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

PURPOSE: 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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

SCFA enemas have a transmural trophic effect and preserve mucosal surface area of defunctioned and atrophic colon in rats.