Effect of Benzene on Drug Metabolizing Enzyme Activities of Lung and Liver Microsomes

In vivo treatment of rabbits with benzene (880 mg/kg, s. c., 3 days) caused 7. I-fold increase in hydroxylation of p-nitrophenol to 4-nitrocatechol in liver microsomes. A 3.7 fold increase was also observed in liver aniline 4- hydroxylation activities. Benzene treatment did not cause any significant changes on drug metabolizing enzyme activities of lung microsomes. Although benzene treatment did not change cytochrome P-450 contents of lung and liver microsomes, it caused 1 nm spectral shift in the absorption maxima of CO difference spectrum of the dithionote reduced liver cytochrome P-450 forming cytochrome P-451.