The effect of some glucocorticoids on hepatic microsomal hydroxylation in the rat and hamster

The effect of some glucocorticoids on hepatic microsomal biphenyl and aniline hydroxylations were investigated in rat and hamster. Steroids were either added to the standard incubation mixture or given as a single dose intraperitoneally before preparation of the liver microsomes for enzyme determination. The addition of steroids in vitro enhanced biphenyl-2-hydroxylation activity in hepatic microsomes of rat but not of hamster and the most pronounced effect was obtained with betamethasone. A similar species difference in the effects of betamethasone on this enzyme was also observed after administration of a single dose of the steroid in vivo.