title: Role of flavin-containing monooxygenase in the in vitro biotransformation of aldicarb in rainbow trout (Oncorhynchus mykiss).
abstract: 1. The in vitro biotransformation of 14C-aldicarb was examined in liver, kidney, and gill microsomes from the rainbow trout (Oncorhynchus mykiss). 2. In all tissues the major metabolite was aldicarb sulphoxide. Addition of the cytochrome P-450 inhibitor, N-benzylimidazole, failed to alter significantly aldicarb sulphoxide levels, while co-incubation with the flavin-containing monooxygenase substrates, N,N-dimethylaniline or methimazole, caused significant decreases in sulphoxide formation in liver and gill microsomes. 3. Aldicarb sulphoxide formation was optimal at pH 8.0, and had Michaelis-Menten kinetics with an apparent Km of 46.7 microM and a Vmax of 0.216 nmol/min per mg. 4. Aldicarb sulphoxide formation was competitively inhibited by co-incubation with N,N-dimethylaniline in liver microsomes. These data indicate that flavin-containing monooxygenase plays an important role in the in vitro biotransformation of aldicarb in rainbow trout.
authors.affiliation: Duke University Marine Laboratory, Beaufort, NC 28516.
authors.forename: D
authors.initials: D
authors.lastname: Schlenk
authors.forename: D R
authors.initials: DR
authors.lastname: Buhler
mesh_terms: D000448:Aldicarb / Q000493:pharmacokinetics*; D000814:Aniline Compounds / Q000494:pharmacology; D000818:Animals; D001711:Biotransformation; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005880:Gills / Q000201:enzymology; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008713:Methimazole / Q000494:pharmacology; D008861:Microsomes / Q000201:enzymology; D010105:Oxygenases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013454:Sulfoxides / Q000378:metabolism; D014337:Trout / Q000378:metabolism*
chemical_list: D000814:Aniline Compounds; D065607:Cytochrome P-450 Enzyme Inhibitors; D013454:Sulfoxides; D008713:Methimazole; C015157:N,N-dimethylaniline; D000448:Aldicarb; D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)