Extent of small bowel resection does not influence the magnitude of intestinal adaptation in the mouse.

ABSTRACT

PURPOSE: The magnitude of intestinal adaptation is considered to correlate with the extent of small bowel resection (SBR). However, this association has never been tested in mice. We sought to test the hypothesis that a greater SBR will induce a greater adaptation response. METHODS: C57/B6 mice underwent 50% SBR, 75% SBR, or sham operation and were killed on postoperative day 7. The magnitude of adaptation was compared between 50% SBR and 75% SBR as changes in villus height, crypt depth, as well as rates of apoptosis and proliferation. RESULTS: Seventy-five percent SBR led to decreased survival and increased weight loss compared with 50% SBR. The remnant ileum of both 50% SBR and 75% SBR displayed similar crypt expansion, enhanced villi, and increased apoptotic indices. Proliferation rates increased after 50% and 75% SBR equally. CONCLUSION: Models of resection greater than 50% in mice result in greater morbidity and mortality and do not magnify the adaptation response to massive SBR. The use of more extreme resection models does not appear to provide added benefit for investigating mechanisms of intestinal adaptation.