Increased activity of testosterone hydroxylases in liver microsomes of diabetic rats treated with insulin.

Liver microsomes from alloxan diabetic rats displayed decreased activity to hydroxylate testosterone only at the 2-alpha and 6-beta positions. Diabetic insulin-treated rats showed higher hydroxylase activities than diabetic and control rats in the formation of all testosterone metabolites analyzed. The sodium dodecylsulfate electrophoretic profile of liver microsomal proteins from each group of rats exhibited distinct increases as well as decreases in the cytochrome P-450 region. Stimulation of testosterone metabolism by insulin may be associated with a higher synthesis of certain cytochrome P-450 isozymes.