Effects of cadmium on glutathione peroxidase, superoxide dismutase, and lipid peroxidation in the rat heart: a possible mechanism of cadmium cardiotoxicity.

Cadmium treatment of rats maintained on a low-selenium diet produced a significant increase in specific heart weight together with histopathological changes. This increase was accompanied by a decrease in the activities of the selenoenzyme, glutathione peroxidase, and the copper-containing enzyme superoxide dismutase, together with a rise in thiobarbiturate-reactive substances in the heart. Increased dietary selenium prevented the lowering of glutathione peroxidase activity but did not influence the effect of cadmium on superoxide dismutase. The effect of cadmium on thiobarbiturate-reactive materials was markedly reduced in the rats fed high dietary selenium.