title: Inhibition of p-aminophenol metabolism: a possible mechanism of enhancement of aniline hydroxylation.
abstract: The p-hydroxylation of aniline has been traditionally determined by measurement of p-aminophenol (PAP) formation. Comparison of isotopic and colorimetric procedures indicate that the actual amount of aniline metabolized exceeds the among of PAP recovered. Data suggest that enhancement of p-hydroxylation of aniline by acetone, malaoxon and paraoxon may result from inhibition of further metabolism of PAP by the microsomal cytochrome b5-dependent desaturase system. Involvement of the desaturase system is supported by observations that: (a) metabolism of PAP was reduced by starvation and stimulated when starvation was followed by feeding a high carbohydrate diet; (b) enrichment of hepatic microsomes with detergent purified cytochrome b5 decreased the amount of aniline apparently metabolized, as measured by the amount of PAP recovered, and (c) a high correlation occurred between effects of acetone, malaoxon and paraoxon on reoxidation of cytochrome b5 and capacity of these three compounds to enchance aniline metabolism.
mesh_terms: D000627:Aminophenols / Q000378:metabolism*; D000814:Aniline Compounds / Q000378:metabolism*; D000818:Animals; D003580:Cytochromes / Q000378:metabolism; D004032:Diet; D006900:Hydroxylation; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats
chemical_list: D000627:Aminophenols; D000814:Aniline Compounds; D003580:Cytochromes; C026729:4-aminophenol