PHARMACOKINETICS OF BENZO[A]PYRENE IN THE RAT

Groups of 4 male Wistar rats were dosed intravenously with C-14-labele d benzo[a]pyrene dissolved in an Emulphor/water vehicle at 3 different dose levels and killed at 1 of 15 specific time intervals from 5 min to 32 h after dosing. C-14-Radiolabel concentration-time data were obt ained for blood, brain, adipose, heart, kidney, liver, lung, spleen, a nd testes. Benzo[a]pyrene concentration-time data were obtained for bl ood, adipose, kidney, liver, and lung. Appropriate mathematical models were fitted to these data and to the data for metabolites derived as the residuals from C-14-radiolabel minus benzo[a]pyrene difference, wh ere applicable. Nonlinear kinetics were found for C-14-radiolabel in l iver, while the data from lung for both C-14-radiolabel and for benzo[ a]pyrene per se supported the binding of benzo[a]pyrene in that tissue .