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Shegani A, Kealey S, Luzi F, Basagni F, Machado JDM, Ekici SD, Ferocino A, Gee AD, Bongarzone S. Radiosynthesis, Preclinical, and Clinical Positron Emission Tomography Studies of Carbon-11 Labeled Endogenous and Natural Exogenous Compounds. Chem Rev 2022; 123:105-229. [PMID: 36399832 PMCID: PMC9837829 DOI: 10.1021/acs.chemrev.2c00398] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The presence of positron emission tomography (PET) centers at most major hospitals worldwide, along with the improvement of PET scanner sensitivity and the introduction of total body PET systems, has increased the interest in the PET tracer development using the short-lived radionuclides carbon-11. In the last few decades, methodological improvements and fully automated modules have allowed the development of carbon-11 tracers for clinical use. Radiolabeling natural compounds with carbon-11 by substituting one of the backbone carbons with the radionuclide has provided important information on the biochemistry of the authentic compounds and increased the understanding of their in vivo behavior in healthy and diseased states. The number of endogenous and natural compounds essential for human life is staggering, ranging from simple alcohols to vitamins and peptides. This review collates all the carbon-11 radiolabeled endogenous and natural exogenous compounds synthesised to date, including essential information on their radiochemistry methodologies and preclinical and clinical studies in healthy subjects.
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Affiliation(s)
- Antonio Shegani
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Steven Kealey
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Federico Luzi
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Filippo Basagni
- Department
of Pharmacy and Biotechnology, Alma Mater
Studiorum−University of Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | - Joana do Mar Machado
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Sevban Doğan Ekici
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Alessandra Ferocino
- Institute
of Organic Synthesis and Photoreactivity, Italian National Research Council, via Piero Gobetti 101, 40129 Bologna, Italy
| | - Antony D. Gee
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,A.G.: email,
| | - Salvatore Bongarzone
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,S.B.:
email,
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2
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The chemistry of labeling heterocycles with carbon-11 or fluorine-18 for biomedical imaging. ADVANCES IN HETEROCYCLIC CHEMISTRY 2020. [DOI: 10.1016/bs.aihch.2019.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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3
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Development and optimization of a novel automated loop method for production of [ 11C]nicotine. Appl Radiat Isot 2018; 140:76-82. [PMID: 29957537 DOI: 10.1016/j.apradiso.2018.05.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 05/04/2018] [Accepted: 05/29/2018] [Indexed: 10/14/2022]
Abstract
A novel, rapid, and automated loop method for the synthesis of [11C]nicotine was developed and optimized. The method involves, a reaction of the precursor, (+) nornicotine or (-) nornicotine, with a gas-phase produced [11C]CH3I in an 800 µL loop at 75 °C for 5 min followed by a semi-preparatory Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) purification. The optimized synthesis and purification process was complete in < 30 min and produced [11C]nicotine with > 99.9% Radiochemical Purity (RCP), no [11C]CH3I, no (+) nornicotine, 105 mCi/µmole specific activity, 7.0 - 7.2 pH, and 16.6% ethanol. The current method can be optimized, to reduce the ethanol content (<10%), and can be translated to a cGMP production of [11C]nicotine for human clinical trials.
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Xu Y, Kim SW, Kim D, Alexoff D, Schueller MJ, Fowler JS. A mild, rapid synthesis of freebase [11C]nicotine from [11C]methyl triflate. Appl Radiat Isot 2016; 118:62-66. [DOI: 10.1016/j.apradiso.2016.08.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/22/2016] [Accepted: 08/28/2016] [Indexed: 11/28/2022]
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Horti AG, Kuwabara H, Holt DP, Dannals RF, Wong DF. Recent PET radioligands with optimal brain kinetics for imaging nicotinic acetylcholine receptors. J Labelled Comp Radiopharm 2013; 56:159-66. [DOI: 10.1002/jlcr.3020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 11/27/2012] [Accepted: 12/07/2012] [Indexed: 01/28/2023]
Affiliation(s)
- Andrew G. Horti
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Hiroto Kuwabara
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Daniel P. Holt
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Robert F. Dannals
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Dean F. Wong
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
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Wu J, Ishikawa M, Zhang J, Hashimoto K. Brain imaging of nicotinic receptors in Alzheimer's disease. Int J Alzheimers Dis 2010; 2010:548913. [PMID: 21253523 PMCID: PMC3022172 DOI: 10.4061/2010/548913] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Accepted: 12/08/2010] [Indexed: 11/30/2022] Open
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand-gated ion channels which are widely distributed in the human brain. Several lines of evidence suggest that two major subtypes (α4β2 and α7) of nAChRs play an important role in the pathophysiology of Alzheimer's disease (AD). Postmortem studies demonstrated alterations in the density of these subtypes of nAChRs in the brain of patients with AD. Currently, nAChRs are one of the most attractive therapeutic targets for AD. Therefore, several researchers have made an effort to develop novel radioligands that can be used to study quantitatively the distribution of these two subtypes in the human brain with positron emission tomography (PET) and single-photon emission computed tomography (SPECT). In this paper, we discuss the current topics on in vivo imaging of two subtypes of nAChRs in the brain of patients with AD.
