缺血预处理对大鼠缺血再灌注小肠能量代谢、Bcl-2和Bax表达的影响

Effect of ischemic preconditioning on energy metabolism and expressions of Bcl-2 and Bax in ischemia/reperfusion of rat small intestine

目的:探讨缺血预处理对小肠细胞能量代谢和凋亡基因bcl2,bax表达的影响及它们与肠细胞凋亡的内在联系.方法:健康SD大鼠36只,雌雄不限,随机分为3组,空白对照组(C组)、缺血预处理组(IPCI/R组)和缺血再灌注组(I/R组),每组12只.按Murry法制备缺血预处理模型,I/R组用血管钳夹闭肠系膜前动脉1h,再灌注2h,IPI/R组用血管钳夹闭肠系膜前动脉10min松开10min,反复4次,余同I/R组.高效液相色谱法测定ATP,ADP含量;免疫组化检测Bcl2及Bax蛋白的表达,每组选24个视野分别测量A值.TUNEL法检测凋亡的小肠细胞并计算凋亡指数.结果:C和IPCI/R组ATP含量高于I/R组(P<0.05);IPCI/R组Bcl2A值高于C组和I/R组(P<0.01),I/R组Bcl2A值低于C组(P<0.05);I/R组BaxA值明显高于C组和IPCI/R组(P<0.01),且IPCI/R组高于C组(P<0.05);与C组比较,I/R组和IPCI/R组凋亡指数较高(P<0.01,P<0.05);与I/R组相比,IPCI/R组凋亡指数较低(P<0.01).结论:缺血预处理能在一定程度上延缓ATP降解并调控Bcl2及Bax蛋白的表达、抑制缺血再灌注介导的小肠细胞凋亡.

AIM： To study the effect of ischemic preconditioning on cell apoptosis following acute intestinal ischemia/reperfusion in rats and explore their relationship. METHODS：Thirty-six SD rats were randomized into 3 groups each consisting of 12 rats： sham-operated control group （C group ）, ischemic reperfusion group（ I/R group, the anterior mesenteric artery occlusion for 60 min followed by reperfusion for 120 min ）, ischemic preconditioning group （ IPC-I/R, clamping the anterior mesenteric artery for 10 min followed by unclamping it for 10 min, all for 4 times before I/R ）. Immunohistochemistry was used to detect the expressions of Bcl-2 and Bax. Twenty-four fields of vision were selected in each group to determine A value. TUNEL method was applied to detect apoptotic intestinal cells, and to calculate the apeptotic index. RESULTS：The contents of ATP in C and IPC- I/R groups were significantly higher than that in I/R group （P 〈 0.05） ;the A value of Bcl-2 in I/R group was remarkably lower than that in C group （ P 〈 0.05 ）, and the A value of Bcl-2 in IPC-I/R group was obviously higher than those in C and I/R groups （ P 〈 0.01 ） ; the A value of Bax in I/R group was significantly higher than those in C and IPC-I/R groups （ P 〈 0. 01 ）, and the A value of Bax in IPC-I/R group was remarkably higher than that in C group （ P 〈 0.05）. Compared with that in C group, the apeptotic indexes in I/R and LPC-I/R group were significantly higher （ P 〈 0. 01 and P 〈 0. 05 ） ; Compared with that in I/R group, the apeptotic index in IPC-I/R group was significantly lower （ P 〈 0. 01 ）. CONCLUSION： Ischemic preconditioning can curb ATP degeneration, enhance the expression of Bcl-2, decrease the expression of Bax, inhibit the apoptosis following small intestinal ischemic reperfusion.