The fate of intratracheally installed benzo(a)pyrene in the isolated perfused rat lung of both control and 20-methylcholanthrene pretreated rats.

The fate of intratracheally installed 3H-benzo(a)pyrene in the isolated perfused rat lung of both control and 20-methylcholanthrene pretreated rats and in perfusion fluid was studied. The covalent binding of benzo(a)pyrene metabolites in the lung tissue itself was greatly enhanced by 20-methylcholanthrene pretreatment of rats. Similarly, the appearance of unchanged 3H-benzo(a)pyrene in the perfusion fluid of 20-methylcholanthrene-lung was decreased as compared to control lung perfusion. This was accompanied with the increase of water-soluble metabolites of benzo(a)-pyrene in the perfusion fluid of 20-methylcholanthrene-lung. When analyzing the metabolite profile of benzo(a)-pyrene in the lungs, especially the phenols (7-fold) and 9,10-diols (5-fold) were found to be increased.