TRANSMURAL TROPHIC EFFECT OF SHORT-CHAIN FATTY-ACID INFUSIONS ON ATROPHIC, DEFUNCTIONED RAT COLON

PURPOSE: This study was designed to investigate and quantify trophic a lterations in the defunctioned, atrophic rat colon after short chain f atty acid (SCFA) treatment was administered in a clinically relevant w ay. METHODS: Diverting colostomy with exclusion of distal colon was pe rformed on adult female rats (58), and treatment was started four week s later. Enemas of either a SCFA solution of sodium-acetate, sodium-pr opionate and sodium-butyrate (concentration, 780 mM), or isotonic sali ne (placebo) were instilled through the anus into the defunctioned col on. 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 per cent higher compared with placebo (P < 0.01), and there was a similarl y significant difference in dry weight (P < 0.05). Using stereologic a ssessment to determine the histologic composition of defunctioned colo n, we found significant increases among SCFA-treated rats in the weigh t of the mucosa (P < 0.05), the submucosa (P < 0.05), and the muscular is propria (P < 0.05) and a 30 percent increase in the mucosal surface area compared with placebo-treated rats (P < 0.05). Measurements of b reaking strength and hydroxyproline content showed no differences betw een treatment groups. CONCLUSIONS: SCFA enemas have a transmural troph ic effect and preserve mucosal surface area of defunctioned and atroph ic colon in rats.