Abstract:[Abstract] objective: To investigate the effect of Glutamine Combined with umbilical cord blood mesenchymal stem cells (MSCs) transplantation on intestinal ischemia-reperfusion injury in rats. Methods:Isolation of umbilical cord blood mesenchymal stem cells in vitro, and observe its fate after CM-DiI fluorescent labeling. 80 SD rats were randomly divided into normal control group, ischemia reperfusion injury group, glutamine group, MSCs transplantation group and combined group with 15 rats in each group. Control group using saline enema, injury group using TNBS (ethanol dilution) enema, and after TNBS modeling 1h, at the end of intravenous glutamine 0.45 g/kg in the glutamine group, MSCs transplantation group in the tail vein of 1 ?010/L umbilical cord blood mesenchymal stem cell suspension, and combined group intravenous glutamine 0.45 g/kg and 1?010/L umbilical cord blood mesenchymal stem cell suspension. ELISA were used to detect midgut fatty acid binding protein (iFABP), interleukin 6 (IL-6), superoxide dismutase (SOD) content in rat serum. The water content of intestinal tissue were detected by 1h and 3h after reperfusion in each group. Expression of NF-kB, Bcl-2 and Caspase-3 mRNA after glutamine combined with MSCs in rat intestinal epithelial cells were observed by RT-PCR and Western blot. Results:The fluorescent tracer method to observe the transplanted MSCs cells distributed in the intestinal mucosal lymphoid tissues and epithelial cells gland, it indicated that MSCs might be involved in the repair process of intestinal ischemia-reperfusion injury. Comparison of contents of SOD, IFABP and IL-6 in serum of rats in each group, the content of IFABP and IL-6 in the serum of injured group was significantly higher than that in the control group, in the glutamine group, the MSCs transplantation group and the combined group were significantly reduced, and the combined group was more obvious. The content of SOD in the injured group was significantly lower than that in the control group, and glutamine group, MSCs transplantation group and the combined group significantly increased, the combined group increased significantly (P<0.05). The water content of intestinal tissue in the injured group was significantly higher than that in the control group after reperfusion 1h and 3h,.Compared with the injury group, the water content of the glutamine group, MSCs transplantation group and the combined group were significantly lower, and the combination group decreased more significantly, and there was no significant difference in glutamine group and MSCs transplantation group (P>0.05). Compared with the control group, injury group intestinal epithelial cells Caspase-3,NF-kB mRNA and protein expression were significantly increased, and expression of Bcl-2 mRNA and protein were significantly lower (P <0.05), the expression of Caspase-3 and NF-kB mRNA and protein were significantly reduced in the glutamine group, MSCs transplantation group and combined group, expression of Bcl-2 mRNA and protein were significantly increased (P <0.05), between glutamine group and MSCs transplantation group were no significant difference (P> 0.05), but the two groups compared with the combined group, the difference were significant (P<0.05). Conclusions: After glutamine and MSCs transplantation, the degree of intestinal ischemia reperfusion injury was obviously reduced in rats, it may reduce intestinal mucosal ischemia-reperfusion injury by inhibiting the expression of Caspase-3 and NF-kB and promoting the expression of Bcl-2.