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Huang Y, Chen Q, Wang Z, Wang Y, Lian A, Zhou Q, Zhao G, Xia K, Tang B, Li B, Li J. Risk factors associated with age at onset of Parkinson's disease in the UK Biobank. NPJ Parkinsons Dis 2024; 10:3. [PMID: 38167894 PMCID: PMC10762149 DOI: 10.1038/s41531-023-00623-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024] Open
Abstract
Substantial evidence shown that the age at onset (AAO) of Parkinson's disease (PD) is a major determinant of clinical heterogeneity. However, the mechanisms underlying heterogeneity in the AAO remain unclear. To investigate the risk factors with the AAO of PD, a total of 3156 patients with PD from the UK Biobank were included in this study. We evaluated the effects of polygenic risk scores (PRS), nongenetic risk factors, and their interaction on the AAO using Mann-Whitney U tests and regression analyses. We further identified the genes interacting with nongenetic risk factors for the AAO using genome-wide environment interaction studies. We newly found physical activity (P < 0.0001) was positively associated with AAO and excessive daytime sleepiness (P < 0.0001) was negatively associated with AAO, and reproduced the positive associations of smoking and non-steroidal anti-inflammatory drug intake and the negative association of family history with AAO. In the dose-dependent analyses, smoking duration (P = 1.95 × 10-6), coffee consumption (P = 0.0150), and tea consumption (P = 0.0008) were positively associated with AAO. Individuals with higher PRS had younger AAO (P = 3.91 × 10-5). In addition, we observed a significant interaction between the PRS and smoking for AAO (P = 0.0316). Specifically, several genes, including ANGPT1 (P = 7.17 × 10-7) and PLEKHA6 (P = 4.87 × 10-6), may influence the positive relationship between smoking and AAO. Our data suggests that genetic and nongenetic risk factors are associated with the AAO of PD and that there is an interaction between the two.
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Affiliation(s)
- Yuanfeng Huang
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China
| | - Qian Chen
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China
- Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
| | - Zheng Wang
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
| | - Yijing Wang
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China
| | - Aojie Lian
- National Health Commission Key Laboratory of Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha 410008, Hunan, China
| | - Qiao Zhou
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China
| | - Guihu Zhao
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
| | - Kun Xia
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, Hunan, China
| | - Beisha Tang
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, Hunan, China
| | - Bin Li
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China.
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China.
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China.
| | - Jinchen Li
- National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China.
- Bioinformatics Center, Xiangya Hospital & Furong Laboratory, Central South University, Changsha 410008, Hunan, China.
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China.
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, Hunan, China.
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Raval NR, Wetherill RR, Wiers CE, Dubroff JG, Hillmer AT. Positron Emission Tomography of Neuroimmune Responses in Humans: Insights and Intricacies. Semin Nucl Med 2023; 53:213-229. [PMID: 36270830 DOI: 10.1053/j.semnuclmed.2022.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 08/30/2022] [Indexed: 11/06/2022]
Abstract
The brain's immune system plays a critical role in responding to immune challenges and maintaining homeostasis. However, dysregulated neuroimmune function contributes to neurodegenerative disease and neuropsychiatric conditions. In vivo positron emission tomography (PET) imaging of the neuroimmune system has facilitated a greater understanding of its physiology and the pathology of some neuropsychiatric conditions. This review presents an in-depth look at PET findings from human neuroimmune function studies, highlighting their importance in current neuropsychiatric research. Although the majority of human PET studies feature radiotracers targeting the translocator protein 18 kDa (TSPO), this review also considers studies with other neuroimmune targets, including monoamine oxidase B, cyclooxygenase-1 and cyclooxygenase-2, nitric oxide synthase, and the purinergic P2X7 receptor. Promising new targets, such as colony-stimulating factor 1, Sphingosine-1-phosphate receptor 1, and the purinergic P2Y12 receptor, are also discussed. The significance of validating neuroimmune targets and understanding their function and expression is emphasized in this review to better identify and interpret PET results.
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Affiliation(s)
- Nakul R Raval
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; Yale PET Center, Yale University, New Haven, CT
| | - Reagan R Wetherill
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Corinde E Wiers
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Jacob G Dubroff
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; Yale PET Center, Yale University, New Haven, CT; Department of Psychiatry, Yale University, New Haven, CT.
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Nisha Aji K, Meyer JH, Rusjan PM, Mizrahi R. Monoamine Oxidase B (MAO-B): A Target for Rational Drug Development in Schizophrenia Using PET Imaging as an Example. ADVANCES IN NEUROBIOLOGY 2023; 30:335-362. [PMID: 36928857 DOI: 10.1007/978-3-031-21054-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Monoamine oxidase B (MAO-B) is an important high-density enzyme involved in the generation of oxidative stress and central in the catabolism of dopamine, particularly in brain subcortical regions with putative implications in the pathophysiology of schizophrenia. In this chapter, we review postmortem studies, preclinical models, and peripheral and genetic studies implicating MAO-B in psychosis. A literature search in PubMed was conducted and 64 studies were found to be eligible for systematic review. We found that MAO-B could be identified as a potential target in schizophrenia. Evidence comes mostly from studies of peripheral markers, showing reduced platelet MAO-B activity in schizophrenia, together with preclinical results from MAO-B knock-out mice resulting in a hyperdopaminergic state and behavioral disinhibition. However, whether brain MAO-B is altered in vivo in patients with schizophrenia remains unknown. We therefore review methodological studies involving MAO-B positron emission tomography (PET) radioligands used to quantify MAO-B in vivo in the human brain. Given the limitations of currently available treatments for schizophrenia, elucidating whether MAO-B could be used as a target for risk stratification or clinical staging in schizophrenia could allow for a rational search for newer antipsychotics and the development of new treatments.
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Affiliation(s)
- Kankana Nisha Aji
- Douglas Research Centre, Clinical and Translational Sciences Lab, Montreal, QC, Canada
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada
| | - Jeffrey H Meyer
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Pablo M Rusjan
- Douglas Research Centre, Clinical and Translational Sciences Lab, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Romina Mizrahi
- Douglas Research Centre, Clinical and Translational Sciences Lab, Montreal, QC, Canada.
- Department of Psychiatry, McGill University, Montreal, QC, Canada.
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Meyer JH, Braga J. Development and Clinical Application of Positron Emission Tomography Imaging Agents for Monoamine Oxidase B. Front Neurosci 2022; 15:773404. [PMID: 35280341 PMCID: PMC8914088 DOI: 10.3389/fnins.2021.773404] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Monoamine oxidase B (MAO-B) is a high-density protein in the brain mainly found on outer mitochondrial membranes, primarily in astroglia, but additionally in serotonergic neurons and in the substantia nigra in the midbrain. It is an enzyme that participates in the oxidative metabolism of important monoamines including dopamine, norepinephrine, benzylamine, and phenylethylamine. Elevated MAO-B density may be associated with astrogliosis and inhibiting MAO-B may reduce astrogliosis. MAO-B density is elevated in postmortem sampling of pathology for many neuropsychiatric diseases including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and alcohol use disorder. Initial development of positron emission tomography (PET) imaging agents focused on analogs of [11C]L-deprenyl, with the most commonly applied being the deuterium substituted [11C]L-deprenyl-D2. This latter radiotracer was modeled with an irreversible trapping compartment reflecting its irreversible binding to MAO-B. Subsequently, [11C]SL25.1188, a reversible binding MAO-B radioligand with outstanding properties including high specific binding and excellent reversibility was developed. [11C]SL25.1188 PET was applied to discover a substantive elevation of MAO-B binding in the prefrontal cortex in major depressive disorder (MDD) with an effect size of more than 1.5. Longer duration of MDD was associated with greater MAO-B binding throughout most gray matter regions in the brain, suggesting progressive astrogliosis. Important applications of [11C]L-deprenyl-D2 PET are detecting a 40% loss in radiotracer accumulation in cigarette smokers, and substantial occupancy of novel therapeutics like EVT301 and sembragiline. Given the number of diseases with elevations of MAO-B density and astrogliosis, and the advance of [11C]SL25.1188, clinical applications of MAO-B imaging are still at an early stage.
