远程缺血后适应对大鼠脑缺血-再灌注损伤的影响

目的探讨远程缺血后适应对大鼠脑缺血-再灌注损伤的保护作用及对内质网应激诱导的凋亡蛋白C／EBP同源蛋白（CHOP）的影响。方法将56只雄性SD大鼠，随机分为假手术组，单纯缺皿组，插栓即刻行缺血后适应组（后适应1组），再灌注即刻行缺血后适应组（后适应2组），每组14只。线栓法制作大鼠大脑中动脉缺血2h模型。远程缺血后适应的实行：在插栓后即刻（后适应1组）及再灌注即刻（后适应2组）夹闭双侧股动脉10min，放开10min，此为一次缺血后适应，共进行3次。于再灌注后24h处死大鼠，测定脑梗死体积；免疫组化测定脑组织皮质和基底核CHOP的表达。结果①假手术组大鼠脑组织未见梗死灶，单纯缺血组、后适应1组、后适应2组脑梗死体积百分比分别为（48±10）％、（22±11）％及（26±12）％。与单纯缺血组比较，两缺血后适应组的梗死灶体积均明显减小，差异有统计学意义（P〈0．01）；两缺血后适应组间差异无统计学意义。②在皮质和基底核区，假手术组仅见少量的CHOP阳性表达细胞，单纯缺血组阳性表达细胞明显增多（P〈0．05）；而两后适应组CHOP阳性表达细胞明显减少，与单纯缺血组比较，差异均有统计学意义（P〈0．05）。两缺血后适应组间比较，差异无统计学意义。结论远程缺血后适应对大鼠脑缺血有保护作用。其保护作用可能与减少脑组织中CHOP含量有关。

Effect of remote ischemic postconditioning on cerebral ischemia/reperfusion injury in rats

Objective To investigate the protective effect of remote ischemic postconditioning on cerebral ischemia/reperfusion injury in rats and the its effect on endoplasmic reticulum stress-induced apoptosis protein - C/EBP homologous protein （CHOP）. Methods Fifty-six male SD rats were randomly allo-cated into sham operation, simple ischemia, remote ischemic postconditioning immediately after occlusion （RIP1） and remote isehemic postconditioning immediately after reperfusion （RIP2） groups （n = 14 in each group）. A rat model of middle cerebral artery occlusion for 2 hours was induced by the intraluminal suture method. The implementation of remote ischemic postconditioning： Bilateral femoral arteries were clipped for 10 minutes and then were released for 10 minutes immediately after inserting the thread （ RIP1 ） and immediately after the reperfusion （RIP2） , and this was repeated for 3 times. The rats were sacrificed at 24 hours after reperfusion, and their infarcted brain volumes were measured. Immunohistochemistry was used to detect the CHOP expressions of brain cortex and basal ganglia. Results No infarcts were found in the brains of rats in the sham group. The percentages of infarcted brain volumes in the simple ischemia, RIP1 and RIP2 groups were 48± 10%, 22±11%, and 26±12%, respectively. The infarct volumes of the RIP1 and RIP2 groups were significantly reduced compared to the simple ischemia group, and there was significant difference （P 〈 0.01 ） ; there was no significant difference between the RIP1 and RIP2 groups. There was only a small amount of CHOP positive cell expression in the cortex and basal ganglia regions in the sham operation group. The positive cell expression in the simple ischemia group was increased significantly （P 〈 0.05 ） ; while the positive cell expressions in the RIP1 and RIP2 groups were decreased significantly, and there were significant differences compared to the simple ischemia group （P 〈 0. 05）. There was no significant difference between the RIP1 and RIP2 groups. Conclusion RIP has protective effect on cerebral ischemia in rats, Its protective effect may be associated with the reduced CHOP levels in brain.