Sister-chromatid exchange induction by polycyclic aromatic hydrocarbons in an intact cell system of adult rat-liver epithelial cells.

Adult rat-liver epithelial cell lines possess intrinsic metabolic capability for the biotransformation of xenobiotics and thus, are sensitive to a broad spectrum of mutagens/carcinogens in a mutagenesis assay at the hypoxanthine-guanine phosphoribosyl transferase locus. To provide another end-point of biological significance in these lines, we have investigated the application of adult rat-liver epithelial cell line 18 in a sister-chromatid exchange assay. Significant dose-dependent increases in the sister-chromatid exchange frequency occurred when liver cells were exposed to benzo[a]pyrene and 7,12-dimethylbenz[a]anthracene. A weak but positive response was elicited by benz[a]anthracene. The present observations thus confirm the capacity of these cells to generate genotoxic metabolites from activation-dependent mutagens/carcinogens and indicate a relationship between the production of mutations and sister-chromatid exchanges by polycyclic aromatic hydrocarbons.