1
|
Kumari N, Kaul A, Varshney R, Singh VK, Srivastava K, Bhagat S, Mishra AK, Tiwari AK. Synthesis and evaluation of technetium-99m labelled 1-(2-methoxyphenyl)piperazine derivative for single photon emission computed tomography imaging for targeting 5-HT 1A. Bioorg Chem 2021; 111:104972. [PMID: 33993020 DOI: 10.1016/j.bioorg.2021.104972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/17/2021] [Accepted: 05/04/2021] [Indexed: 10/21/2022]
Abstract
Quantitative changes in expression level of 5HT1A are somewhere related to common neurological disorders such as anxiety, major depression and schizophrenia. We have designed EDTA conjugated SPECT imaging probe for localization of 5HT1A receptor in brain. For designing SPECT probe we have employed the concept of bivalent approach and a homodimeric system with desirable pharmacokinetics of 5HT1A imaging. 99mTc-EDHT was also evaluated for its stability through serum stability assay and glutathione challenge experiment. Biodistribution study showed the highest accumulation of radioactivity in kidney which depicted the renal mode of excretion from the body. However in brain the uptake of 1.21% ID per gram was observed in initial 5 min of drug administration. On blocking the receptor this percent get decreased to 0.97% ID per gram. The regional distribution in brain was also performed which showed the accumulation of drug in cerebellum, cortex and hippocampus part, which are already known for 5HT1A expression. Dynamic study in rabbit is also in support of results derived from biodistribution and blood kinetics experiment. These finding suggest that 99mTc-EDHT holds promising place for further optimization before nuclear medicine applications in different animal species.
Collapse
Affiliation(s)
- Neelam Kumari
- Department of Chemistry, School of Physical & Decision Sciences (SPDS), Babasaheb Bhimrao Ambedkar University (A Central University), Lucknow 226025, UP, India; Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, Delhi 110054, India; Department of Chemistry, University of Delhi, Delhi 110054, India
| | - Ankur Kaul
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, Delhi 110054, India
| | - Raunak Varshney
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, Delhi 110054, India
| | - Vinay Kumar Singh
- Department of Chemistry, Dr. S.M.N.R University, Lucknow 226018, India
| | - Krishna Srivastava
- Faculty of Chemical Sciences, Shri Ramswaroop Memorial University, Lucknow 225003, UP, India
| | - Sunita Bhagat
- Department of Chemistry, University of Delhi, 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
| | - Anjani Kumar Tiwari
- Department of Chemistry, School of Physical & Decision Sciences (SPDS), Babasaheb Bhimrao Ambedkar University (A Central University), Lucknow 226025, UP, India; Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, Delhi 110054, India.
| |
Collapse
|
2
|
Jha P, Chaturvedi S, Kaul A, Pant P, Anju A, Pal S, Jain N, Mishra AK. Design, physico-chemical and pre-clinical evaluation of a homo-bivalent 99mTc-(BTZ)2DTPA radioligand for targeting dimeric 5-HT1A/5-HT7 receptors. NEW J CHEM 2018. [DOI: 10.1039/c8nj00089a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A 99mTc-labelled bis-benzothiazolone-DTPA radio-complex as a SPECT neuroimaging agent.
Collapse
Affiliation(s)
- Preeti Jha
- Department of Chemistry
- Indian Institute of Technology Delhi (IITD)
- India
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
| | - Shubhra Chaturvedi
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Defence Research and Development Organization
- Delhi-110054
- India
| | - Ankur Kaul
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Defence Research and Development Organization
- Delhi-110054
- India
| | - Pradeep Pant
- Department of Chemistry
- Indian Institute of Technology Delhi (IITD)
- India
| | - Anju Anju
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Defence Research and Development Organization
- Delhi-110054
- India
| | - Sunil Pal
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Defence Research and Development Organization
- Delhi-110054
- India
| | - Nidhi Jain
- Department of Chemistry
- Indian Institute of Technology Delhi (IITD)
- India
| | - Anil K. Mishra
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Defence Research and Development Organization
- Delhi-110054
- India
| |
Collapse
|
3
|
Pike VW. Considerations in the Development of Reversibly Binding PET Radioligands for Brain Imaging. Curr Med Chem 2016; 23:1818-69. [PMID: 27087244 PMCID: PMC5579844 DOI: 10.2174/0929867323666160418114826] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/04/2016] [Accepted: 04/15/2016] [Indexed: 12/17/2022]
Abstract
The development of reversibly binding radioligands for imaging brain proteins in vivo, such as enzymes, neurotransmitter transporters, receptors and ion channels, with positron emission tomography (PET) is keenly sought for biomedical studies of neuropsychiatric disorders and for drug discovery and development, but is recognized as being highly challenging at the medicinal chemistry level. This article aims to compile and discuss the main considerations to be taken into account by chemists embarking on programs of radioligand development for PET imaging of brain protein targets.
