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Courault P, Lancelot S, Costes N, Colom M, Le Bars D, Redoute J, Gobert F, Dailler F, Isal S, Iecker T, Newman-Tancredi A, Merida I, Zimmer L. [ 18F]F13640: a selective agonist PET radiopharmaceutical for imaging functional 5-HT 1A receptors in humans. Eur J Nucl Med Mol Imaging 2023; 50:1651-1664. [PMID: 36656363 PMCID: PMC10119077 DOI: 10.1007/s00259-022-06103-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023]
Abstract
PURPOSE F13640 (a.k.a. befiradol, NLX-112) is a highly selective 5-HT1A receptor ligand that was selected as a PET radiopharmaceutical-candidate based on animal studies. Due to its high efficacy agonist properties, [18F]F13640 binds preferentially to functional 5-HT1A receptors, which are coupled to intracellular G-proteins. Here, we characterize brain labeling of 5-HT1A receptors by [18F]F13640 in humans and describe a simplified model for its quantification. METHODS PET/CT and PET-MRI scans were conducted in a total of 13 healthy male volunteers (29 ± 9 years old), with arterial input functions (AIF) (n = 9) and test-retest protocol (n = 8). Several kinetic models were compared (one tissue compartment model, two-tissue compartment model, and Logan); two models with reference region were also evaluated: simplified reference tissue model (SRTM) and the logan reference model (LREF). RESULTS [18F]F13640 showed high uptake values in raphe nuclei and cortical regions. SRTM and LREF models showed a very high correlation with kinetic models using AIF. As concerns test-retest parameters and the prolonged binding kinetics of [18F]F13640, better reproducibility, and reliability were found with the LREF method. Cerebellum white matter and frontal lobe white matter stand out as suitable reference regions. CONCLUSION The favorable brain labeling and kinetic profile of [18F]F13640, its high receptor specificity and its high efficacy agonist properties open new perspectives for studying functionally active 5-HT1A receptors, unlike previous radiopharmaceuticals that act as antagonists. [18F]F13640's kinetic properties allow injection outside of the PET scanner with delayed acquisitions, facilitating the design of innovative longitudinal protocols in neurology and psychiatry. TRIAL REGISTRATION Trial Registration EudraCT 2017-002,722-21.
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Affiliation(s)
- Pierre Courault
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,Hospices Civils de Lyon (HCL), Lyon, France
| | - Sophie Lancelot
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,Hospices Civils de Lyon (HCL), Lyon, France.,CERMEP, Bron, France
| | - Nicolas Costes
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,CERMEP, Bron, France
| | | | - Didier Le Bars
- Hospices Civils de Lyon (HCL), Lyon, France.,CERMEP, Bron, France
| | | | - Florent Gobert
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,Hospices Civils de Lyon (HCL), Lyon, France
| | | | - Sibel Isal
- Hospices Civils de Lyon (HCL), Lyon, France
| | | | | | | | - Luc Zimmer
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France. .,Hospices Civils de Lyon (HCL), Lyon, France. .,CERMEP, Bron, France.
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Mangeant R, Dubost E, Cailly T, Collot V. Radiotracers for the Central Serotoninergic System. Pharmaceuticals (Basel) 2022; 15:ph15050571. [PMID: 35631397 PMCID: PMC9143978 DOI: 10.3390/ph15050571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 12/10/2022] Open
Abstract
This review lists the most important radiotracers described so far for imaging the central serotoninergic system. Single-photon emission computed tomography and positron emission tomography radiotracers are reviewed and critically discussed for each receptor.
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Affiliation(s)
- Reynald Mangeant
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
| | - Emmanuelle Dubost
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
| | - Thomas Cailly
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
- UNICAEN, IMOGERE, Normandie Univ., 14000 Caen, France
- CHU Côte de Nacre, Department of Nuclear Medicine, 14000 Caen, France
- Correspondence: (T.C.); (V.C.)
| | - Valérie Collot
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
- Correspondence: (T.C.); (V.C.)
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Receptor mapping using methoxy phenyl piperazine derivative: Preclinical PET imaging. Bioorg Chem 2021; 117:105429. [PMID: 34736134 DOI: 10.1016/j.bioorg.2021.105429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/01/2021] [Accepted: 10/11/2021] [Indexed: 12/18/2022]
Abstract
This study aimed at assessing 2-methoxyphenyl piperazine derivative for its binding specificity and suitability in mapping metabotropic glutamate receptor subtype 1, which is implicated in several neuropsychiatric disorders. N-(2-(4-(2-Methoxyphenyl)piperazin-1-yl)ethyl)-N-methylpyridin-2-amine was synthesised and evaluated for brain imaging subsequent to radiolabelling with [11C] radioisotope via methylation process in 98.9% purity and 52 ± 6% yield (decay corrected). The specific activity was in the range of 72-93 GBq/µmol. The haemolysis of blood was 2-5% for initial 4 hr and remained < 10% after 24 h of incubation indicating low toxicity. In vitro autoradiograms after coincubation with unlabelled ligand confirmed the high uptake of the PET radioligand in the mGluR1 receptor rich regions. The PET as well as biodistribution studies also showed high activity in the brain with a direct correlation between receptor abundance distribution pattern and tracer activity. The biodistribution analyses revealed initial high brain uptake (4.18 ± 0.48). The highest uptake was found in cerebellum (SUV 4.7 ± 0.2), followed by thalamus (SUV 3.5 ± 0.1), and striatum (SUV 3 ± 0.1). In contrast, pons had negligible tracer activity. The high uptake observed in all the regions with known mGluR1 activity indicates suitability of the ligand for mGluR1 imaging.
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Narimani A, Sadeghzadeh M, Kurdtabar M. Synthesis, radiolabeling and biological evaluation of [ 125I]-1-[2-(benzylthio)ethyl]-4-(5-iodo-2-methoxyphenyl)piperazine as a new 5-HT 1A receptor ligand. RADIOCHIM ACTA 2017. [DOI: 10.1515/ract-2016-2698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
5-HT1A receptors have been implicated in the pathogenesis of a wide variety of disorders related to the serotonin receptors. WAY100635 is a well-known high affinity 5-HT1A receptor antagonist. Many 11C and 18F radiolabeled derivatives and its radioiodinated analogues have been reported as imaging agents for 5-HT1A receptors. In this regard, the synthesis, radiolabeling and biological evaluation of a new 5-HT1A receptor radioligand, [125I]-1-(2-(benzylthio)ethyl)-4-(5-iodo-2-methoxyphenyl)piperazine ([125I]-BTE-IMPP), are described. Radioiodination of this newly synthesized compound was done by the direct aromatic electrophilic substitution via Iodo-Gen method. Radiochemical yield and radiochemical purity determined by TLC and RTLC were >70% and >95%, respectively. Biodistribution studies of [125I]-BTE-IMPP in rats displayed relatively high uptake in hippocampus (Hip) and low uptake in cerebellum (Cer). The level of the radiotracer uptake was over threefold higher in hippocampus than in cerebellum at 30 min post-injection. Moreover, the brain to blood uptake ratio and the blocking studies results indicated prolonged retention of the radiotracer and relatively good specific binding to 5-HT1A receptor. These findings strongly suggest that [125I]-BTE-IMPP could be a good candidate as an in vivo marker for pharmacological study of 5-HT1A receptors in animal models.
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Affiliation(s)
- Ali Narimani
- Department of Chemistry, College of Basic Sciences, Karaj Branch , Islamic Azad University , Karaj , Iran
- Radiation Application Research School, Nuclear Science and Technology Research Institute , AEOI, Tehran , Iran
| | - Masoud Sadeghzadeh
- Radiation Application Research School, Nuclear Science and Technology Research Institute , AEOI, P.O.Box:11365-3486 , Tehran , Iran
| | - Mehran Kurdtabar
- Department of Chemistry, College of Basic Sciences, Karaj Branch , Islamic Azad University , Karaj , Iran
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Cismesia MA, Ryan SJ, Bland DC, Sanford MS. Multiple Approaches to the In Situ Generation of Anhydrous Tetraalkylammonium Fluoride Salts for S NAr Fluorination Reactions. J Org Chem 2017; 82:5020-5026. [PMID: 28459241 DOI: 10.1021/acs.joc.7b00481] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This article focuses on the development of practical approaches to the in situ generation of anhydrous fluoride salts for applications in nucleophilic aromatic substitution (SNAr) reactions. We report herein that a variety of combinations of inexpensive nucleophiles (e.g., tetraalkylammonium cyanide and phenoxide salts) and fluorine-containing electrophiles (e.g., acid fluoride, fluoroformate, benzenesulfonyl fluoride, and aryl fluorosulfonate derivatives) are effective for this transformation. Ultimately, we demonstrate that the combination of tetramethylammonium 2,6-dimethylphenoxide and sulfuryl fluoride (SO2F2) serves as a particularly practical route to anhydrous tetramethylammonium fluoride. This procedure is applied to the SNAr fluorination of a range of electron-deficient aryl and heteroaryl chlorides as well as nitroarenes.
