astrocytes in culture with QUIN and assayed the endogenous phosphorylating system associated with glial fibrillary acidic protein (GFAP) and vimentin as well as cytoskeletal remodeling. After 24 h incubation with 100 µM QUIN, cells were exposed to {sup 32}P-orthophosphate and/or protein kinase A (PKA), protein kinase dependent of Ca{sup 2+}/calmodulin II (PKCaMII) or protein kinase C (PKC) inhibitors, H89 (20 μM), KN93 (10 μM) and staurosporin (10 nM), respectively. Results showed that hyperphosphorylation was abrogated by PKA and PKC inhibitors but not by the PKCaMII inhibitor. The specific antagonists to ionotropic NMDA and non-NMDA (50 µM DL-AP5 and CNQX, respectively) glutamate receptors as well as to metabotropic glutamate receptor (mGLUR; 50 µM MCPG), mGLUR1 (100 µM MPEP) and mGLUR5 (10 µM 4C3HPG) prevented the hyperphosphorylation provoked by QUIN. Also, intra and extracellular Ca{sup 2+} quelators (1 mM EGTA; 10 µM BAPTA-AM, respectively) prevented QUIN-mediated effect, while Ca{sup 2+} influx through voltage-dependent Ca{sup 2+} channel type L (L-VDCC) (blocker: 10 µM verapamil) is not implicated in this effect. Morphological analysis showed dramatically altered actin cytoskeleton with concomitant change of morphology to fusiform and/or flattened cells with retracted cytoplasm and disruption of the GFAP meshwork, supporting misregulation of actin cytoskeleton. Both hyperphosphorylation and cytoskeletal remodeling were reversed 24 h after QUIN removal. Astrocytes are highly plastic cells and the vulnerability of astrocyte cytoskeleton may have important implications for understanding the neurotoxicity of QUIN in neurodegenerative

Atypical presentation of dopa-responsive dystonia in Taiwan.

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Weng, Yi Ching; Wang, Chun Chieh; Wu, Yih Ru

2018-02-01

The typical clinical presentation of dopa-responsive dystonia, which is also called Segawa disease, is a young age of onset, with predominance in females, diurnal fluctuation of lower limb dystonia, and fair response to low-dose levodopa. This disease has both autosomal dominant and autosomal recessive inheritance. Autosomal dominant Segawa disease is caused by GCH1 mutation on chromosome 14q22.1-q22.2. Here, we report the case of a male patient with genetically confirmed Segawa disease and atypical presentations including no diurnal symptom fluctuation and insufficient response to levodopa. The patient's father who had the same mutation presented parkinsonism in old age. We also review the literature to address the broad clinical heterogeneity of Segawa disease and the influence of onset age on clinical presentation.

18F-DOPA PET/CT and MRI Findings in a Patient With Multiple Meningiomas.

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Calabria, Ferdinando F; Chiaravalloti, Agostino; Calabria, Eros N; Grillea, Giovanni; Schillaci, Orazio

2016-08-01

A 56-year-old man was referred to our Department for a 2-year story of upper limb tremor, severe headache, and episodes of confusion. Brain F-DOPA PET/CT showed multiple areas of tracer uptake in the two hemispheres of the brain. Subsequent MRI displayed demyelinating foci with high contrast enhancement. Histological specimen confirmed the diagnosis of multiple meningiomas.

Transient and steady-state selection in the striatal microcircuit

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Adam eTomkins

2014-01-01

Full Text Available Although the basal ganglia have been widely studied and implicated in signal processing and action selection, little information is known about the active role the striatal microcircuit plays in action selection in the basal ganglia-thalamo-cortical loops. To address this knowledge gap we use a large scale three dimensional spiking model of the striatum, combined with a rate coded model of the basal ganglia-thalamo-cortical loop, to asses the computational role the striatum plays in action selection. We identify a robust transient phenomena generated by the striatal microcircuit, which temporarily enhances the difference between two competing cortical inputs. We show that this transient is sufficient to modulate decision making in the basal ganglia-thalamo-cortical circuit. We also find that the transient selection originates from a novel adaptation effect in single striatal projection neurons, which is amenable to experimental testing. Finally, we compared transient selection with models implementing classical steady-state selection. We challenged both forms of model to account for recent reports of paradoxically enhanced response selection in Huntington's Disease patients. We found that steady-state selection was uniformly impaired under all simulated Huntington's conditions, but transient selection was enhanced given a sufficient Huntington's-like increase in NMDA receptor sensitivity. Thus our models provide an intriguing hypothesis for the mechanisms underlying the paradoxical cognitive improvements in manifest Huntington's patients.

No correlation between body mass index and striatal dopamine transporter availability in healthy volunteers using SPECT and ^[123I]PE2I

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Thomsen, G; Ziebell, M; Jensen, Peter Steen

2013-01-01

Objective: Dopamine plays an important role in both the rewarding and conditioning effects of food. These effects involve mesolimbic, mesocortical, and nigrostriatal pathways. In humans, the most consistent finding has been reduced striatal dopamine D-2/3 receptor availability. In striatum...... controls (BMI...

Frontal, Striatal, and Medial Temporal Sensitivity to Value Distinguishes Risk-Taking from Risk-Aversive Older Adults during Decision Making.

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Goh, Joshua O S; Su, Yu-Shiang; Tang, Yong-Jheng; McCarrey, Anna C; Tereshchenko, Alexander; Elkins, Wendy; Resnick, Susan M

2016-12-07

Aging compromises the frontal, striatal, and medial temporal areas of the reward system, impeding accurate value representation and feedback processing critical for decision making. However, substantial variability characterizes age-related effects on the brain so that some older individuals evince clear neurocognitive declines whereas others are spared. Moreover, the functional correlates of normative individual differences in older-adult value-based decision making remain unclear. We performed a functional magnetic resonance imaging study in 173 human older adults during a lottery choice task in which costly to more desirable stakes were depicted using low to high expected values (EVs) of points. Across trials that varied in EVs, participants decided to accept or decline the offered stakes to maximize total accumulated points. We found that greater age was associated with less optimal decisions, accepting stakes when losses were likely and declining stakes when gains were likely, and was associated with increased frontal activity for costlier stakes. Critically, risk preferences varied substantially across older adults and neural sensitivity to EVs in the frontal, striatal, and medial temporal areas dissociated risk-aversive from risk-taking individuals. Specifically, risk-averters increased neural responses to increasing EVs as stakes became more desirable, whereas risk-takers increased neural responses with decreasing EV as stakes became more costly. Risk preference also modulated striatal responses during feedback with risk-takers showing more positive responses to gains compared with risk-averters. Our findings highlight the frontal, striatal, and medial temporal areas as key neural loci in which individual differences differentially affect value-based decision-making ability in older adults. Frontal, striatal, and medial temporal functions implicated in value-based decision processing of rewards and costs undergo substantial age-related changes. However, age

Neuroprotective effects of curcumin and highly bioavailable curcumin on oxidative stress induced by sodium nitroprusside in rat striatal cell culture.

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Nazari, Qand Agha; Kume, Toshiaki; Izuo, Naotaka; Takada-Takatori, Yuki; Imaizumi, Atsushi; Hashimoto, Tadashi; Izumi, Yasuhiko; Akaike, Akinori

2013-01-01

Curcumin, a polyphenolic compound extracted from Curcuma longa, has several pharmacological activities such as anticancer, anti-inflammatory, and antioxidant effects. The purpose of this study was to investigate the protective effects of curcumin and THERACURMIN, a highly bioavailable curcumin, against sodium nitroprusside (SNP)-induced oxidative damage in primary striatal cell culture. THERACURMIN as well as curcumin significantly prevented SNP-induced cytotoxicity. To elucidate the cytoprotective effects of curcumin and THERACURMIN, we measured the intracellular glutathione level in striatal cells. Curcumin and THERACURMIN significantly elevated the glutathione level, which was decreased by treatment with SNP. Moreover, curcumin showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability. Finally, a ferrozine assay showed that curcumin (10-100 µg/mL) has potent Fe(2+)-chelating ability. These results suggest that curcumin and THERACURMIN exert potent protective effects against SNP-induced cytotoxicity by free radical-scavenging and iron-chelating activities.

Local cerebral metabolic rate of glucose (lCMRGlc) in treated and untreated patients with Parkinson's disease

International Nuclear Information System (INIS)

Rougemont, D.; Baron, J.C.; Collard, P.; Bustany, P.; Comar, D.; Agid, Y.

1983-06-01

Local cerebral metabolic rate of glucose (lCMRGlc) was measured twice, using positron emission tomography and 18 F-Fluoro-2-deoxy-D-glucose ( 18 FDG), in 4 patients with Parkinson disease, first unmedicated and then treated with L-DOPA. Despite a dramatic clinical improvement, no significant changes in lCMRGlc could be detected. Moreover, no reproducible differences of lCMRGlc were found between patients with Parkinson disease and with normal brain

Striatal lesions produce distinctive impairments in reaction time performance in two different operant chambers.

