THE INFLUENCE OF BRANCHED CHAIN AMINO ACIDS ON COLONIC ATROPHY AND ANASTOMOTIC STRENGTH IN THE RAT

Abstract

Conventional solutions of parenteral nutrients fail to reverse the colonic atrophy caused by starvation. This may be due to the absence from these solutions of the amino acid glutamine--a fuel for rapidly dividing cells such as colonocytes and fibroblasts. Although glutamine is unstable in solution, the infusion of branched chain amino acids (BCAA) increases the rate of synthesis and release of glutamine from skeletal muscle. We evaluated the hypothesis that the infusion of BCAA into undernourished rats would reduce the extent of mucosal atrophy and enhance the healing of anastomoses in the colon. Undernourished rats were randomized to receive 6 days of either a normal diet (Chow), conventional parenteral nutrition (CPN), or CPN supplemented with 1.8% BCAA (BCAA). The BCAA group had a higher plasma glutamine concentration than the Chow group (P less than 0.05). Compared with the CPN group, the BCAA group had the greater colonic mucosal weight (P less than 0.05) and colonic mucosal protein content (P less than 0.05), but there were no significant differences between groups in the bursting wall tension of the colon or the hydroxyproline content of the anastomoses. Although the infusion of BCAA has a beneficial effect on colonic atrophy, this did not result in the more secure healing of colonic anastomoses in this experimental model.