Effection Of Immunonutrition On The Barrier Function Of Intestine

Objective:To observe the changes of the barrier function of intestine before and after gut ischemia/reperfusion injury, to investigate the injury mechanism of intestinal mucosal barrier, study the effect of immunonutrition on gut barrier protection, and provide experimental foundation for clinical application.Methods:A total of 50 SD rats were divided randomly into 5 groups(n=10 each):①control group;②the ligation of the superior mesenteric artery+enteral nutrition group;③the ligation of the superior mesenteric artery + gastrostomy + enteral immunonutrition group;④gastrostomy + enteral nutrition group;⑤gastrostomy + enteral immunonutrition group. The ischemia-reperfusion model was produced. The rats in each group were fed with isocaloric enteral nutrition after injury and sacrificed by decapitation by the time of seven days after operation, the tissue of intestine were examined by microscopy with HE staining and Immunohistochemistry after sterilization. The peripheral blood samples of the first,fourth and seventh day after operation were collected immediately to detect the T cell subsets by Flow Cytometry, and the concentrations of endotoxin, TNF-α, IL-1β, Diamine oxidase and D-lactate in plasma by ELISA.Results:1. Body weight change:The body weight is significantly lower in the operation groups than in the control group. The body weight change is more sharply in the LSMA-EN group than in the LSMA-EIN group(18.20±7.61 vs 12.00±3.86, P＜0.05), and that of EN group is more sharply than that of EIN group(13.40±2.59 vs 7.60±5.38, P＜0.05).2. Intestinal mucosa pathology:The intestinal thickness, villous height, and crypt depth of rats were lower after operation compared to the control group, however, that in the eternal immunonutrition group was significantly higher than that of eternal nutrition group (P＜0.05).3. Pathological injury classification of intestine mucosa:The grade of Pathological injury classification of intestine mucosa is significantly higher in the operation groups than in the control group(30.70±4.45 vs 14.70±3.16, P＜0.01). The grade of pathological injury classification of intestine mucosa is significantly lower in the LSMA-EIN group than in the LSMA-EN group(25.60±4.33 vs 30.70±4.45, P<0.05), and that of EIN group is significantly lower than that of EN group(16.30±2.75 vs 22.40±2.67, P＜0.01).4. Immunohistochemistry:Occludin showed as yellow-stained in cellar membranes and periplasms. The positive percent is significantly higher in the LSMA-EIN group than in the LSMA-EN group (P<0.05). And the positive percent is significantly higher in the EIN group than in the EN group (P<0.05).SIgA showed as yellow-stained in plasma cells and epithelial cells. The positive percent is significantly higher in the LSMA-EIN group than in the LSMA-EN group (P<0.05). And the positive percent is significantly higher in the EIN group than in the EN group (P<0.05).5. CD4+/CD8+in the post-operation peripheral blood samples were significantly lower than that of preparation(P<0.05). The decline was more sharply in the LSMA-EN group than in the LSMA-EIN group(P<0.05). And the decline was more sharply in the EN group than in the EIN group(P<0.05).6. Endotoxin, TNF-a, IL-1β, DAO, and D-lactate in the post-operation plasma were significantly higher than that of preparation. From day 1st,4th to day 7th, a gradual decline was more sharply in the LSMA-EIN group than in the LSMA-EN group, but still significantly higher than that of preoperation(P<0.05).Conclusions:1. Rats treated with the gut ischemia/reperfusion injury can successfully found the model of intestinal barrier dysfunction; the animals loosed their body weight significantly. The intestinal mucosa necrosis and the expression of occludin, slgA in the intestinal tissue decreased.2. The eternal nutrition can protect the intestinal barrier function in a certain degree.3. Given immunonutrition can protect the intestinal mucosa in the rats suffered from gut ischemia/reperfusion injury. They were helpful to keep the body, increase the expression of Occludin and slgA in the gut, decrease the endotoxin and D-lactate in the plasma, and rapid the repair of the intestinal mucosa.