Genotoxic effects of intragastrically administered benzo[a]pyrene in rat liver and intestinal cells.

The genotoxic effects of intragastrically administered benzo[a]pyrene (BaP) were studied in isolated rat liver and intestinal cells. We found that BaP was unable to induce unscheduled DNA synthesis in rat parenchymal liver cells in vivo. In contrast, alkaline elution showed that at 5 h after administration of BaP a considerable number of alkali-labile sites was present in the DNA of both intestinal cells and parenchymal liver cells, but not in that of non-parenchymal liver cells. The possibility is discussed that these sites were induced by radical intermediates, generated during the metabolization of BaP.