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Affiliation(s)
- Megan A Cismesia
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Sarah J Ryan
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Douglas C Bland
- Core Research & Development, The Dow Chemical Company , 1710 Building, Midland, Michigan 48674, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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Pratt WE, Clissold KA, Lin P, Cain AE, Ciesinski AF, Hopkins TR, Ilesanmi AO, Kelly EA, Pierce-Messick Z, Powell DS, Rosner IA. A systematic investigation of the differential roles for ventral tegmentum serotonin 1- and 2-type receptors on food intake in the rat. Brain Res 2016; 1648:54-68. [PMID: 27431937 PMCID: PMC5018453 DOI: 10.1016/j.brainres.2016.07.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 10/21/2022]
Abstract
Central serotonin (5-HT) pathways are known to influence feeding and other ingestive behaviors. Although the ventral tegmentum is important for promoting the seeking and consumption of food and drugs of abuse, the roles of 5-HT receptor subtypes in this region on food intake have yet to be comprehensively examined. In these experiments, food restricted rats were given 2-h access to rat chow; separate groups of non-restricted animals had similar access to a sweetened fat diet. Feeding and locomotor activity were monitored following ventral tegmentum stimulation or blockade of 5-HT1A, 5-HT1B, 5-HT2A, 5-HT2B, or 5-HT2C receptors. 5-HT1A receptor stimulation transiently inhibited rearing behavior and chow intake in food-restricted rats, and had a biphasic effect on non-restricted rats offered the palatable diet. 5-HT1B receptor agonism transiently inhibited feeding in restricted animals, but did not affect intake of non-restricted rats. In contrast, 5-HT1B receptor antagonism decreased palatable feeding. Although stimulation of ventral tegmental 5-HT2B receptors with BW723C86 did not affect hunger-driven food intake, it significantly affected palatable feeding, with a trend for an increasing intake at 2.0µg/side but not at 5.0µg/side. Antagonism of the same receptor modestly but significantly inhibited feeding of the palatable diet at 5.0µg/side ketanserin. Neither stimulation nor blockade of 5-HT2A or 5-HT2C receptors caused prolonged effects on intake or locomotion. These data suggest that serotonin's effects on feeding within the ventral tegmentum depend upon the specific receptor targeted, as well as whether intake is motivated by food restriction or the palatable nature of the offered diet.
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Affiliation(s)
- Wayne E Pratt
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States.
| | - Kara A Clissold
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | - Peagan Lin
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | - Amanda E Cain
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | - Alexa F Ciesinski
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | - Thomas R Hopkins
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | - Adeolu O Ilesanmi
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | - Erin A Kelly
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | | | - Daniel S Powell
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
| | - Ian A Rosner
- Department of Psychology, Wake Forest University, Winston-Salem, NC, United States
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7
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Becker G, Bolbos R, Costes N, Redouté J, Newman-Tancredi A, Zimmer L. Selective serotonin 5-HT1A receptor biased agonists elicitdistinct brain activation patterns: a pharmacoMRI study. Sci Rep 2016; 6:26633. [PMID: 27211078 PMCID: PMC4876409 DOI: 10.1038/srep26633] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 05/06/2016] [Indexed: 11/09/2022] Open
Abstract
Serotonin 1A (5-HT1A) receptors are involved in several physiological and pathological processes and constitute therefore an important therapeutic target. The recent pharmacological concept of biased agonism asserts that highly selective agonists can preferentially direct receptor signaling to specific intracellular responses, opening the possibility of drugs targeting a receptor subtype in specific brain regions. The present study brings additional support to this concept thanks to functional magnetic resonance imaging (7 Tesla-fMRI) in anaesthetized rats. Three 5-HT1A receptor agonists (8-OH-DPAT, F13714 and F15599) and one 5-HT1A receptor antagonist (MPPF) were compared in terms of influence on the brain blood oxygen level-dependent (BOLD) signal. Our study revealed for the first time contrasting BOLD signal patterns of biased agonists in comparison to a classical agonist and a silent antagonist. By providing functional information on the influence of pharmacological activation of 5-HT1A receptors in specific brain regions, this neuroimaging approach, translatable to the clinic, promises to be useful in exploring the new concept of biased agonism in neuropsychopharmacology.
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Affiliation(s)
- G Becker
- Université Claude Bernard Lyon 1, Centre de Recherche en Neurosciences de Lyon, CNRS, INSERM, Lyon, France.,Hospices Civils de Lyon, Lyon, France
| | - R Bolbos
- CERMEP - Imagerie du vivant, Lyon, France
| | - N Costes
- CERMEP - Imagerie du vivant, Lyon, France
| | - J Redouté
- CERMEP - Imagerie du vivant, Lyon, France
| | | | - L Zimmer
- Université Claude Bernard Lyon 1, Centre de Recherche en Neurosciences de Lyon, CNRS, INSERM, Lyon, France.,Hospices Civils de Lyon, Lyon, France.,CERMEP - Imagerie du vivant, Lyon, France
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8
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Zimmer L, Le Bars D. Current status of positron emission tomography radiotracers for serotonin receptors in humans. J Labelled Comp Radiopharm 2013; 56:105-13. [DOI: 10.1002/jlcr.3001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 11/08/2012] [Accepted: 11/08/2012] [Indexed: 12/19/2022]
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9
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Hassanzadeh L, Erfani M, Najafi R, Shafiei M, Amini M, Shafiee A, Ebrahimi SES. Synthesis, radiolabeling and bioevaluation of a novel arylpiperazine derivative containing triazole as a 5-HT1A receptor imaging agents. Nucl Med Biol 2012; 40:227-32. [PMID: 23141548 DOI: 10.1016/j.nucmedbio.2012.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Revised: 09/20/2012] [Accepted: 10/03/2012] [Indexed: 11/29/2022]
Abstract
INTRODUCTION It has been recognized that serotonin plays a main role in various pathological conditions such as anxiety, depression, aggressiveness, schizophrenia, suicidal behavior, panic and autism. 1-(2-Methoxyphenyl) piperazine pharmacophore, a fragment of the true 5-HT(1A) antagonist WAY100635, is found in numerous selective 5-HT(1A) imaging agents. In this paper, we have reported the synthesis of a novel derivative of 1-(2-methoxyphenyl) piperazine that is labeled with (99m)Tc (CO)(3) via click chemistry. METHODS The bidentate alkyne, propargylglycine was reacted with phenyl piperazine triazole derivative in the presence of a catalytic amount of Cu (I) to form tridentate ligand. The ligand was radiolabeled with the precursor [(99m)Tc] [(H(2)O)(3) (CO)(3)](+) and characterized by HPLC. The bioevaluation of radio labeled ligand was carried out in rats. RESULTS Triazole complex was labeled by (99m)Tc-tricarbonyl and its radiochemical yield was more than >95% which was determined by HPLC. In vivo stability studies in human serum albumin show a 93% ratio of complex after a 24h period. The calculated partition coefficient (logP) was 0.34±0.02. Receptor binding assays indicated about 70% specific binding of radioligand to 5-HT(1A) receptors. Biodistribution studies have shown brain hippocampus uptake of 0.40±0.08 %ID/g at 30 min post injection. CONCLUSIONS Results indicate that this (99m)Tc-tricabonyl-arylpiperazine derivative has specific binding to 5-HT(1A) receptors and presented suitable characters for its use as a CNS imaging agent.
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Affiliation(s)
- Leila Hassanzadeh
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
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10
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Hassanzadeh L, Erfani M, Sadat Ebrahimi SE. 2-Amino-3-(1-(4-(4-(2-methoxyphenyl) piperazine-1-yl)butyl)-1H-1,2,3-triazol-4-yl) propanoic acid: synthesized,99mTc-tricarbonyl labeled, and bioevaluated as a potential 5HT1Areceptor ligand. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.2953] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Leila Hassanzadeh
- Department of Medicinal Chemistry, Faculty of Pharmacy; Tehran University of Medical Sciences; PO Box 6446-14155; Tehran; Iran
| | - Mostafa Erfani
- Nuclear Science Research School, Nuclear Science & Technology Research Institute (NSTRI); Atomic Energy Organization of Iran (AEOI); Karegar Avenue, PO Box 11365-3486; Tehran; Iran
| | - Seyed Esmaeil Sadat Ebrahimi
- Department of Medicinal Chemistry, Faculty of Pharmacy; Tehran University of Medical Sciences; PO Box 6446-14155; Tehran; Iran
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11
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Eleventh international symposium on radiopharmaceutical chemistry: Abstracts. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.2580370301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Hayashi K, Furutsuka K, Ito T, Muto M, Aki H, Fukumura T, Suzuki K. Fully automated synthesis and purification of 4-(2′-methoxyphenyl)-1-[2′-(N-2″-pyridinyl)-p-[18F]fluorobenzamido]ethylpiperazine. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.1958] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
| | | | | | - Masatoshi Muto
- Tokyo Nuclear Service Co., Ltd.; 1-3-5 Taito, Taito-ku; Tokyo; 110-0016; Japan
| | - Hatsumi Aki
- Department of Pharmaceuticals, Faculty of Pharmaceutical Sciences; Fukuoka University; 8-19-1 Nanakuma, Jonan-ku; Fukuoka; 814-80; Japan
| | - Toshimitsu Fukumura
- Radiopharmaceutical Production Team, Molecular Probe Group, Molecular Imaging Center; National Institute of Radiological Sciences (NIRS); 4-9-1 Anagawa, Inage-ku; Chiba; 263-8555; Japan
| | - Kazutoshi Suzuki
- Radiopharmaceutical Production Team, Molecular Probe Group, Molecular Imaging Center; National Institute of Radiological Sciences (NIRS); 4-9-1 Anagawa, Inage-ku; Chiba; 263-8555; Japan
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Design, synthesis and in vitro evaluation of bridgehead fluoromethyl analogs of N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-N-(pyridin-2-yl)cyclohexanecarboxamide (WAY-100635) for the 5-HT1A receptor. Eur J Med Chem 2011; 46:5728-35. [DOI: 10.1016/j.ejmech.2011.06.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 06/10/2011] [Accepted: 06/16/2011] [Indexed: 11/19/2022]
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14
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Shao X, Hoareau R, Hockley BG, Tluczek LJM, Henderson BD, Padgett HC, Scott PJH. Highlighting the Versatility of the Tracerlab Synthesis Modules. Part 1: Fully Automated Production of [F]Labelled Radiopharmaceuticals using a Tracerlab FX(FN). J Labelled Comp Radiopharm 2011; 54:292-307. [PMID: 21769163 PMCID: PMC3137381 DOI: 10.1002/jlcr.1865] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The field of radiochemistry is moving towards exclusive use of automated synthesis modules for production of clinical radiopharmaceutical doses. Such a move comes with many advantages, but also presents radiochemists with the challenge of re-configuring synthesis modules for production of radiopharmaceuticals that require non-conventional radiochemistry whilst maintaining full automation. This review showcases the versatility of the Tracerlab FX(FN) synthesis module by presenting simple, fully automated methods for producing [(18)F]FLT, [(18)F]FAZA, [(18)F]MPPF, [(18)F]FEOBV, [(18)F]sodium fluoride, [(18)F]fluorocholine and [(18)F]SFB.
