1
|
Zeng Y, Chen Y, Zhang S, Ren H, Xia J, Liu M, Shan B, Ren Y. Natural Products in Modulating Methamphetamine-Induced Neuronal Apoptosis. Front Pharmacol 2022; 12:805991. [PMID: 35058785 PMCID: PMC8764133 DOI: 10.3389/fphar.2021.805991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/09/2021] [Indexed: 11/13/2022] Open
Abstract
Methamphetamine (METH), an amphetamine-type psychostimulant, is highly abused worldwide. Chronic abuse of METH causes neurodegenerative changes in central dopaminergic neurons with numerous neuropsychiatric consequences. Neuronal apoptosis plays a critical role in METH-induced neurotoxicity and may provide promising pharmacological targets for preventing and treating METH addiction. In recent years, accumulating evidence has revealed that natural products may possess significant potentials to inhibit METH-evoked neuronal apoptosis. In this review, we summarized and analyzed the improvement effect of natural products on METH-induced neuronal apoptosis and their potential molecular mechanisms on modulating dopamine release, oxidative stress, mitochondrial-dependent apoptotic pathway, endoplasmic reticulum stress-mediated apoptotic pathway, and neuroinflammation. Hopefully, this review may highlight the potential value of natural products in modulating METH-caused neuronal apoptosis and provide useful information for future research and developments of novel and efficacious pharmacotherapies in this field.
Collapse
Affiliation(s)
- Yiwei Zeng
- College of Acupuncture-moxibustion and Tuina, College of Basic Medicine, College of Nursing, College of Chinese Classics, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yunhui Chen
- College of Acupuncture-moxibustion and Tuina, College of Basic Medicine, College of Nursing, College of Chinese Classics, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Su Zhang
- College of Acupuncture-moxibustion and Tuina, College of Basic Medicine, College of Nursing, College of Chinese Classics, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Huan Ren
- College of Acupuncture-moxibustion and Tuina, College of Basic Medicine, College of Nursing, College of Chinese Classics, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jialin Xia
- College of Acupuncture-moxibustion and Tuina, College of Basic Medicine, College of Nursing, College of Chinese Classics, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Mengnan Liu
- Traditional Chinese Medicine Hospital Affiliated to Southwest Medical University, Luzhou, China
| | - Baozhi Shan
- School of Humanities, Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Yulan Ren
- College of Acupuncture-moxibustion and Tuina, College of Basic Medicine, College of Nursing, College of Chinese Classics, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| |
Collapse
|
2
|
Hondebrink L, Zwartsen A, Westerink RHS. Effect fingerprinting of new psychoactive substances (NPS): What can we learn from in vitro data? Pharmacol Ther 2017; 182:193-224. [PMID: 29097307 DOI: 10.1016/j.pharmthera.2017.10.022] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The use of new psychoactive substances (NPS) is increasing and currently >600 NPS have been reported. However, limited information on neuropharmacological and toxicological effects of NPS is available, hampering risk characterization. We reviewed the literature on the in vitro neuronal modes of action to obtain effect fingerprints of different classes of illicit drugs and NPS. The most frequently reported NPS were selected for review: cathinones (MDPV, α-PVP, mephedrone, 4-MEC, pentedrone, methylone), cannabinoids (JWH-018), (hallucinogenic) phenethylamines (4-fluoroamphetamine, benzofurans (5-APB, 6-APB), 2C-B, NBOMes (25B-NBOMe, 25C-NBOMe, 25I-NBOMe)), arylcyclohexylamines (methoxetamine) and piperazine derivatives (mCPP, TFMPP, BZP). Our effect fingerprints highlight the main modes of action for the different NPS studied, including inhibition and/or reversal of monoamine reuptake transporters (cathinones and non-hallucinogenic phenethylamines), activation of 5-HT2receptors (hallucinogenic phenethylamines and piperazines), activation of cannabinoid receptors (cannabinoids) and inhibition of NDMA receptors (arylcyclohexylamines). Importantly, we identified additional targets by relating reported effect concentrations to the estimated human brain concentrations during recreational use. These additional targets include dopamine receptors, α- and β-adrenergic receptors, GABAAreceptors and acetylcholine receptors, which may all contribute to the observed clinical symptoms following exposure. Additional data is needed as the number of NPS continues to increase. Also, the effect fingerprints we have obtained are still incomplete and suffer from a large variation in the reported effects and effect sizes. Dedicated in vitro screening batteries will aid in complementing specific effect fingerprints of NPS. These fingerprints can be implemented in the risk assessments of NPS that are necessary for eventual control measures to reduce Public Health risks.
