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1.
Front Pediatr ; 10: 1000657, 2022.
Article in English | MEDLINE | ID: mdl-36507149

ABSTRACT

Background: In Europe, meningococcal (Men) vaccines are available against 5 of the 6 serogroups responsible of nearly all cases of invasive meningococcal disease (IMD). Meningococcal vaccination has been introduced in the national immunization programs (NIPs) for children and adolescents of numerous European countries, but with no consistent strategy across countries. Objectives: To describe IMD epidemiology, NIPs, and vaccination coverage rates (VCRs) in children and adolescents in 8 Western European countries. Methods: Epidemiological data (from 1999 to 2019), NIPs regarding meningococcal vaccination status, and VCRs were collected from the European Centre for Disease Prevention and Control (ECDC) and/or national websites. Results: MenB was the most common serogroup. In Belgium, Spain, France, the Netherlands, the United Kingdom (UK), and Portugal, incidence was greater for MenW than MenC. In 2019, MenB risk was covered in 2 countries (Italy, UK). MenC risk was covered in all countries, via MenC only (countries: N = 3), MenACWY only (N = 2), or MenC (infants/children) and MenACWY (adolescents) (N = 3) vaccination. VCRs were higher in children than adolescents. Conclusion: Our study confirmed the diversity of NIPs, including in neighboring European countries with similar factors like economic resources and epidemiological risk, thus indicating that other factors underlie NIPs. Convergence toward a more common immunization program including MenACWY and MenB vaccination would promote equity and safe travel regarding infectious diseases for young people, and possibly improve the understanding of vaccination by patients and healthcare professionals.

2.
Transl Psychiatry ; 11(1): 255, 2021 04 30.
Article in English | MEDLINE | ID: mdl-33931591

ABSTRACT

Mental health issues, including major depressive disorder, which can lead to suicidal behavior, are considered by the World Health Organization as a major threat to global health. Alterations in neurotransmitter signaling, e.g., serotonin and glutamate, or inflammatory response have been linked to both MDD and suicide. Phosphodiesterase 8A (PDE8A) gene expression is significantly decreased in the temporal cortex of major depressive disorder (MDD) patients. PDE8A specifically hydrolyzes adenosine 3',5'-cyclic monophosphate (cAMP), which is a key second messenger involved in inflammation, cognition, and chronic antidepressant treatment. Moreover, alterations of RNA editing in PDE8A mRNA has been described in the brain of depressed suicide decedents. Here, we investigated PDE8A A-to-I RNA editing-related modifications in whole blood of depressed patients and suicide attempters compared to age-matched and sex-matched healthy controls. We report significant alterations of RNA editing of PDE8A in the blood of depressed patients and suicide attempters with major depression, for which the suicide attempt took place during the last month before sample collection. The reported RNA editing modifications in whole blood were similar to the changes observed in the brain of suicide decedents. Furthermore, analysis and combinations of different edited isoforms allowed us to discriminate between suicide attempters and control groups. Altogether, our results identify PDE8A as an immune response-related marker whose RNA editing modifications translate from brain to blood, suggesting that monitoring RNA editing in PDE8A in blood samples could help to evaluate depressive state and suicide risk.


Subject(s)
Depressive Disorder, Major , Suicide, Attempted , 3',5'-Cyclic-AMP Phosphodiesterases/genetics , Depressive Disorder, Major/genetics , Humans , Phosphoric Diester Hydrolases , RNA Editing , Suicidal Ideation
3.
Transl Psychiatry ; 9(1): 112, 2019 03 14.
Article in English | MEDLINE | ID: mdl-30872571

ABSTRACT

Author forgot to attach a supplementary doc file which includes the supplementary methods and supplementary figure legends.

4.
Transl Psychiatry ; 9(1): 91, 2019 02 15.
Article in English | MEDLINE | ID: mdl-30770787

ABSTRACT

Phosphodiesterases (PDE) are key modulators of signal transduction and are involved in inflammatory cell activation, memory and cognition. There is a two-fold decrease in the expression of phosphodiesterase 8A (PDE8A) in the temporal cortex of major depressive disorder (MDD) patients. Here, we studied PDE8A mRNA-editing profile in two architectonically distinct neocortical regions in a clinically well-characterized cohort of age- and sex-matched non-psychiatric drug-free controls and depressed suicide decedents. By using capillary electrophoresis single-stranded conformational polymorphism (CE-SSCP), a previously validated technique to identify A-to-I RNA modifications, we report the full editing profile of PDE8A in the brain, including identification of two novel editing sites. Editing of PDE8A mRNA displayed clear regional difference when comparing dorsolateral prefrontal cortex (BA9) and anterior cingulate cortex (BA24). Furthermore, we report significant intra-regional differences between non-psychiatric control individuals and depressed suicide decedents, which could discriminate the two populations. Taken together, our results (i) highlight the importance of immune/inflammatory markers in major depressive disorder and suicide and (ii) establish a direct relationship between A-to-I RNA modifications of peripheral markers and A-to-I RNA editing-related modifications in brain. This work provides the first immune response-related brain marker for suicide and could pave the way for the identification of a blood-based biomarker that predicts suicidal behavior.