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Affiliation(s)
- Jin Wu
- Division of Clinical Neuroscience, Center for Forensic Mental Health, Chiba University, 1-8-1 Inohana Chiba 260-8670, Japan
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Development of radioligands with optimized imaging properties for quantification of nicotinic acetylcholine receptors by positron emission tomography. Life Sci 2009; 86:575-84. [PMID: 19303028 DOI: 10.1016/j.lfs.2009.02.029] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 02/05/2009] [Accepted: 02/12/2009] [Indexed: 11/20/2022]
Abstract
AIMS There is an urgent need for positron emission tomography (PET) imaging of the nicotinic acetylcholine receptors (nAChR) to study the role of the nicotinic system in Alzheimer's and Parkinson's diseases, schizophrenia, drug dependence and many other disorders. Greater understanding of the underlying mechanisms of the nicotinic system could direct the development of medications to treat these disorders. Central nAChRs also contribute to a variety of brain functions, including cognition, behavior and memory. MAIN METHODS Currently, only two radiotracers, (S)-3-(azetidin-2-ylmethoxy)-2-[(18)F]fluoropyridine (2-[(18)F]FA) and (S)-5-(azetidin-2-ylmethoxy)-2-[(18)F]fluoropyridine (6-[(18)F]FA), are available for studying nAChRs in human brain using PET. However, the "slow" brain kinetics of these radiotracers hamper mathematical modeling and reliable measurement of kinetic parameters since it takes 4-7 h of PET scanning for the tracers to reach steady state. The imaging drawbacks of the presently available nAChR radioligands have initiated the development of radioligands with faster brain kinetics by several research groups. KEY FINDINGS This minireview attempts to survey the important achievements of several research groups in the discovery of PET nicotinic radioligands reached recently. Specifically, this article reviews papers published from 2006 through 2008 describing the development of fifteen new nAChR (11)C-and (18)F-ligands that show improved imaging properties over 2-[(18)F]FA. SIGNIFICANCE The continuous efforts of radiomedicinal chemists led to the development of several interesting PET radioligands for imaging of nAChR including [(18)F]AZAN, a potentially superior alternative to 2-[(18)F]FA.
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Kadir A, Darreh-Shori T, Almkvist O, Wall A, Grut M, Strandberg B, Ringheim A, Blomquist G, Långström B, Nordberg A. PET imaging of the in vivo brain acetylcholinesterase activity and nicotine binding in galantamine-treated patients with AD. Neurobiol Aging 2008; 29:1204-17. [PMID: 17379359 DOI: 10.1016/j.neurobiolaging.2007.02.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 01/18/2007] [Accepted: 02/14/2007] [Indexed: 10/23/2022]
Abstract
The effect of galantamine treatment on cortical acetylcholinesterase (AChE) activity and nicotinic receptor binding was investigated by positron emission tomography (PET) in 18 patients with mild Alzheimer's disease (AD) in relation to galantamine concentration and the patients' cognitive performances. The first 3 months of the study was of a randomized double-blind placebo-controlled design, during which 12 patients received galantamine (16-24mg/day) and 6 patients the placebo, and this was followed by 9 months' galantamine treatment in all patients. The patients underwent PET examinations to measure cortical AChE activity ((11)C-PMP) and (11)C-nicotine binding. Neuropsychological tests were performed throughout the study. Inhibition (30-40%) of cortical AChE activity was observed after 3 weeks to 12 months of galantamine treatment. No significant change in mean cortical (11)C-nicotine binding was observed during the study. (11)C-Nicotine binding, however, positively correlated with plasma galantamine concentration. Both the changes of AChE activity and (11)C-nicotine binding correlated positively with the results of a cognitive test of attention. In conclusion, galantamine caused sustained AChE inhibition for up to 12 months. At the individual level, the in vivo cortical AChE inhibition and (11)C-nicotine binding were associated with changes in the attention domain of cognition rather than episodic memory.