Collapse
Affiliation(s)
- Laura Hondebrink
- Dutch Poisons Information Center (DPIC), University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Anne Zwartsen
- Dutch Poisons Information Center (DPIC), University Medical Center Utrecht, Utrecht University, The Netherlands; Neurotoxicology Research Group, Division Toxicology, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.177, NL-3508 TD, Utrecht, The Netherlands
| | - Remco H S Westerink
- Neurotoxicology Research Group, Division Toxicology, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.177, NL-3508 TD, Utrecht, The Netherlands.
| |
Collapse
|
3
|
A comparison of psychotic symptoms in subjects with methamphetamine versus cocaine dependence. Psychopharmacology (Berl) 2017; 234:1535-1547. [PMID: 28190084 DOI: 10.1007/s00213-017-4551-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 01/25/2017] [Indexed: 01/02/2023]
Abstract
RATIONALE The psychostimulant drugs cocaine and methamphetamine are potent indirect dopamine receptor agonists which act through similar but not identical mechanisms. Studies in humans have observed that a large proportion of those who chronically use these drugs experience psychotic symptoms. However, direct comparisons of psychotic symptom severity between cocaine and methamphetamine users are lacking. OBJECTIVES The goal of the present study was to directly compare severity of psychotic symptoms between cocaine- and methamphetamine-dependent individuals. Additionally, we sought to determine how concurrent cocaine + methamphetamine dependence would influence psychotic symptoms. METHODS We recruited 153 polysubstance-using subjects meeting DSM-IV-TR criteria for cocaine dependence, 38 with methamphetamine dependence, and 32 with cocaine + methamphetamine dependence. Psychotic symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS) and analyzed using a five-factor model. All participants were also assessed for physical and mental illnesses as well as recent substance use. Most subjects completed a comprehensive neurocognitive battery. RESULTS While all three groups exhibited high total PANSS scores, the positive symptom subscale was significantly higher in the methamphetamine-dependent (17.03 ± 6.3) than the cocaine-dependent group (13.51 ± 4.12) and non-significantly higher (p = 0.08) than the cocaine + methamphetamine group (14.44 ± 5.50). Groups also differed on demographic variables, viral infection, and other indices of substance use, which were unlikely to account for the difference in positive symptoms. There were only modest differences between groups in neurocognitive function. CONCLUSIONS Methamphetamine dependence was associated with more severe positive symptoms of psychosis than cocaine dependence. Concurrent cocaine + methamphetamine dependence did not increase psychosis severity.
Collapse
|
4
|
Hiranita T, Freyberg Z. Importance of Substrate-Coupled Proton Antiport by the Vesicular Monoamine Transporter in the Actions of Amphetamines in Drosophila Brain. ACTA ACUST UNITED AC 2016; 4. [PMID: 28164142 DOI: 10.4172/2329-6488.1000e136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Takato Hiranita
- Division of Neurotoxicology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), AR 72079-9502, USA
| | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| |
Collapse
|
5
|
Neuroprotective effects of various doses of topiramate against methylphenidate-induced oxidative stress and inflammation in isolated rat amygdala: the possible role of CREB/BDNF signaling pathway. J Neural Transm (Vienna) 2016; 123:1463-1477. [PMID: 27665547 DOI: 10.1007/s00702-016-1619-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 09/05/2016] [Indexed: 12/26/2022]
Abstract
Methylphenidate (MPH) abuse damages brain cells. The neuroprotective effects of topiramate (TPM) have been reported previously, but its exact mechanism of action still remains unclear. This study investigated the in vivo role of various doses of TPM in the protection of rat amygdala cells against methylphenidate-induced oxidative stress and inflammation. Seventy adult male rats were divided into seven groups. Groups 1 and 2 received normal saline (0.7 ml/rat) and MPH (10 mg/kg), respectively, for 21 days. Groups 3, 4, 5, 6, and 7 were concurrently treated with MPH (10 mg/kg) and TPM (10, 30, 50, 70, and 100 mg/kg), respectively, for 21 days. elevated plus maze (EPM) was used to assess motor activity disturbances. In addition, oxidative, antioxidantand inflammatory factors and CREB, Ak1, CAMK4, MAPK3, PKA, BDNF, and c FOS gene levels were measured by RT-PCR, and also, CREB and BDNF protein levels were measured by WB in isolated amygdalae. MPH significantly disturbed motor activity and TPM (70 and 100 mg/kg) neutralized its effects. MPH significantly increased lipid peroxidation, mitochondrial GSSG levels and IL-1β and TNF-α level and CAMK4 gene expression in isolated amygdala cells. In contrast, superoxide dismutase, glutathione peroxidase, and glutathione reductase activities and CREB, BDNF Ak1, MAPK3, PKA, BDNF, and c FOS expression significantly decreased. The various doses of TPM attenuated these effects of MPH. It seems that TPM can be used as a neuroprotective agent and is a good candidate against MPH-induced neurodegeneration.
