银杏叶提取物预处理对胰腺移植受体大鼠 小肠肠黏膜屏障的影响

目的 ：探讨银杏叶提取物（EGb）对胰腺移植受体大鼠肠黏膜屏障的保护作用及其机制。方法 ：12只正常SD大鼠为对照组;糖尿病大鼠随机分为胰腺移植组（PT组， n =12）及银杏叶提取物预处理胰腺移植组（EGb组， n =12），大鼠均接受同系胰腺移植。EGb组于移植前1d和30min予受体静脉注射EGb （1.5mL/kg）。移植术后5 d测定小肠通透性和吸收功能，检测血清TNF-α，NO，SOD和淀粉酶活性。取受体回肠黏膜组织测定小肠黏膜湿重、微绒毛厚度及宽度、MDA含量及MPO活性。同时取肠系膜静脉血、肠系膜淋巴结、肝及脾组织行细菌培养，观察细菌易位情况。结果 ：EGb组血清TNF-α含量（ P <0.01）、淀粉酶活性（ P <0.01）、MDA含量（ P <0.05）、MPO活性（ P <0.05）、小肠通透性（ P <0.01）、细菌易位率（ P <0.01）和小肠黏膜损伤程度均低于PT组;血清NO和SOD含量、小肠吸收功能均高于PT组( P <0.01)。结论 ：EGb预处理可保护胰腺移植受体大鼠小肠肠黏膜屏障，降低细菌易位率，机制可能与抗氧化、清除自由基、减少TNF-α生成、减轻嗜中性粒细胞黏附与聚集、增加内源性NO的生成有关。

The effect of the Extract of Ginkgo biloba on intestinal mucosal barrier after pancreas transplantation in rats

Abstract:Objective ：To investigate the protective effect of extract of Ginkgo biloba (EGb) on intestinal mucosal barrier after rats pancreas transplantation(PT), and analyze the possible mechanism. Methods ：In the control group, 12 normal rats received sham operation, and 24 steptozozin-induced diabetic SD rats were randomly assigned to 2 groups: Group PT consisted of 12 diabetic rats which received pancreas transplantation, group EGb consisted of 12 diabetic rats that received EGb（1.5 mg/kg） injected intravenously 1 day and 30min respectively before pancreas transplantation. The intestinal permeability, absorptional function and morphology, the TNF-α, NO, SOD and amylase activity in serum, and MDA, SOD and MPO in interstitial tissue were monitored 5 days after PT. Simultaneously, bacteria translocation in the superior mesenteric vein, mesenteric lymph node, liver and spleen was observed. Results ：(1)The mean TNF-α level( P <0.01) and amylase activity in serum( P <0.01), the mean intestinal permeability ( P <0.01), the mean bacteria translocation rate( P <0.01), the mean degree of MDA level and MPO activity( P <0.05) in intestinal mucous, and intestinal mucosal injury of group EGb were lower than those in Group PT. (2)The mean NO level ( P <0.01) and SOD activity ( P <0.01) in serum and the intestinal absorption function of group EGb were higher than those in Group PT. Conclusions ：EGb can protect the intestinal mucosal barrier of pancreas transplant recipient, and decrease the rate of bacteria translocation. The mechanism may be related to antioxidation and elimination of free radicals, decrease synthesis of TNF-α, decrease of adhesion and aggregation of PMNs, and increase production of endogenous NO.