Sex‐related difference in oxidative metabolism of testosterone and erythromycin by hamster liver microsomes

Abstract The activities of testosterone hydroxylases and erythromycin N -demethylase were significantly higher in liver microsomes from female hamsters than in the male counterparts. SDS-polyacrylamide gel electrophoresis revealed a difference in protein composition between male and female liver microsomes in the molecular mass region comprising cytochrome P-450. Western blot analysis showed further that antibodies to rat male-specific cytochrome P-450 crossreacted with at least two proteins in both male and female hamster microsomes, but one of the female proteins had a different molecular mass from that of the male proteins. It is concluded that sex difference in liver microsomal cytochrome P-450 is not restricted to rats and mice, as has previously been believed.