Effects of B2-deficiency on lipoperoxide and its scavenging system in the rat lens.

The level of NADPH-cytochrome c reductase, glutathione reductase and hepatic B2 was significantly decreased in rats fed a B2-deficient diet. The synthesis of ester forms of B2 was decreased more in the lenses of rats fed this diet for 8 weeks than in those fed this diet for 4 weeks. The glutathione reductase activity in the lens decreased as the duration of a B2-deficient diet increased; this may be ascribable to a decrease in the formation in the lenticular riboflavin ester as a coenzyme. The level of lipid peroxides increased in the serum and lenses of rats on the B2-deficient diet, however, compared to the controls, the changes in the activities of superoxide dismutase and glutathione S-transferase were not significant. Lenticular glutathione peroxidase activity was decreased significantly in rats fed the B2-deficient diet for 8 weeks. We suggest that B2 deficiency brings about metabolic disorders in the redox system to maintain lens transparency, that lipoperoxide is accumulated, and that the efficiency of the scavenging system and the activities of glutathione peroxidase and reductase are decreased.