Subject(s)
3',5'-Cyclic-AMP Phosphodiesterases/genetics , Depressive Disorder, Major/genetics , Prefrontal Cortex/metabolism , RNA Editing/genetics , RNA, Messenger/metabolism , Suicide, Completed , Adolescent , Adult , Autopsy , Case-Control Studies , Gyrus Cinguli/metabolism , Humans , Male , Middle Aged , Polymorphism, Single-Stranded Conformational , Young Adult
5.
Aging Clin Exp Res ; 28(5): 1015-21, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26639669

ABSTRACT

INTRODUCTION: Neuroleptics are known to induce Parkinsonism, tardive dyskinesia and their long-term use was associated with increased risk of hip fractures and impaired cognitive function and even death. METHODS: The primary objective of Neurodem study was to determine the IAI of patients with Alzheimer's disease in French NH. RESULTS: 1022 patients were enrolled. The IAI was 24.8 %. Multivariate logistic analysis showed that having a severe form of dementia, resident without MMS evaluation the last 12 months and having a prescription for an anxiolytic drug were associated with a higher risk of having a prescription for an antipsychotic drug. CONCLUSION: The results from our study show that the percentage of patients receiving an antipsychotic drug (24.8 %) was higher than the national average (18 %). Effective educational activities about appropriate use of antipsychotic drugs in patients with Alzheimer's disease are needed.


Subject(s)
Alzheimer Disease/drug therapy , Antipsychotic Agents/adverse effects , Nursing Homes , Aged , Aged, 80 and over , Dementia/drug therapy , Female , Humans , Iatrogenic Disease , Male
6.
Neurotox Res ; 23(1): 49-62, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22528247

ABSTRACT

Many drugs in clinical trials, or already on the market, can have psychiatric side effects, independently of their therapeutic indication (e.g., Acomplia, Taranabant, and Roaccutane). There is currently no in vitro or in vivo approved test for the detection/prediction of such adverse effects, and the Food and Drugs Administration (FDA) can only issue general alerts on specific therapeutic classes. The development of a screening assay is therefore of real interest. The anti-viral and anti-tumor action of human interferon-alpha (hIFNα) is associated with a variety of neuropsychiatric side effects, including major depression, suicidal ideation and suicide. RNA editing of the serotonin 2C receptor (HTR2C) by adenosine deaminases acting on RNA (ADARs) is a post-transcriptional modification, the regulation of which is altered in depressed suicide victims. In this study, we show that in the SH-SY5Y neuroblastoma cell line, hIFNα specifically activates the ADAR1a isoform and thereby modifies the HTR2C mRNA editing profile. As this hIFNα-induced altered profile partly overlaps with that observed in the brain of depressed suicide victims, we investigated whether it could be used as a signature to identify drugs with depression and/or suicidal side effects. By means of the Biocortech proprietary screening assay, which allows the relative quantification of all the edited HTR2C isoforms in a sample, we blind-tested the effect of 50 marketed molecules on HTR2C mRNA editing in SH-SY5Y cells and identified 17 compounds with an IFN-like editing profile. This new toxicogenomic assay can identify compounds with potential psychiatric adverse events with a positive predictive value of 90 %.


