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Cselényi Z, Jucaite A, Ewing P, Stenkrona P, Kristensson C, Johnström P, Schou M, Bolin M, Halldin C, Larsson B, Grime K, Eriksson UG, Farde L. Proof of lung muscarinic receptor occupancy by tiotropium: Translational Positron Emission Tomography studies in non-human primates and humans. FRONTIERS IN NUCLEAR MEDICINE (LAUSANNE, SWITZERLAND) 2023; 2:1080005. [PMID: 39354985 PMCID: PMC11440881 DOI: 10.3389/fnume.2022.1080005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/23/2022] [Indexed: 10/03/2024]
Abstract
Introduction Molecular imaging has not been used to support the development of drugs for the treatment of pulmonary disorders. The aim of the present translational study was to advance quantitative pulmonary PET imaging by demonstrating occupancy of the reference asthma drug tiotropium at muscarinic acetylcholine receptors (mAChR). Methods PET imaging was performed using the muscarinic radioligand [11C]VC-002. The key methodological step involved estimating muscarinic receptor binding while disentangling it from the background of non-specific binding. The relationship between tiotropium exposure and receptor occupancy (RO) was assessed in non-human primates (NHPs) after intravenous injection of tiotropium doses at a broad dose interval (0.03-1 µg/kg). The feasibility of measuring RO in the human lung was then confirmed in seven healthy human subjects after inhalation of a single therapeutic dose of tiotropium (18 µg). Results There was an evident effect of tiotropium on [11C]VC-002 binding to mAChRs in lungs in both NHPs and humans. In NHPs, RO was 11 to 78% and increased in a dose dependent manner. Non-displaceable binding in NHPs was about 10% of total binding. In humans, RO was 6%-65%, and non-displaceable binding was about 20% of total binding at baseline. Discussion The results demonstrate that [11C]VC-002 binds specifically to mAChRs in the lungs enabling the assessment of RO following administration of muscarinic antagonist drugs. Furthermore, the methodology has potential not only for dose finding and comparison of drug formulations in future applied studies, but also for evaluating changes in lung receptor distribution during disease or in response to therapy. Clinical Trial Registration ClinicalTrials.gov, identifier: NCT03097380.
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Affiliation(s)
- Zsolt Cselényi
- PET Science Centre, Precision Medicine and Biosamples, R&D, AstraZeneca AB, Stockholm, Sweden
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Aurelija Jucaite
- PET Science Centre, Precision Medicine and Biosamples, R&D, AstraZeneca AB, Stockholm, Sweden
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Pär Ewing
- DMPK, Research & Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca AB, Gothenburg, Sweden
| | - Per Stenkrona
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Cecilia Kristensson
- Clinical Development, Research & Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca AB, Gothenburg, Sweden
| | - Peter Johnström
- PET Science Centre, Precision Medicine and Biosamples, R&D, AstraZeneca AB, Stockholm, Sweden
| | - Magnus Schou
- PET Science Centre, Precision Medicine and Biosamples, R&D, AstraZeneca AB, Stockholm, Sweden
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Martin Bolin
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Bengt Larsson
- DMPK, Research & Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca AB, Gothenburg, Sweden
| | - Ken Grime
- Clinical Development, Research & Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca AB, Gothenburg, Sweden
| | - Ulf G Eriksson
- Clinical Development, Research & Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca AB, Gothenburg, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
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2
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Fu H, Rong J, Chen Z, Zhou J, Collier T, Liang SH. Positron Emission Tomography (PET) Imaging Tracers for Serotonin Receptors. J Med Chem 2022; 65:10755-10808. [PMID: 35939391 DOI: 10.1021/acs.jmedchem.2c00633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) and 5-HT receptors (5-HTRs) have crucial roles in various neuropsychiatric disorders and neurodegenerative diseases, making them attractive diagnostic and therapeutic targets. Positron emission tomography (PET) is a noninvasive nuclear molecular imaging technique and is an essential tool in clinical diagnosis and drug discovery. In this context, numerous PET ligands have been developed for "visualizing" 5-HTRs in the brain and translated into human use to study disease mechanisms and/or support drug development. Herein, we present a comprehensive repertoire of 5-HTR PET ligands by focusing on their chemotypes and performance in PET imaging studies. Furthermore, this Perspective summarizes recent 5-HTR-focused drug discovery, including biased agonists and allosteric modulators, which would stimulate the development of more potent and subtype-selective 5-HTR PET ligands and thus further our understanding of 5-HTR biology.
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Affiliation(s)
- Hualong Fu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jian Rong
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Zhen Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Thomas Collier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
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Ghosh KK, Padmanabhan P, Yang CT, Ng DCE, Palanivel M, Mishra S, Halldin C, Gulyás B. Positron emission tomographic imaging in drug discovery. Drug Discov Today 2021; 27:280-291. [PMID: 34332093 DOI: 10.1016/j.drudis.2021.07.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/07/2021] [Accepted: 07/23/2021] [Indexed: 01/02/2023]
Abstract
Positron emission tomography (PET) is an extensively used nuclear functional imaging technique, especially for central nervous system (CNS) and oncological disorders. Currently, drug development is a lengthy and costly pursuit. Imaging with PET radiotracers could be an effective way to hasten drug discovery and advancement, because it facilitates the monitoring of key facets, such as receptor occupancy quantification, drug biodistribution, pharmacokinetic (PK) analyses, validation of target engagement, treatment monitoring, and measurement of neurotransmitter concentrations. These parameters demand careful analyses for the robust appraisal of newly formulated drugs during preclinical and clinical trials. In this review, we discuss the usage of PET imaging in radiopharmaceutical development; drug development approaches with PET imaging; and PET developments in oncological and cardiac drug discovery.
