The effect of methionine on colonic wound healing in malnourished rats

Recent studies have suggested that the healing of colonic anastomoses is impaired in malnourished subjects. It has been claimed that the healing of skin and abdominal wounds in experimental animals is improved by the administration of the essential amino acid methionine, and in the present study the effects of methionine on colonic wound healing were studied in malnourished rats. Test animals were fed a protein-free diet for 7 weeks before surgery. Methionine-treated animals received the amino acid by subcutaneous injection during the seventh week of protein deprivation and throughout the postoperative period. Anastomoses were made in the left colon, and colonic wound healing was assessed by measurements of the bursting wall tension and collagen content of anastomoses. The results were compared with those of control animals fed a normal rat diet. Protein deprivation for 7 weeks resulted in a 34% reduction in body weight, and a significant reduction in the tensile strength and collagen content of colonic anastomoses was observed. Methionine supplements had no apparent effect on these parameters of wound healing. The concept of single amino acid supplementation in cachetic patients undergoing surgery is an attractive one, but it has yet to be established that methionine supplements alone can alter the course of wound healing in such cases.