1
|
Albujuq NR, Meana JJ, Diez-Alarcia R, Muneta-Arrate I, Naqvi A, Althumayri K, Alsehli M. Design, Synthesis, Molecular Docking, and Biological Evaluation of Novel Pimavanserin-Based Analogues as Potential Serotonin 5-HT 2A Receptor Inverse Agonists. J Med Chem 2023. [PMID: 37378639 DOI: 10.1021/acs.jmedchem.3c00662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
There is concern for important adverse effects with use of second-generation antipsychotics in Parkinson's disease psychosis (PDP) and dementia-related psychosis. Pimavanserin is the only antipsychotic drug authorized for PDP and represents an inverse agonist of 5-HT2A receptors (5-HT2AR) lacking affinity for dopamine receptors. Therefore, the development of serotonin 5-HT2AR inverse agonists without dopaminergic activity represents a challenge for different neuropsychiatric disorders. Using ligand-based drug design, we discovered a novel structure of pimavanserin analogues (2, 3, and 4). In vitro competition receptor binding and functional G protein coupling assays demonstrated that compounds 2, 3, and 4 showed higher potency than pimavanserin as 5-HT2AR inverse agonists in the human brain cortex and recombinant cells. To assess the effect of molecular substituents for selectivity and inverse agonism at 5-HT2ARs, molecular docking and in silico predicted physicochemical parameters were performed. Docking studies were in agreement with in vitro screenings and the results resembled pimavanserin.
Collapse
Affiliation(s)
- Nader R Albujuq
- Department of Chemistry, School of Science, The University of Jordan, Amman 11942, Jordan
| | - J Javier Meana
- Department of Pharmacology, University of the Basque Country UPV/EHU, 48940 Leioa, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, 48940 Leioa, Bizkaia, Spain
- Biocruces Bizkaia Health Research Institute, 48903 Barakaldo, Bizkaia, Spain
| | - Rebeca Diez-Alarcia
- Department of Pharmacology, University of the Basque Country UPV/EHU, 48940 Leioa, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, 48940 Leioa, Bizkaia, Spain
- Biocruces Bizkaia Health Research Institute, 48903 Barakaldo, Bizkaia, Spain
| | - Itziar Muneta-Arrate
- Department of Pharmacology, University of the Basque Country UPV/EHU, 48940 Leioa, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, 48940 Leioa, Bizkaia, Spain
| | - Arshi Naqvi
- Chemistry Department, College of Science, Taibah University, Al Madinah, Al Munwarah 30002, Saudi Arabia
| | - Khalid Althumayri
- Chemistry Department, College of Science, Taibah University, Al Madinah, Al Munwarah 30002, Saudi Arabia
| | - Mosa Alsehli
- Chemistry Department, College of Science, Taibah University, Al Madinah, Al Munwarah 30002, Saudi Arabia
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Casey AB, Cui M, Booth RG, Canal CE. "Selective" serotonin 5-HT 2A receptor antagonists. Biochem Pharmacol 2022; 200:115028. [PMID: 35381208 PMCID: PMC9252399 DOI: 10.1016/j.bcp.2022.115028] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 01/29/2023]
Abstract
Blockade of the serotonin 5-HT2A G protein-coupled receptor (5-HT2AR) is a fundamental pharmacological characteristic of numerous antipsychotic medications, which are FDA-approved to treat schizophrenia, bipolar disorder, and as adjunctive therapies in major depressive disorder. Meanwhile, activation of the 5-HT2AR by serotonergic psychedelics may be useful in treating neuropsychiatric indications, including major depressive and substance use disorders. Serotonergic psychedelics and other 5-HT2AR agonists, however, often bind other receptors, and standard 5-HT2AR antagonists lack sufficient selectivity to make well-founded mechanistic conclusions about the 5-HT2AR-dependent effects of these compounds and the general neurobiological function of 5-HT2ARs. This review discusses the limitations and strengths of currently available "selective" 5-HT2AR antagonists, the molecular determinants of antagonist selectivity at 5-HT2ARs, and the utility of molecular pharmacology and computational methods in guiding the discovery of novel unambiguously selective 5-HT2AR antagonists.