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Affiliation(s)
- Krishna Kanta Ghosh
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
| | - Parasuraman Padmanabhan
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore.
| | - Chang-Tong Yang
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Department of Nuclear Medicine and Molecular Imaging, Radiological Sciences Division, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - David Chee Eng Ng
- Department of Nuclear Medicine and Molecular Imaging, Radiological Sciences Division, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Mathangi Palanivel
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
| | - Sachin Mishra
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore
| | - Christer Halldin
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institute and Stockholm County Council, SE-171 76 Stockholm, Sweden
| | - Balázs Gulyás
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore; Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institute and Stockholm County Council, SE-171 76 Stockholm, Sweden
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Varnäs K, Finnema SJ, Johnström P, Arakawa R, Halldin C, Eriksson LI, Farde L. Effects of sevoflurane anaesthesia on radioligand binding to monoamine oxidase-B in vivo. Br J Anaesth 2020; 126:238-244. [PMID: 33036760 PMCID: PMC8258980 DOI: 10.1016/j.bja.2020.08.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/24/2020] [Accepted: 08/31/2020] [Indexed: 11/28/2022] Open
Abstract
Background The molecular actions underlying the clinical effects of inhaled anaesthetics such as sevoflurane and isoflurane are not fully understood. Unexpected observations in positron emission tomography (PET) studies with [11C]AZD9272, a metabotropic glutamate receptor 5 (mGluR5) radioligand with possible affinity for monoamine oxidase-B (MAO-B), suggest that its binding is sensitive to anaesthesia with sevoflurane. The objective of the present study was to assess the effects of sevoflurane anaesthesia on the binding of [11C]AZD9272 and of [11C]L-deprenyl-D2, a radioligand selective for MAO-B in non-human primates (NHPs). Methods Altogether, 12 PET measurements were conducted with a high-resolution research tomograph using the ligands [11C]AZD9272 or [11C]L-deprenyl-D2 in six cynomolgus monkeys anaesthetised with sevoflurane or ketamine/xylazine. Results The specific binding of [11C]AZD9272 and [11C]L-deprenyl-D2 was markedly reduced during anaesthesia with sevoflurane compared with ketamine/xylazine. The reduction was 80–90% (n=3) for [11C]AZD9272 and 77–80% (n=3) for [11C]L-deprenyl-D2. Conclusions Sevoflurane anaesthesia inhibited radioligand binding to MAO-B in the primate brain. The observation of lower MAO-B binding at clinically relevant concentrations of sevoflurane warrants further exploration of the potential role of MAO-B related mechanisms in regulation of systemic blood pressure during anaesthesia.
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Affiliation(s)
- Katarina Varnäs
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.
| | - Sjoerd J Finnema
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Peter Johnström
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden; PET Science Centre, Precision Medicine and Biosamples, R&D Oncology, AstraZeneca, Karolinska Institutet, Stockholm, Sweden
| | - Ryosuke Arakawa
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Lars I Eriksson
- Perioperative Medicine and Intensive Care, Section for Anesthesiology and Intensive Care Medicine, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
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Deen M, Hougaard A, Hansen HD, Schain M, Dyssegaard A, Knudsen GM, Ashina M. Association Between Sumatriptan Treatment During a Migraine Attack and Central 5-HT1B Receptor Binding. JAMA Neurol 2020; 76:834-840. [PMID: 31135819 DOI: 10.1001/jamaneurol.2019.0755] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Importance Triptans, the most efficient acute treatment for migraine attacks, are 5-HT1B/1D receptor agonists, but their precise mechanism of action is not completely understood. The extent to which triptans enter the central nervous system and bind to 5-HT1B receptors in the brain is unknown. Objectives To determine the occupancy of sumatriptan to central 5-HT1B receptors, and to investigate changes in brain serotonin levels during migraine attacks. Design, Setting, and Participants This study of 8 patients in Denmark used a within-participant design and was conducted from April 20, 2015, to December 5, 2016. Participants were otherwise healthy patients with untreated episodic migraine without aura, aged between 18 and 65 years, and recruited from the general community. Data analysis was performed from January 2017 to April 2018. Interventions All participants underwent positron emission tomographic scans after injection of [11C]AZ10419369, a specific 5-HT1B receptor radiotracer. All participants were scanned 3 times: (1) during an experimentally induced migraine attack, (2) after a subcutaneous injection of 6-mg subcutaneous sumatriptan, and (3) on a migraine attack-free day. Scans 1 and 2 were conducted on the same study day. Each scan lasted for 90 minutes. Main Outcome and Measure The primary outcome was the nondisplaceable binding potential of [11C]AZ10419369 across 7 brain regions involved in pain modulation. The binding potential reflects receptor density, and changes in binding potential reflects displacement of the radiotracer. The occupancy of sumatriptan was estimated from the 2 scans before and after sumatriptan administration. Results Eight patients with migraine were included in the study; of these participants, 7 (87%) were women. The mean (SD) age of participants on study day 1 was 29.5 (9.2) years and on study day 2 was 30.0 (8.9) years. Sumatriptan was associated with statistically significantly reduced 5-HT1B receptor binding across pain-modulating regions (mean [SD] binding potential, 1.20 [0.20] vs 1.02 [0.22]; P = .001), corresponding to a mean (SD) drug occupancy rate of 16.0% (5.3%). Furthermore, during migraine attacks, as compared with outside of attacks, 5-HT1B receptor binding was statistically significantly associated with reduced in pain-modulating regions (mean [SD] binding potential, 1.36 [0.22] vs 1.20 [0.20]; P = .02). Conclusions and Relevance Treatment with sumatriptan during migraine attacks appeared to be associated with a decrease in 5-HT1B receptor binding, a finding that is most likely associated with the binding of sumatriptan to central 5-HT1B receptors, but the contribution of ongoing cerebral serotonin release to the lower binding cannot be excluded; the migraine attack-associated decrease in binding could indicate that migraine attacks are associated with increases in endogenous serotonin.
