Development of short-term mutagenicity test systems in vitro - metabolic activation of indirectly acting mutagens by three immortal rat hepatocyte lines

The metabolic capacity to activate the indirectly acting promutagens aflatoxin B1, cyclophosphamide, benzo(a)pyrene, 7,12-dimethylbenz(a)anthracene and dimethylnitrosamine into DNA-reactive metabolites was investigated in three immortalized rat hepatocyte cell lines by analysing chromosome aberrations and sister chromatid exchange (SCE). In all three cell lines a significant clastogenic and SCE inducing response was observed after exposure to each test compound. Furthermore, activities of the two enzymes aryl hydrocarbon hydroxylase and aldrinepoxidase, which play major roles in the cytochrome P450-dependent metabolism, could be determined in all cell lines. (...) Due to the wide, efficient and stable spectrum of their metabolizing capacities, the tested rat hepatocyte lines offer promising perspectives as alternative assay system for the detection of indirectly acting mutagens.