BENZO(A)PYRENE TOXICOKINETICS IN THE CRICKET FOLLOWING INJECTION INTOTHE HEMOLYMPH

The metabolic disposition of C-14-labelled benzo(a)pyrene (BP) ire the cricket (Acheta domesticus) was investigated after injection into the haemolymph. C-14-BP was taken up rapidly by the nerve cord, malpighia n tubules, reproductive organs, gut, and muscle:cuticle of the cricket . The elimination half-lives of C-14-BP in these tissues ranged from 8 .9 to 17.8 h. The haemolymph C-14-BP concentration-time curve could be described by a one-compartment open pharmacokinetic model. C-14-BP wa s metabolized by the cricket mainly to unconjugated and conjugated BP metabolites since very little unchanged C-14-BP was found in the excre ta at 48 h post-dosing. GLPC-MSD and HPLC/ES-MS analyses showed the pr esence of at least two BP metabolites in the excreta. The BP metabolit es were identified tenatively as the diol derivatives of benzo(a)pyren e and benzo(a)pyrene quinone. (C) 1998 Elsevier Science B.V. All right s reserved.