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Affiliation(s)
- Marie Deen
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark.,Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anders Hougaard
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark
| | - Hanne Demant Hansen
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Martin Schain
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Agnete Dyssegaard
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Messoud Ashina
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Lindberg A, Lu S, Nag S, Schou M, Liow JS, Zoghbi SS, Frankland MP, Gladding RL, Morse CL, Takano A, Amini N, Elmore CS, Lee YS, Innis RB, Halldin C, Pike VW. Synthesis and evaluation of two new candidate high-affinity full agonist PET radioligands for imaging 5-HT 1B receptors. Nucl Med Biol 2019; 70:1-13. [PMID: 30811975 DOI: 10.1016/j.nucmedbio.2019.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/17/2019] [Accepted: 01/21/2019] [Indexed: 11/17/2022]
Abstract
INTRODUCTION The serotonin 1B receptor subtype is of interest in the pathophysiology and treatment of depression, anxiety, and migraine. Over recent years 5-HT1B receptor binding in human brain has been examined with PET using radioligands that are partial but not full agonists. To explore how the intrinsic activity of a PET radioligand may affect imaging performance, two high-affinity full 5-HT1B receptor agonists (AZ11136118, 4; and AZ11895987, 5) were selected from a large compound library and radiolabeled for PET examination in non-human primates. METHODS [11C]4 was obtained through Pd(0)-mediated insertion of [11C]carbon monoxide between prepared iodoarene and homochiral amine precursors. [11C]5 was obtained through N-11C-methylation of N-desmethyl precursor 6 with [11C]methyl triflate. [11C]4 and [11C]5 were studied with PET in rhesus or cynomolgus monkey. [11C]4 was studied with PET in mice and rats to measure brain uptake and specific binding. Ex-vivo experiments in rats were performed to identify whether there were radiometabolites in brain. Physiochemical parameters for [11C]4 (pKa, logD and conformational energetics) were evaluated. RESULTS Both [11C]4 and [11C]5 were successfully produced in high radiochemical purity and in adequate amounts for PET experiments. After intravenous injection of [11C]4, brain radioactivity peaked at a low level (0.2 SUV). Pretreatment with tariquidar, an inhibitor of the brain P-gp efflux transporter, increased brain exposure four-fold whereas pretreatment with a high pharmacological dose of the 5-HT1B antagonist, AR-A000002, had no effect on the binding. Ex-vivo experiments in rats showed no radiometabolites entering brain. [11C]5 also failed to enter monkey brain under baseline conditions. CONCLUSIONS [11C]4 and [11C]5 show too low brain uptake and specific binding to be useful PET radioligands. Low brain uptake is partly ascribed to efflux transporter action as well as unfavorable conformations.
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Affiliation(s)
- Anton Lindberg
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden; Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA.