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Brasted, P J; Döbrössy, M D; Robbins, T W; Dunnett, S B

1998-08-01

The dorsal striatum plays a crucial role in mediating voluntary movement. Excitotoxic striatal lesions in rats have previously been shown to impair the initiation but not the execution of movement in a choice reaction time task in an automated lateralised nose-poke apparatus (the "nine-hole box"). Conversely, when a conceptually similar reaction time task has been applied in a conventional operant chamber (or "Skinner box"), striatal lesions have been seen to impair the execution rather than the initiation of the lateralised movement. The present study was undertaken to compare directly these two results by training the same group of rats to perform a choice reaction time task in the two chambers and then comparing the effects of a unilateral excitotoxic striatal lesion in both chambers in parallel. Particular attention was paid to adopting similar parameters and contingencies in the control of the task in the two test chambers. After striatal lesions, the rats showed predominantly contralateral impairments in both tasks. However, they showed a deficit in reaction time in the nine-hole box but an apparent deficit in response execution in the Skinner box. This finding confirms the previous studies and indicates that differences in outcome are not simply attributable to procedural differences in the lesions, training conditions or tasks parameters. Rather, the pattern of reaction time deficit after striatal lesions depends critically on the apparatus used and the precise response requirements for each task.

Neuroinflammation alters voltage-dependent conductance in striatal astrocytes.

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Karpuk, Nikolay; Burkovetskaya, Maria; Kielian, Tammy

2012-07-01

Neuroinflammation has the capacity to alter normal central nervous system (CNS) homeostasis and function. The objective of the present study was to examine the effects of an inflammatory milieu on the electrophysiological properties of striatal astrocyte subpopulations with a mouse bacterial brain abscess model. Whole cell patch-clamp recordings were performed in striatal glial fibrillary acidic protein (GFAP)-green fluorescent protein (GFP)(+) astrocytes neighboring abscesses at postinfection days 3 or 7 in adult mice. Cell input conductance (G(i)) measurements spanning a membrane potential (V(m)) surrounding resting membrane potential (RMP) revealed two prevalent astrocyte subsets. A1 and A2 astrocytes were identified by negative and positive G(i) increments vs. V(m), respectively. A1 and A2 astrocytes displayed significantly different RMP, G(i), and cell membrane capacitance that were influenced by both time after bacterial exposure and astrocyte proximity to the inflammatory site. Specifically, the percentage of A1 astrocytes was decreased immediately surrounding the inflammatory lesion, whereas A2 cells were increased. These changes were particularly evident at postinfection day 7, revealing increased cell numbers with an outward current component. Furthermore, RMP was inversely modified in A1 and A2 astrocytes during neuroinflammation, and resting G(i) was increased from 21 to 30 nS in the latter. In contrast, gap junction communication was significantly decreased in all astrocyte populations associated with inflamed tissues. Collectively, these findings demonstrate the heterogeneity of striatal astrocyte populations, which experience distinct electrophysiological modifications in response to CNS inflammation.

Potential radiopharmaceuticals for the detection of ocular melanoma. Pt. 3

International Nuclear Information System (INIS)

Langevelde, A. van; Molen, H.D. van der; Journee-de Korver, J.G.; Paans, A.M.J.; Pauwels, E.K.J.; Vaalburg, W.; Rijksuniversiteit Leiden

1988-01-01

In order to investigate the possibility of using [1- 11 C] labelled 3,4-dihydroxyphenylalanine (DOPA) and tyrosine as radiopharmaceuticals for the detection of eye melanoma, the biodistributions of the same 1- and 3- 14 C-labelled compounds were investigated in Syrian golden hamsters with Greene melanoma. The results of these investigations were compared with positron emission tomography (PET) images of 11 C labelled DOPA and tyrosine. The synthesis of these 11 C labelled compounds procures of DL mixture, from which D and L forms can be separated. One h after intravenous injection, both 14 C labelled DL-, L- and D-DOPA showed a high uptake in tumour tissue, that of DL- and D-DOPA being the highest. These high uptakes, together with relatively low uptake in bone, skin and eye resulted in high tumour/non tumour ratio (for DL-DOPA 5.9, 4.5 and 6.6 respectively). Extraction of the tumour tissue with trichloroacetic acid showed that L-DOPA was mainly incorporated into melanin, whereas D-DOPA was not. Also, the uptake 1 h after intravenous injection of 1- 14 C-L- and DL-tyrosine into the tumour were high, but L- and DL- were less different; tumour/non tomour ratios were favorable. PET images of the tumour obtained 40-80 min after injection of the [1- 11 C] labelled DOPA and tyrosine confirmed that melanoma detection was promising and that D-DOPA produced a better melanoma image than L-DOPA. (orig.)

Elevated Striatal Reactivity Across Monetary and Social Rewards in Bipolar I Disorder

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Dutra, Sunny J.; Cunningham, William A.; Kober, Hedy; Gruber, June

2016-01-01

Bipolar disorder (BD) is associated with increased reactivity to rewards and heightened positive affectivity. It is less clear to what extent this heightened reward sensitivity is evident across contexts and what the associated neural mechanisms might be. The present investigation employed both a monetary and social incentive delay task among adults with remitted BD type I (N=24) and a healthy non-psychiatric control group (HC; N=25) using fMRI. Both whole-brain and region-of-interest analyses revealed elevated ventral and dorsal striatal reactivity across monetary and social reward receipt, but not anticipation, in the BD group. Post-hoc analyses further suggested that greater striatal reactivity to reward receipt across monetary and social reward tasks predicted decreased self-reported positive affect when anticipating subsequent rewards in the HC, but not BD, group. Results point toward elevated striatal reactivity to reward receipt as a potential neural mechanism of reward reactivity. PMID:26390194

Mitochondrial fragmentation in neuronal degeneration: Toward an understanding of HD striatal susceptibility

International Nuclear Information System (INIS)

Cherubini, Marta; Ginés, Silvia

2017-01-01

Huntington's disease (HD) is an autosomal-dominant progressive neurodegenerative disorder that primarily affects medium spiny neurons within the striatum. HD is caused by inheritance of an expanded CAG repeat in the HTT gene, resulting in a mutant huntingtin (mHtt) protein containing extra glutamine residues. Despite the advances in understanding the molecular mechanisms involved in HD the preferential vulnerability of the striatum remains an intriguing question. This review discusses current knowledge that links altered mitochondrial dynamics with striatal susceptibility in HD. We also highlight how the modulation of mitochondrial function may constitute an attractive therapeutic approach to reduce mHtt-induced toxicity and therefore prevent the selective striatal neurodegeneration. - Highlights: • Mitochondrial dynamics is unbalanced towards fission in HD. • Excessive mitochondrial fragmentation plays a critical role in the selective vulnerability of the striatum in HD. • Therapeutic approaches aimed to inhibit mitochondrial fission could contribute to prevent striatal neurodegeneration in HD.

Distinctive striatal dopamine signaling after dieting and gastric bypass.

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Hankir, Mohammed K; Ashrafian, Hutan; Hesse, Swen; Horstmann, Annette; Fenske, Wiebke K

2015-05-01

Highly palatable and/or calorically dense foods, such as those rich in fat, engage the striatum to govern and set complex behaviors. Striatal dopamine signaling has been implicated in hedonic feeding and the development of obesity. Dieting and bariatric surgery have markedly different outcomes on weight loss, yet how these interventions affect central homeostatic and food reward processing remains poorly understood. Here, we propose that dieting and gastric bypass produce distinct changes in peripheral factors with known roles in regulating energy homeostasis, resulting in differential modulation of nigrostriatal and mesolimbic dopaminergic reward circuits. Enhancement of intestinal fat metabolism after gastric bypass may also modify striatal dopamine signaling contributing to its unique long-term effects on feeding behavior and body weight in obese individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Levodopa in Mucuna pruriens and its degradation

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Pulikkalpura, Haridas; Kurup, Rajani; Mathew, Paravanparampil Jacob; Baby, Sabulal

2015-06-01

Mucuna pruriens is the best known natural source of L-dopa, the gold standard for treatment of Parkinsonism. M. pruriens varieties are protein rich supplements, and are used as food and fodder worldwide. Here, we report L-dopa contents in seeds of fifty six accessions of four M. pruriens varieties, M. pruriens var. pruriens, M. pruriens var. hirsuta, M. pruriens var. utilis and M. pruriens var. thekkadiensis, quantified by HPTLC-densitometry. L-dopa contents varied between 0.58 to 6.42 (%, dr. wt.). High and low L-dopa yielding genotypes/chemotypes of M. pruriens could be multiplied for medicinal and nutritional purposes, respectively. HPTLC profiles of M. pruriens seeds on repeated extraction (24 h) in 1:1 formic acid-alcohol followed by development in butanol:acetic acid:water (4:1:1, v/v) showed consistent degradation of L-dopa (Rf 0.34 ± 0.02) into a second peak (Rf 0.41 ± 0.02). An average of 52.11% degradation of L-dopa was found in seeds of M. pruriens varieties. Since M. pruriens seeds and/or L-dopa are used for treatment of Parkinson’s disease and as an aphrodisiac both in modern and/or traditional systems of medicine, the finding of high level of L-dopa degradation (in pure form and in M. pruriens extracts) into damaging quinones and ROS is very significant.

