title: Ontogenic development of drug-metabolizing enzymes in male chicken liver.
abstract: The ontogenic study of the hepatic biotransformation enzymes revealed the early development of both oxidative and conjugative enzymes in male chickens ranging in age from 3 to 12 weeks. Although the rate of microsomal cytochrome P450 reactions progressively increased during the first 9 weeks, it decreased thereafter. Furthermore, the proteins revealed by the antibodies to anti-cytochrome P450 1A2, 2B4, 2C7, and 3A4 appeared to be constitutively expressed. Hepatic monooxygenases were characterized by different developmental patterns. The demethylase activities increased progressively up to 9 weeks, then they declined, in 12 weeks reaching the activity level observed in 3-week-old chickens. In contrast, alkoxyresorufin O-dealkylases and benzopyrene hydroxylase activities continued to increase with age. Significant variability was noted for aniline hydroxylase. Among conjugation enzymes, UDP-glucuronyltransferase towards p-nitrophenol and isoniazid N-acetyltransferase activities increased with the age of the fowl, but with different profiles. Concerning glutathione S-transferase accepting 1-chloro-2,4-dinitrobenzene or 1,2-dichloro-4-nitrobenzene, the chickens aged from 3 to 9 weeks were less well developed in this enzyme than 12-week-old ones.
authors.affiliation: Laboratoire de pharmacologie-toxicologie, INRA, Toulouse, France.
authors.forename: M
authors.initials: M
authors.lastname: Coulet
authors.forename: C
authors.initials: C
authors.lastname: Eeckhoutte
authors.forename: P
authors.initials: P
authors.lastname: Galtier
mesh_terms: D000367:Age Factors; D000818:Animals; D015153:Blotting, Western; D002645:Chickens; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004789:Enzyme Activation; D008099:Liver / Q000201:enzymology*; D008297:Male; D004364:Pharmaceutical Preparations / Q000378:metabolism*
chemical_list: D004364:Pharmaceutical Preparations; D003577:Cytochrome P-450 Enzyme System