| | - Shuiyu Lu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Sangram Nag
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Magnus Schou
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden; PET Science Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, SE-17176 Stockholm, Sweden
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Michael P Frankland
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Robert L Gladding
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Nahid Amini
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Charles S Elmore
- Isotope Chemistry, Early Chemical Development, Pharmaceutical Sciences, IMED Biotech Unit, AstraZeneca, SE-43250 Göteborg, Sweden
| | - Yong Sok Lee
- Center for Molecular Modeling, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892-5624, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
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Yang KC, Takano A, Halldin C, Farde L, Finnema SJ. Serotonin concentration enhancers at clinically relevant doses reduce [ 11C]AZ10419369 binding to the 5-HT 1B receptors in the nonhuman primate brain. Transl Psychiatry 2018; 8:132. [PMID: 30013068 PMCID: PMC6048172 DOI: 10.1038/s41398-018-0178-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/14/2018] [Accepted: 04/03/2018] [Indexed: 12/25/2022] Open
Abstract
The serotonin (5-HT) system plays an important role in the pathophysiology and treatment of several major psychiatric disorders. Currently, no suitable positron emission tomography (PET) imaging paradigm is available to assess 5-HT release in the living human brain. [11C]AZ10419369 binds to 5-HT1B receptors and is one of the most 5-HT-sensitive radioligands available. This study applied 5-HT concentration enhancers which can be safely studied in humans, and examined their effect on [11C]AZ10419369 binding at clinically relevant doses, including amphetamine (1 mg/kg), 3,4-methylenedioxymethamphetamine (MDMA; 1 mg/kg) or 5-hydroxy-L-tryptophan (5-HTP; 5 mg/kg). Twenty-six PET measurements (14 for amphetamine, 6 for MDMA and 6 for 5-HTP) using a bolus and constant infusion protocol were performed in four cynomolgus monkeys before or after drug administration. Binding potential (BPND) values were determined with the equilibrium method (integral interval: 63-123 min) using cerebellum as the reference region. BPND values were significantly decreased in several examined brain regions after administration of amphetamine (range: 19-31%), MDMA (16-25%) or 5-HTP (13-31%). Reductions in [11C]AZ10419369 binding were greater in striatum than cortical regions after administration of 5-HTP, while no prominent regional differences were found for amphetamine and MDMA. In conclusion, [11C]AZ10419369 binding is sensitive to changes in 5-HT concentration induced by amphetamine, MDMA or 5-HTP. The robust changes in BPND, following pretreatment drugs administered at clinically relevant doses, indicate that the applied PET imaging paradigms hold promise to be successfully used in future human studies.
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Affiliation(s)
- Kai-Chun Yang
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Personalized Health Care and Biomarkers, AstraZeneca PET Science Center at Karolinska Institutet, Stockholm, Sweden
| | - Sjoerd J Finnema
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
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Hazari PP, Pandey A, Chaturvedi S, Mishra AK. New Trends and Current Status of Positron-Emission Tomography and Single-Photon-Emission Computerized Tomography Radioligands for Neuronal Serotonin Receptors and Serotonin Transporter. Bioconjug Chem 2017; 28:2647-2672. [PMID: 28767225 DOI: 10.1021/acs.bioconjchem.7b00243] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The critical role of serotonin (5-hydroxytryptamine; 5-HT) and its receptors (5-HTRs) in the pathophysiology of diverse neuropsychiatric and neurodegenerative disorders render them attractive diagnostic and therapeutic targets for brain disorders. Therefore, the in vivo assessment of binding of 5-HT receptor ligands under a multitude of physiologic and pathologic scenarios may support more-accurate identification of disease and its progression and the patient's response to therapy as well as the screening of novel therapeutic strategies. The present Review aims to focus on the current status of radioligands used for positron-emission tomography (PET) and single-photon-emission computerized tomography (SPECT) imaging of human brain serotonin receptors. We further elaborate upon and emphasize the attributes that qualify a radioligand for theranostics on the basis of its frequency of use in clinics, its benefit to risk assessment in humans, and its continuous evolution, along with the major limitations.
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Affiliation(s)
- Puja Panwar Hazari
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
| | - Ankita Pandey
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
| | - Shubhra Chaturvedi
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
| | - Anil Kumar Mishra
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
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Ganz M, Feng L, Hansen HD, Beliveau V, Svarer C, Knudsen GM, Greve DN. Cerebellar heterogeneity and its impact on PET data quantification of 5-HT receptor radioligands. J Cereb Blood Flow Metab 2017; 37:3243-3252. [PMID: 28075185 PMCID: PMC5584698 DOI: 10.1177/0271678x16686092] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/18/2016] [Accepted: 11/22/2016] [Indexed: 11/15/2022]
Abstract
In the quantification of positron emission tomography (PET) radiotracer binding, a commonly used method is reference tissue modeling (RTM). RTM necessitates a proper reference and a ubiquitous choice for G-protein coupled receptors is the cerebellum. We investigated regional differences in uptake within the grey matter of the cerebellar hemispheres (CH), the cerebellar white matter (CW), and the cerebellar vermis (CV) for five PET radioligands targeting the serotonin system. Furthermore, we evaluated the impact of choosing different reference regions when quantifying neocortical binding. The PET and MR images are part of the Cimbi database: 5-HT1AR ([11C]CUMI-101, n = 8), 5-HT1BR ([11C]AZ10419369, n = 36), 5-HT2AR ([11C]Cimbi-36, n = 29), 5-HT4R ([11C]SB207145, n = 59), and 5-HTT ([11C]DASB, n = 100). We employed SUIT and FreeSurfer to delineate CV, CW, and CH and quantified mean standardized uptake values (SUV) and nondisplaceable neocortical binding potential (BPND). Statistical difference was assessed with paired nonparametric two-sided Wilcoxon signed-rank tests and multiple comparison corrected via false discovery rate. We demonstrate significant radioligand specific regional differences in cerebellar uptake. These differences persist when using different cerebellar regions for RTM, but the influence on the neocortical BPND is small. Nevertheless, our data highlight the importance of validating each radioligand carefully for defining the optimal reference region.