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Affiliation(s)
- A Kadir
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
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9
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Gao Y, Horti AG, Kuwabara H, Ravert HT, Hilton J, Holt DP, Kumar A, Alexander M, Endres CJ, Wong DF, Dannals RF. Derivatives of (−)-7-Methyl-2-(5-(pyridinyl)pyridin-3-yl)-7-azabicyclo[2.2.1]heptane Are Potential Ligands for Positron Emission Tomography Imaging of Extrathalamic Nicotinic Acetylcholine Receptors. J Med Chem 2007; 50:3814-24. [PMID: 17629263 DOI: 10.1021/jm070224t] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of novel racemic 7-methyl-2-(5-(pyridinyl)pyridin-3-yl)-7-azabicyclo[2.2.1]heptane derivatives with picomolar in vitro binding affinity at nicotinic acetylcholine receptors (nAChRs) were synthesized and their enantiomers were resolved by semipreparative chiral HPLC. The (-)-enantiomers showed substantially greater in vitro inhibition binding affinity than the corresponding (+)-enantiomers. The compounds with best binding affinities have been radiolabeled with positron emitting isotopes 11C and 18F as potential radioligands for positron emission tomography imaging of the nAChR. In vivo enantioselectivity of the radiolabeled (-)-7-methyl-2-(5-(pyridinyl)pyridin-3-yl)-7-azabicyclo[2.2.1]heptane derivatives was observed in biodistribution studies in rodents and baboon. One of the radiolabeled compounds, (-)-7-methyl-2-exo-[3'-(2-[18F]fluoropyridin-5-yl))-5'-pyridinyl]-7-azabicyclo[2.2.1]heptane, exhibited good properties as a first practical PET radioligand for imaging of extrathalamic nAChR in baboon brain and holds promise for further investigation for human studies.
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Affiliation(s)
- Yongjun Gao
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287-0816, USA
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Pogocki D, Ruman T, Danilczuk M, Danilczuk M, Celuch M, Wałajtys-Rode E. Application of nicotine enantiomers, derivatives and analogues in therapy of neurodegenerative disorders. Eur J Pharmacol 2007; 563:18-39. [PMID: 17376429 DOI: 10.1016/j.ejphar.2007.02.038] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 02/04/2007] [Accepted: 02/15/2007] [Indexed: 12/21/2022]
Abstract
This review gives a brief overview over the major aspects of application of the nicotine alkaloid and its close derivatives in the therapy of some neurodegenerative disorders and diseases (e.g. Alzheimer's disease, Parkinson's disease, Tourette's syndrome, schizophrenia etc.). The issues concerning methods of nicotine analysis and isolation, and some molecular aspects of nicotine pharmacology are included. The natural and synthetic analogues of nicotine that are considered for medical practice are also mentioned. The molecular properties of two naturally occurring nicotine enantiomers are compared--the less-common but less-toxic (R)-nicotine is suggested as a natural compound that may find its place in pharmaceutical practice.
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Affiliation(s)
- Dariusz Pogocki
- Rzeszów University of Technology, Faculty of Chemistry, Department of Biochemistry and Biotechnology, 6 Powstańców Warszawy Ave. 35-959 Rzeszów, Poland
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Roeda D, Kuhnast B, Hammadi A, Dollé F. The Service Hospitalier Frédéric Joliot – contributions to PET chemistry over the years. J Labelled Comp Radiopharm 2007. [DOI: 10.1002/jlcr.1420] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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12
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Berger G, Mazière M, Sastre J, Comar D. Carrier-free 11 C Formaldehyde : An approach. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580170107] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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13
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Gueguen P, Morgat JL, Maziere M, Berger G, Comar D, Maman M. Enzymatic synthesis of 11C-labelled S-adenosylmethionine. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580190202] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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14
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Seeman JI, Secor HV, Forrest G. Convenient syntheses of N-CD3 labelled nicotine and nicotine analogues. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580160304] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chang YL, Tsai PL, Chou YC, Tien JH, Tsai TH. Simultaneous determination of nicotine and its metabolite, cotinine, in rat blood and brain tissue using microdialysis coupled with liquid chromatography: Pharmacokinetic application. J Chromatogr A 2005; 1088:152-7. [PMID: 16130745 DOI: 10.1016/j.chroma.2005.01.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
To elucidate the disposition of nicotine in the brain is important because the neuropharmacological effects from nicotine exposure are centrally predominated. The aim of the present study was to develop a rapid and simple method for the simultaneous determination of unbound nicotine and its main metabolite, cotinine, in rat blood and brain tissue. We coupled a multiple sites microdialysis sampling technique with HPLC-UV system to characterize the pharmacokinetics of both nicotine and cotinine. Microdialysis probes were inserted into the jugular vein/right atrium and brain striatum of Sprague-Dawley rats, and nicotine (2 mg/kg, i.v.) was administered via the femoral vein. Dialysates were collected every 10 min and injected directly into a HPLC system. Both nicotine and cotinine were separated by a phenyl-hexyl column (150 mm x 4.6 mm) from dialysates within 12 min. The mobile phase consisted of an acetonitrile-methanol-20 mM monosodium phosphate buffer (55:45:900, v/v/v, pH adjusted to 5.1) with a flow-rate of 1 ml/min. The wavelength of the UV detector was set at 260 nm. The limit of quantification for nicotine and cotinine were 0.25 microg/ml and 0.05 microg/ml, respectively. Intra- and inter-day precision and accuracy of both measurements fell well within the predefined limits of acceptability. The blood and brain concentration-time profile of nicotine and cotinine suggests that nicotine is easily to get into the central nervous system and cotinine exhibits a long retention time and accumulates in blood.
