Enzymatic Hydrolysis of Biliary Conjugates of 3,4-Benzpyrene on Filter Paper

Abstract

METABOLITES of numerous biologically active endogenous and exogenous organic compounds are excreted in bile and urine as glucuronic acid conjugates. In the course of studying the mechanism of action of carcinogenic polycyclic hydrocarbons, we wished to identify the metabolites of certain of these agents. For this purpose, ¹⁴C-3,4-benzpyrene was injected into rats, and bile was collected by an indwelling cannula, utilizing a technique already described¹. The bile fractions were collected in an automatic fraction collector, and enzymatic hydrolysis with β-glucuronidase was undertaken. Characterization of all the metabolites by this technique proved to be impossible because of the extreme instability of some of the hydrolysis products. We therefore attempted to determine whether the extent of oxidation and the class of conjugate formed could be established by direct analysis of the conjugates.