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Affiliation(s)
- Xia Shao
- The University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Raphaël Hoareau
- The University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Brian G. Hockley
- The University of Michigan School of Medicine, Ann Arbor, MI, USA
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Al Hussainy R, Verbeek J, van der Born D, Braker AH, Leysen JE, Knol RJ, Booij J, Herscheid J(KDM. Design, Synthesis, Radiolabeling, and in Vitro and in Vivo Evaluation of Bridgehead Iodinated Analogues of N-{2-[4-(2-Methoxyphenyl)piperazin-1-yl]ethyl}-N-(pyridin-2-yl)cyclohexanecarboxamide (WAY-100635) as Potential SPECT Ligands for the 5-HT1A Receptor. J Med Chem 2011; 54:3480-91. [DOI: 10.1021/jm1009956] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rana Al Hussainy
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Joost Verbeek
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Dion van der Born
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Anton H. Braker
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Josée E. Leysen
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Remco J. Knol
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Jan Booij
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - J. (Koos) D. M. Herscheid
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
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16
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Lu C, Jiang Q. 2-[4-(2-Meth-oxy-phen-yl)piperazin-1-yl]-N-(pyridin-2-yl)acetamide. Acta Crystallogr Sect E Struct Rep Online 2010; 67:o223. [PMID: 21522722 PMCID: PMC3050313 DOI: 10.1107/s1600536810053067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 12/17/2010] [Indexed: 11/10/2022]
Abstract
In the title compound, C18H22N4O2, the piperizine ring adopts a chair conformation and the dihedral angle between the pyridine and benzene rings is 67.6 (9)°. The conformations of the attachment of the anisole and N-ethylpyridin-2-amine groups to the piperazine ring are (+)antiperiplanar. Intramolecular C—H⋯O and N—H⋯N interactions occur. In the crystal, intermolecular C—H⋯N hydrogen bonds are present. There are two crystallographically independent but identical molecules per asymmetric unit.
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Affiliation(s)
- Chunxiong Lu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, People's Republic of China
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XIIth international symposium on radiopharmaceutical chemistry: Abstracts and programme. J Labelled Comp Radiopharm 2010. [DOI: 10.1002/jlcr.2580400401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Lu C, Jiang Q. N-{2-[4-(2-Methoxyphenyl)piperazin-1-yl]ethyl}-4-nitro- N-(2-pyridyl)benzamide. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o2697. [PMID: 21587665 PMCID: PMC2983282 DOI: 10.1107/s1600536810038080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 09/23/2010] [Indexed: 11/10/2022]
Abstract
In the title compound, C25H27N5O4, the piperizine ring adopts a chair conformation. The dihedral angles between the pyridine ring and the two benzene rings are 65.5 (4) and 70.7 (4)°, while the dihedral angle between the two benzene rings is 17.3 (3)°. An intramolecular C—H⋯O hydrogen bond occurs.
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Koivula T, Laine J, Lipponen T, Perhola O, Kämäräinen EL, Bergström K, Solin O. Assessment of labelled products with different radioanalytical methods: study on 18F-fluorination reaction of 4-[18F]fluoro-N-[2-[1-(2-methoxyphenyl)-1-piperazinyl]ethyl-N-2-pyridinyl-benzamide (p-[18F]MPPF). J Radioanal Nucl Chem 2010. [DOI: 10.1007/s10967-010-0802-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Jiang QF, Lu CX. N-{2-[4-(2-Methoxyphenyl)piperazin-1-yl]ethyl}pyridin-2-amine monohydrate. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o1727. [PMID: 21587944 PMCID: PMC3006790 DOI: 10.1107/s1600536810022816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 06/14/2010] [Indexed: 11/10/2022]
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Blom E, Karimi F, Långström B. [18F]/19F exchange in fluorine containing compounds for potential use in18F-labelling strategies. J Labelled Comp Radiopharm 2009. [DOI: 10.1002/jlcr.1670] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Marona-Lewicka D, Chemel BR, Nichols DE. Dopamine D4 receptor involvement in the discriminative stimulus effects in rats of LSD, but not the phenethylamine hallucinogen DOI. Psychopharmacology (Berl) 2009; 203:265-77. [PMID: 18604600 DOI: 10.1007/s00213-008-1238-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Accepted: 06/11/2008] [Indexed: 10/21/2022]
Abstract
RATIONALE Lysergic acid diethylamide (LSD) differs from other types of hallucinogens in that it possesses direct dopaminergic effects. The exact nature of this component has not been elucidated. OBJECTIVE The present study sought to characterize the effects of several dopamine D(4) agonists and antagonists on the discriminative stimulus effect of LSD at two pretreatment times and 2,5-dimethoxy-4-iodoamphetamine (DOI), a selective 5-HT(2A/2C) agonist. MATERIALS AND METHODS Male Sprague-Dawley rats were trained in a two-lever, fixed ratio (FR) 50, food-reinforced task with LSD-30 (0.08 mg/kg, i.p., 30-min pretreatment time), LSD-90 (0.16 mg/kg, i.p., 90-min pretreatment time), and DOI (0.4 mg/kg, i.p., 30-min pretreatment time) as discriminative stimuli. Substitution and combination tests with the dopamine D(4) agonists, ABT-724 and WAY 100635, were performed in all groups. Combination tests were run using the dopamine D(4) antagonists A-381393 and L-745,870 and two antipsychotic drugs, clozapine and olanzapine. RESULTS WAY 100635 produced full substitution in LSD-90 rats, partial substitution in LSD-30 rats, and saline appropriate responding in DOI-trained rats. ABT-724 partially mimicked the LSD-90 and LSD-30 cues, but produced no substitution in DOI-trained rats. In combination tests, both agonists shifted the dose-response curve of LSD leftward, most potently for the LSD-90 cue. The D(4) antagonists significantly attenuated both the LSD-90 and LSD-30 cue, but had no effect on the DOI cue. CONCLUSION Dopamine D(4) receptor activation plays a significant modulatory role in the discriminative stimulus effects in LSD-90-trained rats, most markedly for the later temporal phase of LSD, but has no effect on the cue produced by DOI.
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Affiliation(s)
- Danuta Marona-Lewicka
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences-RHPH, Purdue University, 575 Stadium Mall Dr., West Lafayette, IN 47907-2091, USA
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Abstract
The serotonergic system, including the serotonin 1A (5-HT(1A)) receptor, has been implicated in the pathophysiology of a number of neuropsychiatric disorders. Current data show substantial interindividual variation in the regional concentration of this receptor site, the source of which is unclear. Monoamine oxidase A (MAO-A) is a key regulator of serotonin metabolism, and polymorphic variation in the X-linked MAO-A gene influences its expression. We hypothesized that polymorphism in the MAO-A gene would be associated with sex-specific variation in 5-HT(1A) receptor expression. We used positron emission tomography and [(11)C]WAY-100635 to quantify 5-HT(1A) receptors in a group of 31 healthy and unmedicated depressed individuals. The same individuals were genotyped for an upstream variable number tandem repeat polymorphism in the promoter of the MAO-A gene. ANOVA of 5-HT(1A) receptor availability demonstrated a significant effect of MAO-A genotype in the raphe nuclei, medial and inferior temporal cortex, insula, medial prefrontal cortex, and anterior cingulate (p < 0.05). The effect persisted when age, race, body mass index, and diagnosis were included in the model. Genotypes with greater putative MAO-A activity were associated with greater 5-HT(1A) receptor availability in women, but not in men. Genotype predicted a substantial 42-74% of the variance in receptor availability in women, depending on the brain region (p < 0.05). Depression diagnosis was not associated with MAO-A genotype or 5-HT(1A) receptor availability in these regions. These results demonstrate a sex-specific interaction between two key molecules of the human serotonergic system, and suggest a neurobiological basis for sexual dimorphism in serotonin-modulated phenotypes.