Subject(s)
Depression/chemically induced , Depression/genetics , RNA Editing/genetics , RNA, Messenger/genetics , Receptor, Serotonin, 5-HT2C/genetics , Suicidal Ideation , Cell Line, Tumor , Depression/metabolism , Genomics/methods , Humans , Interferon-alpha/adverse effects , Mutagenicity Tests/methods , RNA, Messenger/biosynthesis , Receptor, Serotonin, 5-HT2C/metabolism
7.
Mol Pharmacol ; 73(3): 748-57, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18083778

ABSTRACT

Despite the importance of 5-hydroxytryptamine (5-HT)(2C) (serotonin) receptors in the control of depressive states, actions of antidepressants at these receptors remain poorly characterized. This issue was addressed both in human embryonic kidney (HEK)-293 cells coexpressing unedited human 5-HT(2CINI) receptors and Galpha(q) protein and in cultured mouse cortical neurons. Indicative of constitutive activity, the inverse agonist SB206,553 decreased basal inositol phosphate (IP) production in HEK-293 cells. The tetracyclic antidepressants mirtazapine and mianserin likewise suppressed basal IP formation. Conversely, the tricyclics amitriptyline and clomipramine, the m-chlorophenylpiperazine derivatives trazodone and nefazodone, and the 5-HT reuptake inhibitors fluoxetine and citalopram were inactive alone, although they blocked 5-HT-induced IP production. Inverse agonist actions of 5-methyl-1-(3-pyridylcarbamoyl)-1,2,3,5-tetrahydropyrrolo[2,3-f]indole (SB206,553) and mirtazapine were abolished by the neutral antagonist 6-chloro-5-methyl-1-[6-(2-methylpyridin-3-yloxy)pyridin-3-ylcarbamoyl]indoline (SB242,084), which was inactive alone. As assessed by confocal microscopy and enzyme-linked immunosorbent assay, prolonged treatment of HEK-293 cells with SB206,553, mirtazapine, or mianserin, but not the other antidepressants, enhanced cell surface expression of 5-HT(2C) receptors: 5-HT-induced IP production was also increased, and both these actions were blocked by SB242,084. Cortical neurons were shown by reverse transcription-polymerase chain reaction to predominantly express constitutively active 5-HT(2C) receptor isoforms. Prolonged pretreatment with SB206,553 or mirtazapine triggered an otherwise absent 5-HT-induced elevation in cytosolic Ca(2+) concentrations. SB242,084, which was inactive alone, abolished these effects of SB206,553 and mirtazapine. In conclusion, the tetracyclic antidepressants mirtazapine and mianserin, but not other clinically established antidepressants, suppress constitutive activity at recombinant and native 5-HT(2C) receptors. The clinical significance of inverse agonist versus neutral antagonist properties both during and after drug administration will be of interest to elucidate.


Subject(s)
Antidepressive Agents, Tricyclic/pharmacology , Cell Membrane/metabolism , Receptor, Serotonin, 5-HT2C/drug effects , Serotonin Antagonists/pharmacology , Serotonin Receptor Agonists/pharmacology , Signal Transduction , Cell Culture Techniques , Cell Line , Cerebral Cortex/cytology , Dose-Response Relationship, Drug , GTP-Binding Protein alpha Subunits, Gq-G11/genetics , GTP-Binding Protein alpha Subunits, Gq-G11/metabolism , Gene Expression , Humans , Inhibitory Concentration 50 , Inositol Phosphates/analysis , Inositol Phosphates/biosynthesis , Kidney/cytology , Neurons/physiology , RNA, Messenger/metabolism , Receptor, Serotonin, 5-HT2C/genetics , Receptor, Serotonin, 5-HT2C/metabolism , Recombinant Proteins/metabolism , Transfection
8.
Electrophoresis ; 28(16): 2843-52, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17702068

ABSTRACT

A new method has been developed allowing the identification and relative quantification of different forms of mRNA after RNA editing. This method was applied to the serotonin 2c receptor mRNA that potentially exhibits 32 different forms after adenosine to inosine editing at five different sites located in a row of 13 nucleotides. CE was used to characterize fluorescently labeled ssDNA molecules on the basis of their conformational polymorphism. The relative amount of these 32 mRNA forms has been estimated by measuring the fluorescence intensity of each individual DNA strand. Accuracy of quantification was established by diluting one form into another or into a mixture of cDNA, showing linear and precise proportion of each form (0.06

Subject(s)
Electrophoresis, Capillary/methods , RNA Editing , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor, Serotonin, 5-HT2C/genetics , Adenosine/genetics , Animals , Base Sequence , Brain/metabolism , DNA Primers/genetics , DNA, Complementary/genetics , DNA, Complementary/isolation & purification , Inosine/genetics , Mice , Mice, Inbred BALB C , Rats , Rats, Wistar
9.
Psychoneuroendocrinology ; 30(5): 461-82, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15721058