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Affiliation(s)
- Yuh-Lih Chang
- Department of Pharmacy, Taipei Veterans General Hospital, Taipei, Taiwan
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Abstract
Cigarette smoking is a leading cause of mortality and morbidity and a particularly common and intractable addictive disorder. Research shows that nicotine is a sine qua non of tobacco addiction and that it produces the hallmark effects of addictive drugs: sensitization, tolerance, physical dependence, and euphoria/elation. Research on the development of smoking reveals that although smoking prevalence has declined from a peak in the mid-1990s, close to 30% of twelfth graders still smoke. Smoking in adolescents is related to development of physical dependence, ethnicity, impulsivity, affective disorder, and peer influences. However, which of these exerts the greatest causal effects is unknown, and their influence no doubt varies across individuals and across development. Once dependence on tobacco smoking is established, evidence suggests that tobacco motivation is strongly influenced by a reduction in withdrawal symptoms, an expectation of stress reduction, and conditioned reinforcement. Nicotine motivation may also be influenced by modulation in stimulus incentive value.
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Affiliation(s)
- Timothy B Baker
- Department of Psychology, University of Wisconsin, and Center for Tobacco Research & Intervention, University of Wisconsin Medical School, Madison, Wisconsin 53711, USA.
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17
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Brown LL, Kulkarni S, Pavlova OA, Koren AO, Mukhin AG, Newman AH, Horti AG. Synthesis and evaluation of a novel series of 2-chloro-5-((1-methyl-2-(S)-pyrrolidinyl)methoxy)-3-(2-(4-pyridinyl)vinyl)pyridine analogues as potential positron emission tomography imaging agents for nicotinic acetylcholine receptors. J Med Chem 2002; 45:2841-9. [PMID: 12061886 DOI: 10.1021/jm010550n] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reportedly, 2-[(18)F]fluoro-A-85380, 1, a promising radiotracer for imaging the nicotinic acetylcholine receptor (nAChR) by positron emission tomography (PET) in humans, exhibits slow penetration through the blood-brain barrier (BBB) due to its low lipophilicity. A ligand for nAChRs with greater lipophilicity than that of 1 would be potentially more favorable for PET imaging of nAChR due to its faster penetration through the BBB. Herein, a novel series of compounds has been developed based on the high affinity ligand for nAChRs, 2-chloro-5-((1-methyl-2-(S)-pyrrolidinyl)methoxy)-3-(2-(4-pyridinyl)vinyl)pyridine, 3b. The in vitro binding affinities for the new series were found to be in the range of K(i) = 9-331 pM. A molecular modeling study showed differences in the comformational profiles and the electronic properties of these compounds, which provides further insight into the structure-activity relationships at nAChR. Lipophilicities of the compounds 3b-6b have been found to be substantially higher than that of 1. As a result, compounds 3b-6b might exhibit a faster penetration through the BBB than the less lipophilic 1. The N-methyl derivatives 3b and 6b demonstrated very high affinities at nAChRs (K(i) = 28 and 23 pM, respectively) and will be targets for development of (11)CH(3)-labeled derivatives as radiotracers for PET imaging of nAChRs.
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Affiliation(s)
- LaVerne L Brown
- Neuroimaging Research Branch and Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA
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Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand gated ion channels which are widely distributed in the human brain. Multiple subtypes of these receptors exist, each with individual pharmacological and functional profiles. They mediate the effects of nicotine, a widely used drug of abuse, are involved in a number of physiological and behavioural processes and are additionally implicated in a number of pathological conditions such as Alzheimer's disease, Parkinson's disease and schizophrenia. The nAChRs have a pentameric structure composed of five membrane spanning subunits, of which nine different types have thus far been identified and cloned. The multiple subunits identified provide the basis for the heterogeneity of structure and function observed in the nAChR subtypes and are responsible for the individual characteristics of each. A substantial amount of information on human nAChR structure and function has come from studies on neuroblastoma cell lines which naturally express nAChRs and from recombinant nAChRs expressed in Xenopus oocytes. In vitro brain nAChR distribution can be mapped with a number of appropriate agonist and antagonist radioligands and subunit distribution may be mapped by in situ hybridization using subunit specific mRNA probes. Receptor distribution in the living human brain can be studied with noninvasive imaging techniques such as PET and SPECT, with a significant reduction in nAChRs in the brains of Alzheimer's patients having been identified with [11C] nicotine in PET studies. Despite the significant body of knowledge now accumulated about nAChRs, much remains to be elucidated. This review will attempt to describe the current knowledge on the nAChR subtypes in the human brain, their functional roles and neuropathological involvement.
