Microsomal cytochrome P450 monooxygenases in the house fly (Musca domestica L.): Biochemical changes associated with pyrethroid resistance and phenobarbital induction

摘要: Abstract Differences in the microsomal cytochrome P450 monooxygenase system and its inducibility by sodium phenobarbital (PB) were investigated insecticide-susceptible (S+) pyrethroid-resistant (LPR) house fly strains. In comparison to S+ strain, LPR had higher levels of total P450s, b 5 , NADPH-cytochrome c (P450) reductase, six activities: aryl hydrocarbon hydroxylation (AHH), aldrin epoxidation (AE), 7-ethoxycoumarin O -deethylation (ECOD), p -chloro- N -methylaniline -demethylation (PCMA), ethoxyresorufin (EROD), methoxyresorufin (MROD). The largest differences between strains noted for MROD (64×) EROD (56×) activities, these appeared be correlated with monooxygenase-mediated pyrethroid resistance strain. Comparisons susceptible resistant dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that strain showed a marked increase 54,400-Da protein band, suggesting this may isozyme involved conferring part resistance. vivo administration 0.25% PB sugar water flies induced three components system, as well increased all activities. contrast, treatment no significant effect on level or EROD, AHH, AE activity flies. Additionally, caused decrease PCMA while ECOD reductase significantly increased. SDS-PAGE indicated induction an at least seven proteins apparent molecular masses 47,400; 49,400; 51,500; 52,200; 54,400; 56,000; 57,500 Da. However, observable difference was PB-induced conjunction changes turnover numbers activities flies, suggest both quantitative qualitative monooxygenases.