title: Inducibility of various cytochrome P450 isozymes by phenobarbital and some other xenobiotics in Drosophila melanogaster.
abstract: The inducibility of cytochrome P450 isozymes has been investigated in the Drosophila melanogaster insecticide susceptible (Oregon R) and insecticide resistant (91R) strains. Both the level and induction kinetics of 7-ethoxycoumarin O-deethylase activity were stimulated by phenobarbital (PB) to a lower extent than that of aryl hydrocarbon hydroxylase in the Oregon R strain. The basal level of the cytochrome P450-linked activities in insecticide resistant flies was higher than that noted in susceptible ones. However, treatment with PB has increased levels of 7-ethoxycoumarin O-deethylase and aryl hydrocarbon hydroxylase activities more in susceptible flies than in resistant ones. In contrast to PB, the polycyclic aromatic hydrocarbon benzo[a]pyrene induced both activities in 91R flies to a greater extent than in Oregon R ones. The potent PB-like inducer in mice but not in rats 1.4-bis[2-(dichloropyridyloxy)]-benzene failed to induce the cytochrome P450 system in D. melanogaster, when triphenyldioxane (PB-like inducer in rats but not in mice) markedly affected this system in a PB-like manner. The SDS-PAGE followed by immunoblotting analysis using monoclonal antibodies 13-2e and 8-1d have shown that the level of the 56,000 and 54,000 Da insecticide resistance-related forms has increased in the susceptible strain by PB and some other PB like inducers. The relationship between these isozymes appearance and 7-ethoxycoumarin O-deethylase activity has been discussed.
authors.affiliation: Laboratory of Carcinogen Screening Methods, Cancer Research Center, AMS of Russia, Moscow.
authors.forename: S Y
authors.initials: SY
authors.lastname: Fuchs
authors.forename: V S
authors.initials: VS
authors.lastname: Spiegelman
authors.forename: G A
authors.initials: GA
authors.lastname: Belitsky
mesh_terms: D015660:7-Alkoxycoumarin O-Dealkylase / Q000096:biosynthesis; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D004790:Enzyme Induction; D007527:Isoenzymes / Q000096:biosynthesis*; D010634:Phenobarbital / Q000494:pharmacology*
chemical_list: D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System; D015660:7-Alkoxycoumarin O-Dealkylase; D001189:Aryl Hydrocarbon Hydroxylases; D010634:Phenobarbital