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Frey BN, Rosa-Neto P, Lubarsky S, Diksic M. Correlation between serotonin synthesis and 5-HT1A receptor binding in the living human brain: A combined α-[11C]MT and [18F]MPPF positron emission tomography study. Neuroimage 2008; 42:850-7. [DOI: 10.1016/j.neuroimage.2008.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 04/27/2008] [Accepted: 05/09/2008] [Indexed: 10/22/2022] Open
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Fiske E, Portas CM, Grønli J, Sørensen E, Bjorvatn B, Bjørkum AA, Ursin R. Increased extracellular 5-HT but no change in sleep after perfusion of a 5-HT1A antagonist into the dorsal raphe nucleus of rats. Acta Physiol (Oxf) 2008; 193:89-97. [PMID: 18081887 DOI: 10.1111/j.1748-1716.2007.01792.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM The 5-HT(1A) receptor antagonist 4-Iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinyl-benzamide hydrochloride (p-MPPI) (10 microM) was perfused into the dorsal raphe nucleus (DRN) to study simultaneously the effects of the drug on the DRN and frontal cortex extracellular serotonin (5-hydroxytryptamine, 5-HT) levels and concurring behavioural states. METHODS Waking, slow wave sleep and rapid eye movement sleep were determined by polygraphic recordings during microdialysis perfusion and extracellular sample collection. The samples were analysed by microbore high-performance liquid chromatography coupled with electrochemical detection for analysis of 5-HT. RESULTS p-MPPI perfusion into the DRN (n = 6) produced a sixfold 5-HT increase in the DRN during all behavioural states. The increased 5-HT level was most likely related to the blockage of 5-HT(1A) receptors in the DRN by p-MPPI. No significant effect was seen on sleep. CONCLUSION Despite the dramatic increase in DRN extracellular 5-HT produced by p-MPPI, only a transient and nonsignificant effect on sleep was recorded. It is suggested that the usual coupling between 5-HT level and behavioural state may be lost when an excessive serotonergic output is pharmacologically achieved.
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Affiliation(s)
- E Fiske
- Department of Biomedicine, University of Bergen, Bergen, Norway.
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Itsenko O, Blom E, Långström B, Kihlberg T. The Use of Lithium Amides in the Palladium-Mediated Synthesis of [Carbonyl-11C]Amides. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700255] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Defraiteur C, Plenevaux A, Scuvée-Moreau J, Rouchet N, Goblet D, Luxen A, Seutin V. Characterization of 4-(2-hydroxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p-fluorobenzamido]ethyl]piperazine (p-DMPPF) as a new potent 5-HT1A antagonist. Br J Pharmacol 2007; 152:952-8. [PMID: 17704821 PMCID: PMC2078231 DOI: 10.1038/sj.bjp.0707431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE The identification of potent and selective radioligands for the mapping of 5-HT receptors is interesting both for clinical and experimental research. The aim of this study was to compare the potency of a new putative 5-HT(1A) receptor antagonist, p-DMPPF, (4-(2-hydroxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p-fluorobenzamido]ethyl]piperazine) with that of the well-known 5-HT(1A) antagonists, WAY-100635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]-ethyl]-N-(2-pyridinyl) cyclohexanecarboxamide) and its fluorobenzoyl analogue, p-MPPF (4-(2-methoxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p-fluorobenzamido]ethyl]piperazine). EXPERIMENTAL APPROACH Single cell extracellular recordings of dorsal raphe (DR) neurones were performed in rat brain slices. The potency of each compound at antagonizing the effect of the 5-HT(1A) agonist, 8-OH-DPAT [8-hydroxy-2-(di-n-propylamino)-tetraline], was quantified using the Schild equation. The pharmacological profile of p-DMPPF was defined using competition binding assays. KEY RESULTS Consistently with a 5-HT(1A) receptor antagonist profile, incubation of slices with an equimolar (10 nM) concentration of each compound markedly reduced the inhibitory effect of 8-OH-DPAT on the firing rate of DR neurones, causing a significant rightward shift in its concentration-response curve. The rank order of potency of the antagonists was WAY-100635>p-DMPPF>or=p-MPPF. The sensitivity of DR neurones to the inhibitory effect of 8-OH-DPAT was found to be heterogeneous. The binding experiments demonstrated that p-DMPPF is highly selective for 5-HT(1A) receptors, with a K(i) value of 7 nM on these receptors. CONCLUSIONS AND IMPLICATIONS The potency of the new compound, p-DMPPF, as a 5-HT(1A) antagonist is similar to that of p-MPPF in our electrophysiological assay. Its selectivity towards 5-HT(1A) receptors makes it a good candidate for clinical development.
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Affiliation(s)
- C Defraiteur
- Cyclotron Research Center, Liege University Liege, Belgium
| | - A Plenevaux
- Cyclotron Research Center, Liege University Liege, Belgium
- Author for correspondence:
| | - J Scuvée-Moreau
- Laboratory of Pharmacology, Research Center for Cellular and Molecular Neurobiology (CNCM), Institute of Pathology B36, Liege University Liege, Belgium
| | - N Rouchet
- Laboratory of Pharmacology, Research Center for Cellular and Molecular Neurobiology (CNCM), Institute of Pathology B36, Liege University Liege, Belgium
| | - D Goblet
- Cyclotron Research Center, Liege University Liege, Belgium
| | - A Luxen
- Cyclotron Research Center, Liege University Liege, Belgium
| | - V Seutin
- Laboratory of Pharmacology, Research Center for Cellular and Molecular Neurobiology (CNCM), Institute of Pathology B36, Liege University Liege, Belgium
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O’Connor NA, Paisner DA, Huryn D, Shea KJ. Screening of 5-HT1A receptor antagonists using molecularly imprinted polymers. J Am Chem Soc 2007; 129:1680-9. [PMID: 17284006 PMCID: PMC3192871 DOI: 10.1021/ja067276c] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Molecular imprinting produces network polymers with recognition sites for imprint molecules. The high binding affinity and selectivity in conjunction with the polymers' physical robustness positions molecular imprinted polymers (MIPs) as candidates for use as preliminary screens in drug discovery. As such, MIPs can serve as crude mimics of native receptors. In an effort to evaluate the relationship between MIPs and native receptors, imprinted polymers for WAY-100635, an antagonist of the serotonin (5-HT) receptor subtype 5-HT1A were prepared. The resulting MIP P(WAY) was evaluated as an affinity matrix in the screening of serotonin receptor antagonists with known affinities for the native receptor. Rough correlations in affinity between the synthetic P(WAY) and native receptor 5-HT1A were found. These findings provide some support for the analogy between MIPs and native receptors and their possible use as surrogates.
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Affiliation(s)
| | - David A. Paisner
- Department of Chemistry, University of California, Irvine, 92717
| | - Donna Huryn
- Department of Chemistry, University of Pennsylvania, 19104-6323
| | - Kenneth J. Shea
- Department of Chemistry, University of California, Irvine, 92717
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Müller CP, Carey RJ, Huston JP, De Souza Silva MA. Serotonin and psychostimulant addiction: Focus on 5-HT1A-receptors. Prog Neurobiol 2007; 81:133-78. [PMID: 17316955 DOI: 10.1016/j.pneurobio.2007.01.001] [Citation(s) in RCA: 232] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 12/04/2006] [Accepted: 01/03/2007] [Indexed: 01/03/2023]
Abstract
Serotonin(1A)-receptors (5-HT(1A)-Rs) are important components of the 5-HT system in the brain. As somatodendritic autoreceptors they control the activity of 5-HT neurons, and, as postsynaptic receptors, the activity in terminal areas. Cocaine (COC), amphetamine (AMPH), methamphetamine (METH) and 3,4-methylenedioxymethamphetamine ("Ecstasy", MDMA) are psychostimulant drugs that can lead to addiction-related behavior in humans and in animals. At the neurochemical level, these psychostimulant drugs interact with monoamine transporters and increase extracellular 5-HT, dopamine and noradrenalin activity in the brain. The increase in 5-HT, which, in addition to dopamine, is a core mechanism of action for drug addiction, hyperactivates 5-HT(1A)-Rs. Here, we first review the role of the various 5-HT(1A)-R populations in spontaneous behavior to provide a background to elucidate the contribution of the 5-HT(1A)-Rs to the organization of psychostimulant-induced addiction behavior. The progress achieved in this field shows the fundamental contribution of brain 5-HT(1A)-Rs to virtually all behaviors associated with psychostimulant addiction. Importantly, the contribution of pre- and postsynaptic 5-HT(1A)-Rs can be dissociated and frequently act in opposite directions. We conclude that 5-HT(1A)-autoreceptors mainly facilitate psychostimulant addiction-related behaviors by a limitation of the 5-HT response in terminal areas. Postsynaptic 5-HT(1A)-Rs, in contrast, predominantly inhibit the expression of various addiction-related behaviors directly. In addition, they may also influence the local 5-HT response by feedback mechanisms. The reviewed findings do not only show a crucial role of 5-HT(1A)-Rs in the control of brain 5-HT activity and spontaneous behavior, but also their complex role in the regulation of the psychostimulant-induced 5-HT response and subsequent addiction-related behaviors.