A new framework for cortico-striatal plasticity: behavioural theory meets in vitro data at the reinforcement-action interface.

Directory of Open Access Journals (Sweden)

Kevin N Gurney

2015-01-01

Full Text Available Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike timing, dopamine level, and dopamine receptor type. Second, there is a credit assignment problem-action selection signals occur long before the consequent dopamine reinforcement signal. Third, the two types of striatal output neuron have apparently opposite effects on action selection. Whether these factors rule out the interface hypothesis and how they interact to produce reinforcement learning is unknown. We present a computational framework that addresses these challenges. We first predict the expected activity changes over an operant task for both types of action-coding striatal neuron, and show they co-operate to promote action selection in learning and compete to promote action suppression in extinction. Separately, we derive a complete model of dopamine and spike-timing dependent cortico-striatal plasticity from in vitro data. We then show this model produces the predicted activity changes necessary for learning and extinction in an operant task, a remarkable convergence of a bottom-up data-driven plasticity model with the top-down behavioural requirements of learning theory. Moreover, we show the complex dependencies of cortico-striatal plasticity are not only sufficient but necessary for learning and extinction. Validating the model, we show it can account for behavioural data describing extinction, renewal, and reacquisition, and replicate in vitro experimental data on cortico-striatal plasticity. By bridging the levels between the single synapse and

Development of striatal patch/matrix organization in organotypic co-cultures of perinatal striatum, cortex and substantia nigra.

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Snyder-Keller, A; Costantini, L C; Graber, D J

2001-01-01

Organotypic cultures of fetal or early postnatal striatum were used to assess striatal patch formation and maintenance in the presence or absence of dopaminergic and glutamatergic influences. Vibratome-cut slices of the striatum prepared from embryonic day 19 to postnatal day 4 rat pups were maintained in static culture on clear membrane inserts in Dulbecco's modified Eagle's medium/F12 (1:1) with 20% horse serum. Some were co-cultured with embryonic day 12-16 ventral mesencephalon and/or embryonic day 19 to postnatal day 4 cortex, which produced a dense dopaminergic innervation and a modest cortical innervation. Donors of striatal and cortical tissue were previously injected with bromo-deoxyuridine (BrdU) on embryonic days 13 and 14 in order to label striatal neurons destined to populate the patch compartment of the striatum. Patches of BrdU-immunoreactive cells were maintained in organotypic cultures of late prenatal (embryonic days 20-22) or early postnatal striatum in the absence of nigral dopaminergic or cortical glutamatergic influences. In slices taken from embryonic day 19 fetuses prior to the time of in vivo patch formation, patches were observed to form after 10 days in vitro, in 39% of nigral-striatal co-cultures compared to 6% of striatal slices cultured alone or in the presence of cortex only. Patches of dopaminergic fibers, revealed by tyrosine hydroxylase immunoreactivity, were observed in the majority of nigral-striatal co-cultures. Immunostaining for the AMPA-type glutamate receptor GluR1 revealed a dense patch distribution in nearly all cultures, which developed in embryonic day 19 cultures after at least six days in vitro. These findings indicate that striatal patch/matrix organization is maintained in organotypic culture, and can be induced to form in vitro in striatal slices removed from fetuses prior to the time of in vivo patch formation. Furthermore, dopaminergic innervation from co-cultured pieces of ventral mesencephalon enhances patch

Local cerebral metabolic rate of glucose (lCMRGlc) in treated and untreated patients with Parkinson's disease

Energy Technology Data Exchange (ETDEWEB)

Rougemont, D; Baron, J C; Collard, P; Bustany, P; Comar, D; Agid, Y

1983-06-01

Local cerebral metabolic rate of glucose (lCMRGlc) was measured twice, using positron emission tomography and /sup 18/F-Fluoro-2-deoxy-D-glucose (/sup 18/FDG), in 4 patients with Parkinson disease, first unmedicated and then treated with L-DOPA. Despite a dramatic clinical improvement, no significant changes in lCMRGlc could be detected. Moreover, no reproducible differences of lCMRGlc were found between patients with Parkinson disease and with normal brain.

Striatal hypometabolism in premanifest and manifest Huntington's disease patients

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Lopez-Mora, Diego Alfonso; Camacho, Valle; Fernandez, Alejandro; Montes, Alberto; Carrio, Ignasi [Autonomous University of Barcelona, Nuclear Medicine Department, Hospital Sant Pau, Barcelona (Spain); Perez-Perez, Jesus; Martinez-Horta, Sauel; Kulisevsky, Jaime [Autonomous University of Barcelona, Movement Disorders Unit, Neurology Department, Hospital Sant Pau, Barcelona (Spain); Sampedro, Frederic [University of Barcelona, Barcelona (Spain); Lozano-Martinez, Gloria Andrea; Gomez-Anson, Beatriz [Autonomous University of Barcelona, Neuroradiology, Radiology Department, Hospital Sant Pau, Barcelona (Spain)

2016-11-15

To assess metabolic changes in cerebral {sup 18}F-FDG PET/CT in premanifest and manifest Huntington's disease (HD) subjects compared to a control group and to correlate {sup 18}F-FDG uptake patterns with different disease stages. Thirty-three gene-expanded carriers (Eight males; mean age: 43 y/o; CAG > 39) were prospectively included. Based on the Unified Huntington's Disease Rating Scale Total Motor Score and the Total Functional Capacity, subjects were classified as premanifest (preHD = 15) and manifest (mHD = 18). Estimated time disease-onset was calculated using the Langbehn formula, which allowed classifying preHD as far-to (preHD-A) and close-to (PreHD-B) disease-onset. Eighteen properly matched participants were included as a control group (CG). All subjects underwent brain {sup 18}F-FDG PET/CT and MRI. {sup 18}F-FDG PET/CT were initially assessed by two nuclear medicine physicians identifying qualitative metabolic changes in the striatum. Quantitative analysis was performed using SPM8 with gray matter atrophy correction using the BPM toolbox. Visual analysis showed a marked striatal hypometabolism in mHD. A normal striatal distribution of {sup 18}F-FDG uptake was observed for most of the preHD subjects. Quantitative analysis showed a significant striatal hypometabolism in mHD subjects compared to CG (p < 0.001 uncorrected, k = 50 voxels). In both preHD groups we observed a significant striatal hypometabolism with respect to CG (p < 0.001 uncorrected, k = 50 voxels). In mHD subjects we observed a significant striatal hypometabolism with respect to both preHD groups (p < 0.001 uncorrected, k = 50 voxels). {sup 18}F-FDG PET/CT might be a helpful tool to identify patterns of glucose metabolism in the striatum across the stages of HD and might be relevant in assessing the clinical status of gene-expanded HD carriers due to the fact that dysfunctional glucose metabolism begins at early preHD stages of the disease. {sup 18}F-FDG PET/CT appears as a

Enhanced Striatal β1-Adrenergic Receptor Expression Following Hormone Loss in Adulthood Is Programmed by Both Early Sexual Differentiation and Puberty: A Study of Humans and Rats

Science.gov (United States)

Perry, Adam N.; Westenbroek, Christel; Hedges, Valerie L.; Becker, Jill B.; Mermelstein, Paul G.

2013-01-01

After reproductive senescence or gonadectomy, changes occur in neural gene expression, ultimately altering brain function. The endocrine mechanisms underlying these changes in gene expression beyond immediate hormone loss are poorly understood. To investigate this, we measured changes in gene expression the dorsal striatum, where 17β-estradiol modulates catecholamine signaling. In human caudate, quantitative PCR determined a significant elevation in β1-adrenergic receptor (β1AR) expression in menopausal females when compared with similarly aged males. No differences were detected in β2-adrenergic and D1- and D2-dopamine receptor expression. Consistent with humans, adult ovariectomized female rats exhibited a similar increase in β1AR expression when compared with gonadectomized males. No sex difference in β1AR expression was detected between intact adults, prepubertal juveniles, or adults gonadectomized before puberty, indicating the necessity of pubertal development and adult ovariectomy. Additionally, increased β1AR expression in adult ovariectomized females was not observed if animals were masculinized/defeminized with testosterone injections as neonates. To generate a model system for assessing functional impact, increased β1AR expression was induced in female-derived cultured striatal neurons via exposure to and then removal of hormone-containing serum. Increased β1AR action on cAMP formation, cAMP response element-binding protein phosphorylation and gene expression was observed. This up-regulation of β1AR action was eliminated with 17β-estradiol addition to the media, directly implicating this hormone as a regulator of β1AR expression. Beyond having implications for the known sex differences in striatal function and pathologies, these data collectively demonstrate that critical periods early in life and at puberty program adult gene responsiveness to hormone loss after gonadectomy and potentially reproductive senescence. PMID:23533220

Centrality of striatal cholinergic transmission in basal ganglia function

Directory of Open Access Journals (Sweden)

Paola eBonsi

2011-02-01

Full Text Available Work over the past two decades revealed a previously unexpected role for striatal cholinergic interneurons in the context of basal ganglia function. The recognition that these interneurons are essential in synaptic plasticity and motor learning represents a significant step ahead in deciphering how the striatum processes cortical inputs, and why pathological circumstances cause motor dysfunction.Loss of the reciprocal modulation between dopaminergic inputs and the intrinsic cholinergic innervation within the striatum appears to be the trigger for pathophysiological changes occurring in basal ganglia disorders. Accordingly, there is now compelling evidence showing profound changes in cholinergic markers in these disorders, in particular Parkinson’s disease and dystonia.Based on converging experimental and clinical evidence, we provide an overview of the role of striatal cholinergic transmission in physiological and pathological conditions, in the context of the pathogenesis of movement disorders.

Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

International Nuclear Information System (INIS)

Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

1988-01-01

We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17β-estradiol (E 2 ) at both low (0.1 μg/kg) and high (20 μg/kg) doses confirmed its ability to increase the number of striatal 3 H-Spiperone ( 3 H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E 2 , to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity

Effects of cholecystokinin octapeptide on striatal dopamine metabolism and on apomorphine-induced stereotyped cage-climbing in mice

Energy Technology Data Exchange (ETDEWEB)

Kovacs, G L; Szabo, G; Telegdy, G [Institute of Pathophysiology, University Medical School, Szeged, Hungary; Penke, B [Institute of Medical Chemistry, University Medical School, Szeged, Hungary

1981-01-29

The effects of sulfated (CCK-8-SE) and non-sulfated (CCK-8-NS) cholecystokinin octapeptide on striatal dopamine (DA) metabolism have been investigated on mice. CCK-8-NS facilitated the disappearance of striatal DA, measured after synthesis inhibition with 350 mg/kg of ..cap alpha..-methyl-p-tyrosine. CCK-8-SE did not affect DA disappearance. In vitro uptake of (/sup 3/H)DA by striatal slices was affected by neither CCK-8-SE, nor CCK-8-NS (10/sup -5/ M). Potassium-induced in vitro release of (/sup 3/H)DA from striatal slices was significantly increased by 10/sup -5/ M CCK-8-NS: however, CCK-8-SE likewise increased DA release in this model system. Apomorphine-induced (1.0 mg/kg) stereotyped cage-climbing behavior was not affected by CCK-8-SE but was enhanced by CCK-8-NS. This effect could be antagonized by haloperidol, but not by naloxone. The data suggest that CCK-8-NS affects striatal DA release, disappearance and receptor sensitivity in the mouse. Dopaminergic mechanisms should therefore be regarded as a possible mode of action of CCK-8-NS on brain functions.

Effects of cholecystokinin octapeptide on striatal dopamine metabolism and on apomorphine-induced stereotyped cage-climbing in mice

International Nuclear Information System (INIS)

Kovacs, G.L.; Szabo, G.; Telegdy, G.; Penke, B.

1981-01-01

The effects of sulfated (CCK-8-SE) and non-sulfated (CCK-8-NS) cholecystokinin octapeptide on striatal dopamine (DA) metabolism have been investigated on mice. CCK-8-NS facilitated the disappearance of striatal DA, measured after synthesis inhibition with 350 mg/kg of α-methyl-p-tyrosine. CCK-8-SE did not affect DA disappearance. In vitro uptake of [ 3 H]DA by striatal slices was affected by neither CCK-8-SE, nor CCK-8-NS (10 -5 M). Potassium-induced in vitro release of [ 3 H]DA from striatal slices was significantly increased by 10 -5 M CCK-8-NS: however, CCK-8-SE likewise increased DA release in this model system. Apomorphine-induced (1.0 mg/kg) stereotyped cage-climbing behavior was not affected by CCK-8-SE but was enhanced by CCK-8-NS. This effect could be antagonized by haloperidol, but not by naloxone. The data suggest that CCK-8-NS affects striatal DA release, disappearance and receptor sensitivity in the mouse. Dopaminergic mechanisms should therefore be regarded as a possible mode of action of CCK-8-NS on brain functions. (Auth.)

Growth Hormone and Endocrinopathies

Energy Technology Data Exchange (ETDEWEB)

Kim, K W; Choe, K O; Park, C Y; Lee, H; Son, H Y; Huh, K B; Ryu, K J [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1979-03-15

This is an analysis of 39 patients studied at the Yonsei Medical Center from January, 1976 to March 1979. Of these 35 patient were suspected of having hypothalamic insufficiency and subjected to the L-Dopa stimulation test to observe growth hormone secretary function while four acromegaly patient received the glucose loading test and L-Dopa stimulation test. The results are as follows: 1) The basal level of GH in the various disease was as follows: a) The basal level was lower than the control level but was not statistically significant b) In diabetes the mean value tended to higher than the control level but was not significant statistically c) In all four acromegaly patients the GH level was significantly higher than the control level 2) Of 13 patients with diabetes, nine had diabetic retinopathy, and of those nine, six showed increased L-Dopa response. However, of the four non retinopathic DM patients, only one showed increased response to L-Dopa. 3) Two patients out of ten with Sheehan's syndrome responded to L-Dopa stimulation. 4) One Patient of eight with pituitary chromophobe adenoma responded to L-Dopa stimulation. 5) Four acromegaly patients revealed 3 acidophilic adenoma and one chromophobe adenoma histologically. Of patients receiving the L-Dopa stimulation test. Two showed a paradoxical response. Two patients who received the glucose loading test showed suppressed response. 6) Of two craniopharyngioma patients, one showed increased GH response after L-Dopa stimulation. Increased response of GH after L-Dopa stimulation was seen in one two craniopharyngioma patients and also in one of two patients with short structure.

Growth Hormone and Endocrinopathies

Energy Technology Data Exchange (ETDEWEB)

Kim, K. W.; Choe, K. O.; Park, C. Y.; Lee, H.; Son, H. Y.; Huh, K. B.; Ryu, K. J. [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1979-03-15

This is an analysis of 39 patients studied at the Yonsei Medical Center from January, 1976 to March 1979. Of these 35 patient were suspected of having hypothalamic insufficiency and subjected to the L-Dopa stimulation test to observe growth hormone secretary function while four acromegaly patient received the glucose loading test and L-Dopa stimulation test. The results are as follows: 1) The basal level of GH in the various disease was as follows: a) The basal level was lower than the control level but was not statistically significant b) In diabetes the mean value tended to higher than the control level but was not significant statistically c) In all four acromegaly patients the GH level was significantly higher than the control level 2) Of 13 patients with diabetes, nine had diabetic retinopathy, and of those nine, six showed increased L-Dopa response. However, of the four non retinopathic DM patients, only one showed increased response to L-Dopa. 3) Two patients out of ten with Sheehan's syndrome responded to L-Dopa stimulation. 4) One Patient of eight with pituitary chromophobe adenoma responded to L-Dopa stimulation. 5) Four acromegaly patients revealed 3 acidophilic adenoma and one chromophobe adenoma histologically. Of patients receiving the L-Dopa stimulation test. Two showed a paradoxical response. Two patients who received the glucose loading test showed suppressed response. 6) Of two craniopharyngioma patients, one showed increased GH response after L-Dopa stimulation. Increased response of GH after L-Dopa stimulation was seen in one two craniopharyngioma patients and also in one of two patients with short structure.

Growth Hormone and Endocrinopathies

International Nuclear Information System (INIS)

Kim, K. W.; Choe, K. O.; Park, C. Y.; Lee, H.; Son, H. Y.; Huh, K. B.; Ryu, K. J.

1979-01-01

This is an analysis of 39 patients studied at the Yonsei Medical Center from January, 1976 to March 1979. Of these 35 patient were suspected of having hypothalamic insufficiency and subjected to the L-Dopa stimulation test to observe growth hormone secretary function while four acromegaly patient received the glucose loading test and L-Dopa stimulation test. The results are as follows: 1) The basal level of GH in the various disease was as follows: a) The basal level was lower than the control level but was not statistically significant b) In diabetes the mean value tended to higher than the control level but was not significant statistically c) In all four acromegaly patients the GH level was significantly higher than the control level 2) Of 13 patients with diabetes, nine had diabetic retinopathy, and of those nine, six showed increased L-Dopa response. However, of the four non retinopathic DM patients, only one showed increased response to L-Dopa. 3) Two patients out of ten with Sheehan's syndrome responded to L-Dopa stimulation. 4) One Patient of eight with pituitary chromophobe adenoma responded to L-Dopa stimulation. 5) Four acromegaly patients revealed 3 acidophilic adenoma and one chromophobe adenoma histologically. Of patients receiving the L-Dopa stimulation test. Two showed a paradoxical response. Two patients who received the glucose loading test showed suppressed response. 6) Of two craniopharyngioma patients, one showed increased GH response after L-Dopa stimulation. Increased response of GH after L-Dopa stimulation was seen in one two craniopharyngioma patients and also in one of two patients with short structure.