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Affiliation(s)
- Jeffrey H. Meyer
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- *Correspondence: Jeffrey H. Meyer,
| | - Joeffre Braga
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
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Abstract
BACKGROUND Animal models are critical to improve our understanding of the neuronal mechanisms underlying nicotine withdrawal. Nicotine dependence in rodents can be established by repeated nicotine injections, chronic nicotine infusion via osmotic minipumps, oral nicotine intake, tobacco smoke exposure, nicotine vapor exposure, and e-cigarette aerosol exposure. The time course of nicotine withdrawal symptoms associated with these methods has not been reviewed in the literature. AIM The goal of this review is to discuss nicotine withdrawal symptoms associated with the cessation of nicotine, tobacco smoke, nicotine vapor, and e-cigarette aerosol exposure in rats and mice. Furthermore, age and sex differences in nicotine withdrawal symptoms are reviewed. RESULTS Cessation of nicotine, tobacco smoke, nicotine vapor, and e-cigarette aerosol exposure leads to nicotine withdrawal symptoms such as somatic withdrawal signs, changes in locomotor activity, anxiety- and depressive-like behavior, learning and memory deficits, attention deficits, hyperalgesia, and dysphoria. These withdrawal symptoms are most pronounced within the first week after cessation of nicotine exposure. Anxiety- and depressive-like behavior, and deficits in learning and memory may persist for several months. Adolescent (4-6 weeks old) rats and mice display fewer nicotine withdrawal symptoms than adults (>8 weeks old). In adult rats and mice, females show fewer nicotine withdrawal symptoms than males. The smoking cessation drugs bupropion and varenicline reduce nicotine withdrawal symptoms in rodents. CONCLUSION The nicotine withdrawal symptoms that are observed in rodents are similar to those observed in humans. Tobacco smoke and e-cigarette aerosol contain chemicals and added flavors that enhance the reinforcing properties of nicotine. Therefore, more valid animal models of tobacco and e-cigarette use need to be developed by using tobacco smoke and e-cigarette aerosol exposure methods to induce dependence.
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Affiliation(s)
| | - Azin Behnood-Rod
- Department of Psychiatry, University of Florida, Gainesville, USA
| | | | - Ryann Wilson
- Department of Psychiatry, University of Florida, Gainesville, USA
| | - Vijayapandi Pandy
- Department of Pharmacology, Chalapathi Institute of Pharmaceutical Sciences, Guntur, India
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Meyer JH, Cervenka S, Kim MJ, Kreisl WC, Henter ID, Innis RB. Neuroinflammation in psychiatric disorders: PET imaging and promising new targets. Lancet Psychiatry 2020; 7:1064-1074. [PMID: 33098761 PMCID: PMC7893630 DOI: 10.1016/s2215-0366(20)30255-8] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 01/14/2023]
Abstract
Neuroinflammation is a multifaceted physiological and pathophysiological response of the brain to injury and disease. Given imaging findings of 18 kDa translocator protein (TSPO) and the development of radioligands for other inflammatory targets, PET imaging of neuroinflammation is at a particularly promising stage. This Review critically evaluates PET imaging results of inflammation in psychiatric disorders, including major depressive disorder, schizophrenia and psychosis disorders, substance use, and obsessive-compulsive disorder. We also consider promising new targets that can be measured in the brain, such as monoamine oxidase B, cyclooxygenase-1 and cyclooxygenase-2, colony stimulating factor 1 receptor, and the purinergic P2X7 receptor. Thus far, the most compelling TSPO imaging results have arguably been found in major depressive disorder, for which consistent increases have been observed, and in schizophrenia and psychosis, for which patients show reduced TSPO levels. This pattern highlights the importance of validating brain biomarkers of neuroinflammation for each condition separately before moving on to patient stratification and treatment monitoring trials.
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Affiliation(s)
- Jeffrey H Meyer
- Campbell Family Mental Health Research Institute, Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm, Sweden
| | - Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - William C Kreisl
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Ioline D Henter
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA.
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Fowler CD, Turner JR, Imad Damaj M. Molecular Mechanisms Associated with Nicotine Pharmacology and Dependence. Handb Exp Pharmacol 2019; 258:373-393. [PMID: 31267166 DOI: 10.1007/164_2019_252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tobacco dependence is a leading cause of preventable disease and death worldwide. Nicotine, the main psychoactive component in tobacco cigarettes, has also been garnering increased popularity in its vaporized form, as derived from e-cigarette devices. Thus, an understanding of the molecular mechanisms underlying nicotine pharmacology and dependence is required to ascertain novel approaches to treat drug dependence. In this chapter, we review the field's current understanding of nicotine's actions in the brain, the neurocircuitry underlying drug dependence, factors that modulate the function of nicotinic acetylcholine receptors, and the role of specific genes in mitigating the vulnerability to develop nicotine dependence. In addition to nicotine's direct actions in the brain, other constituents in nicotine and tobacco products have also been found to alter drug use, and thus, evidence is provided to highlight this issue. Finally, currently available pharmacotherapeutic strategies are discussed, along with an outlook for future therapeutic directions to achieve to the goal of long-term nicotine cessation.
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Affiliation(s)
- Christie D Fowler
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, USA
| | - Jill R Turner
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA
| | - M Imad Damaj
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA. .,Translational Research Initiative for Pain and Neuropathy at VCU, Richmond, VA, USA.
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Hogg RC. Contribution of Monoamine Oxidase Inhibition to Tobacco Dependence: A Review of the Evidence. Nicotine Tob Res 2015; 18:509-23. [PMID: 26508396 DOI: 10.1093/ntr/ntv245] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/15/2015] [Indexed: 11/12/2022]
Abstract
BACKGROUND There is a hypothesis that substances present in, or derived from, tobacco smoke inhibit monoamine oxidase (MAO) in the brains of smokers, reducing the degradation of catecholamine neurotransmitters involved in central reward pathways and acting synergistically with nicotine to increase its addictive effects. OBJECTIVE The objective of this review was to evaluate the evidence for a role of MAO inhibition by tobacco-derived substances in tobacco dependence. INVESTIGATIONAL PLAN Relevant studies on the effects of tobacco use on MAO levels or activity in humans were identified by electronic searches. RESULTS The identified data show a clear association between smoking and lower density of MAO-A and MAO-B binding sites in the brains of smokers and strong evidence that MAO is inhibited by a substance or substances in, or derived from, tobacco smoke. There was little evidence to support the hypothesis that low MAO levels/activity is a predictive factor for tobacco use. Substances that inhibit MAO in in vitro assays have been isolated from tobacco leaves and tobacco smoke; however, no single substance has been shown to be absorbed from tobacco smoke and to inhibit MAO in the brains of human smokers. Nevertheless, it is possible that MAO inhibition in smokers could result from additive or synergistic effects of several tobacco-derived substances. MAO inhibition potentiates the reinforcing effects of intravenous nicotine in rodents; however, no data were identified to support the hypothesis that MAO inhibitors in or derived from tobacco or tobacco additives affect tobacco dependence in human smokers. IMPLICATIONS This comprehensive review describes the available evidence for the role of MAO inhibition in tobacco dependence and points the way for further research in this field. In view of the large number of MAO inhibitors identified in tobacco and tobacco smoke, identification of the putative inhibitors responsible for the lower level/activity of MAO in smokers may be impractical. Future studies must address whether the lower level/activity of MAO observed in smokers is also seen in users of other tobacco products and if this change is implicated in their dependence-inducing effects.
