Intestinal growth adaptation and glucagon-like peptide 2 in rats with ileal-jejunal transposition or small bowel resection

Glucagon-like peptide 2 (GLP-2), produced by enteroendocrine L-cells, regul ates intestinal growth. This study investigates circulating and intestinal GLP-2 levels in conditions with altered L-cell exposure to nutrients. Rats were allocated to the following experimental groups: ileal-jejunal transpos ition, resection of the proximal or distal half of the small intestine, and appropriate sham-operated controls. After two weeks, ileal-jejunal transpo sition led to pronounced growth of the transposed segment and also of the r emaining intestinal segments. Plasma GLP-2 levels increased twofold, wherea s GLP-2 levels in the intestinal segments were unchanged. In resected rats with reduced intestinal capacity, adaptive small bowel growth was more pron ounced following proximal resection than distal small bowel resection. Circ ulating GLP-2 levels increased threefold in proximally resected animals, an d twofold in the distally resected group. Tissue GLP-2 levels were unchange d in resected rats. The data indicate that transposition of a distal part o f the small intestine, and thereby exposure of L cells to a more nutrient-r ich chyme, leads to intestinal growth. The adaptive intestinal growth is as sociated with increased plasma levels of GLP-2, and GLP-2 seems to act in a n endocrine as well as a paracrine manner.