Effect of glutamine on intestinal barrier function following liver transplantation in rats

Glutamine is an important fuel for intestinal mucosal epithelial cells, and it promotes intestinal mucosal cell differentiation and proliferation. Most liver transplantation (LT) patients suffer from intestinal barrier dysfunction. Whether enteral glutamine supplementation has beneficial effects on intestinal barrier function following LT is not known. We investigated the effect of glutamine (Gln) supplementation on NF-κB and on the intestinal barrier in rats after an allogenic LT with concomitant immunosuppressive therapy.

Inbred Sprague-Dawley rats (n=40) receiving allogenic LT were randomly divided into Gln and control groups (n=20, each). Gln group rats were administered Gln (0.4 g/kg·day) by gastric infusion for 6 days, while control rats received saline. Ten rats from each group were sampled for basal parameters on the 3rd day, prior to LT. The remaining 10 from each group were sampled after receiving LT. Twenty inbred Sprague-Dawley rats were selected as donors. The 20 recipients underwent orthotopic LT after 3 days of treatment and were given immunosuppressive therapy for 6 days post-operation. They were euthanized for sample collection on the 7th day. NF-κB protein in the intestinal mucosa, portal plasma Gln, endotoxin and TNF-α levels, ileocecal sIgA content, bacterial translocation and mucosal ultrastructure were assessed.

On the postoperative day 6, the Gln group had increased plasma Gln and ileocecal sIgA (secretory IgA). Gln group also showed improvement in mucosal microvilli structure and had reduced levels of intestinal mucosal NF-κB, portal endotoxin and TNF-α and decreased bacterial translocation as compared to the control group.

Parenteral supplementation of glutamine ameliorated mucosal injury during allogenic LT, and improved intestinal barrier function. These findings suggest that glutamine supplementation may be an effective therapy to ensure successful recovery from liver transplantation.