title: The effect of Sudan III on drug metabolizing enzymes.
abstract: We have examined the induction of drug metabolizing enzymes in rat liver microsomes by azo dye, 1-(p-phenylazophenylazo)-2-naphthol (Sudan III). Marked increases were observed in the levels of cytochrome P-448 as well as in p-nitroanisole O-demethylase (p-NAD), amaranth (AR) and neoprontosil reductases (NPR) and 7-ethoxycoumarin O-deethylase (ECD) activities. On the other hand, aminopyrene N-demethylase activity was not significantly increased. Further, induced ECD activity was inhibited 90% by a specific antibody against cytochrome P-448 while the inhibition observed with an antibody against cytochrome P-450 was less than 25%. Simultaneous administration of Sudan III and 3-methylcholanthene (3-MC) induced cytochrome P-448 up to a level brought about by either Sudan III or 3-MC treatment alone. In contrast, Sudan III did not induce cytochrome P-448 in the 3-MC insensitive DBA/2 mouse. Solubilized microsomes from Sudan III-treated rats showed an identical sodium dodecyl sulfate polyacrylamide gel electrophoretic (SDS-PAGE) pattern with those from 3-MC-treated animals. It is concluded that the cytochrome P-448 induced in liver by Sudan III is very similar to that induced by 3-MC. Sudan III also induced UDP-glucuronyltransferase activity towards 1-naphthol and estradiol. It did not induce NADPH-cytochrome c reductase, nor any of the enzymes which constitute the microsomal electron transport chain except for cytochrome P-448.
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000494:pharmacology*; D019388:Cytochrome P-450 CYP1A2; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D003580:Cytochromes / Q000096:biosynthesis*; D004579:Electron Transport; D004790:Enzyme Induction / Q000187:drug effects*; D014453:Glucuronosyltransferase / Q000096:biosynthesis; D007118:Immunoassay; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013053:Spectrophotometry
chemical_list: D001391:Azo Compounds; D003580:Cytochromes; D004364:Pharmaceutical Preparations; D003577:Cytochrome P-450 Enzyme System; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2; D014453:Glucuronosyltransferase; C033006:sudan III