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Affiliation(s)
- Melanie Ganz
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen, Denmark
| | - Ling Feng
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen, Denmark
| | - Hanne Demant Hansen
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen, Denmark
| | - Vincent Beliveau
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus Svarer
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Douglas N Greve
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
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Dopamine and serotonin modulation of motor and non-motor functions of the non-human primate striato-pallidal circuits in normal and pathological states. J Neural Transm (Vienna) 2017; 125:485-500. [PMID: 28176009 DOI: 10.1007/s00702-017-1693-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/30/2017] [Indexed: 10/20/2022]
Abstract
Thanks to the non-human primate (NHP), we have shown that the pharmacological disturbance of the anterior striatum or of external globus pallidus triggers a set of motivation and movement disorders, depending on the functional subterritory involved. One can, therefore, assume that the aberrant activity of the different subterritories of basal ganglia (BG) could lead to different behavioral disorders in neuropsychiatric disorders as Tourette's syndrome and Parkinson's disease. We are now addressing in the NHP the impact of modulating dopamine or serotonin within the BG on behavioral disorders. Indeed, we have shown a prominent role of serotonergic degeneration within the ventral striatum and caudate nucleus in neuropsychiatric symptoms in de novo PD patients. Of note, the serotonergic modulation of these BG regions in the NHP plays also a critical role in the induction or treatment of behavioral disorders. Given that both dopamine and serotonin are targeted to treat neuropsychiatric disorders, we are studying the effects of modulating dopamine and serotonin transporters in the different territories of the striatum, and more particularly within the ventral striatum on decision-making processing at both behavioral and neuronal levels. Finally, we evidence the need to extend the pharmacological approach to the receptors of these two neuromodulator systems as the use of substances targeting receptor subtypes preferentially localized in the associative and limbic territories of BG could be very effective to specifically improve the behavioral disorders in Parkinson's disease, Gilles de la Tourette syndrome but also in several psychiatric disorders such as depression, anxiety, anorexia, or impulse control disorders.
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11
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Varnas K, Jureus A, Johnstrom P, Ahlgren C, Schott P, Schou M, Gruber S, Jerning E, Malmborg J, Halldin C, Afzelius L, Farde L. Integrated Strategy for Use of Positron Emission Tomography in Nonhuman Primates to Confirm Multitarget Occupancy of Novel Psychotropic Drugs: An Example with AZD3676. ACTA ACUST UNITED AC 2016; 358:464-71. [DOI: 10.1124/jpet.116.234146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/06/2016] [Indexed: 01/10/2023]
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12
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Kumar JSD, Mann JJ. PET tracers for serotonin receptors and their applications. Cent Nerv Syst Agents Med Chem 2015; 14:96-112. [PMID: 25360773 DOI: 10.2174/1871524914666141030124316] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 10/26/2014] [Accepted: 10/28/2014] [Indexed: 11/22/2022]
Abstract
Serotonin receptors (5-HTRs) are implicated in the pathophysiology of a variety of neuropsychiatric and neurodegenerative disorders and are also targets for drug therapy. In the CNS, most of these receptors are expressed in high abundance in specific brain regions reflecting their role in brain functions. Quantifying binding to 5-HTRs in vivo may permit assessment of physiologic and pathologic conditions, and monitoring disease progression, evaluating treatment response, and for investigating new treatment modalities. Positron emission tomography (PET) molecular imaging has the sensitivity to quantify binding of 5-HTRs in CNS disorders and to measure drug occupancy as part of a process of new drug development. Although research on PET imaging of 5-HTRs have been performed more than two decades, the successful radiotracers so far developed for human studies are limited to 5-HT₁AR, 5-HT₁BR, 5-HT₂AR, 5-HT₄R and 5-HT₆R. Herein we review the development and application of radioligands for PET imaging of 5-HTRs in living brain.
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Affiliation(s)
| | - J John Mann
- Division of Molecular Imaging and Neuropathology, New York State Psychiatric institute, 1051 Riverside Drive, Box: 42, New York, NY, 10032, USA.
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13
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Kågedal M, Varnäs K, Hooker AC, Karlsson MO. Estimation of drug receptor occupancy when non-displaceable binding differs between brain regions – extending the simplified reference tissue model. Br J Clin Pharmacol 2015; 80:116-27. [PMID: 25406494 PMCID: PMC4500331 DOI: 10.1111/bcp.12558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 10/28/2014] [Indexed: 11/28/2022] Open
Abstract
AIM The simplified reference tissue model (SRTM) is used for estimation of receptor occupancy assuming that the non-displaceable binding in the reference region is identical to the brain regions of interest. The aim of this work was to extend the SRTM to also account for inter-regional differences in non-displaceable concentrations, and to investigate if this model allowed estimation of receptor occupancy using white matter as reference. It was also investigated if an apparent higher affinity in caudate compared with other brain regions, could be better explained by a difference in the extent of non-displaceable binding. METHODS The analysis was based on a PET study in six healthy volunteers using the 5-HT1B receptor radioligand [(11)C]-AZ10419369. The radioligand was given intravenously as a tracer dose alone and following different oral doses of the 5-HT1B receptor antagonist AZD3783. Non-linear mixed effects models were developed where differences between regions in non-specific concentrations were accounted for. The properties of the models were also evaluated by means of simulation studies. RESULTS The estimate (95% CI) of Ki(PL) was 10.2 ng ml(-1) (5.4, 15) and 10.4 ng ml(-1) (8.1, 13.6) based on the extended SRTM with white matter as reference and based on the SRTM using cerebellum as reference, respectively. The estimate (95% CI) of Ki(PL) for caudate relative to other brain regions was 55% (48, 62%). CONCLUSIONS The extended SRTM allows consideration of white matter as reference region when no suitable grey matter region exists. AZD3783 affinity appears to be higher in the caudate compared with other brain regions.
