Protective effect of ischemic preconditioning (IPC) in ischemia-induced reperfusion injury of moto-organs

目的：缺血预处理（IPC）意味着重复短暂的缺血事件，然后再灌注到组织中，当其组织随后经受长时间的缺血时，可改善组织存活。本研究的目的是确定周期数是否影响IPC在骨骼肌缺血中的有效性。材料与方法：使用总共41只大鼠后肢，通过暂时切割大腿周围的软组织和骨结构（不包括股血管），并用微血管夹夹住血管，来建立后肢再灌注模型。确定每个IPC循环的设置为缺血10分钟，然后再灌注10分钟。所有动物被分为7组：假手术对照组（SC）（n=8）;无缺血和无IPC的相同手术程序的IR组（n=4）;无IPC、IPC-1、2组（n=7）和IPC-3、4、5组（n=5）后全脑缺血4 h; 1个周期后缺血4 h ...更多信息 每个IPC组进行5个周期的IPC。每只动物在每次手术和钳夹完成后再灌注24小时后处死，用NBT法组织化学评价其胫前肌的活力，并用NIH Image Soft数字化计算机技术计算各组的平均坏死面积比率（%NAR）。使用ANOVA和事后检验比较各组之间的%NAR，每个值表示为平均值±SEM。结果如下：各组的%NAR如下：SC组; 0±0，IR组; 66.2±5.9，IPC-1组; 27.5±8.0，IPC-2组; 29.5±6.2，IPC-3组; 9.6±3.4，IPC-4组; 10.3±2.2，和IPC-5组; 11.4±2.4。所有IPC组的%NARs均显著低于IR组（p<0.0001）。IPC-3、4和5组的%NAR显著低于IPC-1和IPC-2组（p<0.01）。结论：在本研究的基础上，明确了骨骼肌IPC的适宜周期数为3 ~ 5个周期。未来的研究计划研究IPC有效性的化学和病理学证据。少

Objective: Ischemic preconditioning (IPC) implies that repeated brief episodes of ischemia followed by reperfusion to tissue results in improved tissue survival when its tissue is subsequently subjected to prolonged ischemia. The aim of the present study is to determine if the number of cycles influences the effectiveness of IPC in skeletal muscle ischemia. Materials and Methods: using a total of 41 rat hindlimbs, the hindlimb-reperfusion model was created by temporary cutting both soft-tissue and bony structures, exclusive of femoral vessels, around the thighs, and clamping the vessels with a microvascular clip. The setting of each IPC cycle was determined to be 10 minutes of ischemia followed by 10 minutes of reperfusion. All animals were devided into seven groups: sham controls (SC) group (n=8); the same surgical procedures with no ischemia and no IPC, IR group (n=4); 4-hr global ischemia following no IPC, IPC-1, 2 group (n=7), and IPC-3, 4, 5 (n=5); 4-hr ischemia following 1 cycle … More to 5 cycles of IPC in each IPC group. Each animal was sacrificed after 24-hr reperfusion following the completion of each surgical and clamping procedure, the viability of its anterior tibial muscle was histochemically evaluated using NBT method, and the average necrosis area ratio (%NAR) of each group was caltulated by degitalized computer technique using NIH Image Soft. The %NAR was compared between groups using ANOVA and post hoc test, and each value was expressed as Mean±SEM.. Results: The %NAR of each group was as follows: SC group; 0±0, IR group; 66.2±5.9, IPC-1 group; 27.5±8.0, IPC-2 group; 29.5±6.2, IPC-3 group; 9.6±3.4, IPC-4 group; 10.3±2.2, and IPC-5 group ; 11.4±2.4. The %NARs of all IPC groups were significantly lower than that of IR group (p<0.0001). The %NAR of IPC-3, 4, and 5 were significantly lower, when compared with those of IPC-I and IPC-2 groups (p<0.01). Conclusion: The appropriate cycle number of IPC in skeletal muscle was clarified to be 3 to 5 cycles on the basis of the present study. The future studies are planed to study chemical and pathological evidence on the effectiveness of IPC. Less