中文摘要：

目的研究小肠低灌流时谷氨酰胺和葡萄糖在肠刷状缘的转运变化、载体表达及其对组织形态学的影响。方法SD大鼠随机分为低灌流组（肠系膜上动脉阻断60min）和对照组（剖腹，不阻断血流），每组6只。同时在肠袢内原位灌注甘露醇、葡萄糖或谷氨酰胺。Ca^2＋沉淀法制备肠刷状缘膜囊；快速混合滤过法检测Na^＋依赖性葡萄糖及谷氨酰胺转运；双盲观察组织形态。结果组织乳酸盐浓度值低灌流组4．9±0．3．与对照组的3．1±0．2比较明显增高（P〈0．01）。尤其葡萄糖灌注组的乳酸盐浓度值6．0±0．3，显著高于甘露醇灌注组的2．9±0．2（P〈0．01）和谷氨酰胺灌注组的3．1±0．3（P〈0．01）；但甘露醇组与谷氨酰胺组比较，差异无统计学意义（P〉0．05）。低灌流组肠刷状缘膜囊Na^＋依赖性葡萄糖的转运及其载体表达为（76±10）pmol·mg^-1·10s^-1，明显低于对照组的（290±13）pmol·mg^-1·10s^-1，P〈0．01；而谷氨酰胺则未见明显变化。在低灌流组中，葡萄糖灌注引起的组织结构损害最为严重。结论肠内营养中葡萄糖及谷氨酰胺在创伤及应激情况下的转运和载体表达调控不同。

英文摘要：

Objective To study the transport of glutamine and glucose, expression of their transporters and tissue morphology in intestinal hypoperfusion. Methods Sprague-Dawley rats were randomized to receive 60 min of intestinal hypoperfusion （superior mesenteric artery clamp） or serve as normoxic controls （celiotomy only）. At the same time, jejunal loops were randomized to receive in situ perfusion of mannitol,glucose,or glutamine.Intestinal brush border membrane vesicles （BBMV） were prepared by calcium precipitation. Sodium-dependent uptake of glucose and glutamine into BBMV were quantitated by rapid mixing and filtration. Histology examination and immunohistochemistry were performed by pathologists blinded to the groups. Results When compared with the control group, tissue lactate concentration of the hypoperfused group increased significantly （4.9±0.3 vs 3.1±0.2）, especially in the glucose perfused groups （P〈0.01）. Transport and transporters of glucose in brush border, but not glutamine, decreased during hypoperfusion [ （76±10）pmol·mg^-1·10 s^-1 vs （290±13）pmol·mg^-1·10 s^-1]. Tissue structural damage was most severe in glucose perfused groups during hypoperfusion. Conclusion Transport and expression of transporters of glucose and glutamine in enteral nutrition are differently regulated under conditions of trauma and stress.