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Affiliation(s)
- Christian P Müller
- Institute of Physiological Psychology I, University of Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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Aznavour N, Zimmer L. [18F]MPPF as a tool for the in vivo imaging of 5-HT1A receptors in animal and human brain. Neuropharmacology 2006; 52:695-707. [PMID: 17101155 DOI: 10.1016/j.neuropharm.2006.09.023] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2006] [Revised: 09/21/2006] [Accepted: 09/29/2006] [Indexed: 11/18/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) and its various receptors are involved in numerous CNS functions and psychiatric disorders. 5-HT(1A), the best-characterized subtype of currently known 5-HT receptors, is tightly implicated in the pathogenesis of depression, anxiety, epilepsy and eating disorders. It thus represents an important target for drug therapy. Specific radioligands and positron emission tomography (PET) allow for a quantitative imaging of brain 5-HT(1A) receptor distribution in living animals and humans. Recently, the selective 5-HT(1A) receptor antagonist, MPPF, has been successfully labeled with [(18)F]fluorine ([(18)F]MPPF), and an increasing number of academic and industry centres have used this radiotracer in preclinical and clinical studies. After a brief account of some of the structural, distributional and electrophysiological characteristics of brain 5-HT(1A) receptors, this review focuses on studies conducted with [(18)F]MPPF, with emphasis on preclinical results illustrating the actual and potential value of this PET radioligand for clinical research and drug development.
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Affiliation(s)
- Nicolas Aznavour
- Laboratoire de Neuropharmacologie, Université Lyon 1, Lyon, France
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Chemel BR, Roth BL, Armbruster B, Watts VJ, Nichols DE. WAY-100635 is a potent dopamine D4 receptor agonist. Psychopharmacology (Berl) 2006; 188:244-51. [PMID: 16915381 DOI: 10.1007/s00213-006-0490-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 06/16/2006] [Indexed: 11/28/2022]
Abstract
RATIONALE AND OBJECTIVES WAY-100635 is a prototypical 5-HT1A receptor antagonist and has been used widely as a pharmacological probe to investigate the distribution and function of 5-HT1A receptors. Results from our studies suggested that WAY-100635 was potently inducing effects unrelated to its 5-HT1A receptor affinity. In the present work, we evaluated the in vitro pharmacology of this compound at two D2-like receptor subtypes. METHOD The functional properties and binding affinities of WAY-100635 were evaluated in HEK 293 cells stably expressing dopamine D2L or D4.4 receptors. RESULTS Initial screens performed by the NIMH Psychoactive Drug Screening Program indicated that WAY-100635 displayed 940, 370, and 16 nM binding affinities at D2L, D3, and D4.2 receptors, respectively. Subsequent saturation analyses demonstrated that the Kd of [3H]WAY-100635 at D4.2 receptors was 2.4 nM, only tenfold higher than 5-HT1A. WAY-100635 and its major metabolite, WAY-100634, were potent agonists in HEK-D4.4 cells (EC50=9.7+/-2.2 and 0.65+/-0.2 nM, respectively). WAY-100635 behaved as a full agonist, and WAY-100634 was a nearly full agonist. In HEK-D2L cells, WAY-100635 weakly antagonized the effects of 300 nM quinpirole. Subsequent radioligand binding studies confirmed that WAY-100635 possesses high affinity for D4.4 receptors but binds weakly to D2L receptors (3.3+/-0.6 and 420+/-11 nM, respectively). CONCLUSIONS This study demonstrates that WAY-100635 is not a "selective" 5-HT1A receptor antagonist, as previously reported, and conclusions drawn from studies that employed WAY-100635 as a selective 5-HT1A antagonist may need to be reevaluated.
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Affiliation(s)
- Benjamin R Chemel
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907-2091, USA
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Defraiteur C, Lemaire C, Luxen A, Plenevaux A. Radiochemical synthesis and tissue distribution of p-[18F]DMPPF, a new 5-HT1A ligand for PET, in rats. Nucl Med Biol 2006; 33:667-75. [PMID: 16843842 DOI: 10.1016/j.nucmedbio.2006.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Revised: 03/16/2006] [Accepted: 03/31/2006] [Indexed: 10/24/2022]
Abstract
Several studies have demonstrated the potential of p-[(18)F]MPPF as a radiopharmaceutical to study the 5-HT(1A) receptor family in animals and humans. A structural modification leading to a higher radioactive signal at an equipotent dose would greatly enhance this potential. With this goal, the desmethylated 4-(2'-methoxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p-fluorobenzamido]ethyl]-piperazine (p-MPPF), identified as p-DMPPF, was synthesized, labeled with fluorine-18 and evaluated through ex vivo tissue distribution in rats. The new compounds p-DMPPF, p-DMPPNO(2), MEM-p-MPPF and MEM-p-MPPNO(2) were isolated and fully identified ((1)H and (13)C NMR, LC-MS). The final compound, p-[(18)F]DMPPF, was obtained ready for injection, with an overall radiochemical yield of 10% (EOB corrected) within 90 min and a specific activity of 62 GBq/mumol. Tissue distributions showed that the carbon-fluorine bond was stable in vivo and that this compound could cross the blood-brain barrier. For kidney, lung, heart, spleen, bone, testicle, liver and muscle, the percentage of injected dose per gram of tissue obtained with p-[(18)F]DMPPF was of the same order of magnitude as that of p-[(18)F]MPPF. The amount of radioactivity reaching the brain was much higher (approximately fivefold at 60 min) for p-[(18)F]DMPPF compared with p-[(18)F]MPPF, which was taken as reference. The distribution and specificity were in total agreement with the known localization of 5-HT(1A) receptors in rats. The radioactivity increase was more important for specific tissues (hippocampus and frontal cortex) than for cerebellum or striatum, leading to better contrast (hippocampus/cerebellum=5.8 at 60 min). The levels of metabolites found in plasma showed that p-[(18)F]DMPPF appears to be less metabolized than p-[(18)F]MPPF. p-[(18)F]DMPPF deserves further evaluation as a radiopharmaceutical candidate.
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Affiliation(s)
- Caroline Defraiteur
- Cyclotron Research Center, Liege University, Sart Tilman B.30, B-4000 Liege, Belgium
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Udo de Haes JI, Harada N, Elsinga PH, Maguire RP, Tsukada H. Effect of fenfluramine-induced increases in serotonin release on [18F]MPPF binding: a continuous infusion PET study in conscious monkeys. Synapse 2006; 59:18-26. [PMID: 16237679 DOI: 10.1002/syn.20209] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
[(18)F]MPPF is a selective and reversible antagonist to the serotonin-1A (5-HT(1A)) receptor. The aim of the present study was to investigate whether the binding of [(18)F]MPPF is sensitive to increases in 5-HT levels. We used the 5-HT releasing agent and reuptake inhibitor fenfluramine (FEN) to increase the concentration of 5-HT. [(18)F]MPPF binding was assessed using positron emission tomography (PET) in conscious monkeys. Possible effects of blood flow on ligand binding were excluded by using a bolus-infusion paradigm. Control scans were obtained to assess the state of ligand equilibrium. FEN (5 or 10 mg/kg, i.v.) was administered between 90 and 130 min after the start of the [(18)F]MPPF infusion. The binding potential (BP) was calculated for an early interval (30 min preceding FEN administration) and late interval (20-50 min after administration of FEN). Microdialyses results showed a 20- and 35-fold increase in extracellular 5-HT levels in the prefrontal cortex after injection of FEN at a dose of 5 mg/kg and 10 mg/kg respectively. However, despite these large increases in 5-HT levels, no differences in BP were found between the control and FEN scans. These results may imply that the majority of 5-HT(1A) receptors is in the low affinity state in the living brain.
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Affiliation(s)
- Joanna I Udo de Haes
- Department of Biological Psychiatry, University Medical Center Groningen, The Netherlands.
