Insulin treatment reversed/preventedthe activity changes in renal and cardiac superoxidedismutase, renal and cardiac catalase, and hepaticglutathione peroxidase as well as the hepaticchanges in lipid peroxidation and reduced and oxidizedglutathione, and the increase in cardiac glutathione.Thus, prudence should be exercised in theuse of experimentally galactosemic rats as a modelfor diabetes until the correspondence of the modelshas been more fully characterized. This evidence concerns the gene CAT and diabetes mellitus.