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Affiliation(s)
- D Paterson
- Department of Clinical Neuroscience, Occupational Therapy and Elderly Care Research, Karolinska Institute, Huddinge Univerity Hospital, Sweden
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Scheffel U, Horti AG, Koren AO, Ravert HT, Banta JP, Finley PA, London ED, Dannals RF. 6-[18F]Fluoro-A-85380: an in vivo tracer for the nicotinic acetylcholine receptor. Nucl Med Biol 2000; 27:51-6. [PMID: 10755645 DOI: 10.1016/s0969-8051(99)00082-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
6-[18F]Fluoro-3-(2(S)-azetidinylmethoxy)pyridine (6-[18F]fluoro-A-85380 or 6-[18F]FA), a new tracer for positron emission tomography, was synthesized by no-carrier-added [18F] fluorination of 6-iodo-3-((1-tert-butoxycarbonyl-2(S)-azetidinyl)methoxy)pyridine followed by acidic deprotection. 6-[18F]FA followed the regional densities of brain nicotinic acetylcholine receptors (nAChRs) reported in the literature. Evidence of binding to nAChRs and high specificity of the binding in vivo was demonstrated by inhibition with nAChR selective ligands as well as with unlabeled 6-FA. A preliminary toxicology study of the 6-FA showed a relatively low biological effect.
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Affiliation(s)
- U Scheffel
- Division of Nuclear Medicine and Radiation Health Sciences, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205-2179, USA
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Valette H, Bottlaender M, Dollé F, Guenther I, Coulon C, Hinnen F, Fuseau C, Ottaviani M, Crouzel C. Characterization of the nicotinic ligand 2-[18F]fluoro-3-[2(S)-2-azetidinylmethoxy]pyridine in vivo. Life Sci 1999; 64:PL93-7. [PMID: 10072197 DOI: 10.1016/s0024-3205(98)00573-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The biodistribution of the nicotinic acetylcholine receptor (nAChR) radioligand 2-[18F]fluoro-3-[2(S)-2-azetidinylmethoxy]pyridine ([18F]fluoro-A-85380, half-life of fluorine-18 = 110 min) in selected rat brain areas was assessed in vivo. The radiotracer showed a good penetration in the brain. The regional distribution of the radioligand was consistent with the density of nAChRs determined from previous studies in vitro. Sixty minutes post-injection, the highest uptake was observed in the thalamus, (1% I.D./g tissue), an intermediate one in the frontal cortex (0.78% I.D./g tissue), and the lowest in the cerebellum (0.5% I.D./g tissue). Pretreatment with several nAChR ligands (nicotine, cytisine, epibatidine, unlabeled fluoro-A-85380) substantially reduced uptake of the radioligand in the three cerebral areas. Pretreatment with the nAChR channel blocker mecamylamine or with the muscarinic receptor antagonist dexetimide had no appreciable effect on the uptake of fluoro-A-85380. These results support the high in vivo selectivity and specificity of fluoro-A-85380. Therefore, [18F]fluoro-A-85380 may be useful for positron emission tomography study of nAChRs in humans.
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Affiliation(s)
- H Valette
- CEA, Service Hospitalier Frédéric Joliot, DSV/DRM, Orsay, France
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Kassiou M, Ravert HT, Mathews WB, Musachio JL, London ED, Dannals RF. Synthesis of 3-[(1-[11C]methyl-2(S)-pyrrolidinyl) methoxy]pyridine and 3-[(1-[11C]methyl-2(R)-pyrrolidinyl) methoxy]pyridine: Radioligands for in vivo studies of neuronal nicotinic acetylcholine receptors. J Labelled Comp Radiopharm 1998. [DOI: 10.1002/(sici)1099-1344(199705)39:5<425::aid-jlcr984>3.0.co;2-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Koren AO, Horti AG, Mukhin AG, Gündisch D, Kimes AS, Dannals RF, London ED. 2-, 5-, and 6-Halo-3-(2(S)-azetidinylmethoxy)pyridines: synthesis, affinity for nicotinic acetylcholine receptors, and molecular modeling. J Med Chem 1998; 41:3690-8. [PMID: 9733494 DOI: 10.1021/jm980170a] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
3-(2(S)-Azetidinylmethoxy)pyridine (A-85380) has been identified recently as a ligand with high affinity for nicotinic acetylcholine receptors (nAChRs). Here we report the synthesis and in vitro nAChR binding of a series of 10 pyridine-modified analogues of A-85380. The novel compounds feature a halogen substituent at position 2, 5, or 6 of the 3-pyridyl fragment. Those with the substituents at position 5 or 6, as well as the 2-fluoro analogue, possess subnanomolar affinity for nAChRs in membranes from rat brain. For these ligands, Ki values range from 11 to 210 pM, as measured by competition with (+/-)-[3H]epibatidine. In contrast, 2-chloro, 2-bromo, and 2-iodo analogues exhibit substantially lower affinity. AM1 quantum chemical calculations demonstrate that the bulky substituents at position 2 cause notable changes in the molecular geometry. The high-affinity members of the series and (+)-epibatidine display a tight fit superposition of low-energy stable conformers. The new ligands with high affinity for nAChRs may be of interest as pharmacological probes, potential medications, and candidates for developing radiohalogenated tracers to study nAChRs.