Striatal [[sup 11]C]-N-methyl-spiperone binding in patients with focal dystonia (torticollis) using positron emission tomography

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Leenders, K [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Hartvig, P [Hospital Pharmacy, Univ. Hospital, Uppsala (Sweden); Forsgren, L; Holmgren, G; Almay, B [Dept. of Neurology, Umeaa Univ., Umeaa (Sweden); Eckernaes, S A [Dept. of Neurology, Univ. Hospital, Uppsala (Sweden); Lundqvist, H; Laangstroem, B [Uppsala Univ. PET-Center, Uppsala (Sweden)

1993-01-01

Specific binding of [[sup 11]C]-N-methyl-spiperone to striatal dopamine D2 receptors was assessed using positron emission tomography (PET) in 6 patients with adult-onset focal dystonia (predominantly spasmodic torticollis) and in 5 healthy subjects. No significant difference in average specific striatal tracer uptake between patients and healthy subjects was found. However, in the 5 patients showing lateralisation of clinical signs a trend to higher striatal tracer uptake in the contralateral hemisphere was observed. (authors).

Abnormal fronto-striatal activation as a marker of threshold and subthreshold Bulimia Nervosa.

Science.gov (United States)

Cyr, Marilyn; Yang, Xiao; Horga, Guillermo; Marsh, Rachel

2018-04-01

This study aimed to determine whether functional disturbances in fronto-striatal control circuits characterize adolescents with Bulimia Nervosa (BN) spectrum eating disorders regardless of clinical severity. FMRI was used to assess conflict-related brain activations during performance of a Simon task in two samples of adolescents with BN symptoms compared with healthy adolescents. The BN samples differed in the severity of their clinical presentation, illness duration and age. Multi-voxel pattern analyses (MVPAs) based on machine learning were used to determine whether patterns of fronto-striatal activation characterized adolescents with BN spectrum disorders regardless of clinical severity, and whether accurate classification of less symptomatic adolescents (subthreshold BN; SBN) could be achieved based on patterns of activation in adolescents who met DSM5 criteria for BN. MVPA classification analyses revealed that both BN and SBN adolescents could be accurately discriminated from healthy adolescents based on fronto-striatal activation. Notably, the patterns detected in more severely ill BN compared with healthy adolescents accurately discriminated less symptomatic SBN from healthy adolescents. Deficient activation of fronto-striatal circuits can characterize BN early in its course, when clinical presentations are less severe, perhaps pointing to circuit-based disturbances as useful biomarker or risk factor for the disorder, and a tool for understanding its developmental trajectory, as well as the development of early interventions. © 2018 Wiley Periodicals, Inc.

A HUMANIZED CLINICALLY CALIBRATED QUANTITATIVE SYSTEMS PHARMACOLOGY MODEL FOR HYPOKINETIC MOTOR SYMPTOMS IN PARKINSON’S DISEASE

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Hugo eGeerts

2016-02-01

Full Text Available The current treatment of Parkinson’s disease with dopamine-centric approaches such as L-DOPA and dopamine agonists, although very succesfull, is in need of alternative treatment strategies, both in terms of disease modification and symptom management. Various non-dopaminergic treatment approaches did not result in a clear clinical benefit, despite showing a clear effect in preclinical animal models. In addition, polypharmacy is common, sometimes leading to unintended effects on non-motor symptoms such as in cognitive and psychiatric domains. To explore novel targets for symptomatic treatment and possible synergistic pharmacodynamic effects between different drugs, we developed a Quantitative Systems Pharmacology (QSP platform of the closed cortico-striatal-thalamic-cortical basal ganglia loop of the dorsal motor circuit. This mechanism-based simulation platform is based on the known neuro-anatomy and neurophysiology of the basal ganglia and explicitly incorporates domain expertise in a formalized way. The calculated beta/gamma power ratio of the local field potential in the subthalamic nucleus correlates well (R2=0.71 with clinically observed extra-pyramidal symptoms triggered by antipsychotics during schizophrenia treatment (43 drug-dose combinations. When incorporating Parkinsonian (PD pathology and reported compensatory changes, the computer model suggests a major increase in b/g ratio (corresponding to bradykinesia and rigidity from a dopamine depletion of 70% onwards. The correlation between the outcome of the QSP model and the reported changes in UPDRS III Motor Part for 22 placebo-normalized drug-dose combinations is R2=0.84. The model also correctly recapitulates the lack of clinical benefit for perampanel, MK-0567 and flupirtine and offers a hypothesis for the translational disconnect. Finally, using human PET imaging studies with placebo response, the computer model predicts well the placebo response for chronic treatment, but not

New and highly sensitive assay for L-5-hydroxytryptophan decarboxylase activity by high-performance liquid chromatography-voltammetry.

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Rahman, M K; Nagatsu, T; Kato, T

1980-12-12

This paper describes a new, inexpensive and highly sensitive assay for aromatic L-amino acid decarboxylase (AADC) activity, using L-5-hydroxytryptophan (L-5-HTP) as substrate, in rat and human brains and serum by high-performance liquid chromatography (HPLC) with voltammetric detection. L-5-HTP was used as substrate and D-5-HTP for the blank. After isolating serotonin (5-HT) formed enzymatically from L-5-HTP on a small Amberlite CG-50 column, the 5-HT was eluted with hydrochloric acid and assayed by HPLC with a voltammetric detector. N-Methyldopamine was added to each incubation mixture as an internal standard. This method is sensitive enough to measure 5-HT, formed by the enzyme, 100 fmol to 140 pmol or more. An advantage of this method is that one can incubate the enzyme for longer time (up to 150 min), as compared with AADC assay using L-DOPA as substrate, resulting in a very high sensitivity. By using this new method, AADC activity was discovered in rat serum.

Manipulation of dopamine metabolism contributes to attenuating innate high locomotor activity in ICR mice.

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Yamaguchi, Takeshi; Nagasawa, Mao; Ikeda, Hiromi; Kodaira, Momoko; Minaminaka, Kimie; Chowdhury, Vishwajit S; Yasuo, Shinobu; Furuse, Mitsuhiro

2017-06-15

Attention-deficit hyperactivity disorder (ADHD) is defined as attention deficiency, restlessness and distraction. The main characteristics of ADHD are hyperactivity, impulsiveness and carelessness. There is a possibility that these abnormal behaviors, in particular hyperactivity, are derived from abnormal dopamine (DA) neurotransmission. To elucidate the mechanism of high locomotor activity, the relationship between innate activity levels and brain monoamines and amino acids was investigated in this study. Differences in locomotor activity between ICR, C57BL/6J and CBA/N mice were determined using the open field test. Among the three strains, ICR mice showed the greatest amount of locomotor activity. The level of striatal and cerebellar DA was lower in ICR mice than in C57BL/6J mice, while the level of L-tyrosine (L-Tyr), a DA precursor, was higher in ICR mice. These results suggest that the metabolic conversion of L-Tyr to DA is lower in ICR mice than it is in C57BL/6J mice. Next, the effects of intraperitoneal injection of (6R)-5, 6, 7, 8-tetrahydro-l-biopterin dihydrochloride (BH 4 ) (a co-enzyme for tyrosine hydroxylase) and L-3,4-dihydroxyphenylalanine (L-DOPA) on DA metabolism and behavior in ICR mice were investigated. The DA level in the brain was increased by BH 4 administration, but the increased DA did not influence behavior. However, L-DOPA administration drastically lowered locomotor activity and increased DA concentration in several parts of the brain. The reduced locomotor activity may have been a consequence of the overproduction of DA. In conclusion, the high level of locomotor activity in ICR mice may be explained by a strain-specific DA metabolism. Copyright © 2017 Elsevier B.V. All rights reserved.

Elevated Striatal Dopamine Function in Immigrants and Their Children: A Risk Mechanism for Psychosis

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Egerton, A.; Howes, O. D.; Houle, S.; McKenzie, K.; Valmaggia, L. R.; Bagby, M. R.; Tseng, H-H; Bloomfield, M. A. P.; Kenk, M.; Bhattacharyya, S.; Suridjan, I.; Chaddock, C. A.; Winton-Brown, T. T.; Allen, P.; Rusjan, P.

2017-01-01

Migration is a major risk factor for schizophrenia but the neurochemical processes involved are unknown. One candidate mechanism is through elevations in striatal dopamine synthesis and release. The objective of this research was to determine whether striatal dopamine function is elevated in immigrants compared to nonimmigrants and the relationship with psychosis. Two complementary case–control studies of in vivo dopamine function (stress-induced dopamine release and dopamine synthesis capaci...

The basal ganglia matching tools package for striatal uptake semi-quantification: description and validation

International Nuclear Information System (INIS)

Calvini, Piero; Rodriguez, Guido; Nobili, Flavio; Inguglia, Fabrizio; Mignone, Alessandro; Guerra, Ugo P.

