Activity and inducibility of cytochrome P-450-1A in the liver of mice with different sensitivity to hepatocarcinogenic effect of o-aminoazotoluene

Specific activity of cytochrome P-450-1a is detected in the liver of 7 inbred mouse strains sensitive (SWR, C3HA, DD, and CBA) and resistant (AKR, CC57BR, and C57BL) to o-aminoazotoluene-induced hepatocarcinogenesis: 7-ethoxyresorufin-O-diethylase a nd 7-methoxyresorufin-O-dimethylase, induced by benzo(a)pyre ne and o-aminoazotoluene. Mice sensitive (CC57BR and C57BL) and resistant (AKR) to P-450-1a induction were resistant to induction of liver tumor and, similarly, mice both resistant (SWR and DD) and sensitive (C3HA and CBA) to P-450-1a induction were sensitive to hepatic tumor induction. Therefore, there was no correlation between inducibility of cytochrome P-450-1a and sensitivity to o-aminoazotoluene-induced hepatocarcinogenesis at the initial stages of chemical carcinogenesis.