Epithelial cell loss in remaining intestine after small bowel resection in the rat.

It is known that after small bowel resection, mucosal hyperplasia and increased cell turnover occur in the remaining intestine, particularly the ileum. At the end of their life span, epithelial cells are extruded into the bowel lumen. Comparative estimates of this cell loss may be obtained by collecting the DNA from a perfused gut segment. Male Sprague-Dawley rats underwent resection of 50 cm of proximal or distal small intestine or sham operation. One and six months after surgery, 50 cm of the remaining proximal or distal remnant were perfused with saline in vivo and the perfusate DNA was assayed. The DNA recovered from the perfusate of the distal remnant was at least twice as much as that from sham control segments. This was associated with comparable increases in mucosal weight, DNA, and protein concentration per centimeter of distal remnant. No significant changes were found in perfusate DNA recovered from proximal remnants. This correlated with minimal, if any, changes in mucosal weight, DNA, or protein concentration per centimeter of these remnants. Increased desquamation of epithelial cells may reflect the hyperplasia of intestinal mucosa after bowel resection. Recovery of intraluminal DNA may prove useful as an index of intestinal adaptation.