ABSTRACT

OBJECTIVE: Although various brain regions have been shown to respond to the presentation of visual sexual stimuli (VSS), whether these regions are specifically mediating sexual arousal or whether they mediate general emotional or motivational arousal is unknown. To clarify this issue, our purpose was to map the regions where the response to VSS was related to plasma testosterone. Specific objectives were (i) to identify regions that respond differentially to VSS in untreated hypogonadal patients compared with healthy controls and (ii) to identify in hypogonadal patients the regions that respond differentially to VSS as a function of therapeutically induced increased testosterone levels. METHOD: In nine male hypogonadal patients, in the same patients under treatment, and in eight healthy males, we used Positron Emission Tomography to investigate responses of regional cerebral blood flow to VSS. Statistical Parametric Mapping was used to locate regions that demonstrated a differential response. RESULTS: Regions responding differentially both in untreated patients compared with controls and in untreated patients compared with themselves under treatment were the right orbitofrontal cortex, insula and claustrum, where the activation was higher in controls than in untreated patients and where activation increased under treatment, and the left inferior frontal gyrus, that demonstrated a deactivation only in controls and in patients under treatment. That these responses appear to depend on testosterone indicates that these regions mediate sexual arousal and not only a process of general emotional or motivational arousal.


Subject(s)
Brain/physiopathology , Hypogonadism/physiopathology , Hypogonadism/psychology , Photic Stimulation , Adult , Blood Pressure/drug effects , Brain/diagnostic imaging , Brain Chemistry/physiology , Brain Mapping , Cerebrovascular Circulation/physiology , Chorionic Gonadotropin/therapeutic use , Erotica , Hormone Replacement Therapy , Humans , Hypogonadism/diagnostic imaging , Image Processing, Computer-Assisted , Male , Middle Aged , Neuropsychological Tests , Penile Erection/physiology , Positron-Emission Tomography , Socioeconomic Factors , Testosterone/blood , Testosterone/therapeutic use , Wit and Humor as Topic/psychology
10.
Brain Res ; 1030(1): 1-10, 2004 Dec 24.
Article in English | MEDLINE | ID: mdl-15567332

ABSTRACT

Our study was devoted to determine in freely moving rats whether the increase in tissue concentration of tyrosine hydroxylase (TH) elicited by a single administration of RU 24722 could modify the catecholaminergic reactivity of neuronal processes present in the rostrolateral part of the pericerulean area (r-lPCA) in response to tail pinch. Catecholaminergic activity was monitored by measuring in vivo the concentration of dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) using microdialysis coupled to HPLC detection. In this study, the microdialysis probe was implanted at a sufficient distance from the lateral border of rostral nucleus locus ceruleus (LC) to avoid a large contribution of the noradrenergic cell bodies in the measurements performed. We first evidenced that DOPAC measured in the r-lPCA indicated the functional state of catecholaminergic metabolism in neuronal processes (dendrites and fibers) laying in this region. We also showed that the enhancement of TH protein concentration in the r-lPCA following RU 24722 treatment supported an increased in vivo catecholaminergic metabolism in this region. Furthermore, catecholaminergic metabolism response to tail pinch was potentiated in animals with greater TH tissue concentration. Thus, our study reveals that the modulation of both TH concentration and catecholaminergic metabolism in the r-lPCA may be critical in the functioning of cells and neuronal elements present in this region, notably in adaptive responses to noxious stimuli.


Subject(s)
3,4-Dihydroxyphenylacetic Acid/metabolism , Locus Coeruleus/drug effects , Locus Coeruleus/metabolism , Nociceptors/metabolism , Vincamine/analogs & derivatives , Vincamine/pharmacology , Animals , Hydroxyindoleacetic Acid/metabolism , Male , Microdialysis , Physical Stimulation , Rats , Rats, Sprague-Dawley , Tail , Tyrosine 3-Monooxygenase/metabolism
11.
Psychiatry Res ; 124(2): 67-86, 2003 Oct 30.
Article in English | MEDLINE | ID: mdl-14561426

ABSTRACT

Although hypoactive sexual desire disorder (HSDD) is a common condition and has long been hypothesized to result from malfunctions of the cerebral control mechanisms that adjust the level of sexual motivation, very little is known about the pathophysiology of this disorder. The primary objective was to identify in patients with HSDD brain regions where functional perturbations disrupt the regulation of sexual motivation. We used positron emission tomography to compare seven male patients with HSDD with eight healthy men on their regional cerebral blood flow responses to visual sexual stimuli (VSS) of graded intensity. Statistical Parametric Mapping was used to locate brain regions that demonstrated a differential activation (or deactivation) across the groups. Whereas in control subjects the medial orbitofrontal cortex showed a deactivation in response to VSS, in HSDD patients there was an abnormally maintained activity of this region, which has been implicated in the inhibitory control of motivated behavior. By contrast, the reverse pattern-activation in control subjects, deactivation or unchanged activity in patients-was found in the secondary somatosensory cortex and inferior parietal lobules, regions mediating emotional and motor imagery processes, as well as in those areas of the anterior cingulate gyrus and of the frontal lobes that are involved in premotor processes.


