Transmural trophic effect of short chain fatty acid infusions on atrophic, defunctioned rat colon

Abstract

This study was designed to investigate and quantify trophic alterations in the defunctioned, atrophic rat colon after short chain fatty acid (SCFA) treatment was administered in a clinically relevant way. Diverting colostomy with exclusion of distal colon was performed on adult female rats (58), and treatment was started four weeks later. Enemas of either a SCFA solution of sodium-acetate, sodium-propionate and sodium-butyrate (concentration, 780 mM), or isotonic saline (placebo) were instilled through the anus into the defunctioned colon. This was done twice daily for 7 or 14 days before death. After SCFA instillation for 14 days, the colonic wet weight was 18 percent higher compared with placebo (P < 0.01), and there was a similarly significant difference in dry weight (P < 0.05). Using stereologic assessment to determine the histologic composition of defunctioned colon, we found significant increases among SCFA-treated rats in the weight of the mucose (P < 0.05), the submucosa (P < 0.05), and the muscularis propria (P < 0.05) and a 30 percent increase in the mucosal surface area compared with placebo-treated in the mucosal surface area compared with placebo-treated rats (P < 0.05). Measurements of breaking strength and hydroxyproline content showed no differences between treatment groups. SCFA enemas have a transmural trophic effect and preserve mucosal surface area of defunctioned and atrophic colon in rats.