Collapse
Affiliation(s)
- Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Rm. B3C346A, 10 Center Drive, Bethesda, MD 20892, USA.
| |
Collapse
|
4
|
García G, Abet V, Alajarín R, Álvarez-Builla J, Delgado M, García-García L, Bascuñana-Almarcha P, Peña-Salcedo C, Kelly J, Pozo MA. N-(4-[(18)F]-fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}carboxamides as analogs of WAY100635. New PET tracers of serotonin 5-HT(1A) receptors. Eur J Med Chem 2014; 85:795-806. [PMID: 25171752 DOI: 10.1016/j.ejmech.2014.07.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 10/25/2022]
Abstract
N-(4-[(18)F]-Fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-carboxamides were prepared by labeling their 4-nitropyridin-2-yl precursors through nitro substitution by the (18)F anion. In vitro and in vivo tests showed that the cyclohexanecarboxamide derivative is a reversible, selective and high affinity 5-HT1A receptor antagonist (IC50 = 0.29 nM, ki = 0.18 nM) with high brain uptake, slow brain clearance and stability to defluorination when compared with conventional standards. This PET radioligand is a promising candidate for an improved in vivo quantification of 5-HT1A receptors in neuropsychiatric disorders.
Collapse
Affiliation(s)
- Gonzalo García
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Valentina Abet
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Ramón Alajarín
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Julio Álvarez-Builla
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain.
| | - Mercedes Delgado
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Luis García-García
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Pablo Bascuñana-Almarcha
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Carmen Peña-Salcedo
- Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain
| | - James Kelly
- Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain
| | - Miguel A Pozo
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain; Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain.
| |
Collapse
|
5
|
Kumar JSD, Parsey RV, Kassir SA, Majo VJ, Milak MS, Prabhakaran J, Simpson NR, Underwood MD, Mann JJ, Arango V. Autoradiographic evaluation of [3H]CUMI-101, a novel, selective 5-HT1AR ligand in human and baboon brain. Brain Res 2013; 1507:11-8. [PMID: 23454434 DOI: 10.1016/j.brainres.2013.02.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 02/14/2013] [Accepted: 02/20/2013] [Indexed: 01/01/2023]
Abstract
[11C]CUMI-101 is the first selective serotonin receptor (5-HT1AR) partial agonist radiotracer for positron emission tomography (PET) tested in vivo in nonhuman primates and humans. We evaluated specific binding of [3H]CUMI-101 by quantitative autoradiography studies in postmortem baboon and human brain sections using the 5-HT1AR antagonist WAY-100635 as a displacer. The regional and laminar distributions of [3H]CUMI-101 binding in baboon and human brain sections matched the known distribution of [3H]8-OH-DPAT and [3H]WAY-100635. Prazosin did not measurably displace [3H]CUMI-101 binding in baboon or human brain sections, thereby ruling out [3H]CUMI-101 binding to α1-adrenergic receptors. This study demonstrates that [11C]CUMI-101 is a selective 5-HT1AR ligand for in vivo and in vitro studies in baboon and human brain.
Collapse
Affiliation(s)
- J S Dileep Kumar
- Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
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.
Collapse
Affiliation(s)
- Leila Hassanzadeh
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | | | | | | | | |
Collapse
|
7
|
Al Hussainy R, Verbeek J, der Born DV, Molthoff C, Booij J, Herscheid J(KD. Synthesis, biodistribution and PET studies in rats of 18F-Labeled bridgehead fluoromethyl analogues of WAY-100635. Nucl Med Biol 2012; 39:1068-76. [DOI: 10.1016/j.nucmedbio.2012.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 04/10/2012] [Accepted: 04/15/2012] [Indexed: 10/28/2022]
|
8
|
Lemoine L, Becker G, Vacher B, Billard T, Lancelot S, Newman-Tancredi A, Zimmer L. Radiosynthesis and Preclinical Evaluation of 18F-F13714 as a Fluorinated 5-HT1A Receptor Agonist Radioligand for PET Neuroimaging. J Nucl Med 2012; 53:969-76. [DOI: 10.2967/jnumed.111.101212] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
9
|
Sandell J, Pike VW, Hall H, Marchais S, Wikström HV, Halldin C. [125I]6IPWAY - a candidate radioligand for the 5-HT1A receptor - radiolabeling and preliminary examination with human post mortem autoradiography. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.2580440160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
10
|
Sandell J, Mccarron JA, Halldin C, Pike VW, Gulyas B, Cselenyi Z, Sovago J, Marchais S, Wikström HV, Farde L. [18F]6FPWAY - a prospective 5-HT1A receptor radioligand - radiolabeling and pet examination in monkey - comparison with [11C]6FPWAY. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.2580440158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
11
|
Chiotellis A, Tsoukalas C, Pelecanou M, Pirmettis I, Papadopoulos M. Synthesis, characterization and biological evaluation of novel neutral fac-M(CO)3(SNO) complexes (M=Re, 99mTc) bearing the o-methoxyphenylpiperazine moiety. Appl Radiat Isot 2012; 70:957-64. [PMID: 22464790 DOI: 10.1016/j.apradiso.2012.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 12/07/2011] [Accepted: 03/01/2012] [Indexed: 10/28/2022]
Abstract
The synthesis, characterization and biological evaluation of two new neutral tricarbonyl fac-M(CO)(3)(SNO) (M=Re, (99m)Tc) bearing o-methoxyphenylpiperazine as pharmacophore and S-functionalized cysteine or penicillamine as chelators are reported. Competition binding tests showed good affinity for the 5-HT(1A) receptor (8 and 54 nM for 4a and 4b, respectively). Biodistribution studies in healthy animals showed high initial blood and liver uptake, fast blood and tissue depuration and negligible brain uptake.