Collapse
|
6
|
Rau T, Ziemniak J, Poulsen D. The neuroprotective potential of low-dose methamphetamine in preclinical models of stroke and traumatic brain injury. Prog Neuropsychopharmacol Biol Psychiatry 2016; 64:231-6. [PMID: 25724762 DOI: 10.1016/j.pnpbp.2015.02.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/16/2015] [Accepted: 02/17/2015] [Indexed: 01/06/2023]
Abstract
Methamphetamine is a psychostimulant that was initially synthesized in 1920. Since then it has been used to treat attention deficit hyperactive disorder (ADHD), obesity and narcolepsy. However, methamphetamine has also become a major drug of abuse worldwide. Under conditions of abuse, which involve the administration of high repetitive doses, methamphetamine can produce considerable neurotoxic effects. However, recent evidence from our laboratory indicates that low doses of methamphetamine can produce robust neuroprotection when administered within 12h after severe traumatic brain injury (TBI) in rodents. Thus, it appears that methamphetamine under certain circumstances and correct dosing can produce a neuroprotective effect. This review addresses the neuroprotective potential of methamphetamine and focuses on the potential beneficial application for TBI.
Collapse
Affiliation(s)
- Thomas Rau
- Dept. Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
| | - John Ziemniak
- Gwynedd Pharmaceutical Consulting, Gwynedd Valley, PA, United States
| | - David Poulsen
- Neurosurgery Dept., University at Buffalo, SUNY-School of Medicine and Biomedical Sciences, Buffalo, NY, United States.
| |
Collapse
|
7
|
Hiranita T. Preclinical Efficacy of Novel Vesicular Monoamine Transporter 2 Inhibitors as Antagonists of d-Methamphetamine Self-Administration in Rats. JOURNAL OF ALCOHOLISM AND DRUG DEPENDENCE 2015; 3. [PMID: 27398393 PMCID: PMC4934384 DOI: 10.4172/2329-6488.1000e127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Takato Hiranita
- Division of Neurotoxicology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), 3900 NCTR Road, Jefferson, AR 72079-9501, USA
| |
Collapse
|
8
|
Panenka WJ, Procyshyn RM, Lecomte T, MacEwan GW, Flynn SW, Honer WG, Barr AM. Methamphetamine use: a comprehensive review of molecular, preclinical and clinical findings. Drug Alcohol Depend 2013; 129:167-79. [PMID: 23273775 DOI: 10.1016/j.drugalcdep.2012.11.016] [Citation(s) in RCA: 293] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 11/20/2012] [Accepted: 11/21/2012] [Indexed: 12/11/2022]
Abstract
Methamphetamine (MA) is a highly addictive psychostimulant drug that principally affects the monoamine neurotransmitter systems of the brain and results in feelings of alertness, increased energy and euphoria. The drug is particularly popular with young adults, due to its wide availability, relatively low cost, and long duration of psychoactive effects. Extended use of MA is associated with many health problems that are not limited to the central nervous system, and contribute to increased morbidity and mortality in drug users. Numerous studies, using complementary techniques, have provided evidence that chronic MA use is associated with substantial neurotoxicity and cognitive impairment. These pathological effects of the drug, combined with the addictive properties of MA, contribute to a spectrum of psychosocial issues that include medical and legal problems, at-risk behaviors and high societal costs, such as public health consequences, loss of family support and housing instability. Treatment options include pharmacological, psychological or combination therapies. The present review summarizes the key findings in the literature spanning from molecular through to clinical effects.
