缺血预处理对大鼠小肠移植后肠黏膜的保护作用

目的探讨缺血预处理(ischemic preconditioning,IPC)对缺血-再灌注(ischemia-reperfusion,I/R)大鼠肠黏膜屏障的保护作用。方法建立SD大鼠小肠移植模型;实验分为3组(n=8):假手术组(S)、缺血-再灌注组(I/R)组和缺血预处理组(IPC);观察小肠病理组织形态学变化,检测比较各组大鼠肠黏膜丙二醛(malondialchehyche,MDA)含量、超氧化物歧化酶(superoxide dismutase,SOD)和髓过氧化物酶(myeloperoxidase,MPO)的活性以及肠黏膜细胞凋亡发生率与分布及其凋亡相关蛋白Bcl-2、Bax的表达变化。结果与I/R组相比,IPC大鼠小肠组织病理形态学明显改善(P<0.05),肠组织MDA含量和MPO活性均显著降低(P<0.05),而SOD活性则明显升高(P<0.05);肠黏膜细胞凋亡率明显下降(P<0.05);凋亡相关蛋白Bcl-2表达明显增加(P<0.05);而Bax蛋白表达明显减少。结论 IPC可减轻移植大鼠I/R损伤,与抗氧化作用增强和小肠肠黏膜细胞凋亡相关蛋白Bcl-2和Bax表达调控而抑制肠黏膜细胞凋亡有关。

Protective effects of ischemic preconditioning on the mucosal barrier of transplanted intestine in rats

Objective To investigate the protection of ischemic preconditioning(IPC) against intestinal mucosa barrier in intestinal transplanted rats with ischemia-reperfusion(I/R). Methods Using rat model of intestine I/R injury,Sprague-Dawley male rats were divided into 3 groups with 8 in each group: sham operation(SO) group,I/R group and IPC group,respectively.The changes of intestinal mucosa pathomorphology were detected.Malondialdehyde(MDA) content,superoxide dismutase(SOD) and myeloperoxidase(MPO) activities of intestinal mucosa were detected in each group.Apoptosis of mucosal cells was detected by TUNEL method and the expressions of Bax and Bcl-2 were determined. Results Compared with that in I/R group,the pathomorphology of intestinal mucosa was evidently improved in IPC group(P<0.05);MDA content and MPO activity of intestinal tissues were significantly reduced(P<0.05) while SOD activity was significantly increased(P<0.05).The apoptotic cell index of the mucosal cells was lower in IPC group than in I/R group(P<0.05).In comparison with I/R group,Bcl-2 expression increased(P<0.05) and Bax expression decreased significantly in IPC group. Conclusion IPC plays an important role in protecting against intestinal mucosa barrier in intestinal transplanted rats with ischemia-reperfusion.