2007-01-01

To design a novel algorithm (BasGan) for automatic segmentation of striatal 123 I-FP-CIT SPECT. The BasGan algorithm is based on a high-definition, three-dimensional (3D) striatal template, derived from Talairach's atlas. A blurred template, obtained by convolving the former with a 3D Gaussian kernel (FWHM = 10 mm), approximates striatal activity distribution. The algorithm performs translations and scale transformation on the bicommissural aligned image to set the striatal templates with standard size in an appropriate initial position. An optimization protocol automatically performs fine adjustments in the positioning of blurred templates to best match the radioactive counts, and locates an occipital ROI for background evaluation. Partial volume effect correction is included in the process of uptake computation of caudate, putamen and background. Experimental validation was carried out by means of six acquisitions of an anthropomorphic striatal phantom. The BasGan software was applied to a first set of patients with Parkinson's disease (PD) versus patients affected by essential tremor. A highly significant correlation was achieved between true binding potential and measured 123 I activity from the phantom. 123 I-FP-CIT uptake was significantly lower in all basal ganglia in the PD group versus controls with both BasGan and a conventional ROI method used for comparison, but particularly with the former. Correlations with the motor UPDRS score were far more significant with the BasGan. The novel BasGan algorithm automatically performs the 3D segmentation of striata. Because co-registered MRI is not needed, it can be used by all nuclear medicine departments, since it is freely available on the Web. (orig.)

Episodic Memory Encoding Interferes with Reward Learning and Decreases Striatal Prediction Errors

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Braun, Erin Kendall; Daw, Nathaniel D.

2014-01-01

Learning is essential for adaptive decision making. The striatum and its dopaminergic inputs are known to support incremental reward-based learning, while the hippocampus is known to support encoding of single events (episodic memory). Although traditionally studied separately, in even simple experiences, these two types of learning are likely to co-occur and may interact. Here we sought to understand the nature of this interaction by examining how incremental reward learning is related to concurrent episodic memory encoding. During the experiment, human participants made choices between two options (colored squares), each associated with a drifting probability of reward, with the goal of earning as much money as possible. Incidental, trial-unique object pictures, unrelated to the choice, were overlaid on each option. The next day, participants were given a surprise memory test for these pictures. We found that better episodic memory was related to a decreased influence of recent reward experience on choice, both within and across participants. fMRI analyses further revealed that during learning the canonical striatal reward prediction error signal was significantly weaker when episodic memory was stronger. This decrease in reward prediction error signals in the striatum was associated with enhanced functional connectivity between the hippocampus and striatum at the time of choice. Our results suggest a mechanism by which memory encoding may compete for striatal processing and provide insight into how interactions between different forms of learning guide reward-based decision making. PMID:25378157

Magnetic Resonance Imaging Features of the Nigrostriatal System: Biomarkers of Parkinson’s Disease Stages?

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Hopes, Lucie; Grolez, Guillaume; Moreau, Caroline; Lopes, Renaud; Ryckewaert, Gilles; Carrière, Nicolas; Auger, Florent; Laloux, Charlotte; Petrault, Maud; Devedjian, Jean-Christophe; Bordet, Regis; Defebvre, Luc; Jissendi, Patrice; Delmaire, Christine; Devos, David

2016-01-01

Introduction Magnetic resonance imaging (MRI) can be used to identify biomarkers in Parkinson’s disease (PD); R2* values reflect iron content related to high levels of oxidative stress, whereas volume and/or shape changes reflect neuronal death. We sought to assess iron overload in the nigrostriatal system and characterize its relationship with focal and overall atrophy of the striatum in the pivotal stages of PD. Methods Twenty controls and 70 PD patients at different disease stages (untreated de novo patients, treated early-stage patients and advanced-stage patients with L-dopa-related motor complications) were included in the study. We determined the R2* values in the substantia nigra, putamen and caudate nucleus, together with striatal volume and shape analysis. We also measured R2* in an acute MPTP mouse model and in a longitudinal follow-up two years later in the early-stage PD patients. Results The R2* values in the substantia nigra, putamen and caudate nucleus were significantly higher in de novo PD patients than in controls. Early-stage patients displayed significantly higher R2* values in the substantia nigra (with changes in striatal shape), relative to de novo patients. Measurements after a two-year follow-up in early-stage patients and characterization of the acute MPTP mouse model confirmed that R2* changed rapidly with disease progression. Advanced-stage patients displayed significant atrophy of striatum, relative to earlier disease stages. Conclusion Each pivotal stage in PD appears to be characterized by putative nigrostriatal MRI biomarkers: iron overload at the de novo stage, striatal shape changes at early-stage disease and generalized striatal atrophy at advanced disease. PMID:27035571

Assessment of striatal & postural deformities in patients with Parkinson's disease

Directory of Open Access Journals (Sweden)

Sanjay Pandey

2016-01-01

Interpretation & conclusions: Our results showed that striatal and postural deformities were common and present in about half of the patients with PD. These deformities we more common in patients with advanced stage of PD.

The DOPA decarboxylase (DDC) gene is associated with alerting attention.

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Zhu, Bi; Chen, Chuansheng; Moyzis, Robert K; Dong, Qi; Chen, Chunhui; He, Qinghua; Li, Jin; Li, Jun; Lei, Xuemei; Lin, Chongde

2013-06-03

DOPA decarboxylase (DDC) is involved in the synthesis of dopamine, norepinephrine and serotonin. It has been suggested that genes involved in the dopamine, norepinephrine, and cholinergic systems play an essential role in the efficiency of human attention networks. Attention refers to the cognitive process of obtaining and maintaining the alert state, orienting to sensory events, and regulating the conflicts of thoughts and behavior. The present study tested seven single nucleotide polymorphisms (SNPs) within the DDC gene for association with attention, which was assessed by the Attention Network Test to detect three networks of attention, including alerting, orienting, and executive attention, in a healthy Han Chinese sample (N=451). Association analysis for individual SNPs indicated that four of the seven SNPs (rs3887825, rs7786398, rs10499695, and rs6969081) were significantly associated with alerting attention. Haplotype-based association analysis revealed that alerting was associated with the haplotype G-A-T for SNPs rs7786398-rs10499695-rs6969081. These associations remained significant after correcting for multiple testing by max(T) permutation. No association was found for orienting and executive attention. This study provides the first evidence for the involvement of the DDC gene in alerting attention. A better understanding of the genetic basis of distinct attention networks would allow us to develop more effective diagnosis, treatment, and prevention of deficient or underdeveloped alerting attention as well as its related prevalent neuropsychiatric disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

Energy Technology Data Exchange (ETDEWEB)

Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

1988-01-01

We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17..beta..-estradiol (E/sub 2/) at both low (0.1 ..mu..g/kg) and high (20 ..mu..g/kg) doses confirmed its ability to increase the number of striatal /sup 3/H-Spiperone (/sup 3/H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E/sub 2/, to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity.

A negative relationship between ventral striatal loss anticipation response and impulsivity in borderline personality disorder

OpenAIRE

Herbort, Maike C.; Soch, Joram; W?stenberg, Torsten; Krauel, Kerstin; Pujara, Maia; Koenigs, Michael; Gallinat, J?rgen; Walter, Henrik; Roepke, Stefan; Schott, Bj?rn H.

2016-01-01

Patients with borderline personality disorder (BPD) frequently exhibit impulsive behavior, and self-reported impulsivity is typically higher in BPD patients when compared to healthy controls. Previous functional neuroimaging studies have suggested a link between impulsivity, the ventral striatal response to reward anticipation, and prediction errors. Here we investigated the striatal neural response to monetary gain and loss anticipation and their relationship with impulsivity in 21 female BP...

Probucol increases striatal glutathione peroxidase activity and protects against 3-nitropropionic acid-induced pro-oxidative damage in rats.

Directory of Open Access Journals (Sweden)

Dirleise Colle

Full Text Available Huntington's disease (HD is an autosomal dominantly inherited neurodegenerative disease characterized by symptoms attributable to the death of striatal and cortical neurons. The molecular mechanisms mediating neuronal death in HD involve oxidative stress and mitochondrial dysfunction. Administration of 3-nitropropionic acid (3-NP, an irreversible inhibitor of the mitochondrial enzyme succinate dehydrogenase, in rodents has been proposed as a useful experimental model of HD. This study evaluated the effects of probucol, a lipid-lowering agent with anti-inflammatory and antioxidant properties, on the biochemical parameters related to oxidative stress, as well as on the behavioral parameters related to motor function in an in vivo HD model based on 3-NP intoxication in rats. Animals were treated with 3.5 mg/kg of probucol in drinking water daily for 2 months and, subsequently, received 3-NP (25 mg/kg i.p. once a day for 6 days. At the end of the treatments, 3-NP-treated animals showed a significant decrease in body weight, which corresponded with impairment on motor ability, inhibition of mitochondrial complex II activity and oxidative stress in the striatum. Probucol, which did not rescue complex II inhibition, protected against behavioral and striatal biochemical changes induced by 3-NP, attenuating 3-NP-induced motor impairments and striatal oxidative stress. Importantly, probucol was able to increase activity of glutathione peroxidase (GPx, an enzyme important in mediating the detoxification of peroxides in the central nervous system. The major finding of this study was that probucol protected against 3-NP-induced behavioral and striatal biochemical changes without affecting 3-NP-induced mitochondrial complex II inhibition, indicating that long-term probucol treatment resulted in an increased resistance against neurotoxic events (i.e., increased oxidative damage secondary to mitochondrial dysfunction. These data appeared to be of great

Effect of Exercise Training on Striatal Dopamine D2/D3 Receptors in Methamphetamine Users during Behavioral Treatment.