Collapse
Affiliation(s)
- Austen B Casey
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Meng Cui
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA; Center for Drug Discovery, Northeastern University, Boston, MA 02115, USA
| | - Raymond G Booth
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA; Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA; Center for Drug Discovery, Northeastern University, Boston, MA 02115, USA
| | - Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, 3001 Mercer University Drive, Atlanta, GA 30341, USA
| |
Collapse
|
4
|
Raval NR, Nasser A, Madsen CA, Beschorner N, Beaman EE, Juhl M, Lehel S, Palner M, Svarer C, Plavén-Sigray P, Jørgensen LM, Knudsen GM. An in vivo Pig Model for Testing Novel Positron Emission Tomography Radioligands Targeting Cerebral Protein Aggregates. Front Neurosci 2022; 16:847074. [PMID: 35368260 PMCID: PMC8966485 DOI: 10.3389/fnins.2022.847074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 01/31/2022] [Indexed: 12/11/2022] Open
Abstract
Positron emission tomography (PET) has become an essential clinical tool for diagnosing neurodegenerative diseases with abnormal accumulation of proteins like amyloid-β or tau. Despite many attempts, it has not been possible to develop an appropriate radioligand for imaging aggregated α-synuclein in the brain for diagnosing, e.g., Parkinson's Disease. Access to a large animal model with α-synuclein pathology would critically enable a more translationally appropriate evaluation of novel radioligands. We here establish a pig model with cerebral injections of α-synuclein preformed fibrils or brain homogenate from postmortem human brain tissue from individuals with Alzheimer's disease (AD) or dementia with Lewy body (DLB) into the pig's brain, using minimally invasive surgery and validated against saline injections. In the absence of a suitable α-synuclein radioligand, we validated the model with the unselective amyloid-β tracer [11C]PIB, which has a high affinity for β-sheet structures in aggregates. Gadolinium-enhanced MRI confirmed that the blood-brain barrier was intact. A few hours post-injection, pigs were PET scanned with [11C]PIB. Quantification was done with Logan invasive graphical analysis and simplified reference tissue model 2 using the occipital cortex as a reference region. After the scan, we retrieved the brains to confirm successful injection using autoradiography and immunohistochemistry. We found four times higher [11C]PIB uptake in AD-homogenate-injected regions and two times higher uptake in regions injected with α-synuclein-preformed-fibrils compared to saline. The [11C]PIB uptake was the same in non-injected (occipital cortex, cerebellum) and injected (DLB-homogenate, saline) regions. With its large brain and ability to undergo repeated PET scans as well as neurosurgical procedures, the pig provides a robust, cost-effective, and good translational model for assessment of novel radioligands including, but not limited to, proteinopathies.
Collapse
Affiliation(s)
- Nakul Ravi Raval
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Arafat Nasser
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Clara Aabye Madsen
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Natalie Beschorner
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Emily Eufaula Beaman
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Morten Juhl
- Cardiology Stem Cell Centre, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Szabolcs Lehel
- Department of Clinical Physiology, Nuclear Medicine and Positron Emission Tomography (PET), Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Mikael Palner
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- Department of Clinical Research, Clinical Physiology and Nuclear Medicine, University of Southern Denmark, Odense, Denmark
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Louise Møller Jørgensen
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Copenhagen Spine Research Unit, Copenhagen University Hospital (Rigshospitalet), Glostrup, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
5
|
Abstract
PURPOSE/BACKGROUND Pimavanserin is a selective serotonin 5-HT 2A receptor inverse agonist/antagonist being investigated in patients with negative symptoms of schizophrenia. This analysis aimed to characterize exposure-response relationships of pimavanserin in this population. METHODS/PROCEDURES Exposure-response models were developed using data from ADVANCE. Patients with negative symptoms of schizophrenia receiving background antipsychotics were randomized to pimavanserin 20 mg (adjusted to 34 or 10 mg between weeks 2-8 based on efficacy or tolerability) or placebo for 26 weeks. Time-varying pimavanserin exposure measures were predicted for each patient using a population pharmacokinetic model and individual empiric Bayesian parameter estimates. Response measures were the Negative Symptom Assessment 16 (NSA-16, primary end point), Personal and Social Performance scale, negative symptoms component of the Clinical Global Impression of Schizophrenia-Severity Scale, and adverse events. FINDINGS/RESULTS A higher pimavanserin exposure was associated with greater improvement in NSA-16 score. For a median area under the pimavanserin plasma concentration-time curve from time 0 to 24 hours of 1465 ng × h/mL for the 34-mg dose, the model predicted a 10.5-point reduction in NSA-16 score. This exposure-response relationship with NSA-16 scores was not influenced by covariates. Similar results were observed with Personal and Social Performance and Clinical Global Impression of Schizophrenia-Severity, but not to the extent as NSA-16. There was no significant exposure-response relationship with anxiety, headache, insomnia, or somnolence. IMPLICATIONS/CONCLUSIONS Increasing pimavanserin plasma concentration was associated with improved NSA-16 scores (primary end point) in patients with negative symptoms of schizophrenia. No exposure-response relationship with select adverse events was observed.
