Authors : Fathi Sherif, Göran Wahlstöbm, Lars Oreland
DOI : 10.1111/j.1530-0277.1993.tb05247.x
Volume : 17
Issue : 6
Year : 1993
Page No : 1313-1318
The activities of γ‐aminobutyrate aminotransferase (GABA‐T) and monoamine oxidase (MAO‐A and ‐B) were estimated in various brain regions of rats exposed to ethanol for 90 weeks. During the first period (weeks 1–58), the rats had access to both ethanol (10% w/v) and water during a 24‐hr interval at the end of each week. At this point, the animals were given either a saline injection (intraperito‐neally, group 1) or an ethanol injection (2.0 g/kg ip, group 2). During the second period (weeks 59–90), the rats in groups 1 and 2 had continuous access to both ethanol and water. The third group was composed of untreated control rats. Compared with controls, there was an increase of 20–45% in the mean brain GABA‐T activity in both groups of ethanol‐treated rats. However, analysis of the data for the individual ethanol‐treated rats revealed a considerable difference in brain GABA‐T activity. Thus, ‐30% of the ethanol‐treated rats showed approximately twice the activity of rats in the exposed groups and in the control group. There was no connection between ethanol intake, water intake, or body weight and GABA‐T activity in any of the brain regions examined. There was no effect of ethanol in vitro on the activity of GABA‐T in the brain cortex in concentrations of 20–100 mki, whereas acetaldehyde inhibited the activity by 15% at these concentrations. The present results suggest that there is a bimodal distribution with respect to the effect of ethanol on rat brain GABA‐T activity. With regard to MAO, the activities (both forms) in the brain remained unaffected after 90 weeks of ethanol treatment.