METABOLIC-ACTIVATION OF BENZO[A]PYRENE IN 2 FETAL MOUSE HEPATOCYTE LINES - INDUCTION OF DNA-ADDUCTS AND MICRONUCLEI

We have studied the metabolic competence of two non-transformed epithe lial-like cell lines derived from fetal mouse liver, C 6 and C 2.8, to activate the promutagen benzo[a]pyrene by measuring both the inductio n of DNA adducts through the nuclease P1-enhanced P-32-postlabeling as say and the formation of micronuclei. The pattern and level of DNA add ucts detected in C 6 and C 2.8 cells treated with benzo[a]pyrene were compared with those obtained in human peripheral blood lymphocytes tre ated with the same compound and with [H-3]anti-benzo[a]pyrene diolepox ide. In both the cell lines and in human lymphocytes we observed a con sistent induction of distinct DNA adducts. In C 6 and C 2.8 cells, the most evident adduct showed a position similar to that of the main add uct induced by [H-3]-anti-benzo[a]pyrene diolepoxide in human lymphocy tes. In addition, benzo[a]pyrene caused a significant increase of micr onucleated C 6 and C 2.8 cells, whereas the frequency of micronuclei d id not increase in CHO cells treated, for comparison, in the same way.