Effects of dietary vitamin B-2 and vitamin E on the Δ9- desaturase and catalase activities in the rat liver microsomes

Abstract

The effects of dietary vitamin B-2 and vitamin E on Δ 9- desaturation of stearoyl-CoA, catalase, glutathione peroxidase, Superoxide dismutase and electron transport components in rat liver microsomes have been investigated. Δ 9- desaturase activities were decreased on diets deficient of vitamin B-2, E and supplemented with E. Among the peroxide-scavenging enzymes, only the catalase activity in microsomes correlates significantly with Δ 9- desaturase activity. In vitro addition of bovine catalase had no effect on microsomal Δ 9- desaturase activity on control diet. However, it enhanced the Δ 9- desaturation in microsomes on vitamin B-2-deficient diet which contained low catalase and high superoxide dismutase activities, compared to those in microsomes of control diet. It is suggested that the hydrogen peroxide-generating and -decomposing systems may play an important role on the Δ 9- desaturase activity in microsomes.