CHANGES IN ENZYME LEVELS ACCOMPANYING DIFFERENTIATION OF INTESTINAL EPITHELIAL CELLS

A method that enables the separation of cells of known ages from intestinal crypts and villi is described. The technique utilizes a newly designed planing apparatus and makes possible biochemical and physical analyses of cells in different stages of differentiation. Several enzymes involved in the metabolism of nucleic acid precursors have been assayed in differentiating intestinal epithelial cells. Thymidine kinase was found in young proliferating cells located in the crypts, while thymidylate phosphatase and adenylate deaminase were distributed uniformly from the crypts to the villus tips. Increases in adenosine deaminase, nucleoside phosphorylases and purine phosphoribosyltransferases were found to accompany the differentiation and migration of mucosal cells. The method provides a system for studying changes in macromolecular synthesis and the regulatory control of cell differentiation in the normal intestine. © 1969.