title: Sexual dimorphism and the effects of the X-linked Tfm locus on hexobarbitone metabolism and action in mice.
abstract: 1 Normal males of the testicular feminized strain of mice (Tfm) had longer hexobarbitone-induced sleeping times than females, and hepatic hexobarbitone hydroxylase activity different in that the Km was higher and the Vmax lower in the male. 2 Castration and androgen replacement studies indicated that testicular androgens were responsible for the sexual differences in drug metabolism found in this mouse strain. 3 Hepatic hexobarbitone metabolism and action were feminized in the intact, androgen-insensitive, genetically male Tfm mouse. Furthermore, hexobarbitone hydroxylase activities were less responsive to large doses of testosterone in Tfm mice than in normal males. 4 The Tfm mouse with a deficiency in androgen receptors responded to the enzyme-inductive effects of phenobarbitone and softwood bedding, indicating that these inducers do not act through the androgen receptors.
mesh_terms: D013734:Androgen-Insensitivity Syndrome / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002369:Castration; D005260:Female; D006591:Hexobarbital / Q000378:metabolism* / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008861:Microsomes / Q000378:metabolism; D008862:Microsomes, Liver / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000378:metabolism; D012737:Sex Factors; D012890:Sleep / Q000187:drug effects; D013739:Testosterone / Q000494:pharmacology; D014960:X Chromosome / Q000502:physiology
chemical_list: D013739:Testosterone; D006591:Hexobarbital; D006899:Mixed Function Oxygenases; C021352:hexobarbital hydroxylase