[The change of gut barrier function and gene expression after surgical stress and parenteral nutrition]

Surgical stress and parenteral nutrition (PN) may cause gut mucosal atrophy and alter barrier function. Gene expression of growth factors and enzymes in small intestine may change. The effects of alanyl-glutamine dipeptide (Ala-Gln) on gut barrier and the gene expression of insulin-like factor I (IGF-I) and glutaminase in parenteral infusion rats with massive small intestine resection were investigated. Twenty Wistar rats were catheterized with 60% small bowel resectin. They were divided into two groups. Control group (n = 10) received traditional parenteral nutritional solution, and study group (n = 10) received Ala-Gln enriched nutritional solution (3% Ala-Gln). The rats were maintained with their respective diets for 7 days. The rats in the study group maintained serum glutamine concentration (844.0 +/- 13.2uMol: 640.4 +/- 17.2uMol, P < 0.05), mucosal architecture (mucosal thickness 591 +/- 12uM: 486 +/- 8uM, P < 0.05) and villus height (404 +/- 7uM: 303 +/- 5uM, P < 0.05). Bacterial translocation rate decreased in the study group (70%: 20%, P < 0.05). Ileal mucosal IGF-I mRNA and jejunal mucosal glutaminase mRNA in the study group increased twofold and threefold respectively. The results suggest that Ala-Gln may enhance gut growth and improve gut mucosa integrity and barrier function in part by means of stimulating IGF-I and glutaminase expression in surgical stress.