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Lang L, Jagoda E, Ma Y, Sassaman MB, Eckelman WC. Synthesis and in vivo biodistribution of F-18 labeled 3-cis-, 3-trans-, 4-cis-, and 4-trans-fluorocyclohexane derivatives of WAY 100635. Bioorg Med Chem 2006; 14:3737-48. [PMID: 16488611 DOI: 10.1016/j.bmc.2006.01.064] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Accepted: 01/13/2006] [Indexed: 11/15/2022]
Abstract
Radioligands that are specific for the serotonin 5-HT(1A) receptor will be useful in characterizing the physiological action of this receptor subtype. With radioligands of varying pharmacokinetic properties, investigators can measure not only receptor density, but also the effect of endogenous serotonin concentration. To this end, three additional fluorinated analogs of WAY 100635 were prepared and evaluated as 5-HT(1A) receptor ligands of varying pharmacokinetic properties based on our previous studies. These four compounds are cis-4-fluoro-, trans-4-fluoro-, cis-3-fluoro-, and trans-3-fluoro-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-N-(pyridin-2-yl)cyclohexanecarboxamides (FCWAYs). All four compounds were characterized and radiolabeled with fluorine-18, a 109.7 min half-life radionuclide used in positron emission tomography. We then determined in vitro inhibition constants at the 5-HT(1A) receptor; in vitro metabolic profile, using rat hepatocytes and liquid chromatography/mass spectroscopy (LC/MS); and the rate of defluorination and hippocampus to cerebellum ratio ex vivo. This led to the conclusion that high affinity 4-trans-F-18 FCWAY had the best properties for measuring receptor density given its high hippocampus to cerebellum ratio and 3-cis-F-18 FCWAY had the best properties for measuring dynamic change in receptors, with lower affinity and faster pharmacokinetics.
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Affiliation(s)
- Lixin Lang
- PET Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
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Jagoda EM, Lang L, Tokugawa J, Simmons A, Ma Y, Contoreggi C, Kiesewetter D, Eckelman WC. Development of 5-HT1A receptor radioligands to determine receptor density and changes in endogenous 5-HT. Synapse 2006; 59:330-41. [PMID: 16440292 DOI: 10.1002/syn.20246] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
[(18)F]FCWAY and [(18)F]FPWAY, analogues of the high affinity 5-HT(1A) receptor (5-HT(1A)R) antagonist WAY100635, were evaluated in rodents as potential radiopharmaceuticals for determining 5-HT(1A)R density and changes in receptor occupancy due to changes in endogenous serotonin (5-HT) levels. The in vivo hippocampus specific binding ratio [(hippocampus(uptake)/cerebellum(uptake))-1] of [(18)F]FPWAY was decreased to 32% of the ratio of [(18)F]FCWAY, indicating that [(18)F]FPWAY has lower affinity than [(18)F]FCWAY. The 5-HT(1A)R selectivity of [(18)F]FPWAY was confirmed using ex vivo autoradiography studies with 5-HT(1A)R knockout, heterozygous, and wildtype mice.Pre- or post-treatment of awake rodents in tissue dissection studies with paroxetine had no effect on hippocampal binding of [(18)F]FCWAY or [(18)F]FPWAY compared to controls, indicating neither tracer was sensitive to changes in endogenous 5-HT. In mouse ex vivo autoradiography studies in which awake mice were treated with fenfluramine following the [(18)F]FPWAY, a significant decrease was not observed in the hippocampus specific binding ratios. In rat dissection studies with fenfluramine administered following [(18)F]FPWAY or [(18)F]FBWAY ([(18)F]-MPPF) in awake or urethane-anesthetized rats, no significant differences in the specific binding ratios of the hippocampus were observed compared to their respective controls. [(18)F]FPWAY and [(18)F]FBWAY uptakes in all brain regions were increased variably in the anesthetized group (with the greatest increase in the hippocampus) vs. the awake group, but were decreased in the fenfluramine-treated anesthetized group vs. the anesthetized group. These data are best explained by changes in blood flow caused by urethane and fenfluramine, which varies from region to region in the brain.
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Affiliation(s)
- Elaine M Jagoda
- Positron Emission Tomography PET Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Rapid Synthesis of Arylpiperazine Derivatives for Imaging 5-HT 1AReceptor under Microwave Irradiation. B KOREAN CHEM SOC 2005. [DOI: 10.5012/bkcs.2005.26.11.1701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Udo de Haes JI, Cremers TIFH, Bosker FJ, Postema F, Tiemersma-Wegman TD, den Boer JA. Effect of increased serotonin levels on [18F]MPPF binding in rat brain: fenfluramine vs the combination of citalopram and ketanserin. Neuropsychopharmacology 2005; 30:1624-31. [PMID: 15827572 DOI: 10.1038/sj.npp.1300721] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
[18F]MPPF is a selective serotonin-1A (5-HT1A) receptor antagonist and may be used to measure changes in the functional levels of serotonin (5-HT). The technique is based on the assumption that the injected radiolabeled ligand competes for the same receptor as the endogenous transmitter. Results from studies using serotonergic ligands are not always consistent. The aim of the present study was to investigate if [18F]MPPF binding is decreased after an increase in 5-HT levels. [18F]MPPF binding was assessed in conscious rats using ex vivo autoradiography. We studied the effect of the 5-HT-releasing agent and reuptake inhibitor fenfluramine (10 mg/kg i.p.) and of a combination of the selective serotonin reuptake inhibitor (SSRI) citalopram (10 micromol/kg, s.c.) with the 5-HT2C antagonist ketanserin (100 nmol/kg, s.c). The effect of both treatments on extracellular 5-HT levels was determined using microdialysis. Fenfluramine treatment resulted in a 30-fold increase in extracellular 5-HT levels in the ventral hippocampus and induced a significant reduction of [18F]MPPF binding in the frontal cortex, hypothalamus, amygdala, and hippocampus. The microdialysis results showed a 10-fold 5-HT increase in the ventral hippocampus after combined administration of ketanserin and citalopram. The combination, however, did not affect [18F]MPPF binding. Our data show that [18F]MPPF binding in conscious rats is only reduced after substantial and therefore nonphysiological increases in 5-HT levels. These results may imply that the majority of 5-HT1A receptors is in the low-affinity state, in vivo.
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Affiliation(s)
- Joanna I Udo de Haes
- Department of Biological Psychiatry, University Medical Center Groningen, Groningen, The Netherlands.
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Lundquist P, Wilking H, Höglund AU, Sandell J, Bergström M, Hartvig P, Långström B. Potential of [11C]DASB for measuring endogenous serotonin with PET: binding studies. Nucl Med Biol 2005; 32:129-36. [PMID: 15721758 DOI: 10.1016/j.nucmedbio.2004.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Revised: 11/30/2004] [Accepted: 12/05/2004] [Indexed: 11/30/2022]
Abstract
The serotonin transporter radioligand [11C]-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile, or [11C]DASB, was examined in order to assess its potential for measuring fluctuations in endogenous serotonin concentrations with positron emission tomography. Binding characteristics of [11C]DASB and the propensity for serotonin to displace the tracer were explored in rat brain homogenates. Experiments showed that serotonin displaced [11C]DASB in vitro. Ex vivo experiments performed after tranylcypromine injection (3 or 15 mg/kg) showed a dose-dependent trend in radioactivity uptake and suggested that serotonin may compete with [11C]DASB for transporter binding.
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Affiliation(s)
- Pinelopi Lundquist
- Division of Pharmacokinetics and Drug Therapy, Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden.
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39
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Marchais-Oberwinkler S, Nowicki B, Pike VW, Halldin C, Sandell J, Chou YH, Gulyas B, Brennum LT, Farde L, Wikström HV. N-Oxide analogs of WAY-100635: new high affinity 5-HT1A receptor antagonists. Bioorg Med Chem 2005; 13:883-93. [PMID: 15653354 DOI: 10.1016/j.bmc.2004.10.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Accepted: 10/13/2004] [Indexed: 11/30/2022]
Abstract
WAY-100635 [N-(2-(1-(4-(2-methoxyphenyl)piperazinyl)ethyl))-N-(2-pyridinyl)cyclohexanecarboxamide] 1 and its O-desmethyl derivative DWAY 2 are well-known high affinity 5-HT(1A) receptor antagonists, which when labeled with carbon-11 (beta+; t(1/2) = 20.4 min) in the carbonyl group are effective radioligands for imaging brain 5-HT(1A) receptors with positron emission tomography (PET). In a search for new 5-HT(1A) antagonists with different pharmacokinetic and metabolic properties, the pyridinyl N-oxide moiety was incorporated into analogs of 1 and 2. NOWAY 3, in which the pyridinyl ring of 1 was oxidized to the pyridinyl N-oxide, was prepared via nucleophilic substitution of 2-[4-(2-methoxyphenyl)piperazin-1-yl]ethylamine on 2-chloropyridine-N-oxide followed by acylation with cyclohexanecarbonyl chloride. 6Cl-NOWAY 4, a more lipophilic (pyridinyl-6)-chloro derivative of 3, was prepared by treating 1-(2-methoxyphenyl)-4-(2-(2-(6-bromo)aminopyridinyl-N-oxide)ethyl)piperazine with cyclohexanecarbonyl chloride for acylation and concomitant chloro for bromo substitution. NEWWAY 5, in which the 2-hydroxy-phenyl group of 2 is replaced with a 2-pyridinyl N-oxide group with the intention of mimicking the topology of 2, was prepared in five steps from 2-(chloroacetylamino)pyridine. N-Oxides 3-5 were found to be high affinity antagonists at 5-HT(1A) receptors, with 3 having the highest affinity and a Ki value (0.22 nM) comparable to that of 1 (0.17 nM). By calculation the lipophilicity of 3 (LogP = 1.87) is lower than that of 1 by 1.25 LogP units while TLC and reverse phase HPLC indicate that 3 has slightly lower lipophilicity than 1. On the basis of these encouraging findings, the N-oxide 3 was selected for labeling with carbon-11 in its carbonyl group and for evaluation as a radioligand with PET. After intravenous injection of [carbonyl-11C]3 into cynomolgus monkey there was very low uptake of radioactivity into brain and no PET image of brain 5-HT(1A) receptors was obtained. Either 3 inadequately penetrates the blood-brain barrier or it is excluded from brain by an active efflux mechanism. Rapid deacylation of 3 was not apparent in vivo; in cynomolgus monkey plasma radioactive metabolites of [carbonyl-11C]3 appeared less rapidly than from the radioligands [carbonyl-11C]1 and [carbonyl-11C]2, which are known to be primarily metabolized by deacylation. Ligand 3 may have value as a new pharmacological tool, but not as a radioligand for brain imaging.
