A) Circulating DMBA levels in blood collected by cardiac puncture at the indicated time points following oral or IP DMBA treatment (50 mg/kg). Each time point represents the mean (± SEM) of 2 to 3 different mice. B) Representative HPLC profiles of DMBA metabolites in the blood at 6 h after oral gavage (upper panel) or IP administration (lower panel). Major metabolites identified are: 5, 6-dihydrodiol, 8, 9-+10, 11-dihydrodiol, 7-OH DMBA, DMBA, DBP.