Collapse
Affiliation(s)
- William J Panenka
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | | | | | | | | | | | | |
Collapse
|
9
|
Wimalasena K. Vesicular monoamine transporters: structure-function, pharmacology, and medicinal chemistry. Med Res Rev 2011; 31:483-519. [PMID: 20135628 PMCID: PMC3019297 DOI: 10.1002/med.20187] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Vesicular monoamine transporters (VMAT) are responsible for the uptake of cytosolic monoamines into synaptic vesicles in monoaminergic neurons. Two closely related VMATs with distinct pharmacological properties and tissue distributions have been characterized. VMAT1 is preferentially expressed in neuroendocrine cells and VMAT2 is primarily expressed in the CNS. The neurotoxicity and addictive properties of various psychostimulants have been attributed, at least partly, to their interference with VMAT2 functions. The quantitative assessment of the VMAT2 density by PET scanning has been clinically useful for early diagnosis and monitoring of the progression of Parkinson's and Alzheimer's diseases and drug addiction. The classical VMAT2 inhibitor, tetrabenazine, has long been used for the treatment of chorea associated with Huntington's disease in the United Kingdom, Canada, and Australia, and recently approved in the United States. The VMAT2 imaging may also be useful for exploiting the onset of diabetes mellitus, as VMAT2 is also expressed in the β-cells of the pancreas. VMAT1 gene SLC18A1 is a locus with strong evidence of linkage with schizophrenia and, thus, the polymorphic forms of the VMAT1 gene may confer susceptibility to schizophrenia. This review summarizes the current understanding of the structure-function relationships of VMAT2, and the role of VMAT2 on addiction and psychostimulant-induced neurotoxicity, and the therapeutic and diagnostic applications of specific VMAT2 ligands. The evidence for the linkage of VMAT1 gene with schizophrenia and bipolar disorder I is also discussed.
Collapse
|
10
|
Ortiz AN, Kurth BJ, Osterhaus GL, Johnson MA. Dysregulation of intracellular dopamine stores revealed in the R6/2 mouse striatum. J Neurochem 2009; 112:755-61. [PMID: 19929911 DOI: 10.1111/j.1471-4159.2009.06501.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Huntington's disease (HD) is a fatal, neurodegenerative movement disorder characterized by preferential and extensive striatal degeneration. Here, we used fast-scan cyclic voltammetry to study the mobilization and efflux of reserve pool dopamine (DA) in striatal brain slices from HD model R6/2 mice. When applying stimulus trains of 120 pulses, evoked DA release in wild-type (WT) slices was greater than that in R6/2 slices at the higher frequencies (50 and 60 Hz). To quantify cytosolic and reserve pool DA levels, amphetamine-induced DA efflux was measured after pre-treatment with either tetrabenazine or alpha-methyl-p-tyrosine. Slices from 12-week-old R6/2 mice released less DA than slices from WT mice, while no difference was noted in slices from 6-week old mice. The vesicular release of reserve pool DA, mobilized by treatment with cocaine, was shorter lived in R6/2 slices compared with WT slices even though peak DA release was the same. Moreover, the number of DA reserve pool vesicles in R6/2 mice was less than half of that in WT. Therefore, our data suggest that the same number of DA molecules are present in each reserve pool vesicle in WT and R6/2 mice and that these vesicles are readily mobilized in both genotypes; however, R6/2 mice have fewer DA reserve pool vesicles available for mobilization.
Collapse
Affiliation(s)
- Andrea N Ortiz
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, The University of Kansas, Lawrence, Kansas 66047-7572, USA
| | | | | | | |
Collapse
|
11
|
Cadet JL, Krasnova IN, Jayanthi S, Lyles J. Neurotoxicity of substituted amphetamines: Molecular and cellular mechanisms. Neurotox Res 2007; 11:183-202. [PMID: 17449459 DOI: 10.1007/bf03033567] [Citation(s) in RCA: 194] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The amphetamines, including amphetamine (AMPH), methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA), are among abused drugs in the US and throughout the world. Their abuse is associated with severe neurologic and psychiatric adverse events including the development of psychotic states. These neuropsychiatric complications might, in part, be related to drug-induced neurotoxic effects, which include damage to dopaminergic and serotonergic terminals, neuronal apoptosis, as well as activated astroglial and microglial cells in the brain. The purpose of the present review is to summarize the toxic effects of AMPH, METH and MDMA. The paper also presents some of the factors that are thought to underlie this toxicity. These include oxidative stress, hyperthermia, excitotoxicity and various apoptotic pathways. Better understanding of the cellular and molecular mechanisms involved in their toxicity should help to generate modern therapeutic approaches to prevent or attenuate the long-term consequences of amphetamine use disorders in humans.