Subject(s)
Brain/blood supply , Erotica , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Pattern Recognition, Visual/physiology , Sexual Dysfunctions, Psychological/physiopathology , Tomography, Emission-Computed , Adult , Brain/diagnostic imaging , Emotions/physiology , Frontal Lobe/blood supply , Frontal Lobe/diagnostic imaging , Gyrus Cinguli/blood supply , Gyrus Cinguli/diagnostic imaging , Humans , Male , Middle Aged , Neural Inhibition/physiology , Parietal Lobe/blood supply , Parietal Lobe/diagnostic imaging , Reference Values , Regional Blood Flow/physiology , Sexual Dysfunctions, Psychological/diagnostic imaging , Somatosensory Cortex/blood supply , Somatosensory Cortex/diagnostic imaging
12.
J Cereb Blood Flow Metab ; 22(6): 753-65, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12045674

ABSTRACT

The selectivity of [18F]MPPF (fluorine-18-labeled 4-(2;-methoxyphenyl)-1-[2;-(N-2"-pirydynyl)-p-fluorobenzamido]ethylpiperazine) for serotonergic 5-hydroxytryptamine(1A) (5-HT1A) receptors has been established in animals and humans. The authors quantified the parameters of ligand-receptor exchanges using a double-injection protocol. After injection of a tracer and a coinjection dose of [18F]MPPF, dynamic positron emission tomography (PET) data were acquired during a 160-minute session in five healthy males. These PET and magnetic resonance imaging data were coregistered for anatomical identification. A three-compartment model was used to determine six parameters: Fv (vascular fraction), K1, k2 (plasma/free compartment exchange rate), koff, kon/Vr (association and dissociation rate), Bmax (receptor concentration), and to deduce Kd (apparent equilibrium dissociation rate). The model was fitted with regional PET kinetics and arterial input function corrected for metabolites. Analytical distribution volume and binding potential were compared with indices generated by Logan-Patlak graphical analysis. The 5HT1A specificity for MPPF was evidenced. A Bmax of 2.9 pmol/mL and a Kd of 2.8 nmol/L were found in hippocampal regions, Kd and distribution volume in the free compartment were regionally stable, and the Logan binding potential was linearly correlated to Bmax. This study confirms the value of MPPF in the investigation of normal and pathologic systems involving the limbic network and 5-HT1A receptors. Standard values can be used for the simulation of simplified protocols.


Subject(s)
Aminopyridines/pharmacokinetics , Brain/diagnostic imaging , Piperazines/pharmacokinetics , Receptors, Serotonin/metabolism , Serotonin Antagonists/pharmacokinetics , Tomography, Emission-Computed/methods , Adult , Aminopyridines/administration & dosage , Blood-Brain Barrier , Brain/blood supply , Brain Chemistry , Cerebral Arteries , Fluorine Radioisotopes , Humans , Kinetics , Male , Models, Biological , Piperazines/administration & dosage , Protein Binding , Receptors, Serotonin/analysis , Receptors, Serotonin, 5-HT1 , Reproducibility of Results , Serotonin Antagonists/administration & dosage , Tomography, Emission-Computed/standards
13.
Neurochem Res ; 27(4): 269-75, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11958527

ABSTRACT

Changes in tissue and extracellular serotonin (5-HT) in raphe dorsalis, raphe medialis and in their main projections areas (hippocampus, striatum and frontal cortex) were investigated at short and long-term times after single injection (5 mg/kg ip) of a novel tryptophan hydroxylase inhibitor, p-ethynylphenylalanine (p-EPA). The 5-HT tissue concentration decreased significantly in raphe nuclei, 30 min post-injection and for 4 days, whereas it decreased from 24 hours post-injection in the 5-HT projections. Normal 5-HT levels reappeared after 12 days post-injection in all areas. Moreover, in the projection areas, the extracellular 5-HT levels decreased rapidly, 90, 40 and 30 min after p-EPA injection, in hippocampus, striatum and frontal cortex, respectively. Decreased accumulation of 5-hydroxytryptophan (5-HTP) under NSD-101 perfusion in the serotoninergic projections after p-EPA injection, confirmed the direct inhibitory effect of the drug on the tryptophan hydroxylase activity. These results demonstrated that p-EPA is a useful pharmacological tool which powerfully, acutely and irreversibly reduces the 5-HT levels.