Collapse
|
6
|
Shalgunov V, Xiong M, L'Estrade ET, Raval NR, Andersen IV, Edgar FG, Speth NR, Baerentzen SL, Hansen HD, Donovan LL, Nasser A, Peitersen ST, Kjaer A, Knudsen GM, Syvänen S, Palner M, Herth MM. Blocking of efflux transporters in rats improves translational validation of brain radioligands. EJNMMI Res 2020; 10:124. [PMID: 33074370 PMCID: PMC7572968 DOI: 10.1186/s13550-020-00718-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/24/2020] [Indexed: 11/24/2022] Open
Abstract
Background Positron emission tomography (PET) is a molecular imaging technique that can be used to investigate the in vivo pharmacology of drugs. Initial preclinical evaluation of PET tracers is often conducted in rodents due to the accessibility of disease models as well as economic considerations. Compared to larger species, rodents display a higher expression and/or activity of efflux transporters such as the P-glycoprotein (P-gp). Low brain uptake could, therefore, be species-specific and uptake in rodents not be predictive for that in humans. We hypothesized that a better prediction from rodent data could be achieved when a tracer is evaluated under P-gp inhibition. Consequently, we compared the performance of eight neuroreceptor tracers in rats with and without P-gp inhibition including a specific binding blockade. This data set was then used to predict the binding of these eight tracers in pigs. Methods PET tracers targeting serotonin 5-HT2A receptors ([18F]MH.MZ, [18F]Altanserin, [11C]Cimbi-36, [11C]Pimavanserin), serotonin 5-HT7 receptors ([11C]Cimbi-701, [11C]Cimbi-717 and [11C]BA-10) and dopamine D2/3 receptors ([18F]Fallypride) were used in the study. The brain uptake and target-specific binding of these PET radiotracers were evaluated in rats with and without inhibition of P-gp. Rat data were subsequently compared to the results obtained in pigs. Results Without P-gp inhibition, the amount of target-specific binding in the rat brain was sufficient to justify further translation for three out of eight evaluated tracers. With P-gp inhibition, results for five out of eight tracers justified further translation. The performance in pigs could correctly be predicted for six out of eight tracers when rat data obtained under P-gp inhibition were used, compared to four out of eight tracers without P-gp inhibition. Conclusions P-gp strongly affects the uptake of PET tracers in rodents, but false prediction outcomes can be reduced by evaluating a tracer under P-gp inhibition.
Collapse
Affiliation(s)
- Vladimir Shalgunov
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Mengfei Xiong
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.,Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Department of Public Health and Caring Sciences/Geriatrics, Rudbeck Laboratory, Uppsala University, 75185, Uppsala, Sweden
| | - Elina T L'Estrade
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.,Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Radiation Physics, Nuclear Medicine Physics Unit, Skånes University Hospital, Barngatan 3, 222 42, Lund, Sweden
| | - Nakul R Raval
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Ida V Andersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.,Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Fraser G Edgar
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - Nikolaj R Speth
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Simone L Baerentzen
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Hanne D Hansen
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, MA, 02129, USA
| | - Lene L Donovan
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Arafat Nasser
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Siv T Peitersen
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Cluster for Molecular Imaging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Institute of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Stina Syvänen
- Department of Public Health and Caring Sciences/Geriatrics, Rudbeck Laboratory, Uppsala University, 75185, Uppsala, Sweden
| | - Mikael Palner
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Matthias M Herth
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark. .,Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.