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Affiliation(s)
- A O Koren
- Brain Imaging Center, Intramural Research Program, National Institute on Drug Abuse, 5500 Nathan Shock Drive, Baltimore, Maryland 21224, USA.
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23
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Kassiou M, Scheffel UA, Ravert HT, Mathews WB, Musachio JL, London ED, Dannals RF. Pharmacological evaluation of [11C]A-84543: an enantioselective ligand for in vivo studies of neuronal nicotinic acetylcholine receptors. Life Sci 1998; 63:PL13-8. [PMID: 9667769 DOI: 10.1016/s0024-3205(98)00240-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
[11C]A-84543, 3-[(1-[11C]methyl-2(S)-pyrrolidinyl)methoxy]pyridine, is a specific and enantioselective neuronal nicotinic acetylcholine receptor (nAChR) radiotracer. The in vivo biodistribution of this radiotracer in mice showed high brain uptake and a distribution consistent with the density of nAChRs. Highest uptake was observed in the thalamus (9.6 %ID/g), cortex (9.9 %ID/g), superior colliculus (7.6 %ID/g) and hippocampus (7.6 %ID/g) at 5 min followed by clearance. As a measure of specificity, the thalamus/cerebellar ratio reached a maximum of 2.3 at 30 min post-injection. Radioactivity in the thalamus and superior colliculus was reduced by 33% by pre-administration of unlabeled A-84543. The nAChR agonists (-)nicotine, cytisine, and (+) epibatidine reduced the radioactivity due to [11C]A-84543 in the superior colliculus by 41%, 38%, and 27%, respectively, while lobeline, which also interacts with central nAChRs, produced a 24% inhibition. The noncompetitive nAChR ligand, mecamylamine displayed no inhibitory effect on [11C]A-84543 accumulation in any brain region. Ketanserin (5-HT2/5-HT2C), scopolamine (mAChR antagonist), (+)butaclamol (DA receptor antagonist), and haloperidol (D2/sigma) also displayed no inhibitory effect in any brain region studied. With the pharmacologically less active enantiomer, 3-[(1-[11C]methyl-2(R)-pyrrolidinyl)methoxy] pyridine, high brain uptake was also observed, but with a low thalamus/cerebellar ratio of 1.4 at 30 min post-injection. [11C]A-84543 displays enantioselectivity for nAChRs and may deserve further investigation as a possible PET radiotracer.
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Affiliation(s)
- M Kassiou
- Brain Imaging Section, Division of Intramural Research, National Institute on Drug Abuse, Baltimore, Maryland 21224, USA
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24
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Kämpfer I, Sorger D, Schliebs R, Kärger W, Günther K, Schulze K, Knapp WH. Radioiodination of nicotine with specific activity high enough for mapping nicotinic acetylcholine receptors. EUROPEAN JOURNAL OF NUCLEAR MEDICINE 1996; 23:157-62. [PMID: 8925850 DOI: 10.1007/bf01731839] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A novel radiochemical method is presented to synthesize 5-[123I/125I/131I]-dL-nicotine by radioiodination of 5-bromonicotine. Radioiodination of the precursor 5-dL-bromonicotine was achieved using a copper (I)-assisted nucleophilic exchange reaction in the presence of reducing agent. The reaction conditions were optimized by varying pH, concentration of Sn(II) salt, ascorbic acid, Cu(I)chloride and reaction temperature. After purification by high-performance liquid chromatography the radiochemical purity of the product exceeded 98%, with a radiochemical yield of 55% and a specific activity > or =5 GBq/micromol. Specific binding of the iodinated nicotine was demonstrated in rat brain by autoradiography. The radioactivity from the specific structures was displaced by an excess of non-radioactive nicotine (10(-3)M) with KD and Bmax of 13.1+/-7.8 nM and 22+/-2.7 fmol/mg protein and unspecific binding of about 40%. The in vivo distribution of 5-[131I]iodonicotine was determined in 20 female Wistar rats at various time intervals of 15s to 90 min post injection (p.i.) by well counting and autoradiography. Brain activity peaked within 0.5 min p.i., and then showed a biexponential washout. Initially, activity within the cerebral cortex exceeded that of the cerebellum by a factor of 1.5-2.0. It was also increased in the striatum and thalamus. However, as soon as 15 min p.i. activity was almost homogeneously distributed. In conclusion, synthesis of 5-iodo-dL-nicotine (labelled with 131I, 125I or 123I, respectively) with appropriately high specific activity for receptor studies was achieved and specific binding to nicotine receptors in rat brain was demonstrated; following intravenous injection, however, there is considerable unspecific binding, obviously due to highly flow-dependent tissue retention.
