谷氨酰胺胃肠外营养对急性放射性肠炎大鼠肠屏障功能的影响

目的探讨谷氨酰胺胃肠外营养对急性放射性肠炎大鼠肠屏障功能的作用。方法SD大鼠行全腹部60Coγ射线8Gy放射后,实验动物随机分为三组,常规全成分胃肠外营养组(Standard totalparenteral nutrition,STD组,n=10):大鼠输入常规静脉营养液;谷氨酰胺组(Glutamine-enriched totalparenteral nutrition,GLN组,n=10):大鼠输入附加谷氨酰胺的静脉营养液;正常组(n=10)为未经腹部照射的正常大鼠,连续7d全成分胃肠外营养。采用光镜、电镜观察、结合图像分析系统和无菌采取肠系膜淋巴结做细菌培养。结果GLN组小肠蛋白质和DNA的含量明显高于STD组,GLN组空、回肠绒毛高度、隐窝深度、黏膜厚度、全层壁厚度均显著大于STD组。扫描电镜的观察结果:GLN组和STD组小肠绒毛顶部都有程度不同的糜烂形成,但GLN组绒毛表面糜烂较少,而STD组则较多。GLN组肠系膜淋巴结细菌移位率明显低于STD组。结论附加丙氨酰-GLN二肽的全成分胃肠外营养能有效的保护肠黏膜辐射性损伤后肠屏障功能和防止肠细菌移位。

The effect of the glutamine-enriched parenteral nutrition on gut barrier of rats with acute radiation enteritis

Objective To study the effect of glutamine-enriched parenteral nutrition on the gut barrier of rat with acute radiation enteritis.Method Whole abdomibal radiation was performed in SD rats.The animals were randomly divided into three groups,i.e standard total parenteral nutrition(STD group,n=10)and glutamine-enriched total parenteral nutrition(GLN group,n =10)was infused intravenously and continuouslly for 7 days,and normal nonirradiated animals(n=10),received STD.The relative indices were measured by using the light microscopy,electron microscopy,image analysis system.The percentage of intestinal bacterial translocation and bacteria in mesenteric lymph nodes were detected.Result The measurements of small intestinal villus height,crypt depth,the thickness of mucosa and entire wall of animals receiving the GLN had a singnificant increase when compared with those from the STD group.Scanning electron microscopy demonstrated that the tips of villi in the STD group were much more ulcerated and necrotic that in GLN group.The frequency of the bacteria found in mesenteric lymph nodes was significantly lower in GLN group compared with STD group.Conclusion The GLN can accelerate healing of the injured small intestinal epithelium,and decrease bacteria translocation from gut of acutely radiated bowel.