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Affiliation(s)
- Ron C Hogg
- Medical Writing, OmniScience Ltd, Geneva, Switzerland
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Fowler JS, Logan J, Shumay E, Alia-Klein N, Wang GJ, Volkow ND. Monoamine oxidase: radiotracer chemistry and human studies. J Labelled Comp Radiopharm 2015; 58:51-64. [PMID: 25678277 DOI: 10.1002/jlcr.3247] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/31/2014] [Indexed: 11/09/2022]
Abstract
Monoamine oxidase (MAO) oxidizes amines from both endogenous and exogenous sources thereby regulating the concentration of neurotransmitter amines such as serotonin, norepinephrine, and dopamine as well as many xenobiotics. MAO inhibitor drugs are used in the treatment of Parkinson's disease and in depression stimulating the development of radiotracer tools to probe the role of MAO in normal human biology and in disease. Over the past 30 years since the first radiotracers were developed and the first positron emission tomography (PET) images of MAO in humans were carried out, PET studies of brain MAO in healthy volunteers and in patients have identified different variables that have contributed to different MAO levels in brain and in peripheral organs. MAO radiotracers and PET have also been used to study the current and developing MAO inhibitor drugs including the selection of doses for clinical trials. In this article, we describe the following: (1) the development of MAO radiotracers; (2) human studies including the relationship of brain MAO levels to genotype, personality, neurological, and psychiatric disorders; and (3) examples of the use of MAO radiotracers in drug research and development. We will conclude with outstanding needs to improve the radiotracers that are currently used and possible new applications.
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Affiliation(s)
- Joanna S Fowler
- Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
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Finberg JPM. Update on the pharmacology of selective inhibitors of MAO-A and MAO-B: focus on modulation of CNS monoamine neurotransmitter release. Pharmacol Ther 2014; 143:133-52. [PMID: 24607445 DOI: 10.1016/j.pharmthera.2014.02.010] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 02/25/2014] [Indexed: 12/23/2022]
Abstract
Inhibitors of monoamine oxidase (MAO) were initially used in medicine following the discovery of their antidepressant action. Subsequently their ability to potentiate the effects of an indirectly-acting sympathomimetic amine such as tyramine was discovered, leading to their limitation in clinical use, except for cases of treatment-resistant depression. More recently, the understanding that: a) potentiation of indirectly-acting sympathomimetic amines is caused by inhibitors of MAO-A but not by inhibitors of MAO-B, and b) that reversible inhibitors of MAO-A cause minimal tyramine potentiation, has led to their re-introduction to clinical use for treatment of depression (reversible MAO-A inhibitors and new dose form MAO-B inhibitor) and treatment of Parkinson's disease (MAO-B inhibitors). The profound neuroprotective properties of propargyl-based inhibitors of MAO-B in preclinical experiments have drawn attention to the possibility of employing these drugs for their neuroprotective effect in neurodegenerative diseases, and have raised the question of the involvement of the MAO-mediated reaction as a source of reactive free radicals. Despite the long-standing history of MAO inhibitors in medicine, the way in which they affect neuronal release of monoamine neurotransmitters is still poorly understood. In recent years, the detailed chemical structure of MAO-B and MAO-A has become available, providing new possibilities for synthesis of mechanism-based inhibitors. This review describes the latest advances in understanding the way in which MAO inhibitors affect the release of the monoamine neurotransmitters dopamine, noradrenaline and serotonin (5-HT) in the CNS, with an accent on the importance of these effects for the clinical actions of the drugs.
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Polymorphism in serotonin receptor 3B is associated with pain catastrophizing. PLoS One 2013; 8:e78889. [PMID: 24244382 PMCID: PMC3823944 DOI: 10.1371/journal.pone.0078889] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 09/16/2013] [Indexed: 12/13/2022] Open
Abstract
Pain catastrophizing, a coping style characterized by excessively negative thoughts and emotions in relation to pain, is one of the psychological factors that most markedly predicts variability in the perception of pain; however, only little is known about the underlying neurobiology. The aim of this study was to test for associations between psychological variables, such as pain catastrophizing, anxiety and depression, and selected polymorphisms in genes related to monoaminergic neurotransmission, in particular serotonin pathway genes. Three hundred seventy-nine healthy participants completed a set of psychological questionnaires: the Pain Catastrophizing Scale (PCS), the State-Trait Anxiety Inventory and Beck’s Depression Inventory, and were genotyped for 15 single nucleotide polymorphisms (SNPs) in nine genes. The SNP rs1176744 located in the serotonin receptor 3B gene (5-HTR3B) was found to be associated with pain catastrophizing scores: both the global score and the subscales of magnification and helplessness. This is the first study to show an association between 5-HTR3B and PCS scores, thus suggesting a role of the serotonin pathway in pain catastrophizing. Since 5-HTR3B has previously been associated with descending pain modulation pathways, future studies will be of great interest to elucidate the molecular pathways involved in the relation between serotonin, its receptors and pain catastrophizing.
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A selective reversible monoamine oxidase B inhibitor in smoking cessation: effects on its own and in association with transdermal nicotine patch. Psychopharmacology (Berl) 2012; 223:89-98. [PMID: 22451094 DOI: 10.1007/s00213-012-2692-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 03/11/2012] [Indexed: 10/28/2022]
Abstract
RATIONALE Monoamine oxidase B (MAO-B) activity is reduced in smokers. A MAO-B inhibitor alone or co-administered with nicotine may mimic the effects of smoking and be a candidate drug for smoking cessation. OBJECTIVE This study aims to determine the efficacy and safety of EVT302, a selective reversible MAO-B inhibitor, alone and on top of nicotine patch (NP) in smoking cessation. METHODS This was a randomised, double blind, placebo-controlled phase II, multicentre trial. Smokers (≥10 cigarettes/day) received either EVT302 (N = 145) or placebo (N = 145), or EVT302 (N = 61) or placebo (N = 61) on top of open label NP 21 mg/day for 8 weeks. The main comparison was between EVT302 and placebo without NP. The primary outcome measure was end-of-treatment 4-week continuous abstinence rate (CAR). SECONDARY OUTCOME MEASURES point prevalence abstinence rate, saliva cotinine concentrations in the groups without NP, urge to smoke, nicotine withdrawal symptoms and assessment of subjective effects of cigarettes. RESULTS The 4-week CAR was 15.2 % in the placebo, 17.2 % in the EVT302, 26.8 % in the NP + placebo and 32.8 % in the NP + EVT302 groups, respectively. There was no difference between EVT302 and placebo either alone (adjusted OR: 1.45, 95 % CI: 0.65-3.26) or when co-administered with NP. No statistically significant difference occurred for the secondary outcome measures. CONCLUSIONS The selective, reversible MAO-B inhibitor EVT302 was not superior to placebo in helping smokers quit, in line with data with selegiline and confirms that MAO-B inhibitors are not effective in smoking cessation. Co-administration of NP does not provide a supplementary benefit.
