| Abstract: | The cytotoxicities of polycyclic aromatic hydrocarbon (PAH) subclasses isolated from a complex organic mixture (coal gasification condensate) were studied in vitro in Chinese hamster ovary cells, in the presence of rat liver microsomes from animals pretreated with Aroclor. Toxicity was enhanced by microsomal metabolism and was inversely related to aromatic ring number. Rat liver cytosol, semipurified DT-diaphorase, and uridine diphosphoglucuronic acid decreased the cytotoxicity of a variety of PAH mixtures and representative PAH, as well as individual PAH metabolites. The results indicate that the in vitro toxicity of complex PAH mixtures is caused primarily by hydroxy-PAH and quinone metabolites of the predominant, nonmutagenic two- and three-ring PAHs. |
