title: Polypeptide patterns of hepatic microsomes from Long-Evans rats treated with different xenobiotics.
abstract: Two-dimensional gel electrophoresis was used to analyze hepatic microsomal polypeptides after treatment of immature, male Long-Evans rats with 3-methylcholanthrene, pregnenolone-16 alpha-carbonitrile, isosafrole, SKF-525A, Aroclor-1254, gamma-chlordane, or trans-stilbene oxide. Epoxide hydrolase and cytochromes P-450a, P-450bLE, P-450c, P-450d, and P-450e were all identified as resolved polypeptides in these electrophoretograms. Idiosyncratic polypeptide patterns characterized the microsomal preparations following treatment of rats with each inducing agent. Immunochemically identical cytochromes P-450bLE and P-450e were always present at the same relative levels even though their total amount varied 3-fold after induction by isosafrole, SKF-525A, Aroclor-1254, gamma-chlordane, and trans-stilbene oxide. Cytochromes P-450c and P-450d were coinduced by 3-methylcholanthrene, isosafrole, and Aroclor-1254, but their relative amounts varied. Pregnenolone-16 alpha-carbonitrile treatment resulted in an increase of a single major microsomal polypeptide which was also induced by phenobarbital, isosafrole, SKF-525A, Aroclor-1254, and trans-stilbene oxide. Only one polypeptide was identified as epoxide hydrolase in all of the microsomes analyzed. The results suggest that the levels of cytochromes P-450bLE and P-450e may be subject to coordinate control, whereas the other cytochromes P-450 are independently regulated.
mesh_terms: D000818:Animals; D001140:Aroclors / Q000494:pharmacology; D002706:Chlordan / Q000494:pharmacology; D020111:Chlorodiphenyl (54% Chlorine); D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004851:Epoxide Hydrolases / Q000096:biosynthesis; D007536:Isomerism; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D010452:Peptide Biosynthesis; D010634:Phenobarbital / Q000494:pharmacology; D011285:Pregnenolone Carbonitrile / Q000494:pharmacology; D011335:Proadifen / Q000494:pharmacology; D051381:Rats; D012451:Safrole / Q000494:pharmacology; D013267:Stilbenes / Q000494:pharmacology
chemical_list: D001140:Aroclors; D013267:Stilbenes; D020111:Chlorodiphenyl (54% Chlorine); D002706:Chlordan; D011285:Pregnenolone Carbonitrile; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D011335:Proadifen; D004851:Epoxide Hydrolases; C025906:stilbene oxide; D012451:Safrole; C015959:isosafrole; D010634:Phenobarbital