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Tuesta LM, Fowler CD, Kenny PJ. Recent advances in understanding nicotinic receptor signaling mechanisms that regulate drug self-administration behavior. Biochem Pharmacol 2011; 82:984-95. [PMID: 21740894 PMCID: PMC3163076 DOI: 10.1016/j.bcp.2011.06.026] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 06/15/2011] [Accepted: 06/16/2011] [Indexed: 12/17/2022]
Abstract
Tobacco smoking is one of the leading causes of disease and premature death in the United States. Nicotine is considered the major reinforcing component in tobacco smoke responsible for tobacco addiction. Nicotine acts in the brain through the neuronal nicotinic acetylcholine receptors (nAChRs). The predominant nAChR subtypes in mammalian brain are those containing α4 and β2 subunits. The α4β2 nAChRs, particularly those located in the mesoaccumbens dopamine pathway, play a key role in regulating the reinforcing properties of nicotine. Considering that twelve mammalian nAChR subunits have been cloned, it is likely that nAChRs containing subunits in addition to, or other than, α4 and β2 also play a role in the tobacco smoking habit. Consistent with this possibility, human genome-wide association studies have shown that genetic variation in the CHRNA5-CHRNA3-CHRNB4 gene cluster located in chromosome region 15q25, which encode the α5, α3 and β4 nAChR subunits, respectively, increases vulnerability to tobacco addiction and smoking-related diseases. Most recently, α5-containing nAChRs located in the habenulo-interpeduncular tract were shown to limit intravenous nicotine self-administration behavior in rats and mice, suggesting that deficits in α5-containing nAChR signaling in the habenulo-interpeduncular tract increases vulnerability to the motivational properties of nicotine. Finally, evidence suggests that nAChRs may also play a prominent role in controlling consumption of addictive drugs other than nicotine, including cocaine, alcohol, opiates and cannabinoids. The aim of the present review is to discuss recent preclinical findings concerning the identity of the nAChR subtypes that regulate self-administration of nicotine and other drugs of abuse.
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Affiliation(s)
- Luis M Tuesta
- Laboratory of Behavioral and Molecular Neuroscience, Department of Molecular Therapeutics, The Scripps Research Institute - Scripps Florida, Jupiter, FL 33458, USA
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De Palma G, Dick FD, Calzetti S, Scott NW, Prescott GJ, Osborne A, Haites N, Mozzoni P, Negrotti A, Scaglioni A, Mutti A. A case-control study of Parkinson's disease and tobacco use: Gene-tobacco interactions. Mov Disord 2010; 25:912-9. [PMID: 20461808 DOI: 10.1002/mds.22980] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Giuseppe De Palma
- Department of Experimental and Applied Medicine, University of Brescia, Italy.
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Franken IHA, van Strien JW, Kuijpers I. Evidence for a deficit in the salience attribution to errors in smokers. Drug Alcohol Depend 2010; 106:181-5. [PMID: 19781864 DOI: 10.1016/j.drugalcdep.2009.08.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 07/31/2009] [Accepted: 08/20/2009] [Indexed: 11/26/2022]
Abstract
The persisting use of substances despite of adverse consequences is one of the hallmarks of addictive behaviors such as cigarette smoking. In the present study we used event-related potentials (ERPs) to investigate one aspect of adverse consequences: responses to errors in smokers versus non-smokers. The aim of this study was to determine whether cigarette smokers display error-processing deficits as measured using error-related negativity (ERN) and error positivity (Pe). ERPs during an Eriksen flanker task were recorded from smokers and a non-smoking control group. Smokers showed the same ERN response as controls after making an error. However, the later Pe response was reduced as compared to the control group. On the behavioral level, we observed a trend towards increased error rates of smokers on incongruent trials. The present findings reveal that cigarette smoking is associated with reduced error processing. More specifically, while initial error processing seem intact, brain systems reflecting the motivational significance of a performance error seem compromised. It is argued that these cognitive deficits may cause or contribute to the persistence of smoking behavior and addictive behaviors in general.
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Launay JM, Del Pino M, Chironi G, Callebert J, Peoc'h K, Mégnien JL, Mallet J, Simon A, Rendu F. Smoking induces long-lasting effects through a monoamine-oxidase epigenetic regulation. PLoS One 2009; 4:e7959. [PMID: 19956754 PMCID: PMC2775922 DOI: 10.1371/journal.pone.0007959] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Accepted: 10/17/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Postulating that serotonin (5-HT), released from smoking-activated platelets could be involved in smoking-induced vascular modifications, we studied its catabolism in a series of 115 men distributed as current smokers (S), never smokers (NS) and former smokers (FS) who had stopped smoking for a mean of 13 years. METHODOLOGY/PRINCIPAL FINDINGS 5-HT, monoamine oxidase (MAO-B) activities and amounts were measured in platelets, and 5-hydroxyindolacetic acid (5-HIAA)--the 5-HT/MAO catabolite--in plasma samples. Both platelet 5-HT and plasma 5-HIAA levels were correlated with the 10-year cardiovascular Framingham relative risk (P<0.01), but these correlations became non-significant after adjustment for smoking status, underlining that the determining risk factor among those taken into account in the Framingham risk calculation was smoking. Surprisingly, the platelet 5-HT content was similar in S and NS but lower in FS with a parallel higher plasma level of 5-HIAA in FS. This was unforeseen since MAO-B activity was inhibited during smoking (P<0.00001). It was, however, consistent with a higher enzyme protein concentration found in S and FS than in NS (P<0.001). It thus appears that MAO inhibition during smoking was compensated by a higher synthesis. To investigate the persistent increase in MAO-B protein concentration, a study of the methylation of its gene promoter was undertaken in a small supplementary cohort of similar subjects. We found that the methylation frequency of the MAOB gene promoter was markedly lower (P<0.0001) for S and FS vs. NS due to cigarette smoke-induced increase of nucleic acid demethylase activity. CONCLUSIONS/SIGNIFICANCE This is one of the first reports that smoking induces an epigenetic modification. A better understanding of the epigenome may help to further elucidate the physiopathology and the development of new therapeutic approaches to tobacco addiction. The results could have a larger impact than cardiovascular damage, considering that MAO-dependent 5-HT catabolism is also involved in addiction, predisposition to cancer, behaviour and mental health.
