Effects of long term alcohol ingestion on glutathione metabolising enzymes and taurine contents in the myocardium of rats

The effects of long term intake of dietary alcohol on myocardial glutathione metabolism and taurine content were studied in rats. Alcohol, comprising more than 30% of the dietary calorie content, was administered to male CFY rats for six weeks. Compared with the controls, the left ventricle of the alcohol treated animals had an increased taurine content (18.4(2.6) vs 13.1(2.5) μmol·g wet weight−1) and a slightly, but not significantly, decreased reduced glutathione content. To assess the glutathione metabolism in the myocardium, the activities of glutathione reductase, glutathione peroxidase, glutathione-S-transferase, γ-glutamylcysteine synthetase, and glutathione synthetase were measured. Significant increases were found in the activities of glutathione reductase (0.65(0.03) U.g wet weight−1 in the controls and 0.80(0.05) U.g wet weight−1 in the alcohol treated rats) and glutathione-peroxidase after six weeks of alcohol ingestion. Only slight, non-significant changes were found for the other enzymes investigated. It is thus apparent that in the myocardium of rats treated long term with ethanol the previously observed enhanced lipoperoxidation is not necessarily associated with severe glutathione depletion, and an increase in the activity of glutathione reductase might be responsible, at least in part, for the preservation of glutathione.