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Affiliation(s)
- I Kämpfer
- Department of Nuclear Medicine, University of Leipzig, Liebigstrasse 20a, D-04103 Leipzig, Germany
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25
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Maziere M. Cholinergic neurotransmission studied in vivo using positron emission tomography or single photon emission computerized tomography. Pharmacol Ther 1995; 66:83-101. [PMID: 7630931 DOI: 10.1016/0163-7258(95)00003-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
During the past decade, considerable efforts have been made in the development of radiopharmaceuticals for the in vivo study of the cholinergic neurotransmission using positron emission tomography or single photon emission computerized tomography. The main cholinergic radioligands, labelled with positron- or gamma-photon-emitting radionuclides, are reviewed with respect to use as in vivo markers of either acetylcholinesterase, vesicular acetylcholine transporter, brain and heart muscarinic receptors, or cholinergic nicotinic receptors. The main results obtained in the in vivo study of the physiology, pharmacology or pathology of the different steps of the cholinergic neurotransmission using single photon emission computerized tomography and positron emission tomography are discussed.
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Affiliation(s)
- M Maziere
- CNRS URA 1285, Service Hospitalier Frédéric Joliot, DRIPP, CEA, Orsay, France
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26
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Nybäck H, Halldin C, Ahlin A, Curvall M, Eriksson L. PET studies of the uptake of (S)- and (R)-[11C]nicotine in the human brain: difficulties in visualizing specific receptor binding in vivo. Psychopharmacology (Berl) 1994; 115:31-6. [PMID: 7862909 DOI: 10.1007/bf02244748] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
(S)- and (R)-[11C]nicotine were synthesized by methylation of (S)- and (R)-nornicotine using [11C]methyl iodide. Following their intravenous injection in tracer doses to smoking and nonsmoking healthy males the radioactivity in arterial blood showed a sharp peak at about 1 min followed by a plateau level for the remaining 50 min of recording. Uptake in the brain, as measured by positron emission tomography (PET), was rapid with a peak at 5 min followed by a steady decline towards the end of the measurement. The regional distribution of radioactivity followed essentially the distribution of gray matter with high uptake in the cortex, the thalamus and the basal ganglia and low uptake in the pons, cerebellum and white matter. Levels of the labelled natural enantiomer, (S)-[11C]nicotine, were higher than those of the synthetic enantiomer, (R)-[11C]nicotine, particularly in the smokers. The time-activity curves of (S)-[11C]nicotine uptake were not changed by co-administration of 1.0 mg of unlabelled nicotine with the labelled nicotine. Similarly administration of unlabelled nicotine at the peak of radioactivity, 6 min following (S)-[11C]nicotine, had no effect on the time-activity curves. Thus essential criteria for visualizing receptor binding with the PET technique could not be fulfilled. Calculation of kinetic constants using a two-compartment model gave values indicating that the brain uptake of [11C]nicotine is mainly determined by the cerebral blood flow, extraction of the tracer over the blood-brain barrier and unspecific binding. Thus 11C-labelled nicotine does not seem to be a suitable tracer for PET studies of nicotinic cholinergic receptors in the human brain.
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Affiliation(s)
- H Nybäck
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
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27
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Halldin C, Någren K, Swahn CG, Långström B, Nybäck H. (S)- and (R)-[11C]nicotine and the metabolite (R/S)-[11C]cotinine. Preparation, metabolite studies and in vivo distribution in the human brain using PET. INTERNATIONAL JOURNAL OF RADIATION APPLICATIONS AND INSTRUMENTATION. PART B, NUCLEAR MEDICINE AND BIOLOGY 1992; 19:871-80. [PMID: 1428915 DOI: 10.1016/0883-2897(92)90173-v] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In order to investigate [11C]nicotine binding and metabolism in the living human brain by PET, routine protocols were developed for the preparation and purification of (S)- and (R)-[11C]nicotine and the metabolite (R/S)-[11C]cotinine. (S)- and (R)-[11C]nicotine were prepared by N-methylation with [11C]methyl iodide of the appropriate secondary amine, which was liberated in situ by 2,2,6,6,-tetramethylpiperidine (TMP) from its corresponding biscamsylate-salt. (R/S)-[11C]Cotinine was prepared by N-methylation of the amide precursor using tetrabutylammonium hydroxide as a phase transfer catalyst. Straight-phase semipreparative HPLC was in all purifications found to be superior to reversed-phase since the contamination by the norcompounds was eliminated. Reaction in acetonitrile for both (S)- and (R)-[11C]nicotine (5 min, 130 degrees C) and (R/S)-[11C]cotinine (1 min, 80 degrees C) with subsequent straight-phase HPLC purification resulted in 35-45% radiochemical yield (from EOB and decay-corrected) with a total synthesis time of 30-35 min, a specific radioactivity of 1000-1500 Ci/mmol (37-55 GBq/mumol, EOS) and a radiochemical purity > 99%. The uptake and distribution of these tracers in the human brain was studied in healthy volunteers by PET. The metabolite (R/S)-[11C]cotinine did not cross the blood-brain barrier to any significant degree. The amount of the total radioactivity representing (S)-[11C]nicotine measured in plasma by HPLC was 75% at 4 min and 25% at 50 min.
