Effect of inducers on metabolism of benzo(a)pyrene in vivo and in vitro: analysis by high pressure liquid chromatography

The characterisation of metabolites formed from benzo(a)pyrene (BP) by Aspergillus ochraceus TS and effect of inducers on BP metabolism are reported. The high pressure liquid chromatographic profile of BP metabolites was similar to that of mammalian microsomes furnishing diols, quinones and phenols. The production of BP-4,5-dihydrodiol (K-region diol) by Aspergillus ochraceus TS seems to be novel and provides first report on BP metabolism by eukaryotic fungi. In control, phenols and quinones were produced in excess over dihydrodiols while the induced preparation showed the reverse order. Presumably the induction effecting production of excess dihydrodiols influenced the synthesis of epoxide hydrolase. In addition, a differential increase in BP metabolism was observed with inducers of narrow and broad specificity.