Collapse
Affiliation(s)
- Jean Lud Cadet
- Molecular Neuropsychiatry Branch, DHHS/NIH/NIDA, Intramural Research Program, 5500 Nathan Shock Drive, Baltimore, Maryland 21224, USA.
| | | | | | | |
Collapse
|
12
|
Pedersen K, Simonsen M, Østergaard SD, Munk OL, Rosa-Neto P, Olsen AK, Jensen SB, Møller A, Cumming P. Mapping the amphetamine-evoked changes in [11C]raclopride binding in living rat using small animal PET: Modulation by MAO-inhibition. Neuroimage 2007; 35:38-46. [PMID: 17223363 DOI: 10.1016/j.neuroimage.2006.11.038] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 10/24/2006] [Accepted: 11/01/2006] [Indexed: 11/19/2022] Open
Abstract
The performance of small animal PET for neuroreceptor studies in a psychopharmacological challenge paradigm is not yet well-described. Therefore, we used microPET and [(11)C]raclopride to map the availability of dopamine D(2/3) receptors in brain of anesthetized rats, first in a baseline condition, and again after challenge with saline or d-amphetamine. Parametric maps of the specific binding (binding potential, pB) were calculated using a reference tissue input from cerebellum, and spatially normalized to a digitized stereotaxic coordinate system for rat brain. In volumes of interest (VOIs), the mean baseline pB (n=6) was 2.05 in dorsal striatum (caudate-putamen), and 1.34 in ventral striatum (nucleus accumbens), and did not significantly differ upon retest 2 h later. The availability of [(11)C]raclopride binding sites at baseline was 8% higher in the right striatum. Challenge with amphetamine sulfate (1 mg/kg, i.v., n=4) decreased pB by 19% in both ventral and dorsal striatum. We have earlier predicted that blockade of monoamine oxidase (MAO) should potentiate the amphetamine-evoked dopamine release, thus enhancing the displacement of [(11)C]raclopride binding in vivo. However, pretreatment of rats with pargyline hydrochloride (4 mg/kg, n=4; 20 mg/kg, n=4) 1 day prior to PET did not potentiate the amphetamine-evoked reduction in dopamine receptor availability within the extended striatum. We conclude that small animal PET can be used to investigate stimulant-induced dopamine release, but that the spatial resolution is insufficient to detect differences between relative changes in dorsal vs. ventral divisions of the rat striatum. Furthermore, the present results do not reveal potentiation of the amphetamine-evoked release of dopamine in rats with MAO inhibition.
Collapse
Affiliation(s)
- Kasper Pedersen
- Centre for Functionally Integrative Neuroscience, Aarhus University, Denmark
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Schwartz K, Nachman R, Yossifoff M, Sapir R, Weizman A, Rehavi M. Cocaine, but not amphetamine, short term treatment elevates the density of rat brain vesicular monoamine transporter 2. J Neural Transm (Vienna) 2006; 114:427-30. [PMID: 16897597 DOI: 10.1007/s00702-006-0549-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Accepted: 06/24/2006] [Indexed: 11/30/2022]
Abstract
We compared the effect of 5 days D-amphetamine (5 mg/kg/day i.p.) and cocaine (15 mg/kg/day i.p.) administration on the vesicular monoamine transporter 2 (VMAT2) density in rat brain. VMAT2 expression was assessed by [(3)H]dihydrotetrabenazine high affinity binding. Cocaine administration led to significant increases in VMAT2 density in both prefrontal cortex (+40%, p < 0.01) and striatum (+23%, p < 0.05), while amphetamine did not affect VMAT2 expression. The upregulation of VMAT2 may serve as compensatory mechanism aimed to enhance the vesicular monoamine storage capacity.
Collapse
Affiliation(s)
- K Schwartz
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | | | | | | | | | | |
Collapse
|