| |
Collapse
|
7
|
Hu K, Zhang M, Wu D, Xie Y, Ren J. A Novel Synthesis of Pimavanserin: A Selective Serotonin 5-HT2A Receptor Inverse Agonist. ORG PREP PROCED INT 2020. [DOI: 10.1080/00304948.2019.1697613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Kun Hu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu, China
| | - Meiju Zhang
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu, China
| | - Dongdong Wu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu, China
| | - Yuxuan Xie
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu, China
| | - Jie Ren
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu, China
| |
Collapse
|
8
|
Jørgensen LM, Weikop P, Svarer C, Feng L, Keller SH, Knudsen GM. Cerebral serotonin release correlates with [ 11C]AZ10419369 PET measures of 5-HT 1B receptor binding in the pig brain. J Cereb Blood Flow Metab 2018; 38:1243-1252. [PMID: 28685616 PMCID: PMC6434452 DOI: 10.1177/0271678x17719390] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/26/2017] [Accepted: 05/21/2017] [Indexed: 11/17/2022]
Abstract
Positron emission tomography (PET) can, when used with appropriate radioligands, non-invasively capture temporal and spatial information about acute changes in brain neurotransmitter systems. We here evaluate the 5-HT1B receptor partial agonist PET radioligand, [11C]AZ10419369, for its sensitivity to detect changes in endogenous cerebral serotonin levels, as induced by different pharmacological challenges. To enable a direct translation of PET imaging data to changes in brain serotonin levels, we compared the [11C]AZ10419369 PET signal in the pig brain to simultaneous measurements of extracellular serotonin levels with microdialysis after various acute interventions (saline, escitalopram, fenfluramine). The interventions increased the cerebral extracellular serotonin levels to two to six times baseline, with fenfluramine being the most potent pharmacological enhancer of serotonin release. The interventions induced a varying degree of decline in [11C]AZ10419369 binding in the brain, consistent with the occupancy competition model. The observed correlation between changes in the extracellular serotonin level in the pig brain and the 5-HT1B receptor occupancy indicates that [11C]AZ10419369 binding is sensitive to changes in endogenous serotonin levels to a degree equivalent to that reported of [11C]raclopride to dopamine, a much used approach to detect in vivo change in cerebral dopamine.
Collapse
Affiliation(s)
- Louise M Jørgensen
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences,
University of Copenhagen, Copenhagen, Denmark
| | - Pia Weikop
- Department of Neuroscience and
Pharmacology, The Laboratory of Neuropsychiatry, University of Copenhagen,
Copenhagen, Denmark
- Psychiatric Centre Copenhagen,
University of Copenhagen, Copenhagen, Denmark
| | - Claus Svarer
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
| | - Ling Feng
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
| | - Sune H Keller
- Department of Clinical Physiology,
Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen,
Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences,
University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
9
|
Wu W, Chu Y, Wang S, Sun X, Zhang J, Wang Y, Chen X. Investigation of metabolic profile of pimavanserin in rats by ultrahigh-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:269-276. [PMID: 29105858 DOI: 10.1002/rcm.8025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/23/2017] [Accepted: 10/23/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Pimavanserin, a selective serotonin 2A receptor inverse agonist, is a promising candidate for treating Parkinson's disease psychosis. Our previous study revealed that there might be the presence of extensive metabolites of pimavanserin in rats. However, the metabolic fate of pimavanserin in vivo remains unknown. Thus, it is essential to develop an efficient method to investigate the metabolic profile of pimavanserin in rats. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) to date has the highest mass measurement accuracy and resolution of any mass spectrometry platform. METHODS After a single intragastric administration of pimavanserin at a dose of 50 mg kg-1 , plasma, bile, urine and feces were collected from rats. A novel and efficient strategy was developed to analyze the metabolic profile of pimavanserin in vivo based on ultrahigh-performance liquid chromatography (UHPLC) coupled with FT-ICR-MS. RESULTS A total of 23 metabolites were detected and tentatively identified through comparing their mass spectrometry profiles with those of pimavanserin. These metabolites were found in feces (22), bile (21), rat urine (16) and plasma (15). Results demonstrated that metabolic pathways of pimavanserin in rats included dehydrogenation, demethylation, deethylation, depropylation, debutylation, hydroxylation, dihydroxylation and trihydroxylation. CONCLUSIONS A total of 22 phase I metabolites of pimavanserin were detected and tentatively identified. This report presents the first study of screening and identification of the metabolites of pimavanserin. The UHPLC/FT-ICR-MS method is a powerful tool for exploring and identifying metabolites in complex biological samples.
