title: Inhibitory effect of carbon monoxide on the N- and ring-hydroxylation of 2-acetamidofluorene by hamster hepatic microsomal preparations.
abstract: The effect of CO on N-, 3-, 5- and 7-hydroxylation of 2-acetamidofluorene by liver microsomal fractions from control and 3-methylcholanthrene-pretreated hamsters was studied. All hydroxylations were inhibited by CO, but the degree of inhibition was different for each hydroxylation. The ratios of CO to O(2) needed for 50% inhibition of the N-, 3-, 5- and 7-hydroxylations by control preparations were 8.0:1, 8.2:1, 4.2:1 and 7.1:1 respectively and by preparations from treated animals were 4.2:1, 8.9:1, 2.3:1 and 3.2:1 respectively. These results are discussed in terms of the possible presence of more than one type of cytochrome P-450 involved in hydroxylations of 2-acetamidofluorene by liver microsomal fractions from both control and pretreated hamsters.
mesh_terms: D015073:2-Acetylaminofluorene / Q000378:metabolism*; D000818:Animals; D002245:Carbon Dioxide / Q000008:administration & dosage; D002248:Carbon Monoxide / Q000494:pharmacology*; D006224:Cricetinae; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005449:Fluorenes / Q000378:metabolism*; D006900:Hydroxylation; D066298:In Vitro Techniques; D007274:Injections, Intraperitoneal; D008297:Male; D008748:Methylcholanthrene / Q000008:administration & dosage / Q000494:pharmacology; D008862:Microsomes, Liver / Q000187:drug effects*
chemical_list: D005449:Fluorenes; D002245:Carbon Dioxide; D008748:Methylcholanthrene; D002248:Carbon Monoxide; D003577:Cytochrome P-450 Enzyme System; D015073:2-Acetylaminofluorene