Ethanol disordering of spin-labeled mouse brain membranes: correlation with genetically determined ethanol sensitivity of mice.

Abstract

Disordering of brain and erythrocyte membranes by ethanol in vitro was measured by ESR using 5-doxylstearic acid as spin label. Synaptosomal plasma membranes and erythrocyte membranes were isolated from 2 lines of mice developed, by selective breeding, for differential sensitivity to hypnotic effects of ethanol. Membranes taken from alcohol-sensitive long-sleep mice were more strongly disordered by ethanol in vitro than were membranes from alcohol-resistant short-sleep mice. Within a population of genetically heterogeneous mice, the most ethanol-sensitive animals had the most ethanol-sensitive synaptosomal plasma membranes. In vivo sensitivity of the individual mice was evaluated by measuring brain ethanol levels at a precise behavioral end point, recovery from ataxia. The data extend previous observations of correlations between in vitro and in vivo effects of ethanol and suggest that membrane disordering may be a primary mechanism of acute effects of ethanol.