Myocardial lipid peroxidation in rats treated chronically with hydralazine and its amelioration by vitamin A.

The effect of long-term intake of hydralazine on myocardial lipid peroxidation (measured as formation of thiobarbituric acid-reactive substances and lipid peroxide concentrations), superoxide dismutase activity, and the protective action of vitamin A were studied in rats. Hydralazine was administered to rats for 6 months. Compared with the controls, the left ventricle of the hydralazine-treated animals had an increased thiobarbituric-acid reactive substance content and lipid hydroperoxide concentrations per g of wet tissue. Simultaneous administration of vitamin A prevented the changes in lipid peroxidation and significantly increased the superoxide dismutase activity compared with that in hydralazine-treated rats. The results seem to indicate that the increase of lipid peroxidation in rats treated with hydralazine is due not only to the stimulation, but also to the inhibition of superoxide dismutase activity.