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Affiliation(s)
- Matts Kågedal
- AstraZeneca R&DSE-151 85, Södertälje, Sweden
- Department of Pharmaceutical Biosciences, Uppsala UniversityUppsala, Sweden
| | - Katarina Varnäs
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research and Education, Karolinska HospitalS-171 76, Stockholm, Sweden
| | - Andrew C Hooker
- Department of Pharmaceutical Biosciences, Uppsala UniversityUppsala, Sweden
| | - Mats O Karlsson
- Department of Pharmaceutical Biosciences, Uppsala UniversityUppsala, Sweden
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14
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In vivo occupancy of the 5-HT1A receptor by a novel pan 5-HT1(A/B/D) receptor antagonist, GSK588045, using positron emission tomography. Neuropharmacology 2015; 92:44-8. [DOI: 10.1016/j.neuropharm.2014.11.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 10/27/2014] [Accepted: 11/25/2014] [Indexed: 02/05/2023]
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15
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Tóth M, Häggkvist J, Varrone A, Finnema SJ, Doorduin J, Tokunaga M, Higuchi M, Gulyás B, Halldin C. ABC transporter-dependent brain uptake of the 5-HT1B receptor radioligand [ (11)C]AZ10419369: a comparative PET study in mouse, rat, and guinea pig. EJNMMI Res 2014; 4:64. [PMID: 26116125 PMCID: PMC4452686 DOI: 10.1186/s13550-014-0064-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/06/2014] [Indexed: 01/25/2023] Open
Abstract
Background We have explored the possibility that the serotonin 1B receptor radioligand [11C]AZ10419369 is a substrate for adenosine triphosphate (ATP)-binding cassette (ABC) transporters, such as P-glycoprotein (P-gp), Mrp4, and Bcrp, in rodents and whether there is a species difference regarding its blood-brain barrier (BBB) penetration. Methods In a series of preclinical positron emission tomography measurements, we have administered [11C]AZ10419369 to mice, rats, and guinea pigs under baseline conditions and, on separate experimental days, after administration of the ABC transporter inhibitor, cyclosporin A (CsA). Results During baseline conditions, the brain uptake was low in mice and rats, but not in guinea pigs. After CsA pretreatment, the peak whole brain uptake values of [11C]AZ10419369 increased by 207% in mice, 94% in rats, and 157% in guinea pigs. Binding potentials (BPND) could not be estimated during baseline conditions in mice and rats. After CsA pretreatment, the highest BPND values were obtained in the striatum and thalamus (BPND ≈ 0.4) in mice, while in rats, the highest binding areas were the striatum, thalamus, hypothalamus, and periaqueductal gray (BPND ≈ 0.5). In guinea pigs, we did not find any significant changes in BPND between baseline and CsA pretreatment, except in the striatum. Conclusions The results indicate that BBB penetration of [11C]AZ10419369 was hindered by ABC transporter activity in mouse, rat, and guinea pig. This study highlights the importance of ABC transporters in the design of preclinical positron emission tomography (PET) studies. Electronic supplementary material The online version of this article (doi:10.1186/s13550-014-0064-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Miklós Tóth
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, 171 76, Stockholm, Sweden,
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Chang JCF, Ciaccio P, Schroeder P, Wright L, Westwood R, Berg AL. Pathology and Neurotoxicity in Dogs after Repeat Dose Exposure to a Serotonin 5-HT1B Inhibitor. J Toxicol Pathol 2014; 27:31-42. [PMID: 24791065 PMCID: PMC4000071 DOI: 10.1293/tox.2013-0033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/28/2013] [Indexed: 11/27/2022] Open
Abstract
AZD3783, a cationic amphiphilic drug and a potent inhibitor of the 5-hydroxytryptamine
(5-HT1B) receptor, was explored as a potential treatment for depression. To
support clinical trials, repeat dose toxicity studies in rats and dogs were conducted.
Here we report toxicity findings in dogs after dosing from 1 to 3 months. In the 1-month
study, there were minimal neuronal vacuolation in the brain, a marked increase in liver
enzymes accompanied by hepatocellular degeneration/necrosis and phospholipidosis (PLD),
and PLD/cholecystitis in the gallbladder of animals dosed at 47 mg/kg/day. In the 3-month
study, neurotoxicity resulted in euthanasia of one animal dosed at 30 mg/kg/day after 86
days. Extensive pathologic changes were seen in all animals in retina epithelium
(inclusion bodies), brain (neuronal vacuolation, degeneration, or necrosis and nerve fiber
degeneration), spinal ganglia (vacuolation, degeneration, or necrosis), as well as sciatic
and optic nerves (degeneration). Pigment-laden macrophages were observed in the lung,
kidney, liver, gallbladder, bone marrow, gastrointestinal tract, and lymphoid tissues.
