Specific response to benzo(a)pyrene treatment depending on mode of administration in rats

Mathematical and statistical procedures were used to identify individual response in rats to benzo(a)pyrene (BP) treatment versus dose and regimen (single or repeated administration). Primary experimental data were suitably processed to exclude extreme values. A significant correlation was established between life-span and urine level of (+/-)-trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene (7,8-BP) after BP administration. It was found that, with single administration regimen, individual response to the carcinogenic agent correlated primarily with efficiency of excretion of the active forms of BP while in chronic experiment--with deactivation of the agent by enzymes.