Enteral feeding of glycyl-glutamine dipeptide improves the structure and absorptive function of the small intestine after allogenetic liver transplantation in rats

Abstract

Background: Recipients of liver transplantation could have postoperative structural injury and declined absorptive function in the gastrointestinal tract. Glutamine (Gln) is a special nutrient of small intestinal mucosa and of various kinds of cells proliferating rapidly. But Gln could form a kind of poisonous pyroglutamic acid in water solution, which is the limitation of Gln in clinical practice. Glycyl-glutamine (Gly-Gln) is highly soluble and can be hydrolyzed to release glutamine. This study was undertaken to observe the effect of Gly-Gln dipeptide by enteral feeding on the intestinal structure and absorptive function after allogenetic liver transplantation in rats.

Methods: Twelve male inbred Lewis rats were selected randomly as donors, and 24 male inbred BN rats as recipients of allogenetic liver transplantation. The recipients were also randomly divided into two groups: control group (ALA group, n=12) and experimental group (GLN group, n=12). In each group, 6 normal BN rats were sampled as the normal parameter on the 3rd preoperative day. The 6 recipients in the control group received alanine 0.6 g/kg daily for 3 days before operation and 7 days after operation by gastric perfusion, and the 6 recipients in the experimental group were given Gly-Gln 0.6 g/kg daily the same way. The 12 BN recipients underwent 3-day fasting (free access to water with 0.23% sodium chloride) and orthotopic liver transplantation in aseptic conditions and were given subcutaneous injection of CsA 2 mg/kg daily after the operation. The 12 BN recipients were sampled on the 8th postoperative day. All of the 24 BN rats were subjected to examination of mucosal structure, activities of Na+-K+-ATP and disaccharidase, and D-xylose absorption test.

Results: The 12 BN recipients were alive after liver transplantation. On the 3rd preoperative day, mucosal structure, activities of Na+-K+-ATP and disaccharidase and D-xylose absorption in the two groups were not significantly different. On the 8th postoperative day, the parameters of the two groups were markedly changed compared with those on the 3rd preoperative day. However, the parameters of GLN group were remarkably higher than those of ALA group.

Conclusion: Enteral feeding of Gly-Gln could improve the structure and absorptive function of the small intestine after liver transplantation in rats.