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

目的:探讨缺血预处理对小肠细胞能量代谢和凋亡基因bcl-2,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(IPC-I/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1 h,再灌注2 h, IP-I/R组用血管钳夹闭肠系膜前动脉10 min松开10 min,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Bcl-2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IPC-I/R组ATP含量高于I/R组(P<0.05);IPC-I/R组Bcl-2 A值高于C组和I/R组(P<0.01),I/R组Bcl-2 A值低于C组(P<0.05);I/R组Bax A值明显高于C组和IPC-I/R组(P<0.01),且IPC-I/R组高于C组(P<0.05);与C组比较,I/R组和IPC-I/R组凋亡指数较高(P<0.01, P<0.05);与I/R组相比,IPC-I/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Bcl-2及Bax蛋白的表达、抑制缺血再灌注介导的小肠细胞凋亡.

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

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 apoptotic 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 apoptotic indexes in I/R and IPC-I/R group were significantly higher (P<0.01 and P<0.05); Compared with that in I/R group, the apoptotic 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.