Collapse
Affiliation(s)
- A Chiotellis
- Institute of Radioisotopes, Radiodiagnostic Products, National Centre for Scientific Research Demokritos, Athens, Greece
| | | | | | | | | |
Collapse
|
12
|
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]
|
13
|
Paterson LM, Kornum BR, Nutt DJ, Pike VW, Knudsen GM. 5-HT radioligands for human brain imaging with PET and SPECT. Med Res Rev 2011; 33:54-111. [PMID: 21674551 DOI: 10.1002/med.20245] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The serotonergic system plays a key modulatory role in the brain and is the target for many drug treatments for brain disorders either through reuptake blockade or via interactions at the 14 subtypes of 5-HT receptors. This review provides the history and current status of radioligands used for positron emission tomography (PET) and single photon emission computerized tomography (SPECT) imaging of human brain serotonin (5-HT) receptors, the 5-HT transporter (SERT), and 5-HT synthesis rate. Currently available radioligands for in vivo brain imaging of the 5-HT system in humans include antagonists for the 5-HT(1A), 5-HT(1B), 5-HT(2A), and 5-HT(4) receptors, and for SERT. Here we describe the evolution of these radioligands, along with the attempts made to develop radioligands for additional serotonergic targets. We describe the properties needed for a radioligand to become successful and the main caveats. The success of a PET or SPECT radioligand can ultimately be assessed by its frequency of use, its utility in humans, and the number of research sites using it relative to its invention date, and so these aspects are also covered. In conclusion, the development of PET and SPECT radioligands to image serotonergic targets is of high interest, and successful evaluation in humans is leading to invaluable insight into normal and abnormal brain function, emphasizing the need for continued development of both SPECT and PET radioligands for human brain imaging.
Collapse
Affiliation(s)
- Louise M Paterson
- Neuropsychopharmacology Unit, Division of Experimental Medicine, Imperial College London, Burlington Danes Building, Du Cane Road, London, United Kingdom
| | | | | | | | | |
Collapse
|
14
|
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.
Collapse
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
| | | | | | | | | |
Collapse
|
15
|
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
| |
Collapse
|
16
|
Lu S, Liow JS, Zoghbi SS, Hong J, Innis RB, Pike VW. Evaluation of [C]S14506 and [F]S14506 in rat and monkey as agonist PET radioligands for brain 5-HT(1A) receptors. Curr Radiopharm 2010; 3:9-18. [PMID: 20657759 DOI: 10.2174/1874471011003010009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In vitro and ex vivo measurements have shown that the binding of the selective high-affinity agonist, S14506 (1-[2-(4-fluorobenzoylamino)ethyl]-4-(7-methoxy-naphthyl)piperazine), to 5-HT(1A) receptors, is similar in affinity (K(d) = 0.79 nM) and extent (B(max)) to that of the antagonist, WAY 100635. We aimed to test whether S14506, labeled with a positron-emitter, might serve as a radioligand for imaging brain 5-HT(1A) receptors in vivo with positron emission tomography (PET). Here we evaluated [(11)C]S14506 and [(18)F]S14506 in rat and rhesus monkey in vivo. After intravenous administration of [(11)C]S14506 into rat, radioactivity entered brain, reaching 210% SUV at 2 min. Radioactivity uptake into brain was higher (~ 350% SUV) in rats pre-treated with the P-glycoprotein (P-gp) inhibitor, cyclosporin A. In rhesus monkey, peak brain uptake of radioactivity after administration of [(11)C]S14506 or [(18)F]S14506 was also moderate and for [(11)C]S14506 increased from ~ 170% SUV after 7 min, to 240% SUV in a monkey pre-treated with the P-gp inhibitor, tariquidar. The ratios of radioactivity in 5-HT(1A) receptor-rich regions, such as cingulate or hippocampus to that in receptor-poor cerebellum reached between 1.35 and 1.5 at 60 min for both [(11)C]S14506 and [(18)F]S14506. [(11)C]S14506 gave one major polar radiometabolite in monkey plasma, and [(18)F]S14506 gave three and two more polar radiometabolites in rat and monkey plasma, respectively. The rat radiometabolites of [(18)F]S14506 did not accumulate in brain. [(18)F]S14506 was not radiodefluorinated in monkey. Thus, despite high-affinity and lack of troublesome brain radiometabolites, both [(11)C]S14506 and [(18)F]S14506 were ineffective for imaging rat or monkey brain 5-HT(1A) receptors in vivo, even under P-gp inhibited conditions. Explanations for the failure of these radioligands are offered.