Also seen were vitrel and retinal hemorrhage in the eyes. A brain concentration and
pathology study showed that the concentration of AZD3783 in the brain was approximately 4
times higher than in the plasma after 4 weeks of dosing, however, they were similar in all
regions examined, and did not correlate with areas with pathologic findings. Our findings
with AZD3783 in dogs have not been reported previously with other CNS compounds that
effect through serotonergic pharmacology.
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Affiliation(s)
| | - Paul Ciaccio
- AstraZeneca R&D, Wilmington, DE 19850, USA ; Cubist Pharmaceuticals, 65 Hayden Avenue, Lexington, MA 02421, USA
| | - Patricia Schroeder
- AstraZeneca R&D, Wilmington, DE 19850, USA ; EMD Serono, 45 A Middlesex Turnpike, Billerica, MA 01821, USA
| | - Lindsay Wright
- AstraZeneca R&D, Alderly Park, Macclesfield, Cheshire SK10 4TG, England
| | - Russell Westwood
- AstraZeneca R&D, Alderly Park, Macclesfield, Cheshire SK10 4TG, England
| | - Anna-Lena Berg
- AstraZeneca R&D, Södertälje, Sweden ; MPA, Läkemedelsverket, Uppsala, Sweden
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17
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Modeling of PET data in CNS drug discovery and development. J Pharmacokinet Pharmacodyn 2013; 40:267-79. [PMID: 23660778 DOI: 10.1007/s10928-013-9320-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 04/26/2013] [Indexed: 12/22/2022]
Abstract
Positron emission tomography (PET) is increasingly used in drug discovery and development for evaluation of CNS drug disposition and for studies of disease biomarkers to monitor drug effects on brain pathology. The quantitative analysis of PET data is based on kinetic modeling of radioactivity concentrations in plasma and brain tissue compartments. A number of quantitative methods of analysis have been developed that allow the determination of parameters describing drug pharmacokinetics and interaction with target binding sites in the brain. The optimal method of quantification depends on the properties of the radiolabeled drug or radioligand and the binding site studied. We here review the most frequently used methods for quantification of PET data in relation to CNS drug discovery and development. The utility of PET kinetic modeling in the development of novel CNS drugs is illustrated by examples from studies of the brain kinetic properties of radiolabeled drug molecules.
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18
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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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Evaluation of dopamine D₂/D₃ and serotonin 5-HT₂A receptor occupancy for a novel antipsychotic, lurasidone, in conscious common marmosets using small-animal positron emission tomography. Psychopharmacology (Berl) 2013; 225:329-39. [PMID: 22868411 DOI: 10.1007/s00213-012-2815-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 07/17/2012] [Indexed: 12/13/2022]
Abstract
RATIONALE Lurasidone is a novel antipsychotic drug with potent binding affinity for dopamine D(2) and serotonin (5-hydroxytryptamine, 5-HT)(2A), 5-HT(7), and 5-HT(1A) receptors. Previous pharmacological studies have revealed that lurasidone exhibits a preferable profile (potent antipsychotic activity and lower incidence of catalepsy) to other antipsychotic drugs, although the contribution of receptor subtypes to this profile remains unclear. OBJECTIVES To compare target engagements of lurasidone with those of an atypical antipsychotic, olanzapine, we performed evaluation of dopamine D(2)/D(3) and serotonin 5-HT(2A) receptor occupancy in vivo by positron emission tomography (PET) with conscious common marmosets. METHODS We measured brain receptor occupancies in conscious common marmosets after oral administrations of lurasidone or olanzapine by PET with [(11)C]raclopride and [(11)C]R-(+)-α-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidine methanol (MDL 100907) for D(2)/D(3) and 5-HT(2A) receptors, respectively. RESULTS Increases in brain D(2)/D(3) receptor occupancies of both lurasidone and olanzapine, which reached >80 % at maximum, were observed in the striatum with significant correlations to plasma drug levels. However, lurasidone showed lower 5-HT(2A) receptor occupancy in the frontal cortex within the same dose range, while olanzapine showed broadly comparable 5-HT(2A) and D(2)/D(3) receptor occupancies. CONCLUSIONS Compared with olanzapine, lurasidone preferentially binds to D(2)/D(3) receptors rather than 5-HT(2A) receptors in common marmosets. These results suggest that the contribution of in vivo 5-HT(2A) receptor blocking activity to the pharmacological profile of lurasidone might differ from olanzapine in terms of the low risk of extrapyramidal syndrome and efficacy against negative symptoms.