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Affiliation(s)
- Jean-Marie Launay
- Service de Biochimie et Biologie Moléculaire/Equipe Associée (EA) 3621, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Lariboisière, Faculté de Pharmacie, Université Paris Descartes, Paris, France
| | - Muriel Del Pino
- Signalisation cellulaire, dynamique circulatoire et athérosclérose précoce, Unité Mixte de Recherche (UMR) 7131, Université Pierre et Marie Curie (UPMC) Paris Universitas/Centre Nationale de la Recherche Scientifique (CNRS), Hôpital Broussais, Paris, France
| | - Gilles Chironi
- Signalisation cellulaire, dynamique circulatoire et athérosclérose précoce, Unité Mixte de Recherche (UMR) 7131, Université Pierre et Marie Curie (UPMC) Paris Universitas/Centre Nationale de la Recherche Scientifique (CNRS), Hôpital Broussais, Paris, France
- Centre de médecine préventive cardiovasculaire, AP-HP, Hôpital Européen Georges Pompidou-Broussais, Paris, France
| | - Jacques Callebert
- Service de Biochimie et Biologie Moléculaire/Equipe Associée (EA) 3621, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Lariboisière, Faculté de Pharmacie, Université Paris Descartes, Paris, France
| | - Katell Peoc'h
- Service de Biochimie et Biologie Moléculaire/Equipe Associée (EA) 3621, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Lariboisière, Faculté de Pharmacie, Université Paris Descartes, Paris, France
| | - Jean-Louis Mégnien
- Signalisation cellulaire, dynamique circulatoire et athérosclérose précoce, Unité Mixte de Recherche (UMR) 7131, Université Pierre et Marie Curie (UPMC) Paris Universitas/Centre Nationale de la Recherche Scientifique (CNRS), Hôpital Broussais, Paris, France
- Centre de médecine préventive cardiovasculaire, AP-HP, Hôpital Européen Georges Pompidou-Broussais, Paris, France
| | - Jacques Mallet
- Laboratoire de Génétique Moléculaire de la Neurotransmission et des Processus Neurodégénératifs, UMR 7091, UPMC Paris Universitas/CNRS, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Alain Simon
- Signalisation cellulaire, dynamique circulatoire et athérosclérose précoce, Unité Mixte de Recherche (UMR) 7131, Université Pierre et Marie Curie (UPMC) Paris Universitas/Centre Nationale de la Recherche Scientifique (CNRS), Hôpital Broussais, Paris, France
- Centre de médecine préventive cardiovasculaire, AP-HP, Hôpital Européen Georges Pompidou-Broussais, Paris, France
| | - Francine Rendu
- Signalisation cellulaire, dynamique circulatoire et athérosclérose précoce, Unité Mixte de Recherche (UMR) 7131, Université Pierre et Marie Curie (UPMC) Paris Universitas/Centre Nationale de la Recherche Scientifique (CNRS), Hôpital Broussais, Paris, France
- Faculte de Medecine Pitie-Salpetriere, UMRS 956 Inserm, INSERM, Paris, France
- * E-mail:
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Dlugos AM, Palmer AA, de Wit H. Negative emotionality: monoamine oxidase B gene variants modulate personality traits in healthy humans. J Neural Transm (Vienna) 2009; 116:1323-34. [PMID: 19657584 PMCID: PMC3653168 DOI: 10.1007/s00702-009-0281-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 07/22/2009] [Indexed: 01/14/2023]
Abstract
Monoamine oxidase A and B (MAOA and MAOB) appear to be involved in the pathogenesis of Major Depression, and vulnerability of Major Depression is associated with personality traits relating to positive and negative affect. This study aimed to investigate associations between MAOA and MAOB polymorphisms and personality traits of positive and negative emotionality in healthy volunteers, to elucidate mechanisms underlying personality and the risk for depression. Healthy Caucasian volunteers (N = 150) completed the Multiphasic Personality Questionnaire (MPQ), which includes independent superfactors of Positive Emotionality and Negative Emotionality. Participants were genotyped for 8 MAOA and 12 MAOB single nucleotide polymorphisms (SNPs). Association analyses for both SNPs and haplotypes were performed using the permutation approach implemented in PLINK. Negative Emotionality was significantly associated with the two highly linked MAOB polymorphisms rs10521432 and rs6651806 (p < 0.002). Findings were extended in haplotype analyses. For MAOB the 4-SNP haplotype GACG formed from rs1799836, rs10521432, rs6651806 and rs590551 was significantly related to lower Negative Emotionality scores (p < 0.002). MAOA was not related to personality in this study. Our finding provides the first evidence that MAOB polymorphisms influence levels of negative emotionality in healthy human volunteers. If confirmed, these results could lead to a better understanding of personality traits and inter-individual susceptibility developing psychiatric disorders such as major depression.
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Affiliation(s)
- Andrea M. Dlugos
- Department of Psychiatry and Behavioral Neuroscience, The University of Chicago, 5841 S. Maryland Ave, Chicago, IL MC3077, USA,
| | - Abraham A. Palmer
- Department of Psychiatry and Behavioral Neuroscience, The University of Chicago, 5841 S. Maryland Ave, Chicago, IL MC3077, USA
- Department of Human Genetics, The University of Chicago, Chicago, IL, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, The University of Chicago, 5841 S. Maryland Ave, Chicago, IL MC3077, USA,
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19
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Grimwood S, Hartig PR. Target site occupancy: Emerging generalizations from clinical and preclinical studies. Pharmacol Ther 2009; 122:281-301. [DOI: 10.1016/j.pharmthera.2009.03.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Accepted: 03/04/2009] [Indexed: 01/17/2023]
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20
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D'hoedt D, Bertrand D. Nicotinic acetylcholine receptors: an overview on drug discovery. Expert Opin Ther Targets 2009; 13:395-411. [DOI: 10.1517/14728220902841045] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Abstract
While most cigarette smokers endorse a desire to quit smoking, only 14-49% will achieve abstinence after 6 months or more of treatment. A greater understanding of the effects of smoking on brain function may result in improved pharmacological and behavioral interventions for this condition. Research groups have examined the effects of acute and chronic nicotine/cigarette exposure on brain activity using functional imaging; the purpose of this chapter is to synthesize findings from such studies and present a coherent model of brain function in smokers. Responses to acute administration of nicotine/smoking include reduced global brain activity; activation of the prefrontal cortex, thalamus, and visual system; activation of the thalamus and visual cortex during visual cognitive tasks; and increased dopamine (DA) concentration in the ventral striatum/nucleus accumbens. Responses to chronic nicotine/cigarette exposure include decreased monoamine oxidase (MAO) A and B activity in the basal ganglia and a reduction in alpha4beta2 nicotinic acetylcholine receptor (nAChR) availability in the thalamus and putamen (accompanied by an overall upregulation of these receptors). These findings indicate that smoking enhances neurotransmission through cortico-basal ganglia-thalamic circuits by direct stimulation of nAChRs, indirect stimulation via DA release or MAO inhibition, or a combination of these and possibly other factors. Activation of this circuitry may be responsible for the effects of smoking seen in tobacco-dependent smokers, such as improvements in attentional performance, mood, anxiety, and irritability.
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Affiliation(s)
- Anil Sharma
- Department of Psychiatry and Biobehavioral Sciences, UCLA School of Medicine, Greater Los Angeles VA Healthcare System, 11301 Wilshire Blvd. Bldg 256 Suite 221, Los Angeles, CA 90073, USA.
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Lewis A, Miller JH, Lea RA. Monoamine oxidase and tobacco dependence. Neurotoxicology 2007; 28:182-95. [PMID: 16859748 DOI: 10.1016/j.neuro.2006.05.019] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 04/29/2006] [Accepted: 05/05/2006] [Indexed: 11/25/2022]
Abstract
Tobacco smoking is a leading cause of preventable death around the world, and there are major public health and research efforts in many countries aimed at reducing its usage. However, the molecular mechanisms underlying tobacco dependence are still not completely understood. Nicotine's action on nicotinic acetylcholine receptors, and the downstream release of dopamine, is believed to be the major pathway underlying tobacco dependence. However there is mounting evidence indicating that non-nicotinic components of tobacco smoke also play a role by inhibiting monoamine oxidase (MAO) and subsequently altering neurotransmitter levels. This article provides a review of the current knowledge of the association between MAO and tobacco dependence and suggests that further research into this topic is likely to lead to more effective pharmacotherapies for smoking cessation.