Science.gov (United States)

Robertson, Chelsea L; Ishibashi, Kenji; Chudzynski, Joy; Mooney, Larissa J; Rawson, Richard A; Dolezal, Brett A; Cooper, Christopher B; Brown, Amira K; Mandelkern, Mark A; London, Edythe D

2016-05-01

Methamphetamine use disorder is associated with striatal dopaminergic deficits that have been linked to poor treatment outcomes, identifying these deficits as an important therapeutic target. Exercise attenuates methamphetamine-induced neurochemical damage in the rat brain, and a preliminary observation suggests that exercise increases striatal D2/D3 receptor availability (measured as nondisplaceable binding potential (BPND)) in patients with Parkinson's disease. The goal of this study was to evaluate whether adding an exercise training program to an inpatient behavioral intervention for methamphetamine use disorder reverses deficits in striatal D2/D3 receptors. Participants were adult men and women who met DSM-IV criteria for methamphetamine dependence and were enrolled in a residential facility, where they maintained abstinence from illicit drugs of abuse and received behavioral therapy for their addiction. They were randomized to a group that received 1 h supervised exercise training (n=10) or one that received equal-time health education training (n=9), 3 days/week for 8 weeks. They came to an academic research center for positron emission tomography (PET) using [(18)F]fallypride to determine the effects of the 8-week interventions on striatal D2/D3 receptor BPND. At baseline, striatal D2/D3 BPND did not differ between groups. However, after 8 weeks, participants in the exercise group displayed a significant increase in striatal D2/D3 BPND, whereas those in the education group did not. There were no changes in D2/D3 BPND in extrastriatal regions in either group. These findings suggest that structured exercise training can ameliorate striatal D2/D3 receptor deficits in methamphetamine users, and warrants further evaluation as an adjunctive treatment for stimulant dependence.

DRD2 genotype-based variation of default mode network activity and of its relationship with striatal DAT binding.

Science.gov (United States)

Sambataro, Fabio; Fazio, Leonardo; Taurisano, Paolo; Gelao, Barbara; Porcelli, Annamaria; Mancini, Marina; Sinibaldi, Lorenzo; Ursini, Gianluca; Masellis, Rita; Caforio, Grazia; Di Giorgio, Annabella; Niccoli-Asabella, Artor; Popolizio, Teresa; Blasi, Giuseppe; Bertolino, Alessandro

2013-01-01

The default mode network (DMN) comprises a set of brain regions with "increased" activity during rest relative to cognitive processing. Activity in the DMN is associated with functional connections with the striatum and dopamine (DA) levels in this brain region. A functional single-nucleotide polymorphism within the dopamine D2 receptor gene (DRD2, rs1076560 G > T) shifts splicing of the 2 D2 isoforms, D2 short and D2 long, and has been associated with striatal DA signaling as well as with cognitive processing. However, the effects of this polymorphism on DMN have not been explored. The aim of this study was to evaluate the effects of rs1076560 on DMN and striatal connectivity and on their relationship with striatal DA signaling. Twenty-eight subjects genotyped for rs1076560 underwent functional magnetic resonance imaging during a working memory task and 123 55 I-Fluoropropyl-2-beta-carbomethoxy-3-beta(4-iodophenyl) nortropan Single Photon Emission Computed Tomography ([(123)I]-FP-CIT SPECT) imaging (a measure of dopamine transporter [DAT] binding). Spatial group-independent component (IC) analysis was used to identify DMN and striatal ICs. Within the anterior DMN IC, GG subjects had relatively greater connectivity in medial prefrontal cortex (MPFC), which was directly correlated with striatal DAT binding. Within the posterior DMN IC, GG subjects had reduced connectivity in posterior cingulate relative to T carriers. Additionally, rs1076560 genotype predicted connectivity differences within a striatal network, and these changes were correlated with connectivity in MPFC and posterior cingulate within the DMN. These results suggest that genetically determined D2 receptor signaling is associated with DMN connectivity and that these changes are correlated with striatal function and presynaptic DA signaling.

Blunted striatal response to monetary reward anticipation during smoking abstinence predicts lapse during a contingency-managed quit attempt.

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Sweitzer, Maggie M; Geier, Charles F; Denlinger, Rachel; Forbes, Erika E; Raiff, Bethany R; Dallery, Jesse; McClernon, F J; Donny, Eric C

2016-03-01

Tobacco smoking is associated with dysregulated reward processing within the striatum, characterized by hypersensitivity to smoking rewards and hyposensitivity to non-smoking rewards. This bias toward smoking reward at the expense of alternative rewards is further exacerbated by deprivation from smoking, which may contribute to difficulty maintaining abstinence during a quit attempt. We examined whether abstinence-induced changes in striatal processing of rewards predicted lapse likelihood during a quit attempt supported by contingency management (CM), in which abstinence from smoking was reinforced with money. Thirty-six non-treatment-seeking smokers participated in two functional MRI (fMRI) sessions, one following 24-h abstinence and one following smoking as usual. During each scan, participants completed a rewarded guessing task designed to elicit striatal activation in which they could earn smoking and monetary rewards delivered after the scan. Participants then engaged in a 3-week CM-supported quit attempt. As previously reported, 24-h abstinence was associated with increased striatal activation in anticipation of smoking reward and decreased activation in anticipation of monetary reward. Individuals exhibiting greater decrements in right striatal activation to monetary reward during abstinence (controlling for activation during non-abstinence) were more likely to lapse during CM (p reward. These results are consistent with a growing number of studies indicating the specific importance of disrupted striatal processing of non-drug reward in nicotine dependence and highlight the importance of individual differences in abstinence-induced deficits in striatal function for smoking cessation.

Potentiometric and NMR complexation studies of phenylboronic acid PBA and its aminophosphonate analog with selected catecholamines

Science.gov (United States)

Ptak, Tomasz; Młynarz, Piotr; Dobosz, Agnieszka; Rydzewska, Agata; Prokopowicz, Monika

2013-05-01

Boronic acids are a class of intensively explored compounds, which according to their specific properties have been intensively explored in last decades. Among them phenylboronic acids and their derivatives are most frequently examined as receptors for diverse carbohydrates. In turn, there is a large gap in basic research concerning complexation of catecholamines by these compounds. Therefore, we decided to undertake studies on interaction of chosen catecholamines, namely: noradrenaline (norephinephrine), dopamine, L-DOPA, DOPA-P (phosphonic analog of L-DOPA) and catechol, with simple phenyl boronic acid PBA by means of potentiometry and NMR spectroscopy. For comparison, the binding properties of recently synthesized phenylboronic receptor 1 bearing aminophosphonate function in meta-position were investigated and showed promising ability to bind catecholamines. The protonation and stability constants of PBA and receptor 1 complexes were examined by potentiometry. The obtained results demonstrated that PBA binds the catecholamines with the following affinity order: noradrenaline ⩾ dopamine ≈ L-DOPA > catechol > DOPA-P, while its modified analog 1 reveals slightly different preferences: dopamine > noradrenaline > catechol > L-DOPA > DOPA-P.

Striatal response to reward anticipation: evidence for a systems-level intermediate phenotype for schizophrenia.

Science.gov (United States)

Grimm, Oliver; Heinz, Andreas; Walter, Henrik; Kirsch, Peter; Erk, Susanne; Haddad, Leila; Plichta, Michael M; Romanczuk-Seiferth, Nina; Pöhland, Lydia; Mohnke, Sebastian; Mühleisen, Thomas W; Mattheisen, Manuel; Witt, Stephanie H; Schäfer, Axel; Cichon, Sven; Nöthen, Markus; Rietschel, Marcella; Tost, Heike; Meyer-Lindenberg, Andreas

2014-05-01

Attenuated ventral striatal response during reward anticipation is a core feature of schizophrenia that is seen in prodromal, drug-naive, and chronic schizophrenic patients. Schizophrenia is highly heritable, raising the possibility that this phenotype is related to the genetic risk for the disorder. To examine a large sample of healthy first-degree relatives of schizophrenic patients and compare their neural responses to reward anticipation with those of carefully matched controls without a family psychiatric history. To further support the utility of this phenotype, we studied its test-retest reliability, its potential brain structural contributions, and the effects of a protective missense variant in neuregulin 1 (NRG1) linked to schizophrenia by meta-analysis (ie, rs10503929). Examination of a well-established monetary reward anticipation paradigm during functional magnetic resonance imaging at a university hospital; voxel-based morphometry; test-retest reliability analysis of striatal activations in an independent sample of 25 healthy participants scanned twice with the same task; and imaging genetics analysis of the control group. A total of 54 healthy first-degree relatives of schizophrenic patients and 80 controls matched for demographic, psychological, clinical, and task performance characteristics were studied. Blood oxygen level-dependent response during reward anticipation, analysis of intraclass correlations of functional contrasts, and associations between striatal gray matter volume and NRG1 genotype. Compared with controls, healthy first-degree relatives showed a highly significant decrease in ventral striatal activation during reward anticipation (familywise error-corrected P systems-level functional phenotype is reliable (with intraclass correlation coefficients of 0.59-0.73), independent of local gray matter volume (with no corresponding group differences and no correlation to function, and with all uncorrected P values >.05), and affected by

Autoradiographic evidence for methamphetamine-induced striatal dopaminergic loss in mouse brain: attenuation in CuZn-superoxide dismutase transgenic mice.

