Sex-dependent effect of streptozotocin-induced diabetes mellitus on hepatic steroid metabolism in the rat.

Diabetes mellitus is known to affect drug and steroid metabolism in the rat liver. Recently it has been shown that the effect on drug metabolism is both transient and sex-dependent. This study shows that the effect of diabetes on steroid metabolism is also sex-dependent i.e. only seen in the male and the effect is always to abolish the sex differences in steroid metabolism found in the intact animals. 7 alpha-hydroxylase activity, which is higher in the female, is increased by diabetes in the male whereas 6 beta-hydroxylase, 16 alpha-hydroxylase and 17-oxosteroid reductase, which are all higher in the male, are decreased by diabetes. This is a very similar result to that found for drug metabolism and indicates that insulin plays a role in the maintenance of sex differences in hepatic steroid metabolism in the rat as it does for drug metabolism.