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Finnema SJ, Varrone A, Hwang TJ, Halldin C, Farde L. Confirmation of fenfluramine effect on 5-HT(1B) receptor binding of [(11)C]AZ10419369 using an equilibrium approach. J Cereb Blood Flow Metab 2012; 32:685-95. [PMID: 22167236 PMCID: PMC3318146 DOI: 10.1038/jcbfm.2011.172] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Assessment of serotonin release in the living brain with positron emission tomography (PET) may have been hampered by the lack of suitable radioligands. We previously reported that fenfluramine caused a dose-dependent reduction in specific binding in monkeys using a classical displacement paradigm with bolus administration of [(11)C]AZ10419369. The aim of this study was to confirm our previous findings using an equilibrium approach in monkey. A total of 24 PET measurements were conducted using a bolus infusion protocol of [(11)C]AZ10419369 in three cynomolgus monkeys. Initial PET measurements were performed to assess suitable K(bol) values. The fenfluramine effect on [(11)C]AZ10419369 binding was evaluated in a displacement and pretreatment paradigm. The effect of fenfluramine on [(11)C]AZ10419369 binding potential (BP(ND)) was dose-dependent in the displacement paradigm and confirmed in the pretreatment paradigm. After pretreatment administration of fenfluramine (5.0 mg/kg), the mean BP(ND) of the occipital cortex decreased by 39%, from 1.38±0.04 to 0.84±0.09. This study confirms that the new 5-HT(1B) receptor radioligand [(11)C]AZ10419369 is sensitive to fenfluramine-induced changes in endogenous serotonin levels in vivo. The more advanced methodology is suitable for exploring the sensitivity limit to serotonin release as measured using [(11)C]AZ10419369 and PET.
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Affiliation(s)
- Sjoerd J Finnema
- Psychiatry Section, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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21
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Saulin A, Savli M, Lanzenberger R. Serotonin and molecular neuroimaging in humans using PET. Amino Acids 2011; 42:2039-57. [PMID: 21947614 DOI: 10.1007/s00726-011-1078-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 09/05/2011] [Indexed: 02/07/2023]
Abstract
The serotonergic system is one of the most important modulatory neurotransmitter systems in the human brain. It plays a central role in major physiological processes and is implicated in a number of psychiatric disorders. Along with the dopaminergic system, it is also one of the phylogenetically oldest human neurotransmitter systems and one of the most diverse, with 14 different receptors identified up to this day, many of whose function remains to be understood. The system's functioning is even more diverse than the number of its receptors, since each is implicated in a number of different processes. This review aims at illustrating the distribution and summarizing the main functions of the serotonin (5-hydroxytryptamin, 5-HT) receptors as well as the serotonin transporter (SERT, 5-HTT), the vesicular monoamine transporter 2, monoamine oxidase type A and 5-HT synthesis in the human brain. Recent advances in in vivo quantification of these different receptors and enzymes that are part of the serotonergic system using positron emission tomography are described.
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Affiliation(s)
- Anne Saulin
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
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Zhang M, Zhou D, Wang Y, Maier DL, Widzowski DV, Sobotka-Briner CD, Brockel BJ, Potts WM, Shenvi AB, Bernstein PR, Pierson ME. Preclinical pharmacology and pharmacokinetics of AZD3783, a selective 5-hydroxytryptamine 1B receptor antagonist. J Pharmacol Exp Ther 2011; 339:567-78. [PMID: 21825000 DOI: 10.1124/jpet.110.174433] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The preclinical pharmacology and pharmacokinetic properties of (2R)-6-methoxy-8-(4-methylpiperazin-1-yl)-N-(4-morpholin-4-ylphenyl)chromane-2-carboxamide (AZD3783), a potent 5-hydroxytryptamine 1B (5-HT(1B)) receptor antagonist, were characterized as part of translational pharmacokinetic/pharmacodynamic hypothesis testing in human clinical trials. The affinity of AZD3783 to the 5-HT(1B) receptor was measured in vitro by using membrane preparations containing recombinant human or guinea pig 5-HT(1B) receptors and in native guinea pig brain tissue. In vivo antagonist potency of AZD3783 for the 5HT(1B) receptor was investigated by measuring the blockade of 5-HT(1B) agonist-induced guinea pig hypothermia. The anxiolytic-like potency was assessed using the suppression of separation-induced vocalization in guinea pig pups. The affinity of AZD3783 for human and guinea pig 5-HT(1B) receptor (K(i), 12.5 and 11.1 nM, respectively) was similar to unbound plasma EC(50) values for guinea pig receptor occupancy (11 nM) and reduction of agonist-induced hypothermia (18 nM) in guinea pig. Active doses of AZD3783 in the hypothermia assay were similar to doses that reduced separation-induced vocalization in guinea pig pups. AZD3783 demonstrated favorable pharmacokinetic properties. The predicted pharmacokinetic parameters (total plasma clearance, 6.5 ml/min/kg; steady-state volume of distribution, 6.4 l/kg) were within 2-fold of the values observed in healthy male volunteers after a single 20-mg oral dose. This investigation presents a direct link between AZD3783 in vitro affinity and in vivo receptor occupancy to preclinical disease model efficacy. Together with predicted human pharmacokinetic properties, we have provided a model for the quantitative translational pharmacology of AZD3783 that increases confidence in the optimal human receptor occupancy required for antidepressant and anxiolytic effects in patients.
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Affiliation(s)
- Minli Zhang
- Department of Drug Metabolism and Pharmacokinetics, AstraZeneca Pharmaceuticals, 35 Gatehouse Drive, Waltham, MA 02451, USA.
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