TY - JOUR T1 - Sex Differences in Drug Metabolism by Rat Liver Microsomes JF - Molecular Pharmacology JO - Mol Pharmacol SP - 516 LP - 525 VL - 3 IS - 6 AU - JOHN B. SCHENKMAN AU - INGEBORG FREY AU - HERBERT REMMER AU - RONALD W. ESTABROOK Y1 - 1967/11/01 UR - http://molpharm.aspetjournals.org/content/3/6/516.abstract N2 - Sex differences in drug oxidase activity of liver microsomes from rats have been shown to be related to a difference in substrate affinity for the mixed function oxidase reaction, and not to a difference in the content of cytochrome P-450. These results, as well as spectral studies of substrate interaction with microsomal cytochrome, showed that microsomes isolated from livers of male rats had over twice the magnitude of substrate (hexobarbital and aminopyrine) binding than did microsomes isolated from the livers of female rats. Similar studies with aniline indicated only a small difference in Vmax or substrate induced spectral change between microsomes isolated from livers of male or female rats. ACKNOWLEDGMENTS This work was supported in part by a grant from the National Science Foundation (GB 2451) and grants from the U.S. Public Health Service (GM 12202-02 and GM 27706), and by the Deutsche Forschungsgemeinschaft. ER -