Collapse
Affiliation(s)
- Wenying Wu
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Yanjie Chu
- School of Traditional Chinese Medicine, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Shixiao Wang
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Xiaoyang Sun
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Jingjing Zhang
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Yannian Wang
- School of Traditional Chinese Medicine, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Xiaohui Chen
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 110016, China
| |
Collapse
|
10
|
Villadsen J, Hansen HD, Jørgensen LM, Keller SH, Andersen FL, Petersen IN, Knudsen GM, Svarer C. Automatic delineation of brain regions on MRI and PET images from the pig. J Neurosci Methods 2018; 294:51-58. [DOI: 10.1016/j.jneumeth.2017.11.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/09/2017] [Accepted: 11/12/2017] [Indexed: 12/20/2022]
|
11
|
Jørgensen LM, Weikop P, Villadsen J, Visnapuu T, Ettrup A, Hansen HD, Baandrup AO, Andersen FL, Bjarkam CR, Thomsen C, Jespersen B, Knudsen GM. Cerebral 5-HT release correlates with [ 11C]Cimbi36 PET measures of 5-HT2A receptor occupancy in the pig brain. J Cereb Blood Flow Metab 2017; 37:425-434. [PMID: 26825776 PMCID: PMC5381441 DOI: 10.1177/0271678x16629483] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Positron emission tomography (PET) can, when used with appropriate radioligands, non-invasively generate temporal and spatial information about acute changes in brain neurotransmitter systems. We for the first time evaluate the novel 5-HT2A receptor agonist PET radioligand, [11C]Cimbi-36, for its sensitivity to detect changes in endogenous cerebral 5-HT levels, as induced by different pharmacological challenges. To enable a direct translation of PET imaging data to changes in brain 5-HT levels, we calibrated the [11C]Cimbi-36 PET signal in the pig brain by simultaneous measurements of extracellular 5-HT levels with microdialysis and [11C]Cimbi-36 PET after various acute interventions (saline, citalopram, citalopram + pindolol, fenfluramine). In a subset of pigs, para-chlorophenylalanine pretreatment was given to deplete cerebral 5-HT. The interventions increased the cerebral extracellular 5-HT levels to 2-11 times baseline, with fenfluramine being the most potent pharmacological enhancer of 5-HT release, and induced a varying degree of decline in [11C]Cimbi-36 binding in the brain, consistent with the occupancy competition model. The observed correlation between changes in the extracellular 5-HT level in the pig brain and the 5-HT2A receptor occupancy indicates that [11C]Cimbi-36 binding is sensitive to changes in endogenous 5-HT levels, although only detectable with PET when the 5-HT release is sufficiently high.
Collapse
Affiliation(s)
- Louise M Jørgensen
- 1 Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.,2 Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Pia Weikop
- 3 The Laboratory of Neuropsychiatry, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark.,4 Psychiatric Centre Copenhagen, University of Copenhagen, Denmark
| | - Jonas Villadsen
- 1 Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - Tanel Visnapuu
- 3 The Laboratory of Neuropsychiatry, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark.,5 Center for Excellence in Translational Medicine, University of Tartu, Estonia
| | - Anders Ettrup
- 1 Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - Hanne D Hansen
- 1 Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - Anders O Baandrup
- 6 Research Center for Advanced Imaging, Hospital of Køge and Roskilde, Roskilde, Denmark
| | | | | | - Carsten Thomsen
- 2 Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.,9 Department of Radiology, Rigshospitalet, Copenhagen, Denmark
| | - Bo Jespersen
- 10 Department of Neurosurgery, Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- 1 Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.,2 Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| |
Collapse
|
12
|
Wicke K, Haupt A, Bespalov A. Investigational drugs targeting 5-HT6 receptors for the treatment of Alzheimer’s disease. Expert Opin Investig Drugs 2015; 24:1515-28. [DOI: 10.1517/13543784.2015.1102884] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|