缺血后适应与缺血预适应对大鼠脑缺血再灌注损伤的影响

The effects of ischemic postconditioning and ischemic preconditioning on cerebral ischemia-reperfusion injury

目的探讨缺血后适应与缺血预适应对大鼠脑缺血再灌注损伤的影响。方法用大脑中动脉线栓法制作大鼠局灶性脑缺血再灌注损伤模型。30只sD大鼠分为脑缺血再灌注模型组（模型组）、缺血后适应组及缺血预适应组，每组10只。以脑梗死体积、神经功能缺陷评分、超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量评价缺血预适应与缺血后适应抗脑缺血再灌注损伤的作用。结果缺血后适应组大鼠实验性局灶性脑缺血的梗死体积减少，神经行为改善（P〈0．05），但作用弱于缺血预适应组（P〈0．01）。脑组织匀浆生化指标检测，缺血后适应和预适应可以增强SOD活性，降低MDA含量，与模型组比较，差异有统计学意义（P〈0．01）。结论缺血后适应可减轻局灶性脑缺血再灌注大鼠脑的病理性损伤，但作用弱于缺血预适应。

Objective To study the effects of ischemic postconditioning and ischemic preconditioning on cerebral ischemia-reperfusion injury following middle cerebral artery occlusion in rats. Methods A reversible focal cerebral ischemia-reperfusion injury was modeled using middle cerebral artery occlusion. Thirty male Sprague-Dawley rats were randomized into three groups （n = 10 in each group） ： a cerebral ischemia-reperfusion group, an ischemic postconditioning group and an ischemic preconditioning group. The impairment of neurological function was scored and the infarct volume, the activity of superoxide dismutase and malondiadehyde （MDA） content were measured after the operation. Results In the isehemic postconditioning and preconditioning groups the neurological function was better and the infarction volume was significantly smaller compared with the model group. In the preconditioning group both infarction volume and neurological function were significantly better than in the postconditioning group. In the brain tissues of the preconditioning and postconditioning groups MDA content was lower, while the activity of superoxide dismutase was significantly higher than in the model group. Conclusions Ischemic postconditioning can attenuate pathological injury induced by focal cerebral ischemia and reperfusion. The neuroprotective effect induced by ischemic preconditioning is stronger than that induced by ischemic postconditioning.