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Affiliation(s)
- A Lewis
- Institute of Environmental Science and Research Ltd., 34 Kenepuru Drive, P.O. Box 50-348, Porirua, Wellington, New Zealand
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23
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Brody AL. Functional brain imaging of tobacco use and dependence. J Psychiatr Res 2006; 40:404-18. [PMID: 15979645 PMCID: PMC2876087 DOI: 10.1016/j.jpsychires.2005.04.012] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Revised: 04/22/2005] [Accepted: 04/26/2005] [Indexed: 11/25/2022]
Abstract
While most cigarette smokers endorse a desire to quit smoking, only about 14% to 49% will achieve abstinence after 6 months or more of treatment. A greater understanding of the effects of smoking on brain function may (in conjunction with other lines of research) result in improved pharmacological (and behavioral) interventions. Many research groups have examined the effects of acute and chronic nicotine/cigarette exposure on brain activity using functional imaging; the purpose of this paper is to synthesize findings from such studies and present a coherent model of brain function in smokers. Responses to acute administration of nicotine/smoking include: a reduction in global brain activity; activation of the prefrontal cortex, thalamus, and visual system; activation of the thalamus and visual cortex during visual cognitive tasks; and increased dopamine (DA) concentration in the ventral striatum/nucleus accumbens. Responses to chronic nicotine/cigarette exposure include decreased monoamine oxidase (MAO) A and B activity in the basal ganglia and a reduction in alpha4beta2 nicotinic acetylcholine receptor (nAChR) availability in the thalamus and putamen. Taken together, these findings indicate that smoking enhances neurotransmission through cortico-basal ganglia-thalamic circuits either by direct stimulation of nAChRs, indirect stimulation via DA release or MAO inhibition, or a combination of these factors. Activation of this circuitry may be responsible for the effects of smoking seen in tobacco dependent subjects, such as improvements in attentional performance, mood, anxiety, and irritability.
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Affiliation(s)
- Arthur L Brody
- Department of Psychiatry and Biobehavioral Sciences, UCLA School of Medicine, 300 UCLA Medical Plaza, Suite 2200, Los Angeles, CA 90095, United States.
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24
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Fowler JS, Logan J, Volkow ND, Wang GJ. Translational neuroimaging: positron emission tomography studies of monoamine oxidase. Mol Imaging Biol 2006; 7:377-87. [PMID: 16265597 DOI: 10.1007/s11307-005-0016-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Positron emission tomography (PET) using radiotracers with high molecular specificity is an important scientific tool in studies of monoamine oxidase (MAO), an important enzyme in the regulation of the neurotransmitters dopamine, norepinephrine, and serotonin as well as the dietary amine, tyramine. MAO occurs in two different subtypes, MAO A and MAO B, which have different substrate and inhibitor specificity and which are different gene products. The highly variable subtype distribution with different species makes human studies of special value. MAO A and B can be imaged in the human brain and certain peripheral organs using PET and carbon-11 (half-life 20.4 minutes) labeled mechanism-based irreversible inhibitors, clorgyline and L -deprenyl, respectively. In this article we introduce MAO and describe the development of these radiotracers and their translation from preclinical studies to the investigation of variables affecting MAO in the human brain and peripheral organs.
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McRobbie H, Lee M, Juniper Z. Non-nicotine pharmacotherapies for smoking cessation. Respir Med 2005; 99:1203-12. [PMID: 16011894 DOI: 10.1016/j.rmed.2005.05.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Accepted: 05/15/2005] [Indexed: 10/25/2022]
Abstract
International chronic obstructive pulmonary disease guidelines recommend that smokers be strongly advised to quit, and should be offered help in doing so. The most effective smoking-cessation interventions combine behavioural support with pharmacotherapies. For smokers who do not wish to use nicotine replacement treatments, bupropion is a safe and effective non-nicotine alternative first-line treatment. Nortriptyline and clonidine have demonstrated efficacy in aiding smoking cessation, but are regarded as second-line therapies. A number of other non-nicotine treatments show promise, but more data are required before these can be recommended in assisting smokers to stop.
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Affiliation(s)
- H McRobbie
- Tobacco Dependence Research and Treatment Centre, Barts and The London, Queen Mary's School of Medicine and Dentistry, Turner Street, London E1 2AD, UK.
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Logan J, Fowler JS. Evidence for reduced arterial plasma input, prolonged lung retention and reduced lung monoamine oxidase in smokers. Nucl Med Biol 2005; 32:521-9. [PMID: 15982583 DOI: 10.1016/j.nucmedbio.2005.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 02/28/2005] [Accepted: 03/03/2005] [Indexed: 11/24/2022]
Abstract
UNLABELLED We have previously found that smokers have reduced brain monoamine oxidase (MAO) A and B using positron emission tomography (PET) and the irreversible mechanism-based radiotracers [(11)C]-labeled clorgyline (CLG) and deprenyl (DEP) and their deuterated analogs (D CLG, D DEP). More recently, we have estimated MAO A and B activity in other organs using the deuterium isotope effect to determine binding specificity for MAO and a three-compartment model to estimate k(3), the model term proportional to MAO A activity. Here, we have investigated the robustness of the model term k(3) for estimating lung MAO A and B in light of our unexpected finding that lung MAO activity (k(3)) was reduced for smokers relative to nonsmokers, although radiotracer uptake in the lungs was similar at peak and plateau for the two groups. METHODS Time-activity data from lung and arterial plasma were used from seven nonsmokers and seven smokers scanned previously with CLG and D CLG, and five nonsmokers and nine smokers scanned previously with DEP and D DEP. The measured time-activity curves for lung and plasma and the integrals for the arterial plasma time-activity curves were compared at an early time point (2.5 min) and at the end of the study (55 min). A three-compartment irreversible model was used to estimate the differences between smokers and nonsmokers, and the stability of the parameter (k(3)) while varying model assumptions for the relative fractions of lung tissue, blood and air in the PET voxel. RESULTS The peak in the arterial plasma input function and the integral of the arterial plasma time-activity curve over the first 2.5 min after radiotracer injection were significantly lower for smokers relative to nonsmokers for all four tracers. However, although the peak and plateau of the lung time-activity curves were similar for smokers and nonsmokers, the decline in radioactivity from peak to plateau was slower for smokers for all tracers. Using a three-compartment irreversible model, we estimated the ratio of MAO subtypes A and B in normal lung tissue to be on the order of 3 to 1 (MAO A to B) and that smokers have reduced MAO levels for both subtypes as measured by the model parameter, k(3). The values of k(3) are insensitive to model assumptions of variations in air and tissue fraction in the PET voxel. Most of the effects of changes in these fractions are absorbed into the parameter K(1), which governs the plasma-to-tissue transfer of tracer and is a function of blood flow. K(1) was found to be larger in smokers, although the values depend upon model assumptions of air and tissue fractions. k(3) was found to be significantly lower in smokers; for CLG, a 50% reduction in MAO A for both CLG and D CLG was observed. For DEP, k(3) was also significantly lower in smokers with a reduction of approximately 80% in lung MAO B, although there was a very large coefficient of variation in the smoker's k(3). We also found larger values of lambda (K(1)/k(2)) for smokers relative to nonsmokers for all tracers consistent with a longer lung retention of the nonenzyme-bound tracer, which explains the slower decline in uptake from peak radioactivity for smokers. CONCLUSIONS The measured arterial input function values for smokers and nonsmokers are significantly different for these two tracer pairs for nonsmokers and smokers particularly for the first few minutes after radiotracer injection. Model estimates of k(3) that indicate that smokers have lower lung MAO A and B activity than nonsmokers are robust and insensitive to variations in model assumptions for relative fractions of lung tissue, blood and air in the PET voxel. Although we have only investigated the behavior of [(11)C]clorgyline and [(11)C]l-deprenyl and their deuterium-substituted analogs in this report, the extent to which reduced arterial input and longer lung retention also hold for other tracers for subjects who smoke merits investigation.
