Evidence for the activation of 3-methylcholanthrene as a carcinogen in vivo and asa mutagen in vitro by P1 -450 from inbred strains of mice.

Genetic differences in aromatic hydrocarbon "responsiveness" exist among various mouse strains. New formation of cytochrome P1-450 and the induction aryl hydrocarbon (benzo [a ])pyrene) hydroxylase (as well as numerous other monooxygenase activities) appear to be associated ultimately with genes that cosegregate at a small number of genetic loci. By comparing "responsive" and "nonresponsive" siblings, we can evaluate the susceptibility of each individual to various mutagenic chemicals in vitro or carcinogenic agents in vivo.