Collapse
Affiliation(s)
- Shuiyu Lu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Room B3C346, Bethesda MD 20892-1003, USA
| | | | | | | | | | | |
Collapse
|
17
|
Lemoine L, Verdurand M, Vacher B, Blanc E, Le Bars D, Newman-Tancredi A, Zimmer L. [18F]F15599, a novel 5-HT1A receptor agonist, as a radioligand for PET neuroimaging. Eur J Nucl Med Mol Imaging 2009; 37:594-605. [PMID: 19789870 DOI: 10.1007/s00259-009-1274-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 08/24/2009] [Indexed: 11/30/2022]
Abstract
PURPOSE The serotonin-1A (5-HT(1A)) receptor is implicated in the pathophysiology of major neuropsychiatric disorders. Thus, the functional imaging of 5-HT(1A) receptors by positron emission tomography (PET) may contribute to the understanding of its role in those pathologies and their therapeutics. These receptors exist in high- and low-affinity states and it is proposed that agonists bind preferentially to the high-affinity state of the receptor and therefore could provide a measure of the functional 5-HT(1A) receptors. Since all clinical PET 5-HT(1A) radiopharmaceuticals are antagonists, it is of great interest to develop a( 18)F labelled agonist. METHODS F15599 (3-chloro-4-fluorophenyl-(4-fluoro-4{[(5-methyl-pyrimidin-2-ylmethyl)-amino]-methyl}-piperidin-1-yl)-methanone) is a novel ligand with high affinity and selectivity for 5-HT(1A) receptors and is currently tested as an antidepressant. In pharmacological tests in rat, it exhibits preferential agonist activity at post-synaptic 5-HT(1A) receptors in cortical brain regions. Here, its nitro-precursor was synthesised and radiolabelled via a fluoronucleophilic substitution. Radiopharmacological evaluations included in vitro and ex vivo autoradiography in rat brain and PET scans on rats and cats. Results were compared with simultaneous studies using [(18)F]MPPF, a validated 5-HT(1A) antagonist radiopharmaceutical. RESULTS The chemical and radiochemical purities of [(18)F]F15599 were >98%. In vitro [(18)F]F15599 binding was consistent with the known 5-HT(1A) receptors distribution (hippocampus, dorsal raphe nucleus, and notably cortical areas) and addition of Gpp(NH)p inhibited [(18)F]F15599 binding, consistent with a specific binding to G protein-coupled receptors. In vitro binding of [(18)F]F15599 was blocked by WAY100635 and 8-OH-DPAT, respectively, prototypical 5-HT(1A) antagonist and agonist. The ex vivo and in vivo studies demonstrated that the radiotracer readily entered the rat and the cat brain and generated few brain radioactive metabolites. Remarkably, in microPET studies, [(18)F]F15599 notably displayed a pattern of brain labelling that did not correlate with in vitro observations. Thus, in cat, the highest binding was observed in dorsal raphe and cingulate cortex with little binding in other cortical regions and none in hippocampus. In vivo binding was abolished by WAY100635, indicating specific labelling of 5-HT(1A) receptors. CONCLUSION [(18)F]F15599 is a radiofluorinated agonist presenting interesting characteristics for probing in vitro and in vivo the high-affinity states of the 5-HT(1A) receptors. Its differential labelling of 5-HT(1A) receptors in vitro and in vivo may result from its reported preferential interaction with receptors coupled to specific G-protein subtypes.
Collapse
Affiliation(s)
- Laëtitia Lemoine
- Laboratory of Neuropharmacology, Université de Lyon, EAC CNRS 5006, Lyon, France
| | | | | | | | | | | | | |
Collapse
|
18
|
Borg J. Molecular imaging of the 5-HT1A receptor in relation to human cognition. Behav Brain Res 2008; 195:103-11. [DOI: 10.1016/j.bbr.2008.06.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 06/04/2008] [Accepted: 06/04/2008] [Indexed: 10/21/2022]
|
19
|
Krasikova RN, Andersson J, Truong P, Nag S, Shchukin EV, Halldin C. A fully automated one-pot synthesis of [carbonyl-11C]WAY-100635 for clinical PET applications. Appl Radiat Isot 2008; 67:73-8. [PMID: 18715791 DOI: 10.1016/j.apradiso.2008.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 07/14/2008] [Accepted: 07/16/2008] [Indexed: 10/21/2022]
Abstract
A fully automated synthesis of the important 5HT(1A) receptor radioligand, [carbonyl-(11)C]WAY-100635 (I), was developed based on the optimized one-pot "wet" synthesis procedure. A modern automated apparatus was constructed from commercially available components and operated via LabView software. In average, (906+/-525)MBq (n=94) of (I) was obtained from 40 min bombardment at 50 microA beam current within 50 min synthesis time. The specific radioactivity (SA) at the time of injection was (50.5+/-29.3)GBq/mumol (n=94).