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Affiliation(s)
- Jean Logan
- Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
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Frankle WG, Slifstein M, Talbot PS, Laruelle M. Neuroreceptor Imaging in Psychiatry: Theory and Applications. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2005; 67:385-440. [PMID: 16291028 DOI: 10.1016/s0074-7742(05)67011-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- W Gordon Frankle
- Departments of Psychiatry, Columbia University College of Physicians and Surgeons and New York State Psychiatric Institute, New York, New York 10032, USA
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Abstract
The relationship between smoking and depression is bidirectional. Recent research has focused on nicotine's neurobiologic impact on the brain as it relates to depression. Genetic factors are also important and may account for up to 67% of smoking initiation, maintenance, and dependence. Because nicotine withdrawal may mimic and induce depression, appropriate clinical evaluation and treatment are essential to reduce the high morbidity and mortality associated with smoking and depression and maximize smoking cessation rates.
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Affiliation(s)
- Khatija N Paperwalla
- Department of Psychiatry, Zucker Hillside Hospital, 75-59 23rd Street, Glen Oaks, NY 11004, USA
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Smolka MN, Budde H, Karow AC, Schmidt LG. Neuroendocrinological and neuropsychological correlates of dopaminergic function in nicotine dependence. Psychopharmacology (Berl) 2004; 175:374-81. [PMID: 15114432 DOI: 10.1007/s00213-004-1824-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
RATIONALE There is multiple evidence that nicotine--as with ethanol and other drugs of abuse--stimulates dopamine release in the ventral striatum as a central part of the brain reward circuits. Chronic nicotine exposure leads to changes in these dopaminergic reward circuits. During nicotine withdrawal, an impaired dopaminergic function has been reported. On the behavioral level, this seems to result in motivational disturbances in abstaining smokers. OBJECTIVES To investigate the impact of smoking on dopaminergic function in humans both on a neuroendocrinological and on a neuropsychological level. METHODS Thirty-seven healthy smokers were assessed whilst smoking (test 1) and after abstaining overnight for 12 h (test 2). A control group of 18 non-smokers was also examined twice. Severity of nicotine dependence, incentive motivation, digit span and verbal fluency were assessed. The sensitivity of central dopamine (DA) D2 receptors was assessed with the apomorphine-induced growth hormone (GH) secretion. RESULTS ANOVA revealed that GH response was significantly lower in smokers than in non-smokers (P=0.04). The GH response was significantly inversely correlated with severity of nicotine dependence (r=-0.39). Neuropsychological performance was not influenced by smoking status. After overnight abstinence from nicotine GH response, digit span and verbal fluency were not affected, whereas incentive motivation was significantly impaired in smokers (P=0.04). CONCLUSIONS Smoking is significantly associated with a reduced sensitivity of central DA D2 receptors. This alteration of dopaminergic sensitivity is stable even after 12 h of abstinence from nicotine. Therefore, the hypothesis that the motivational impairment during withdrawal from nicotine is associated with an altered sensitivity of central DA D2 receptors cannot be supported.
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Affiliation(s)
- Michael N Smolka
- Department of Addictive Behaviour and Addiction Medicine, Central Institute of Mental Health, Universität Heidelberg, 68072 Mannheim, Germany.
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Gatley SJ, Volkow ND, Fowler JS, Ding YS, Logan J, Wang GJ, Gifford AN. Positron emission tomography and its use to image the occupancy of drug binding sites. Drug Dev Res 2003. [DOI: 10.1002/ddr.10219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Abstract
Current cigarette smokers have reduced monoamine oxidase (MAO) and there is evidence that this is a pharmacological effect of tobacco smoke exposure rather than a biological characteristic of smokers. This article summarizes human and animal studies documenting the inhibitory effects of tobacco smoke on MAO and discusses MAO inhibition in the context of smoking epidemiology, MAO inhibitor compounds in tobacco, reinvestigations of low platelet MAO in psychiatric disorders and smoking cessation.
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Affiliation(s)
- Joanna S Fowler
- Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
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Nurnberg HG, Hensley PL, Gelenberg AJ, Fava M, Lauriello J, Paine S. Treatment of antidepressant-associated sexual dysfunction with sildenafil: a randomized controlled trial. JAMA 2003; 289:56-64. [PMID: 12503977 DOI: 10.1001/jama.289.1.56] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
CONTEXT Sexual dysfunction is a common adverse effect of antidepressants that frequently results in treatment noncompliance. OBJECTIVE To assess the efficacy of sildenafil citrate in men with sexual dysfunction associated with the use of selective and nonselective serotonin reuptake inhibitor (SRI) antidepressants. DESIGN, SETTING, AND PATIENTS Prospective, parallel-group, randomized, double-blind, placebo-controlled trial conducted between November 1, 2000, and January 1, 2001, at 3 US university medical centers among 90 male outpatients (mean [SD] age, 45 [8] years) with major depression in remission and sexual dysfunction associated with SRI antidepressant treatment. INTERVENTION Patients were randomly assigned to take sildenafil (n = 45) or placebo (n = 45) at a flexible dose starting at 50 mg and adjustable to 100 mg before sexual activity for 6 weeks. MAIN OUTCOME MEASURES The primary outcome measure was score on the Clinical Global Impression-Sexual Function (CGI-SF); secondary measures were scores on the International Index of Erectile Function, Arizona Sexual Experience Scale, Massachusetts General Hospital-Sexual Functioning Questionnaire, and Hamilton Rating Scale for Depression (HAM-D). RESULTS Among the 90 randomized patients, 93% (83/89) of patients treated per protocol took at least 1 dose of study drug and 85% (76/89) completed week 6 end-point assessments with last observation carried forward analyses. At a CGI-SF score of 2 or lower, 54.5% (24/44) of sildenafil compared with 4.4% (2/45) of placebo patients were much or very much improved (P<.001). Erectile function, arousal, ejaculation, orgasm, and overall satisfaction domain measures improved significantly in sildenafil compared with placebo patients. Mean depression scores remained consistent with remission (HAM-D score < or =10) in both groups for the study duration. CONCLUSION In our study, sildenafil effectively improved erectile function and other aspects of sexual function in men with sexual dysfunction associated with the use of SRI antidepressants. These improvements may allow patients to maintain adherence with effective antidepressant treatment.
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Affiliation(s)
- H George Nurnberg
- Department of Psychiatry, Health Sciences Center,University of New Mexico School of Medicine, 2400 Tucker NE, Albuquerque, NM 87131-5288, USA.
