Differences in the cytochrome P-450S from resistant and susceptible house flies

A comparison of difference spectra formed with microsomal cytochrome P-450 from a susceptible and a resistant strain of house flies shows both quantitative and qualitative differences. The differences are similar to those observed for the same spectra between normal and phenobarbital- or 3-methylcholanthrene-treated mammals. The relationship of these findings to resistance, synergism, and cytochrome P-450 in the house fly is discussed.