Benz[a]anthracene-induced alterations in the metabolic activation of benzo[a]pyrene by hamster embryo cell cultures

Abstract Co-administration of benz[ a ]anthracene (BA) with benzo[ a ]pyrene (B[ a ]P) to hamster embryo cell cultures for 24 h resulted in a decrease in the metabolism of benzo[ a ]pyrene by 40%, a decrease in the level of binding of B[ a ]P to DNA by 70% and a 10-fold reduction in mutation induction in a hamster embryo cell-mediated V79 cell mutation assay. This data indicates that the biological effects of co-administration of BA with B[ a ]P result from inhibition of the metabolic activation of B[ a ]P rather than induction of enzymes that detoxify the B[ a ]P.