PREVENTION OF ETHANOL-INDUCED CHANGES IN REACTIVE OXYGEN PARAMETERS BY ALPHA-TOCOPHEROL

Rats were given a 200 mg/kg body weight daily dose of alpha-tocopherol by i.p. injection for 15 days. This resulted in elevated levels of gl utathione in both liver and brain, and in a reduced hepatic rate of ge neration of reactive oxygen species. The depression of hepatic and cer ebral glutathione levels in ethanol-consuming rats was prevented by si multaneous treatment with alpha-tocopherol. Other putative indices of hepatic pro-oxidant events, namely levels of mixed function oxidase an d proteolytic activity, were elevated by alpha-tocopherol both in the presence and absence of ethanol. In addition, levels of enzymes especi ally susceptible to oxidative degradation, glutamine synthetase and cr eatine kinase, were depressed in the liver following treatment with et hanol or alpha-tocopherol. Parameters rapidly responsive to oxidative changes revealed the antioxidant property of alpha-tocopherol, while p rotein-based indices reflecting more extended events suggested a pro-o xidant effect of this vitamin. Results suggest that high levels of alp ha-tocopherol can simultaneously lead to a more reduced intracellular environment and yet to localized evidence of enhanced oxidative events .