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Affiliation(s)
- Sandrine Marchais-Oberwinkler
- Department of Medicinal Chemistry, University Center for Pharmacy, University of Groningen, Antonius Deusinglaan 1, NL-9713 AV Groningen, The Netherlands.
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Andrews CM, Kung HF, Lucki I. The 5-HT1A receptor modulates the effects of cocaine on extracellular serotonin and dopamine levels in the nucleus accumbens. Eur J Pharmacol 2005; 508:123-30. [PMID: 15680262 DOI: 10.1016/j.ejphar.2004.12.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 12/07/2004] [Indexed: 11/20/2022]
Abstract
The regulation of extracellular levels of serotonin (5-HT) and dopamine in response to cocaine by 5-HT1A receptors was examined using in vivo microdialysis and the 5-HT1A receptor antagonist 4-(2'-methoxy-)-phenyl-1-[2'-(N-2''-pyridinyl)-p-fluorobenzamido-]ethyl-piperazine (p-MPPF). Pretreatment with p-MPPF significantly augmented the increase in extracellular levels of both 5-HT and dopamine in the nucleus accumbens produced by systemic administration of cocaine. Levels of 5-HT or dopamine were unaffected by p-MPPF given alone. Extracellular levels of 5-HT and dopamine were increased dramatically by cocaine infused locally into the nucleus accumbens. Systemic injection of cocaine given during the cocaine infusion reduced 5-HT and dopamine levels, presumably by activating inhibitory 5-HT and dopamine autoreceptors outside of the locus of infusion. The reduction of 5-HT and dopamine levels by systemic cocaine during accumbal infusion was blocked by pretreatment with the 5-HT1A receptor antagonist p-MPPF. Taken together, these findings suggest that the 5-HT1A autoreceptor acts to modulate the effects of cocaine on both 5-HT and dopamine levels in the nucleus accumbens.
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Affiliation(s)
- Christine M Andrews
- Institute of Neurological Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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41
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Javadekar-Subhedar V, Chattopadhyay A. Temperature-dependent interaction of the bovine hippocampal serotonin(1A) receptor with G-proteins. Mol Membr Biol 2004; 21:119-23. [PMID: 15204441 DOI: 10.1080/09687680310001058335] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The ligand binding and G-protein coupling of the bovine hippocampal 5-HT1A receptor as a function of temperature was monitored. There is an almost complete and irreversible loss in agonist binding at 50 degrees C. However, the antagonist binding is reduced only by 50%, and this could be reversed if the temperature is lowered to 25 degrees C. Interestingly, the agonist binding of the 5-HT1A receptor in membranes exposed to 50 degrees C is inhibited to a much lesser extent by GTP-gamma-S, a non-hydrolysable analogue of GTP, indicating uncoupling of the 5-HT1A receptor to G-proteins at 50 degrees C. We propose that high temperature selectively and irreversibly inactivates G-proteins thereby affecting G-protein-receptor interaction and agonist binding of the 5-HT1A receptor.
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Praschak-Rieder N, Hussey D, Wilson AA, Carella A, Lee M, Dunn E, Willeit M, Bagby RM, Houle S, Meyer JH. Tryptophan depletion and serotonin loss in selective serotonin reuptake inhibitor-treated depression: an [(18)F] MPPF positron emission tomography study. Biol Psychiatry 2004; 56:587-91. [PMID: 15476688 DOI: 10.1016/j.biopsych.2004.07.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Revised: 07/09/2004] [Accepted: 07/19/2004] [Indexed: 10/26/2022]
Abstract
BACKGROUND Recurrence of depressive symptoms after tryptophan depletion (TD) in selective serotonin reuptake inhibitor (SSRI)-treated depression is an important, unexplained phenomenon. With [(18)F] MPPF positron emission tomography (PET), serotonin (5-hydroxytryptamine, 5-HT) 1A receptor binding potential (5-HT(1A)BP) was measured after TD in various brain regions in citalopram-treated depression. This 5-HT(1A)BP measurement is sensitive to changes in extracellular 5-HT in animal models. METHODS Eight remitted patients with major depressive disorder received [(18)F] MPPF PET scans twice: once after TD and once after sham depletion. Behavioral measures were evaluated with the Hamilton Depression Rating Scale and visual analog scales. RESULTS No effect on regional 5-HT(1A)BP was observed after TD, despite an 86% decrease in total plasma tryptophan and transient depressive relapse in six of eight patients. CONCLUSIONS Large-magnitude changes in extracellular 5-HT are not crucial for the mood effects observed in SSRI-treated subjects after TD. Therefore, greater consideration must be given to other mechanisms that involve vulnerability to small perturbations in extracellular 5-HT, such as impairment of signal transduction.
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Affiliation(s)
- Nicole Praschak-Rieder
- Vivian M. Rakoff PET Imaging Centre and the Mood and Anxiety Disorders Division, Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
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43
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Merlet I, Ryvlin P, Costes N, Dufournel D, Isnard J, Faillenot I, Ostrowsky K, Lavenne F, Le Bars D, Mauguière F. Statistical parametric mapping of 5-HT1A receptor binding in temporal lobe epilepsy with hippocampal ictal onset on intracranial EEG. Neuroimage 2004; 22:886-96. [PMID: 15193619 DOI: 10.1016/j.neuroimage.2004.02.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Revised: 02/09/2004] [Accepted: 02/12/2004] [Indexed: 10/26/2022] Open
Abstract
Experimental data in animals show that 5-HT(1A) receptors are predominantly located in limbic areas and suggest that serotonin, via these receptors, mediates an antiepileptic and anticonvulsant effect. In this PET study, we used an antagonist of the 5-HT(1A) receptor, [(18)F]MPPF, to assess the extent of 5-HT(1A) receptor binding changes in a group of seven temporal lobe epilepsy (TLE) patients with hippocampal ictal onset demonstrated by intracerebral EEG recording. On the basis of MRI-measured hippocampal volumes (HV), patients were classified into "normal HV" or "hippocampal atrophy" (HA). Voxel-based analyses (SPM99) were performed to objectively assess the differences in [(18)F]MPPF binding potential (BP) between patients (taken as a group or as individuals) and a database of 48 controls subjects. In the full group of patients, a significant decreased BP was detected ipsilateral to the epileptogenic zone in the hippocampus, temporal pole, insula, and temporal neocortex. This result was confirmed in the subgroup of patients with HA. In patients with normal HV, the BP decrease was restricted to the temporal pole. TLE patients also demonstrated an increased BP in various regions contralateral to the epileptogenic zone. These data suggest that in TLE patients with hippocampal seizure onset, the decrease in 5-HT(1A) receptor binding partly reflects hippocampal neuronal loss, but is also observed in various regions involved in temporo-limbic epileptogenic networks that appeared normal on MRI. Further studies are warranted to evaluate the clinical usefulness of [(18)F]MPPF-PET as compared to other established PET tracers in drug resistant TLE.
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Affiliation(s)
- Isabelle Merlet
- EA1880, Epilepsy Department, Neurological Hospital, Federative Institute of Neurosciences (IFR19), Lyon, France.
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Rbah L, Leviel V, Zimmer L. Displacement of the PET ligand 18F-MPPF by the electrically evoked serotonin release in the rat hippocampus. Synapse 2003; 49:239-45. [PMID: 12827643 DOI: 10.1002/syn.10235] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The effects of the electrically evoked serotonin release were evaluated on the binding of (18)F-MPPF in the hippocampus of anesthetized rats. The specific binding of (18)F-MPPF was measured by an implanted beta-microprobe and the serotonin (5-HT) extracellular concentration was measured by microdialysis under the same conditions. Our results showed that the 10-, 20-, or 30-min electrical stimulation of the raphe nucleus elicited a significant increase in extracellular 5-HT, only detectable in the presence of a 5-HT reuptake inhibitor in the perfusate (5 microM clomipramine). Interestingly, the raphe stimulations were associated with a 27-76% reversible decrease of the (18)F-MPPF specific binding in the hippocampus, but an unchanged extracellular (18)F-MPPF collected in dialysates. Considered together, these observations suggest that (18)F-MPPF binding is sensitive to 5-HT released at a neuronal level. This compartment, explored by the beta-microprobe, is probably distinct from the extracellular compartment, explored by microdialysis.