Collapse
Affiliation(s)
- Raisa N Krasikova
- Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
20
|
Abstract
The serotonin 5-HT(1A) receptor is implicated in the pathophysiology of major neuropsychiatric disorders, including depression, suicidal behavior, panic disorder, epilepsy, bulimia, schizophrenia, Parkinson's disease, and Alzheimer's disease and is, therefore, an important target for drug therapy. 5-HT(1A) receptors are expressed as somatodendritic autoreceptors in serotonin neurons of the raphé nuclei (presynaptic) and as postsynaptic receptors in cortical and subcortical serotonin terminal fields in the brain. Due to the higher concentration and heterogeneous distribution of this receptor, it is an attractive target for quantification in vivo using positron emission tomography (PET) and single photon emission tomography (SPECT). Here, we review the PET radioligands employed for imaging 5-HT(1A) receptors in living brain.
Collapse
Affiliation(s)
- J S Dileep Kumar
- Department of Psychiatry, Columbia University College of Physicians and Surgeons & New York State Psychiatric Institute, New York, NY 10032, United States.
| | | |
Collapse
|
21
|
McCarron JA, Zoghbi SS, Shetty HU, Vermeulen ES, Wikström HV, Ichise M, Yasuno F, Halldin C, Innis RB, Pike VW. Synthesis and initial evaluation of [11C](R)-RWAY in monkey-a new, simply labeled antagonist radioligand for imaging brain 5-HT1A receptors with PET. Eur J Nucl Med Mol Imaging 2007; 34:1670-82. [PMID: 17579853 DOI: 10.1007/s00259-007-0460-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Accepted: 03/15/2007] [Indexed: 11/28/2022]
Abstract
PURPOSE We aimed to fulfill a need for a radioligand that may be simply labeled with carbon-11 for effective positron emission tomography (PET) imaging of brain 5-HT(1A) receptors. METHODS Racemic RWAY (2,3,4,5,6,7-hexahydro-1-[4-[1-[4-(2-methoxyphenyl)piperazinyl]]-2-phenylbutyryl]-1H-azepine) has high affinity for 5-HT(1A) receptors. The enantiomers of RWAY and O-desmethyl-RWAY, synthesized from commercially available materials, were each labeled with carbon-11 by treating the respective O-desmethyl precursor with [(11)C]iodomethane, and injected into rhesus monkey for measurement of regional brain uptake. The 5-HT(1A) selectivity of (R)-[(11)C]RWAY was checked by administering WAY-100635, before and after radioligand administration. Radiometabolites of (R)-[(11)C]RWAY in blood and urine were analyzed by HPLC with partial elucidation of their structures by LC-MS-MS. RESULTS (R)-[(11)C]RWAY was a 5-HT(1A) receptor antagonist exhibiting high brain uptake with regional distribution consistent with specific binding to 5-HT(1A) receptors. The similar affinity, (S)-[(11)C]RWAY was a weak partial agonist at 5-HT(1A) receptors exhibiting similar brain peak uptake with much less 5-HT(1A) receptor-specific binding. The maximal ratio in receptor-rich cingulate gyrus to receptor-devoid cerebellum reached 6.4 at 87.5 min after injection of (R)-[(11)C]RWAY. After treatment with WAY-100635 before or after (R)-[(11)C]RWAY administration, radioactivity levels in 5-HT(1A) receptor-rich regions were reduced almost to that in cerebellum. Blood and urine radiometabolites were less lipophilic than parent and were not due to hydrolysis but to ring hydroxylations, oxidation, and dephenylation. CONCLUSION (R)-[(11)C]RWAY is simply prepared and an effective antagonist for imaging brain 5-HT(1A) receptors. This radioligand resists hydrolysis in vivo, gives less lipophilic radiometabolites, and warrants further PET studies in human subjects.
Collapse
Affiliation(s)
- Julie A McCarron
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, B3 C346A, 10 Center Drive, Bethesda, MD 20892, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
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.
