title: Putative role of brain acetaldehyde in ethanol addiction.
abstract: The putative contribution of brain acetaldehyde (AcH) to ethanol (EtOH) tolerance and dependence (addiction) is reviewed. Although the role of AcH in EtOH addiction has been controversial, there are data showing a relationship. AcH can be formed in the brain tissues through the peroxidatic activity of catalase and by oxidation via other oxidizing enzymes such as cytochrome P-4502E1. Significant formation of AcH occurs in vitro in brain tissue at concentrations of EtOH that can be achieved by voluntary consumption of EtOH by rodents. AcH itself possesses reinforcing properties, which suggests that some of the behavioral pharmacological effects attributed to EtOH may be a result of the formation of AcH, and supports the involvement of AcH in EtOH addiction. Modulation of aldehyde dehydrogenase (ALDH) and brain catalase activity can change EtOH-related addictive behaviors presumably by changing AcH levels. Moreover, some condensation reaction products of AcH may promote some actions of EtOH and its consumption. On the basis of the findings, it can be concluded that AcH may mediate some of the CNS actions of EtOH including tolerance and dependence, although further exploration the involvement of AcH in EtOH addiction is warranted.
authors.affiliation: University of Colorado Health Sciences Center at Fitzsimons, Department of Pharmacology, Alcohol Research Center, Mail Stop 8303, P.O. Box 6511, Aurora, CO 80045-0511, USA. Xin-sheng.deng@uchsc.edu
authors.forename: Xin-sheng
authors.initials: XS
authors.lastname: Deng
authors.forename: Richard A
authors.initials: RA
authors.lastname: Deitrich
mesh_terms: D000079:Acetaldehyde / Q000378:metabolism*; D000437:Alcoholism / Q000503:physiopathology* / Q000523:psychology; D000444:Aldehyde Dehydrogenase / Q000502:physiology; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002374:Catalase / Q000502:physiology; D019392:Cytochrome P-450 CYP2E1 / Q000502:physiology; D004361:Drug Tolerance / Q000502:physiology; D000431:Ethanol / Q000493:pharmacokinetics; D006801:Humans; D009042:Motivation; D012377:Rodentia
chemical_list: D000431:Ethanol; D002374:Catalase; D019392:Cytochrome P-450 CYP2E1; C096127:ALDH2 protein, human; D000444:Aldehyde Dehydrogenase; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D000079:Acetaldehyde