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Affiliation(s)
- Latifa Rbah
- CERMEP Biomedical Cyclotron, 59 boulevard Pinel, F-69003 Lyon, France
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45
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Zimmer L, Fournet G, Benoît J, Guillaumet G, Le Bars D. Carbon-11 labelling of 8[[3-[4-(2-[(11)C]methoxyphenyl)piperazin-1-yl]-2-hydroxypropyl]oxy]thiochroman, a presynaptic 5-HT(1A) receptor agonist, and its in vivo evaluation in anaesthetised rat and in awake cat. Nucl Med Biol 2003; 30:541-6. [PMID: 12831993 DOI: 10.1016/s0969-8051(03)00027-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A new compound, 8[[3-[4-(2-[(11)C]methoxyphenyl)piperazin-1-yl]-2-hydroxypropyl]oxy]thiochroman was labeled via O-methylation with [(11)C]methyl iodide in good yield and specific activity. Original biological evaluations included (i) the study in anesthetized rat with a beta-sensitive intracerebral probe (beta-Microprobe), allowing to measure locally the kinetic of the new PET ligand, and (ii) a PET-scan on a conditioned cat maintained awake during the acquisition. In both in vivo techniques, the new ligand did not reveal any specific binding in hippocampus indicating that this radiotracer is not suitable for mapping 5HT(1A) receptors using positron emission tomography.
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Affiliation(s)
- Luc Zimmer
- CERMEP, Biomedical Cyclotron, 59 Bd Pinel, 69003 Lyon, France
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46
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Ma Y, Lang L, Kiesewetter DO, Eckelman WC. Liquid chromatography-tandem mass spectrometry identification of metabolites of three phenylcarboxyl derivatives of the 5-HT(1A) antagonist, N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridyl) trans-4-fluorocyclohexanecarboxamide (FCWAY), produced by human and rat hepatocytes. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 780:99-110. [PMID: 12383485 DOI: 10.1016/s1570-0232(02)00434-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We have previously described fluorine-18 radiolabeled FCWAY [N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridyl) trans-4-fluorocyclohexanecarboxamide] as a high affinity ligand for imaging the 5-HT(1A) receptor in vivo. In a search for radiopharmaceuticals with unique imaging applications using positron emission tomography (PET), we have also developed three new phenylcarboxamide analogues of FCWAY. Two of these analogues were generated by replacing the fluorocyclohexane carboxylic acid with fluorobenzoic acid (FBWAY) or with 3-methyl-4-fluorobenzoic acid (MeFBWAY). The final analogue was generated by replacing the pyridyl group with a pyrimidyl group and the fluorocyclohexane carboxylate with fluorobenzoic acid (FPWAY). We evaluated the metabolic profile of these compounds using either human or rat hepatocytes to produce metabolites and LC-MS/MS to identify these metabolites. We also compared the metabolic rate of these compounds in human or rat hepatocytes. These in vitro metabolism studies indicate that hydrolysis of the amide linkage was the major metabolic pathway for FPWAY and FBWAY in human hepatocytes, whereas aromatic oxidation is the major metabolic pathway for MeFBWAY. The comparative metabolic rate in human hepatocytes was FPWAY>FBWAY>MeFBWAY. In rat hepatocytes, aromatic oxidation was the major metabolic pathway for all three analogs and the rate of this process was similar for all of the analogues. These in vitro metabolic studies demonstrated species differences prior to the acquisition and interpretation of in vivo results.
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Affiliation(s)
- Ying Ma
- PET Department, Warren G Magnuson Clinical Center, National Institutes of Health, Bldg 10 Rm 1C401, 10 Center Drive MSC 1180, Bethesda, MD 20892, USA.
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Papagiannopoulou D, Pirmettis I, Tsoukalas C, Nikoladou L, Drossopoulou G, Dalla C, Pelecanou M, Papadopoulou-Daifotis Z, Papadopoulos M, Chiotellis E. Oxotechnetium 99mTcO[SN(R)S][S] complexes as potential 5-HT1A receptor imaging agents. Nucl Med Biol 2002; 29:825-32. [PMID: 12453592 DOI: 10.1016/s0969-8051(02)00343-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of 99mTcO[SN(R)S][S] complexes carrying the 1-(2-methoxyphenyl)piperazine moiety on the tridentate ligand [SN(R)S] was synthesized. For structural characterization and for in vitro binding assays the analogous oxorhenium complexes were prepared. As demonstrated by appropriate competition binding tests in rat hippocampal preparations, all oxorhenium analogues showed affinity for the 5-HT(1A) receptor binding sites with IC(50) values at the nanomolar range (IC(50)= 5.8-103 nM). All 99mTcO[SN(R)S]/[S] complexes showed significant brain uptake in rats at 2 min p.i. (0.24-1.31% ID). However, a clear correlation between distribution of radioactivity in the brain and distribution of 5-HT(1A) receptors could not be established.
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Affiliation(s)
- D Papagiannopoulou
- Institute of Radioisotopes-Radiodiagnostic Products, National Center for Scientific Research Demokritos, 15310 Ag. Paraskevi, Athens, Greece
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48
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Fujio M, Nagata S, Kawamura K, Sugiyama N, Tanaka H, Uno K, Ishiwata K. Synthesis and evaluation of (11)C-labeled (S)-N-[[1-(2-phenylethyl) pyrrolidin-2-yl]methyl]-3-methylthiobenzamide as a PET 5-HT(1A) receptor ligand. Nucl Med Biol 2002; 29:657-63. [PMID: 12234590 DOI: 10.1016/s0969-8051(02)00305-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We prepared 5-HT(1A) receptor ligands (S)-N-[[1-(2-phenylethyl)pyrrolidin-2-yl]methyl]-3-[11C]methylthiobenzamide ([11C](S)-PPMMB) (Ki = 4.3 nM) and the less active [(11)C](R)-PPMMB (Ki = 160 nM) by reduction of the disulfide dimer and subsequent [(11)C]methylation of demethyl (S)- and (R)-PPMMB, respectively. Both radioligands showed similar brain distribution in mice with relatively higher affinity for the hippocampus being rich in 5-HT(1A) receptors than for other brain regions. Uptake of [(11)C](S)-PPMMB was not reduced by carrier-loading nor by pretreatment with 5-HT(1A) receptor ligands. [(11)C](S)-PPMMB is therefore not a suitable radioligand for mapping 5-HT(1A) receptors using positron emission tomography.
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Affiliation(s)
- Masakazu Fujio
- Mitsubishi Pharma Corporation, 7-25, Koyata 3-chome, Iruma, Saitama, 358-0026, Japan
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49
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Doze P, van Waarde A, Tewson TJ, Vaalburg W, Elsinga PH. Synthesis and evaluation of (S)-[18F]-fluoroethylcarazolol for in vivo beta-adrenoceptor imaging in the brain. Neurochem Int 2002; 41:17-27. [PMID: 11918968 DOI: 10.1016/s0197-0186(01)00140-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The beta-adrenergic receptor ligand (S)-4-(3-(2'-[18F]-fluoroethylamino)-2-hydroxypropoxy)-carbazol ((S)-[18F]-fluoroethylcarazolol) was prepared by reaction of [18F]-fluoroethylamine with the corresponding (S)-epoxide and was evaluated in rats by studying its pharmacokinetics and its binding profile both in vitro and in vivo. In vitro, (S)-fluoroethylcarazolol binds preferentially to beta-adrenoceptors (pK(i)=9.3 for beta(1) and 9.4 for beta(2)) and has less affinity to 5HT(1A) and 5HT(1D) receptors (pK(i)=6.7 and 5.2). In vivo, standard uptake values (SUVs) up to 0.63+/-0.07 in cortical regions were found after 60 min. Metabolites (90%) appeared within 10 min in plasma, whereas, in brain 70-75% parent compound was found after 60 min. Clearance from plasma occurred within 5 min. Cerebral uptake could be blocked by 'cold' fluoroethylcarazolol in every region, except medulla. Uptake was also blocked by propranolol and pindolol, but not by WAY 100635. ICI 89406 hardly lowered [18F] levels in brain. ICI 118551 reduced uptake of [18F] in cerebellum (mainly beta(2)) by 30%. Specific binding (tissue minus medulla values) in various brain regions corresponded with those observed for [18F]-fluorocarazolol (r(2)=0.95) and with in vitro beta-adrenoceptor densities (r(2)=0.76). Autoradiography using phosphor images of (S)-[18F]-fluoroethylcarazolol in rat brain showed the characteristic binding pattern of beta-antagonists, while propranolol treatment resulted in low and homogenous uptake. Regional tissue minus medulla values corresponded with in vitro beta-adrenoceptor densities (r(2)=0.77). We conclude that (S)-[18F]-fluoroethylcarazolol is a high affinity ligand that binds specifically to cerebral beta-adrenoceptors in vivo and may be of use for beta-adrenoceptor imaging in the brain with PET.
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Affiliation(s)
- P Doze
- PET Center, Groningen University Hospital, P.O. Box 30001, 9700 RB Groningen, The Netherlands
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Pike VW, Halldin C, Wikström HV. Radioligands for the study of brain 5-HT1A receptors in vivo. PROGRESS IN MEDICINAL CHEMISTRY 2002; 38:189-247. [PMID: 11774795 DOI: 10.1016/s0079-6468(08)70094-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- V W Pike
- Chemistry and Engineering Group, MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, London W12 ONN, UK
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