Collapse
Affiliation(s)
- Nicolas Aznavour
- Laboratoire de Neuropharmacologie, Université Lyon 1, Lyon, France
| | | |
Collapse
|
23
|
Aznavour N, Rbah L, Léger L, Buda C, Sastre JP, Imhof A, Charnay Y, Zimmer L. A comparison of in vivo and in vitro neuroimaging of 5-HT1A receptor binding sites in the cat brain. J Chem Neuroanat 2006; 31:226-32. [PMID: 16517120 DOI: 10.1016/j.jchemneu.2006.01.006] [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: 10/24/2005] [Revised: 01/30/2006] [Accepted: 01/30/2006] [Indexed: 10/24/2022]
Abstract
To validate the cat as a suitable model for positron emission tomography imaging (PET) and to gain further knowledge on the anatomical distribution of the serotonin-1A receptor (5-HT 1A) in the feline brain, we used PET with [18F]MPPF and in vitro autoradiography with [3H]MPPF, [3H]8-OH-DPAT and [3H]paroxetine. PET radioactivity curves with [18F]MPPF were very reproducible in anaesthetized cats, with the highest radioactivity uptakes recorded in the hippocampus, cingulate cortex, septum, infralimbic cortex and raphe nucleus, whereas the lowest were found in the cerebellum. [3H]8-OH-DPAT binding displayed a comparable, albeit lower, regional distribution than with [3H]MPPF. Autoradiography also revealed the presence of 5-HT 1A receptor binding sites in the cortex and in the interpeduncular nucleus, due to its greater sensitivity and spatial resolution compared with PET imaging. The cat constitutes an interesting experimental model for PET imaging, as many physiological concepts have been well established with this animal. Our study also shows the advantages of combining complementary neuroimaging techniques such as in vivo PET imaging and in vitro autoradiography to visualize the distribution of the 5-HT 1A receptors.
Collapse
|
24
|
McCarron JA, Marchais-Oberwinkler S, Pike VW, Tarkiainen J, Halldin C, Sóvagó J, Gulyas B, Wikström HV, Farde L. Two C-Methyl Derivatives of [11C]WAY-100635 – Effects of an Amido α-Methyl Group on Metabolism and Brain 5-HT1A Receptor Radioligand Behavior in Monkey*. Mol Imaging Biol 2005; 7:209-19. [PMID: 15912425 DOI: 10.1007/s11307-005-4127-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE [carbonyl-11C]N-(2-(1-(4-(2-methoxyphenyl)-piperazinyl)ethyl)-N-pyridinyl)cyclohexanecarboxamide ([carbonyl-11C]WAY-100635) is an effective radioligand for imaging brain 5-HT1A receptors with positron emission tomography (PET). However, this radioligand has some drawbacks for deriving relative regional receptor densities, including rapid metabolism, which acts against accurate definition of an arterial input function for compartmental modeling, and very low nonspecific binding in brain, which detracts from the accuracy of modeling by a simplified reference tissue (cerebellum) approach. Here, in a search for a radioligand that overcomes these limitations, we investigated the effects of introducing a single methyl group at either of the carbon atoms alpha to the amide bond in [11C]WAY-100635. PROCEDURES Ligands with a methyl group on the alpha carbon of the cyclohexyl group (SWAY) or the alpha carbon of the C2H4 linker ((R,S)-JWAY) were synthesized and tested for binding affinity and intrinsic activity at 5-HT1A receptors. SWAY was labeled with carbon-11 (t1/2 = 20.4 minutes; beta+ = 99.8%) in its O-methyl group and (R,S)-JWAY in its carbonyl group. Each radioligand was evaluated by PET experiments in cynomolgus monkey. RESULTS SWAY and (R,S)-JWAY were found to be high-affinity antagonists at 5-HT1A receptors. After injection of [11C]SWAY into monkey, radioactivity uptake in brain reached a maximum of 3% at 4.5 minutes and decreased to 0.7% at 72 minutes. However, over the time span of the experiment, radioactivity concentrations in 5-HT1A receptor-rich brain regions were only fractionally higher than in cerebellum. Radioactivity represented by parent radioligand in plasma was 39% at 45 minutes. After injection of [11C](R,S)-JWAY alone, radioactivity uptake in brain reached a maximum of 4.8% at 2.5 minutes and decreased to 1.2% at 90 minutes. At this time, radioactivity concentration in 5-HT1A receptor-rich brain regions was markedly greater than in cerebellum. In another PET experiment, the monkey was predosed with WAY-100635 before [11C](R,S)-JWAY injection. At 90 minutes after injection, the ratio of radioactivity in 5-HT1A receptor-rich regions to that in cerebellum was reduced to near unity. Radioactivity represented by parent radioligand in plasma was 12% at 45 minutes. CONCLUSIONS [11C](R,S)-JWAY, but not [11C]SWAY, gives a sizeable 5-HT1A receptor-selective PET signal in monkey. The presence of a C-methyl group adjacent to the amide bond in SWAY or (R,S)-JWAY fails to counter metabolism.