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Affiliation(s)
- C Halldin
- Department of Psychiatry and Psychology, Karolinska Hospital, Stockholm, Sweden
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28
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Abstract
Probing the regional distribution and affinity of receptors in the brain, in vivo, in human and non human primates has become possible with the use of selective ligands labelled with positron emitting radionuclides and positron emission tomography (PET). After describing the techniques used in positron emission tomography to characterize a ligand receptor binding and discussing the choice of the label and the limitations and complexities of the in vivo approach, the results obtained in the PET studies of various neurotransmission systems: dopaminergic, opiate, benzodiazepine, serotonin and cholinergic systems are reviewed.
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Affiliation(s)
- B Mazière
- Service Hospitalier Frédéric Joliot, Commissariat à l'Energie Atomique, Orsay, France
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29
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Nordberg A, Hartvig P, Lilja A, Viitanen M, Amberla K, Lundqvist H, Andersson Y, Ulin J, Winblad B, Långström B. Decreased uptake and binding of 11C-nicotine in brain of Alzheimer patients as visualized by positron emission tomography. JOURNAL OF NEURAL TRANSMISSION. PARKINSON'S DISEASE AND DEMENTIA SECTION 1990; 2:215-24. [PMID: 2257061 DOI: 10.1007/bf02257652] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Positron emission tomography of the brain following intravenous injection of (+) (R) and (-) (S) N-[11C-methyl]nicotine showed a marked reduced uptake of both isomers, especially the (R) form, in Alzheimer patients as compared to age-matched controls. The significantly larger difference between the uptake values of the (S)- and (R)-enantiomers of 11C-nicotine in Azheimer brains may be of diagnostic value.
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Affiliation(s)
- A Nordberg
- Department of Pharmacology, University of Uppsala, Sweden
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30
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Mazière M, Khalili-Varasteh M, Delforge J, Janier M, Leguludec D, Prenant C, Syrota A. Positron emission tomography and cholinergic mechanisms: an overview. PROGRESS IN BRAIN RESEARCH 1990; 84:347-59. [PMID: 2267307 DOI: 10.1016/s0079-6123(08)60918-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- M Mazière
- Service Hospitalier Frédéric Joliot, URA CEA-CNRS 1285, Orsay, France
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31
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Benowitz NL, Porchet H, Jacob P. Nicotine dependence and tolerance in man: pharmacokinetic and pharmacodynamic investigations. PROGRESS IN BRAIN RESEARCH 1989; 79:279-87. [PMID: 2587748 DOI: 10.1016/s0079-6123(08)62487-5] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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32
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Agon P, Braeckman R, Van Haver D, Denutte H, Goethals P, Donche H, Vermeullen F, Deman J, Kaufman JM. Drug distribution in dog brain studied by positron emission tomography. Biopharm Drug Dispos 1988; 9:567-77. [PMID: 3265876 DOI: 10.1002/bod.2510090607] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We used positron emission tomography to monitor the distribution of radioactivity in dog brain and muscle following i.v. administration of 11C-labelled antipyrine, imipramine, and quinidine. Twenty-five sequential scans of a transaxial slice of the head were performed within 90 min; radioactivity in plasma was measured in a gamma-counter. Following i.v. injection of [11C]antipyrine (50 mg kg-1; 9-68 mCi; n = 10), the decay of plasma activity was accompanied by rapid uptake in brain and variable uptake in muscle, immediately followed by a redistribution leading to equalization of the radioactivity in the tissues. Administration of [11C]imipramine (4 mg kg-1; 30-110 mCi; n = 8) was followed by a rapid build-up of a sustained gradient between high brain, and low plasma and muscle radioactivity. After i.v. injection of [11C]quinidine (1 mg kg-1; 11-87 mCi; n = 10), radioactivity in brain was low, with higher activity in plasma and muscle throughout the experiment. Positron emission tomography thus revealed for each drug a distinct pattern of distribution consistent with established properties of the compounds. This technique seems promising for the study of early drug distribution, notwithstanding certain limitations.
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Affiliation(s)
- P Agon
- Heymans Institute of Pharmacology, University of Gent, Belgium
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33
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Ballinger JR, Bowen BM, Firnau G, Stephen Garnett E, Teare FW. Radiofluorination with reactor-produced Cesium [18F]fluoride: No-carrier-added [18F]2-fluoronicotine and [18F]6-fluoronicotine. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0020-708x(84)90146-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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34
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35
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36
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Mestelan G, Crouzel C, Comar D. Synthesis and distribution kinetics in animals of [alpha-11C] 3,4-dimethoxyphenethylamine. INTERNATIONAL JOURNAL OF NUCLEAR MEDICINE AND BIOLOGY 1977; 4:185-93. [PMID: 608804 DOI: 10.1016/0047-0740(77)90138-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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