[Correlation between cytochrome P-448 content and benzopyrene hydroxylase activity during the induction of microsomal monooxygenases using methylcholanthrene-type xenobiotics].
Using antibodies against electrophoretically homogeneous cytochrome P-448 from rat liver microsomes induced by 3-methylcholanthrene, the changes in the immunologic identity and contents by cytochrome P-448 induced by 3-methylcholanthrene, 3.4-benzpyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), were studied. No cytochrome P-448 was detected in the liver microsomes of control or phenobarbital-induced rats. This form of the cytochrome makes up to about 35% of the total content of the CO-binding hemoprotein during TCDD induction and up to 90% during 3-methylcholanthrene and 3,4-benzpyrene induction. On the other hand, 3-methylcholanthrene, 3,4-benzpyrene and TCDD significantly and equally activates the cytochrome P-448-dependent benzpyrene hydroxylase, since the antibodies against cytochrome P-448 inhibit benzpyrene metabolism in the microsomes by 85-90%. The possible reasons for the TCDD-induced increase in the catalytic activity of cytochrome P-448 as compared to the immunologically identical cytochrome P-448 induced by 3-methylcholanthrene and 3,4-benzpyrene, are discussed.
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism*; D001564:Benzo(a)pyrene; D001579:Benzopyrene Hydroxylase / Q000378:metabolism*; D001580:Benzopyrenes / Q000494:pharmacology*; D019388:Cytochrome P-450 CYP1A2; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D003580:Cytochromes / Q000032:analysis*; D004147:Dioxins / Q000494:pharmacology*; D007122:Immunoelectrophoresis; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology*; D008862:Microsomes, Liver / Q000201:enzymology*; D010634:Phenobarbital / Q000494:pharmacology; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D000906:Antibodies; D001580:Benzopyrenes; D003580:Cytochromes; D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D001564:Benzo(a)pyrene; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D001579:Benzopyrene Hydroxylase; D001189:Aryl Hydrocarbon Hydroxylases; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2; D010634:Phenobarbital
Sootnoshenie soderzhaniia tsitokhroma P-448 i benzopirengidroksilaznoĭ aktivnosti pri induktsii mikrosomnoĭ monooksigenazy ksenobiotikami metilkholantrenovogo tipa.