Collapse
Affiliation(s)
- Julie A McCarron
- MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, London, W12 0NN, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
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.
Collapse
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.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Bantick RA, Rabiner EA, Hirani E, de Vries MH, Hume SP, Grasby PM. Occupancy of agonist drugs at the 5-HT1A receptor. Neuropsychopharmacology 2004; 29:847-59. [PMID: 14985704 DOI: 10.1038/sj.npp.1300390] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Drugs acting on the 5-HT1A receptor are used in the treatment of depression, generalized anxiety disorder, and schizophrenia. This study investigated 5-HT1A receptor occupancy by the 5-HT1A agonist drugs flesinoxan (a highly selective probe for the 5-HT1A receptor) and ziprasidone (a novel atypical antipsychotic drug). Using a within-subject design, 14 healthy volunteers each received two positron emission tomography scans using the selective 5-HT1A antagonist radiotracer [11C]WAY-100635. One scan constituted a baseline, while the other followed either 1 mg flesinoxan or 40 mg ziprasidone orally. In addition, rats were pretreated with intravenous flesinoxan at doses ranging from 0.001 to 5 mg/kg then [11C]WAY-100635 binding measured ex vivo. Cerebral cortical and hippocampal regions of interest, and cerebellar reference regions were sampled to estimate 5-HT1A receptor occupancy (inferred from reductions in specific radioligand binding). In man, occupancy was not significant despite volunteers experiencing side effects consistent with central serotonergic activity. The mean cerebral cortex occupancy (+/- 1 SD) for flesinoxan was 8.7% (+/- 13%), and for ziprasidone 4.6% (+/- 17%). However, in rats, flesinoxan achieved significant and dose-related occupancy (17-57%) at 0.25 mg/kg and above. We conclude that 5-HT1A receptor agonists produce detectable occupancy only at higher doses that would produce unacceptable levels of side effects in man, although lower doses are sufficient to produce pharmacological effects. The development of agonist radiotracers may increase the sensitivity of detecting agonist binding, as 5-HT1A antagonists bind equally to low- and high-affinity receptor states, while agonists bind preferentially to the high-affinity state.
Collapse
Affiliation(s)
- R Alexander Bantick
- Cyclotron Building, CSC, The Hammersmith Hospital, Imperial College London, London, UK.
| | | | | | | | | | | |
Collapse
|
27
|
Karramkam M, Hinnen F, Berrehouma M, Hlavacek C, Vaufrey F, Halldin C, McCarron JA, Pike VW, Dollé F. Synthesis of a [6-pyridinyl-18F]-labelled fluoro derivative of WAY-100635 as a candidate radioligand for brain 5-HT1A receptor imaging with PET. Bioorg Med Chem 2003; 11:2769-82. [PMID: 12788351 DOI: 10.1016/s0968-0896(03)00225-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In recent years, considerable effort has been spent on the design, synthesis and pharmacological characterization of radiofluorinated derivatives of the 5-HT(1A) receptor antagonist, WAY-100635, for the in vivo study of these receptors in human brain with PET. (Pyridinyl-6)-fluoro- and (pyridinyl-5)-fluoro-analogues of WAY-100635 (6-fluoro and 5-fluoro-WAY-100635, 5a/6a) were synthesized as well as the corresponding chloro-, bromo- and nitro-derivatives as precursors for labelling (5b-d and 6b-d). Comparative radiolabelling of these precursors with fluorine-18 (positron-emitting isotope, 109.8 min half-life) clearly demonstrated that only ortho-fluorination in this pyridine series, and not meta-fluorination, is of interest for the preparation of a radioligand by nucleophilic heteroaromatic substitution. 6-[(18)F]Fluoro-WAY-100635 ([(18)F]5a) can be efficiently synthesized in one step, either from the corresponding 6-bromo precursor (using conventional heating at 145 degrees C for 10 min) or from the corresponding 6-nitro precursor (using microwave activation at 100 W for 1 min). Typically, 15-25 mCi (0.55-0.92 GBq) of 6-[(18)F]fluoro-WAY-100635 ([(18)F]5a, 1-2 Ci/micromol or 37-72 GBq/micromol) were obtained in 50-70 min starting from a 100 mCi (3.7 GBq) aliquot of a batch of cyclotron-produced [(18)F]fluoride. This (18)F-labelled radioligand is now being evaluated in PET studies.
Collapse
Affiliation(s)
- Mylène Karramkam
- Service Hospitalier Frédéric Joliot, Département de Recherche Médicale, CEA, 4 place du Général Leclerc, F-91401 Orsay, France
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
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.
