Antioxidant systems in rat lens as a function of age: Effect of chronic administration of vitamin E and ascorbate

Oxidative damage occurring in the lenses of patients with Senile cataract m ay be due to partially reduced forms of oxygen. We assayed the activities o f superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) glutathione r eductase (GSH-Red), and glucose-6-phosphate dehydrogenase (G6PD) in rat len ses at different ages (1,4, and 24 months), and also evaluated lens glutath ione (GSH) levers and the effects of chronic administration of vitamin E an d sodium ascorbate. We observed a significant age-related decrease in GSH-P x, GSH-Red and G6PD activities, but no age-related change in SOD activity. Chronic treatment with both vitamin E and sodium ascorbate failed to restor e enzymatic activities to the levels of younger rats. An age-related reduct ion in GSH content was also observed; however, chronic administration of vi tamin E, but not of sodium ascorbate, restored GSH levels to those of young er rats.