[Hexachlorobenzene induction of 2 forms of cytochrome P-450 in the rat liver microsome].
Induction of the monooxygenase system of xenobiotic metabolism by means of hexachlorobenzene (HCB) was studied in rat liver microsomes as compared with induction using phenobarbital (PB) and 3-methylcholanthrene (3-MC). HCB was shown to increase the content of cytochrome P-450 as well as aminopyrine- and benzphetamine-N-demethylase activities in liver microsomes. At the same time, HCB increased the benzpyrene hydroxylase activity as it was the case in induction with 3-MC. Electrophoresis in SDS-polyacrylamide gel showed that HCB, as phenobarbital does, induced appearance of the protein with a molecular mass 52,000 (cytochrome P-450) but not of the protein of molecular mass 56,000, which is the main isozyme of cytochrome P-450 in 3-MC microsomes (P-448). Except of cytochrome P-450, cytochrome, immunologically similar to cytochrome-P-448 from 3-MC microsomes, constituted 10% of the total content of cytochrome in HCB microsomes as shown by rocket immunoelectrophoresis using monospecific antibodies towards individual cytochromes P-448 and P-450 (anti-P-448 and anti-P-450). Anti-P-450 and especially anti-P-448 inhibited benzpyrene hydroxylase in HCB microsomes. HCB appears to be an inductor of a "mixed" type.
D000818:Animals; D002722:Chlorobenzenes / Q000494:pharmacology*; D019388:Cytochrome P-450 CYP1A2; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000096:biosynthesis*; D003580:Cytochromes / Q000032:analysis / Q000096:biosynthesis; D004790:Enzyme Induction / Q000187:drug effects; D006581:Hexachlorobenzene / Q000494:pharmacology*; D007120:Immunochemistry; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D008862:Microsomes, Liver / Q000187:drug effects* / Q000201:enzymology; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D002722:Chlorobenzenes; D003580:Cytochromes; D006581:Hexachlorobenzene; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2; D010634:Phenobarbital
Induktsiia geksakhlorbenzolom dvukh form tsitokhrom P-450 v mikrosomakh pecheni krys.