Superoxide dismutase activity in diabetic rat retina.

We investigated the changes in superoxide dismutase activity in the retina, cornea, lens, blood, liver and kidney of streptozotocin-induced diabetic rats. Superoxide dismutase activity decreased in the retina; however, no changes were found in the cornea, lens, blood, liver and kidney. Electrophoretic studies showed no qualitative alteration of the enzyme protein in the diabetic rat retina. The present results show that superoxide dismutase activity decreased in the diabetic rat retina, and that superoxide reacted with unsaturated fatty acids of the retinal cells resulting in an increase of lipid peroxide contents. Superoxide dismutase may play a regulatory role in diabetic retinopathy.