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Berlin I, Aubin HJ, Pedarriosse AM, Rames A, Lancrenon S, Lagrue G. Lazabemide, a selective, reversible monoamine oxidase B inhibitor, as an aid to smoking cessation. Addiction 2002; 97:1347-54. [PMID: 12359039 DOI: 10.1046/j.1360-0443.2002.00258.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Previous research has shown that smokers have reduced brain and platelet monoamine oxidase B (MAOB) activity. This is probably due to some components of tobacco smoke. When smokers quit, MAOB activity returns to normal. Reduced MAO activity may increase nicotine's addictive potential. AIMS To assess whether lazabemide, a reversible selective MAOB inhibitor, promotes smoking cessation. STUDY DESIGN Double-blind, randomized, placebo-controlled, multicenter phase II study. Placebo, lazabemide 100 mg/day and 200 mg/day were administered for 8 weeks. This was a dose finding, proof-of-concept, exploratory study. SETTING General practices and anti-smoking clinics in France and Belgium. PARTICIPANTS Smokers smoking > or=15 cigarettes per day and motivated to quit. MAIN OUTCOME MEASURE Sustained abstinence during the last 4 weeks of the study. FINDINGS The study was discontinued prematurely by the sponsor before randomization of the planned 420 smokers because of liver toxicity observed in other indications. Data of 330 randomized subjects could be analysed. Sustained abstinence during the last 4 weeks of treatment was 9%, 11% and 17% in the intent-to-treat population [P for trend: 0.036 (one-sided)]; 11%, 14% and 21% in the intent-to-treat population of smokers without those excluded because of discontinuation of the study [n = 262, P for trend: 0.02 (one-sided)], and 19%, 27% and 35% in completers [P for trend: 0.03 (one-sided)], in the placebo, lazabemide 100 mg/day and lazabemide 200 mg/day groups, respectively. Point prevalence abstinence (intent-to-treat population) at the end of treatment (week 8) was 17%, 19% and 30% in the placebo, lazabemide 100 mg/day and lazabemide 200 mg/day groups, respectively (placebo vs. lazabemide 200 mg/day: P = 0.01, one-sided). No treatment emergent major adverse event occurred. More nausea and insomnia were reported with lazabemide than with placebo. CONCLUSIONS MAOB inhibitors are promising treatments as an aid in smoking cessation. There may be an interest to develop MAOB inhibitors with an acceptable toxicity profile. Further studies may associate MAOB inhibitors with nicotine replacement therapies to increase therapeutic efficacy.
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Affiliation(s)
- Ivan Berlin
- Département de Pharmacologie, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Paris, France.
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Netter P, Toll C, Lujic C, Reuter M, Hennig J. Addictive and nonaddictive smoking as related to responsivity to neurotransmitter systems. Behav Pharmacol 2002; 13:441-9. [PMID: 12394420 DOI: 10.1097/00008877-200209000-00017] [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: 11/26/2022]
Abstract
In a double-blind crossover design on 36 male smokers, differences in hormone responses to a serotonergic (citalopram) and dopaminergic (bromocriptine) challenge were tested, to compare transmitter responsivities in addicted and pleasure-motivated smokers with respective controls. A general score of smoking addiction, according to DSM IV criteria, was associated with a blunted prolactin decrease to bromocriptine, indicating a possible nicotine-induced desensitization of DA receptors. The single questionnaire-based symptom of tolerance was associated with a blunted cortisol response to citalopram, indicating a particular desensitization of serotonin receptors. Nontolerant but addicted subjects exhibited increased serotonergic responsivity, interpreted as resulting from low serotonin levels associated with lack of impulse control. The questionnaire-based score of pleasure-motivated (='indulgent') smoking was associated with high dopaminergic activity (pronounced prolactin responses), confirming findings obtained in subjects exhibiting reward-related personality factors.
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Affiliation(s)
- P Netter
- Department of Psychology, University of Giessen, Germany.
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Lopes FL, Nascimento I, Zin WA, Valença AM, Mezzasalma MA, Figueira I, Nardi AE. Smoking and psychiatric disorders: a comorbidity survey. Braz J Med Biol Res 2002; 35:961-7. [PMID: 12185388 DOI: 10.1590/s0100-879x2002000800013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Epidemiological and clinical studies have shown a positive correlation between smoking and psychiatric disorders. To investigate the prevalence of cigarette smoking, 277 psychiatric outpatients with anxiety or depressive disorders (DSM-IV) answered a self-evaluation questionnaire about smoking behavior and were compared with a group of 68 control subjects. The diagnoses (N = 262) were: 30.2% (N = 79) major depressive disorder, 23.3% (N = 61) panic disorder, 15.6% (N = 41) social anxiety disorder, 7.3% (N = 19) other anxiety disorders, and 23.7% (N = 62) comorbidity disorders. Among them, 26.3% (N = 69) were smokers, 23.7% (N = 62) were former smokers and 50.0% (N = 131) were nonsmokers. The prevalence of nicotine dependence among the smokers was 59.0% (DSM-IV). The frequency of cigarette smoking did not show any significant difference among the five classes of diagnosis. The social anxiety disorder patients were the heaviest smokers (75.0%), with more unsuccessful attempts to stop smoking (89.0%). The frequency of former smokers was significantly higher among older subjects and nonsmokers were significantly younger (chi2 = 9.13, d.f. = 2, P = 0.01). Our data present some clinical implications suggesting that in our psychiatric outpatient sample with anxiety disorder, major depression and comorbidity (anxiety disorder and major depression), the frequency of cigarette smoking did not differ from the frequency found in the control group or in general population studies. Some specific features of our population (outpatients, anxiety and depressive disorders) might be responsible for these results.
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Affiliation(s)
- F L Lopes
- Laboratório de Pânico e Respiração, Instituto de Psiquiatria, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
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Abstract
The authors review developments in understanding smoking cessation interventions over the past decade. Noteworthy is the unprecedented growth of research and knowledge that has left a deeper understanding of how best to use new and existing behavioral and pharmacologic tools and strategies to help smokers quit. The status of public-health-level interventions is evaluated, questions are raised concerning their efficacy, and suggestions are offered for further refinement of these intervention strategies. Development of cessation guidelines is reviewed, and the state of knowledge concerning behavioral and pharmacologic interventions is summarized. The authors also present agendas for behavioral and pharmacologic research related to smoking cessation and discuss individual difference factors among smokers that may prove to be important in designing new and refining existing treatments.
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Affiliation(s)
- Raymond Niaura
- Centers for Behavioral and Preventive Medicine, Brown Medical School, the Miriam Hospital, Providence, Rhode Island 02903, USA.
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Kosel M, Gnerre C, Voirol P, Amey M, Rochat B, Bouras C, Testa B, Baumann P. In vitro biotransformation of the selective serotonin reuptake inhibitor citalopram, its enantiomers and demethylated metabolites by monoamine oxidase in rat and human brain preparations. Mol Psychiatry 2002; 7:181-8. [PMID: 11840311 DOI: 10.1038/sj.mp.4000946] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2000] [Revised: 04/16/2001] [Accepted: 04/19/2001] [Indexed: 02/06/2023]
Abstract
This study was conducted to identify enzyme systems eventually catalysing a local cerebral metabolism of citalopram, a widely used antidepressant of the selective serotonin reuptake inhibitor type. The metabolism of citalopram, of its enantiomers and demethylated metabolites was investigated in rat brain microsomes and in rat and human brain mitochondria. No cytochrome P-450 mediated transformation was observed in rat brain. By analysing H2O2 formation, monoamine oxidase A activity in rat brain mitochondria could be measured. In rat whole brain and in human frontal cortex, putamen, cerebellum and white matter of five brains monoamine oxidase activity was determined by the stereoselective measurement of the production of citalopram propionate. All substrates were metabolised by both forms of MAO, except in rat brain, where monoamine oxidase B activity could not be detected. Apparent Km and Vmax of S-citalopram biotransformation in human frontal cortex by monoamine oxidase B were found to be 266 microM and 6.0 pmol min(-1) mg(-1) protein and by monoamine oxidase A 856 microM and 6.4 pmol min(-1) mg(-1) protein, respectively. These Km values are in the same range as those for serotonin and dopamine metabolism by monoamine oxidases. Thus, the biotransformation of citalopram in the rat and human brain occurs mainly through monoamine oxidases and not, as in the liver, through cytochrome P-450.
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Affiliation(s)
- M Kosel
- Unité de Biochimie et Psychopharmacologie Clinique, Département Universitaire de Psychiatrie Adulte, CH-1008 Prilly-Lausanne, Switzerland
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Affiliation(s)
- R Niaura
- Centers for Behavioral and Preventive Medicine, Miriam Hospital, Brown Medical School, 02903, Providence, RI, USA.
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