A possible role of xanthine oxidase in producing oxidative stress in the heart of chronically ethanol treated rats.

Examination of hearts and livers of rats fed ethanol for 25-30 weeks showed significant increases in catalase and glutathione peroxidase activity. Further examination revealed that the xanthine dehydrogenase/oxidase activity ratio in both tissues were decreased, suggesting that an interconversion of the dehydrogenase into oxidase might have occurred. Such an interconversion would be expected to enhance the formation of superoxide anions during acetaldehyde metabolism by xanthine oxidase. Since a role of oxidative or free radical damage in the etiology of ethanol-induced liver pathology is becoming increasingly apparent, the observation that the biochemical changes in the heart and liver are comparable suggests that oxidative damage is involved in alcoholic pathology of the heart as well as liver.