Benzpyrene hydroxylase activity in the gastrointestinal tract.

Abstract

Summary Quantitative and morphologic histochemical studies of the activity of the benzpyrene hydroxylase system in the gastrointestinal tract have been carried out. In normal rats activity is found only in the small intestine. In rats in which an increase in activity is induced by oral administration of 1,2-benzanthracene, activity is found throughout the entire gastrointestinal tract but varies in magnitude from one region to another. The effects of starvation and of a low-fat diet have been studied and were found to markedly lower the activity of the enzyme system. In addition to the rat, benzpyrene hydroxylase activity has been found to be present in the duodenum of mouse, guinea pig, rabbit, hamster, dog, monkey, baboon, and man. The possible role of this type of system as a protective mechanism against polycyclic hydrocarbons which might reach the gastrointestinal tract is discussed.