Bombesin stimulates mucosal growth in jejunal and ileal Thiry-Vella fistulas

Objective: The authors determined whether the trophic effects of bombesin (BBS) on the small bowel mucosa are mediated by either nonluminal factors or endogenous luminal secretion. Summary Background Data: The gut hormone bombesin stimulates growth of small bowel mucosa. The mechanisms responsible for this trophic effect are not known. Methods: Rats underwent construction of a Thiry-Vella fistula (TVF) of either the jejunum or ileum. On postoperative day 10, the two groups were subdivided to receive either saline (control) or bombesin (10 μg/kg, subcutaneously, three times a day). After 14 days, rats were killed and the TVF was removed. The mucosa was scraped and weighed, and DNA and protein content was determined. Results: Bombesin significantly increased mucosal weight and DNA and protein content of both the jejunal and ileal TVF compared with the control rats. Conclusions: Bombesin mediated stimulation of small bowel mucosal growth is mediated by factors that are independent of luminal contents and pancreaticobiliary secretion. Bombesin may prove to be an important enterotrophic factor for gut mucosal proliferation.