Alterations in the metabolism of 7,12-dimethylbenz[a]anthracene and various xenobiotics by rat hepatic microsomes following Sudan III treatment in vivo.
Sudan III treatment of Long-Evans rats results in increased hepatic monooxygenase activity using ethoxycoumarin and aniline as substrates. Monooxygenase activity towards amino-pyrine and nitrosodimethylamine is not affected. Sudan III treatment results in increased microsomal cytochrome P448 and increased amounts of a protein band which comigrates with purified cytochrome P448 during SDS polyacrylamide gel electrophoresis. The proportions of the different dihydrodiols formed during the incubation of 7,12-dimethylbenz[a]anthracene with microsomes vary between untreated and treated animals. Thus, extracts of microsomes from untreated rats were found to contain materials with chromatographic properties identical to those of the 3,4-dihydrodiol and the 5,6-dihydrodiol when examined on two different h.p.l.c. systems. Extracts of microsomes from Sudan III treated animals were found to contain materials with chromatographic properties identical to those of the 5,6-dihydrodiol and the 8,9-dihydrodiol when similarly examined. These findings suggest that the protective effect of Sudan III against DMBA induced leukaemia is mediated by an alteration in monooxygenase activity.
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000378:metabolism*; D000818:Animals; D001391:Azo Compounds / Q000494:pharmacology*; D019388:Cytochrome P-450 CYP1A2; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D003580:Cytochromes / Q000032:analysis; D005260:Female; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D001391:Azo Compounds; D003580:Cytochromes; D015127:9,10-Dimethyl-1,2-benzanthracene; D003577:Cytochrome P-450 Enzyme System; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2; C033006:sudan III