Liver microsomal alkoxyphenoxazone O-dealkylases of white Leghorn chickens: response to mixed function oxidase inducers.
1. The cytochrome P-450 substrates, methoxy-, ethoxy-, pentoxy- and benzyloxyphenoxazone were investigated in liver microsomes of phenobarbital- and beta-napththoflavone-induced White Leghorn chickens and compared to the rat mammalian model. 2. Thirty-two-fold increases in benzyloxyphenoxazone O-dealkylase and 27-fold increases in ethoxyphenoxazone O-dealkylase activities were observed in beta-naphthoflavone-treated chickens compared to only an 18-fold increase in ethoxyphenoxazone O-dealkylase activity in beta-naphthoflavone-treated rats. 3. Decreases in pentoxy- and benzyloxyphenoxazone O-dealkylase activities were observed in phenobarbital-treated chickens in contrast to increases of 197-fold in pentoxy- and 98-fold in benzyloxyphenoxazone O-dealkylases in the phenobarbital-treated rats.
Louisiana Veterinary Medical Diagnostic Laboratory, Louisiana State University, Baton Rouge 70803.
M I
MI
Banton
G W
GW
Winston
W
W
Flory
D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology; D002645:Chickens / Q000378:metabolism*; D019362:Cytochrome P-450 CYP2B1; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000378:metabolism*; D004790:Enzyme Induction; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000096:biosynthesis*; D010088:Oxidoreductases / Q000187:drug effects / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D019324:beta-Naphthoflavone
D001571:Benzoflavones; D019324:beta-Naphthoflavone; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D019362:Cytochrome P-450 CYP2B1; D010634:Phenobarbital