[New aspects of acetaldehyde metabolism in human tissues and erythrocytes]

Abstract

Acetaldehyde, the active metabolite of ethanol oxidation, has been implicated to be mainly responsible for the diverse toxic effects of alcohol drinking. Aldehyde dehydrogenase (ALDH) catalyzes the oxidation of acetaldehyde in human liver and other organs. Impaired acetaldehyde metabolism by way of reduced ALDH activity may be the primary cause of tissue injury. Erythrocyte ALDH activity has been found to be decreased in alcoholics and returns to normal values on reducing the alcohol intake. The purpose of this study was to determine the interindividual variation in ALDH activity in different human tissues and erythrocytes. Results of the present study show that significant interindividual variation occurs in ALDH activity in different tissues. This variability in ALDH activity might explain the widely observed interindividual and ethnic/racial differences in alcohol intolerance and susceptibility to ethanol- and acetaldehyde-related tissue and organ damage. The study also confirms earlier observations that erythrocyte ALDH activity significantly varies in healthy individuals without alcohol abuse. This fact should be taken into consideration while evaluating the erythrocyte ALDH activity as a potential marker of alcoholism.