EXPOSURE TO ENVIRONMENTAL TOBACCO-SMOKE RESULTS IN AN INCREASED PRODUCTION OF (-ANTI-BENZO[A]PYRENE-7,8-DIHYDRODIOL-9,10-EPOXIDE IN JUVENILE FERRET LUNG HOMOGENATES())

Six-week-old ferrets were exposed head-only to clean air or environmen tal tobacco smoke (ETS) at an average particulate concentration of 38 +/- 13 mg/m(3) for 2 h/d, 5 d/wk for up to 15 wk. Twenty-four hours af ter the last exposure, the ferrets were sacrificed and the metabolism of benzo[a]pyrene and (-)-7R-trans-benzo[a]pyrene-7,8-dihydrodiol was studied in lung homogenates. The results show that after ETS exposure total metabolism of benzo[a]pyrene, measured by the accumulation of he xane nonextractable radioactivity, was increased by 35% in the males a nd 66% in the females (p <.05), respectively, of that observed with ai r-exposed controls. With (-)-7R-trans-benzo[a]pyrene-7,8-dihydrodiol a s substrate, the formation of both benzo[a]pyrene-r-7,t-8,9,c-10-tetra hydrotetraol and enzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide-derived te traols by lung homogenates of ETS-exposed male and female ferrets was significantly increased compared to the air-exposed controls (p <.01). DNA-bound radioactivity was significantly increased in both the males (p <.01) and females (p <.05) compared to the air-exposed ferrets.