Small bowel segment reversal induces intestinal hyperplasia but reduces whole-body growth in massive bowel resected rats

Abstract

Background: Surgical reversal of a small bowel segment has been proposed as a means to improve nutritional status in individuals with extensive bowel resection. However, clinical experience remains controversial. The aim of this study was to determine the effects of bowel segment reversal on intestinal adaptation and whole-body anabolism.

Methods: Male Wistar rats underwent a 70% small bowel resection with (REV) or without (CON) reversal of a 5-cm small bowel segment (5 cm distal to resected segment), or sham-operation (SHAM). After surgery (day 0), rats were fed with powdered diet from day 2 to day 12. Body weight, nitrogen balance, carcass compositions, and serum concentrations of albumin and insulin-like growth factor (IGF)-1 were determined to assess whole-body anabolism. The composition and architecture of the small intestine were measured to assess the intestinal growth response. Serum concentrations of tumor-necrosis factor (TNF)-alpha and interleukin (IL)-6 were measured to assess the response of postoperative cytokines.

Results: Surgical reversal significantly increased the intestinal protein and DNA contents in the proximal segment compared with surgical resection. REV rats had a significantly slower rate of weight gain and lower serum levels of albumin and IGF-1, and had significantly greater levels of circulating white blood cells, blood urea nitrogen, and IL-6 compared with CON and SHAM rats. There were no significant differences in serum concentrations of TNF-alpha and carcass percentages of water, protein, and fat among groups.

Conclusions: Small bowel segment reversal stimulates jejunal hyperplasia but the surgical reversal induced-elevation in serum IL-6 may eliminate the whole-body anabolism in massive bowel-resected rats.