Collapse
Affiliation(s)
- Luc Zimmer
- CERMEP, Biomedical Cyclotron, 59 Bd Pinel, 69003 Lyon, France
| | | | | | | | | |
Collapse
|
29
|
Tsoukalas C, Pirmettis I, Patsis G, Pelecanou M, Bodo K, Raptopoulou CP, Terzis A, Papadopoulos M, Chiotellis E. Novel oxorhenium and oxotechnetium MO(NS)(S)2 complexes in the development of 5-HT1A receptor imaging agents. J Inorg Biochem 2003; 93:213-20. [PMID: 12576284 DOI: 10.1016/s0162-0134(02)00574-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The [NS][S](2) mixed-ligand system was applied to synthesize oxorhenium and oxotechnetium complexes of the general formula MO(o-CH(3)OC(6)H(4)N(CH(2)CH(2))(2)NCH(2)CH(2)S)(p-CH(3)C(6)H(4)S)(2) (M=Re in 1, M=(99)Tc in 2, and M=(99m)Tc in 3). The bidentate [NS] ligand includes the 1-(2-methoxyphenyl)piperazine moiety which is a fragment of the true 5-HT(1A) antagonist WAY 100635. The oxorhenium complex 1 was prepared by a ligand exchange reaction using ReOCl(3)(PPh(3))(2) as precursor while [Bu(4)N][(99)TcOCl(4)] and (99)Tc-gluconate were used as precursors in the synthesis of the oxotechnetium-99 complex 2. Both complexes were characterized by elemental analysis and spectroscopic methods. Crystallographic analysis of 1 showed that the rhenium coordination geometry is trigonal bipyramidal. The basal plane of the trigonal bipyramid is defined by the oxo group and two sulphur atoms, one belonging to the [NS] ligand and the other to an aromatic thiol, while the apical positions are occupied by the nitrogen of the [NS] ligand and the sulphur of the second aromatic thiol. The oxotechnetium-99 complex 2 has almost identical unit cell parameters to those of the oxorhenium complex 1 indicating, in combination with the other analytical data, that the complexes are isostructural. The binding affinity of the oxorhenium complex 1 for the 5-HT(1A) receptor subtype was determined in rat brain hippocampal preparations (IC(50)=106 nM). The oxotechnetium-99m complex 3 was prepared by a ligand exchange reaction using (99m)Tc-glucoheptonate as the precursor. Its structure was established by comparative HPLC studies using the oxotechnetium-99 complex 2 as a reference. Complex 3 was administered by intravenous injection in rats. At 2 min post injection, 0.153% of the injected dose per gram of tissue was measured in rat brain.
Collapse
Affiliation(s)
- Charalambos Tsoukalas
- Institute of Radioisotopes-Radiodiagnostic Products, National Centre for Scientific Research 'Demokritos', 15310 Ag. Paraskevi, Athens, Greece
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
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.
Collapse
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.
| | | | | | | |
Collapse
|
31
|
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.
Collapse
Affiliation(s)
- D Papagiannopoulou
- Institute of Radioisotopes-Radiodiagnostic Products, National Center for Scientific Research Demokritos, 15310 Ag. Paraskevi, Athens, Greece
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
PURPOSE OF REVIEW We aim to review recent neuroimaging contributions to our understanding of the cause and pathogenesis of Parkinson's disease, as well as treatment-related complications of disease, with a focus on functional anatomy and neurochemistry. RECENT FINDINGS Recent reports describe altered dopaminergic activity in extrastriatal regions, as well as changes in other monoaminergic systems, such as serotonin. Attempts to correlate altered dopaminergic function with personality traits have also been described in the last year. The role of different markers of presynaptic dopaminergic integrity in the assessment of disease progression is discussed, as is the role of biomarkers in detection of preclinical disease. Cerebral activation studies not only confirm altered function of cortico-striatal-thalamo-cortical loops in Parkinson's, but also emphasize the importance of networks involving the cerebellum. The ability to detect changes in synaptic availability of dopamine using positron emission tomography with [(11)C]raclopride is reviewed, including the application to detect altered levels of dopamine in response to pharmacological, mechanical and behavioral stimuli. Such studies have been used to identify altered patterns associated with the development of motor fluctuations, as well as a biochemical substrate underlying the placebo effect in Parkinson's. SUMMARY Functional imaging studies can provide novel insights into the etiopathogenesis of Parkinson's disease, as well as the mechanisms that contribute to complications of long-term therapy. They also shed light on the mechanisms that may underly behavioral changes and benefit derived from surgical interventions.
Collapse
Affiliation(s)
- Raúl de la Fuente-Fernández
- Pacific Parkinson's Research Centre, University of British Columbia, Purdy Pavilion, 2221 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2B5
| | | |
Collapse
|
33
|
Halldin C, Hall H, Amir A, Radu D, Perrone R, Berardi F, Colabufo N, Leopoldo M. A new 5-HT1A receptor radioligand, PB64b - radiolabeling and post-mortem autoradiography in human brain. J Labelled Comp Radiopharm 2001. [DOI: 10.1002/jlcr.2580440163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|