Differential induction of UDP glucuronosyltransferase activities towards various substrates after polycyclic aromatic hydrocarbon administration to rats.

Administration of the carcinogens, benzo[a]pyrene and 1,2-benzanthracene, increased UDP glucuronosyltransferase activities towards 4-nitrophenol, 3-hydroxybenzo[a]pyrene, 7-hydroxycoumarin and 1-naphthol to a greater extent than did pretreatment with the noncarcinogens, anthracene and phenanthrene. However, the activity towards morphine was preferentially increased by the noncarcinogens. Activities towards testosterone and oestrone were only slightly increased by the four hydrocarbons. The results suggest that even within a single class of inducer various compounds are capable of causing a differential stimulation of UDP glucuronosyltransferase activities towards certain substrates.