Androgenic suppression of mouse hepatic FAD-containing monooxygenase activity.
Sex-related differences in the activity of hepatic FAD-containing monooxygenase (FAD-M) were found in C3H/St mice. Adult female mice had enzyme activities nearly two-fold greater than male mice and these differences, which were absent in sexually immature mice, became apparent at the onset of puberty. The sex differences in hepatic FAD-M appeared to be mediated through the suppressive effect of testosterone; castration of male mice enhanced enzyme activity, while androgenic replacement returned activities to control levels. Testosterone's suppressive effect was found to be relatively specific for hepatic FAD-M. Treatment of castrated male mice with both the anti-androgen flutamide and testosterone returned enzyme activity to control levels, suggesting that testosterone's regulation of hepatic microsomal FAD-M is receptor-mediated. Female gonadectomy had no effect on this enzyme's activity.
D000375:Aging; D000818:Animals; D002369:Castration; D005260:Female; D005485:Flutamide / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000254:growth & development; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D010105:Oxygenases / Q000037:antagonists & inhibitors*; D012737:Sex Factors; D013739:Testosterone / Q000494:pharmacology*
D013739:Testosterone; D005485:Flutamide; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)