DNA-REPAIR IN HUMAN-LYMPHOCYTES TREATED IN-VITRO WITH (+ -)-ANTI-SYN-BENZO[A]PYRENE AND (+/-)-SYN-BENZO[A]PYRENE DIOLEPOXIDE/

Human PBL were treated in vitro with the ultimate reactive metabolites of BaP anti- and syn-BaPDE and DNA damage and repair were measured. T he incorporation of radioactivity into DNA due to UDS was higher after treatment with anti-BaPDE. Radioactive DNA adduct dosimetry applied t o PBL treated with tritiated syn- and anti-BaPDE demonstrated that ant i-BaPDE gave more DNA adducts, which were more efficiently removed tha n syn adducts in the 24 h following the treatment. HPLC analysis of de oxynucleosides obtained from the enzymatic digestion of DNA showed tha t in treated PBL the major DNA adduct involved deoxyguanosine. DNA str and breaks, detected by FADU, were induced at comparable levels by ant i- and syn-BaPDE (0.1-0.4 mug/ml), and persisted after 20 h of post-tr eatment incubation. Only in the case of syn-BaPDE did the percentage o f double-stranded DNA tend to increase with time after the treatment.