Abstract

In order to verify the hypothesis that intestinal cell proliferation is controlled by a mitotic inhibitor, extracts of villous epithelial cells from different species were analysed to study their effect on the proliferation of various intestinal cells. Villous extracts from rat and rabbit strongly and reversibly inhibited cell division and DNA synthesis in a rat intestinal epithelial cell line and a primary culture of rabbit intestinal epithelial cells. This non-cytotoxic, tissue specific but not species specific factor is present in both villous cells and crypt cells, with the highest concentrations occurring in the superficial epithelial cells. Assay of a partial purification of this factor showed that it has a molecular weight of approximately 190,000 daltons.