Subject(s)
Alanine/analogs & derivatives , Alanine/pharmacology , Brain/metabolism , Serotonin/metabolism , Tryptophan Hydroxylase/antagonists & inhibitors , Animals , Brain/drug effects , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Frontal Lobe/drug effects , Frontal Lobe/metabolism , Hippocampus/drug effects , Hippocampus/metabolism , Kinetics , Male , Raphe Nuclei/drug effects , Raphe Nuclei/metabolism , Rats , Rats, Sprague-Dawley , Time Factors
14.
J Neurochem ; 80(2): 278-86, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11902118

ABSTRACT

By using a combination of an original beta+-sensitive intracerebral probe and microdialysis, the effect of increased endogenous serotonin on specific binding of 18F-MPPF [4-(2'-methoxyphenyl)-1-[2'-[N-(2"-pyridinyl)-p-fluorobenzamido]ethyl]piperazine] to the serotonin-1A (5-HT1A) receptors was investigated in the hippocampus of the anaesthetized rat. Our beta-sensitive probe prototype was sensitive enough to obtain specific 18F-MPPF time-activity curves in the rodent (hippocampus/cerebellum ratio approximately 2). The serotonin neuronal release was pharmacologically enhanced using fenfluramine at three different doses (1, 2 and 10 mg/kg intravenous) multiplying by 2-15 the extracellular serotonin in the hippocampus. These extracellular variations of extracellular serotonin resulted in dose-ranging decreases in 18F-MPPF-specific binding in the same rat. Our results showed for the first time that 18F-MPPF binding could be modulated by modifications of extracellular serotonin in the rat hippocampus. These results were confirmed by the enhancement of extracellular radioactivity collected in dialysates after the displacement of 18F-MPPF by fenfluramine. After modelization, 18F-MPPF binding could constitute an interesting radiotracer for positron emission tomography in evaluating the serotonin endogenous levels in limbic areas of the human brain.


Subject(s)
Hippocampus/metabolism , Piperazines/pharmacokinetics , Pyridines/pharmacokinetics , Receptors, Serotonin/metabolism , Serotonin/metabolism , Animals , Binding, Competitive , Cerebellum/metabolism , Extracellular Space/metabolism , Fenfluramine/pharmacology , Humans , Male , Microdialysis , Piperazines/pharmacology , Pyridines/pharmacology , Rats , Rats, Sprague-Dawley , Receptors, Serotonin, 5-HT1 , Serotonin Agents/pharmacology , Serotonin Antagonists/pharmacology , Tomography, Emission-Computed
15.
J Nucl Med ; 43(2): 227-33, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11850489

ABSTRACT

UNLABELLED: Our aim was to show the ability of a recently developed beta(+)-range-sensitive intracerebral probe (SIC) to measure, in vivo, the binding of radioligands in small animals. METHODS: The potential of the device for pharmacokinetic studies was evaluated by measurement of the dynamic striatal binding of (11)C-raclopride, a well-documented D(2) dopaminergic receptor ligand, in rat brain after intravenous injection of the labeled compound. The effects of preinjection of the unlabeled ligand (raclopride, 2 mg/kg intravenously) and of increasing the synaptic dopamine level (amphetamine treatment, 1 mg/kg intravenously) or of depleting synaptic dopamine (reserpine pretreatment, 5 mg/kg intraperitoneally) on in vivo (11)C-raclopride binding were monitored by SIC. RESULTS: The radioactivity curves measured as a function of time were reproducible and consistent with previous studies using PET imaging (ratio of striatum to cerebellum, 2.6 +/- 0.3 after 20 min). Further studies showed significant displacement of (11)C-raclopride by its stable analog. Finally, the device proved its capacity to accurately detect changes in (11)C-raclopride binding after a sudden (amphetamine) or a gradual (reserpine) modulation of endogenous dopamine levels. CONCLUSION: These results show that the new device can monitor binding of PET ligands in anesthetized rodents in vivo, with high temporal resolution.


Subject(s)
Carbon Radioisotopes , Cerebellum/metabolism , Corpus Striatum/metabolism , Dopamine Antagonists , Raclopride , Receptors, Dopamine D2/metabolism , Animals , Beta Particles , Ligands , Male , Radioligand Assay , Radiometry/instrumentation , Rats , Rats, Sprague-Dawley
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