Abstract
Background: In rats with diverting colostomies the effects of growth hormone can be differentiated from the actions of fecal passage. Methods: After sham operation or diverting colostomy rats were treated with biosynthetic growth hormone (b-hGH) for 4 weeks. Results: In defunctioned colon of b-hGH-treated rats there were increases in mucosal surface area and the weight of mucosa and muscularis propria compared with the atrophic colon of saline-treated rats. The breaking strength of defunctioned colon rings was greater and the defatted dry weight and hydroxyproline content of these specimens were also increased. In intact colon b-hGH stimulated luminal surface area, the weight of mucosal and submucosal layers, and the hydroxyproline content compared with controls. The breaking strength was highest in specimens from saline-treated rats. Conclusions: B-hGH has a growth-promoting role throughout the whole thickness of the colonic wall in rats also in the absence of fecal passage.