Hepatic mixed-function oxidase activity in mice treated with methylated benzenes and methylated naphthalenes

Eight methylated benzene and five methylated naphthalene compounds were injected ip into adult male mice daily for 3 days. On the fourth day livers from control and treated mice were compared with regard to weight, microsomal N- and O-demethylase activity, and various spectral characteristics of microsomal cytochrome P-450. Three methylated benzenes and one methylated naphthalene produced significant increases in liver weight/body weight ratios, O-demethylation of p-nitroanisole, N-demethylation of aminopyrene, or a combination of these.