title: Evidence for the involvement of multiple forms of cytochrome P-450 in the occurrence of sex-related differences of drug metabolism in the rat.
abstract: Multiple forms of cytochrome P-450 in liver microsomes of untreated male and female rats could be divided into several fractions by the use of omega-amino-n-octyl Seph. 4B and DE-52 columns. Male cytochrome P-450 fractions (I-b - I-e) differed from female fractions (I-b - I-e) with respect to absorption peaks in carbon monoxide difference spectra and 7-propoxycoumarin O-depropylation activities. Although male and female I-a fractions showed quite similar protein bands on SDS-polyacrylamide gel electrophoresis, some protein bands in other male fractions (I-b - I-e) were absent in corresponding female fractions. Immunochemical examinations using immunoglobulin G raised to cytochrome P-450 purified from untreated male rats also showed that liver microsomes from male and female rats contain different forms of cytochrome P-450. Based on these results, we propose that sex-related differences of drug metabolizing activities in liver microsomes are caused by multiple forms of cytochrome P-450.
mesh_terms: D000818:Animals; D005591:Chemical Fractionation; D003374:Coumarins / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000276:immunology; D005260:Female; D005779:Immunodiffusion; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D011506:Proteins / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D012727:Sex Characteristics; D013053:Spectrophotometry
chemical_list: D003374:Coumarins; D011506:Proteins; D003577:Cytochrome P-450 Enzyme System; C030123:coumarin