Science.gov (United States)

Hirata, H; Ladenheim, B; Carlson, E; Epstein, C; Cadet, J L

1996-04-01

Methamphetamine (METH) has long-lasting neurotoxic effects on the nigrostriatal dopamine (DA) system of rodents. METH-induced neurotoxicity is thought to involve release of DA in presynaptic DA terminals, which is associated with increased formation of oxygen-based free radicals. We have recently shown that METH-induced striatal DA depletion is attenuated in transgenic (Tg) mice that express the human CuZn-superoxide dismutase (SOD) enzyme. That study did not specifically address the issue of loss of DA terminals. In the present study, we have used receptor autoradiographic studies of [(125)I]RTI-121-labeled DA uptake sites to evaluate the effects of several doses of METH on striatal DA terminals of Non-Tg as well as of heterozygous and homozygous SOD-Tg mice. In Non-Tg mice, METH caused decreases in striatal DA uptake sites in a dose-dependent fashion. The loss of DA terminals was more prominent in the lateral region than in the medial subdivisions of the striatum. In SOD-Tg mice, the loss of DA terminals caused by METH was attenuated in a gene dosage-dependent fashion, with the homozygous mice showing the greatest protection. Female mice were somewhat more resistant than male mice against these deleterious effects of METH. These results provide further evidence for a role of superoxide radicals in the long-term effects of METH. They also suggest the notion of a gender-specific handling of oxidative stress.

Interactions of neurotoxins with non-NMDA glutamate receptors: an autoradiographic study

International Nuclear Information System (INIS)

Kuenig, G.; Niedermeyer, B.; Krause, F.; Hartmann, J.; Deckert, J.; Heinsen, H.; Beckmann, H.; Riederer, P.; Ransmayr, G.

1994-01-01

Neurotoxic substances are discussed to cause neurode-generation by acting as excitotoxins on glutamate receptors. We investigated the properties of L-beta-oxalyl-amino-alanine (L-BOAA) and 3,4,6-trihydroxyphenlyalanine (6-OH-Dopa) at the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) glutamate receptor and that of L-BOAA and domoic acid at the kainate glutamate receptor in human hippocampus. (3 H)AMPA binding in hippocampal subfields was inhibited by L-BOAA and 6-OH-Dopa with mean IC50-values in the low micromolar range. (3H)Kainate binding was inhibited by L-BOAA with similar potency as (3H)AMPA binding and by domoic acid with mean IC50-values in the low nanomolar range. These results support the notion that symptoms like anterograde amnesia and epileptic seizures seen in domoic acid intoxication and limbic symptoms, e.g. cognitive and mood impairment observed in neurolathyrism may be caused by excitotoxic action on non-NMDA receptors. The potent interaction of 6-OH-Dopa with the AMPA-receptor may point to a possible dopaminergic-glutamatergic interaction in the development of neurodegenerative diseases like Parkinson's and Huntington's disease. (author)

Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

International Nuclear Information System (INIS)

Eells, J.T.; Dubocovich, M.L.

1988-01-01

The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [ 3 H]dopamine and [ 3 H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [ 3 H]dopamine and [ 3 H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [ 3 H]norepinephrine or [ 3 H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

18F-DOPA PET/CT for assessment of response to induction chemotherapy in a child with high-risk neuroblastoma

International Nuclear Information System (INIS)

Piccardo, Arnoldo; Lopci, Egesta; Foppiani, Luca; Morana, Giovanni; Conte, Massimo

2014-01-01

Functional imaging plays a crucial role in the assessment of neuroblastoma. The evaluation of response to induction chemotherapy is a cornerstone in scheduling proper treatment management in patients affected by high-risk neuroblastoma. 123 I-metaiodobenzylguanidine has been recognized as the radiopharmaceutical of choice in neuroblastoma assessment. To date, the clinical role of PET/CT in pediatric malignancy is not well established. 18 F-DOPA-PET/CT has been recently used in neuroblastoma, and compared with 123 I-MIBG-scan. Scant new data are available about the role of this tool in the evaluation of treatment response after induction chemotherapy. We investigate the role of 18 F-DOPA-PET/CT in characterizing the response to induction chemotherapy in a child affected by high-risk-neuroblastoma, in whom the rare association of 123 I-MIBG-negative primary tumor and MIBG-positive bone marrow metastases was observed. (orig.)

18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism

DEFF Research Database (Denmark)

Christiansen, Charlotte Dahl; Petersen, Henrik; Nielsen, Anne Lerberg

2018-01-01

(68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. Methods: PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUVmax) by two independent examiners......, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Results: Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed...... in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut...

Motor and cortico-striatal-thalamic connectivity alterations in intrauterine growth restriction.

Science.gov (United States)

Eixarch, Elisenda; Muñoz-Moreno, Emma; Bargallo, Nuria; Batalle, Dafnis; Gratacos, Eduard

2016-06-01

Intrauterine growth restriction is associated with short- and long-term neurodevelopmental problems. Structural brain changes underlying these alterations have been described with the use of different magnetic resonance-based methods that include changes in whole structural brain networks. However, evaluation of specific brain circuits and its correlation with related functions has not been investigated in intrauterine growth restriction. In this study, we aimed to investigate differences in tractography-related metrics in cortico-striatal-thalamic and motor networks in intrauterine growth restricted children and whether these parameters were related with their specific function in order to explore its potential use as an imaging biomarker of altered neurodevelopment. We included a group of 24 intrauterine growth restriction subjects and 27 control subjects that were scanned at 1 year old; we acquired T1-weighted and 30 directions diffusion magnetic resonance images. Each subject brain was segmented in 93 regions with the use of anatomical automatic labeling atlas, and deterministic tractography was performed. Brain regions included in motor and cortico-striatal-thalamic networks were defined based in functional and anatomic criteria. Within the streamlines that resulted from the whole brain tractography, those belonging to each specific circuit were selected and tractography-related metrics that included number of streamlines, fractional anisotropy, and integrity were calculated for each network. We evaluated differences between both groups and further explored the correlation of these parameters with the results of socioemotional, cognitive, and motor scales from Bayley Scale at 2 years of age. Reduced fractional anisotropy (cortico-striatal-thalamic, 0.319 ± 0.018 vs 0.315 ± 0.015; P = .010; motor, 0.322 ± 0.019 vs 0.319 ± 0.020; P = .019) and integrity cortico-striatal-thalamic (0.407 ± 0.040 vs 0.399 ± 0.034; P = .018; motor, 0.417 ± 0.044 vs 0

Postural & striatal deformities in Parkinson`s disease: Are these rare?

Directory of Open Access Journals (Sweden)

Sanjay Pandey

2016-01-01

Full Text Available Parkinson`s disease (PD is the most common neurodegenerative disease and is characterized by tremor, rigidity and akinesia. Diagnosis is clinical in the majority of the patients. Patients with PD may have stooped posture but some of them develop different types of postural and striatal deformities. Usually these deformities are more common in atypical parkinsonian disorders such as progressive supranuclear palsy and multisystem atrophy. But in many studies it has been highlighted that these may also be present in approximately one third of PD patients leading to severe disability. These include antecollis or dropped head, camptocormia, p0 isa syndrome, scoliosis, striatal hands and striatal toes. The pathogenesis of these deformities is a complex combination of central and peripheral influences such as rigidity, dystonia and degenerative skeletal changes. Duration of parkinsonism symptoms is an important risk factor and in majority of the patients these deformities are seen in advanced statge of the disease. The patients with such symptoms may initially respond to dopaminergic medications but if not intervened they may become fixed and difficult to treat. Pain and restriction of movement are most common clinical manifestations and these may mimick symptoms of musculoskeletal disorders like rheumatoid arthritis. Early diagnosis is important as the patients may respond to adjustment in dopaminergic medications. Recent advances such as deep brain stimulation (DBS and ultrasound guided botulinum toxin injection are helpful in management of these deformities in patients with PD.

Striatal structure and its association with N-Acetylaspartate and glutamate in autism spectrum disorder and obsessive compulsive disorder

NARCIS (Netherlands)

Naaijen, Jilly; Zwiers, Marcel P.; Forde, Natalie J.; Williams, Steven C. R.; Durston, Sarah; Brandeis, Daniel; Glennon, Jeffrey C.; Franke, Barbara; Lythgoe, David J.; Buitelaar, Jan K.

Autism spectrum disorders (ASD) and obsessive compulsive disorder (OCD) are often comorbid and are associated with changes in striatal volumes and N-Acetylaspartate (NAA) and glutamate levels. Here, we investigated the relation between dorsal striatal volume and NAA and glutamate levels. We

DARPP-32 interaction with adducin may mediate rapid environmental effects on striatal neurons.

Science.gov (United States)