Epithelial cell population kinetics of isolated ileal loops (thirty-vella fistulae) after 40% small in testinal resection. Autoradiographic studies in the rat.

The influence of 40% small intestinal resection on epithelial cell population kinetics of isolated ileal loops (Thirty-Vella fistulae) was investigated by autoradiography with H3-thymidine in the rat. Sixty days after resection increases were found in the size of the proliferative (0.05 less than P less than 0.1) and villous (P less than 0.01) zones. In isolated ileal loops of animals not subjected to 40% small bowel resection proliferative and villous zones were reduced in size in comparison to those of ileum in continuity in a group subjected to jejunal transection and anastomosis (P less than 0.002). The findings support the hypothesis that villous size is increased after resection by the action of a systemic factor. However, they provide only limited evidence for the influence of a systemic factor on crypt cell proliferation.