Role of gastrin in gastrointestinal adaptation after small bowel resection.

Gastrin is a trophic hormone for the mucosa of the oxyntic gland area of the stomach, the proximal small intestine, and the colon. It also has trophic effects on the pancreas. All these tissues undergo hyperplasia to some extent following distal small bowel resection. This study evaluates the role of gastrin in postresectional hyperplasia by examining the growth of these tissues in antrectomized rats following intestinal resection. Antrectomy itself caused atrophy of the oxyntic gland mucosa, colonic mucosa, and the pancreas but had no effect on ileal mucosa. Resection by itself stimulated growth of all tissues and significantly increased serum gastrin levels. After resection in antrectomized animals, all tissues underwent an adaptational response. The increase in total DNA content after resection in antrectomized rats was as great in all tissues, except the colon, as it was in animals with intact antrums and normal gastrin levels. These results indicate that gastrin plays no role in the postresectional hyperplasia observed in the various tissues of the gastrointestinal tract.