缺血后处理对大鼠局灶性脑缺血再灌注损伤的影响

Effects of Ischemlc postcondltioning on focal cerebral ischemia reperfusion injury in rats

目的探讨缺血后处理对大鼠局灶性脑缺血再灌注损伤的影响。方法36只雄性SD 大鼠随机分为3组(n=12),对照组:即单纯缺血再灌注组;缺血后处理15s组(I-15 s组):大脑中动脉线栓阻闭(MCAO)90 min后,再灌注15 s,缺血15 s,反复3次;缺血后处理30 s组(I-30 s组):MCAO 90 min后,再灌注30 s,缺血30 s,反复3次。再灌注24 h后对所有动物行神经功能障碍评分(NDS),然后取大脑测定脑梗死容积。结果再灌注24 h后I-15 s和I-30 s组NDS与对照组比较差异无统计学意义(P>0.05)。再灌注24 h后脑梗死容积I-15s组为(271±97)mm3,I-30 s组为(217±85)mm3,小于对照组[(378±103)mm3](P<0.01),I-15 s和I-30 s组比较差异无统计学意义(P>0.05)。结论缺血后处理可减轻局灶性脑缺血再灌注大鼠脑的病理性损伤。

Objective To investigate whether ischemic postconditioning could induce isehemic tolerance to focal cerebral ischemia reperfusion injury. Methods Thirty-six male SD rats aged 9-10 weeks weighing 270-350 g were randomly assigned to 3 groups （ n = 12 each） ： control group （C） ; 15 second postischemia group （ 1-15 s） and 30 second postischemia group （1-30 s） . The animals were anesthetized with isoflurane. The spontaneous breathing was kept. Carotid arteries were exposed through a middle longitudinal incision in the neck. Right external carotid artery was ligated. A nylon thread with rounded tip was inserted into right intenaal carotid artery and threaded cranially until resistance was felt （ 17-18 ram）. The middle cerebral artery （MCA） was occluded in this way. The nylon thread was withdrawn to allow reperfusion, 90 rain MCAO was followed by three 15 or 30 episodes of ischemia at 15 s or 30 s intervals for reperfusion. The neurologic deficit scores （0 = no deficit, 5 = death） were recorded 24 h after the last ischemic episode. The animals were then killed and brain infarct volumes were measured. Results There was no significant difference in neurologic deficit scores among the 3 groups （ P 〉 0.05） The infarct volume in control group was significantly larger than that in 1-15 s and 1-30 s groups. There was no significant difference in the brain infarct volume between 1-15 s and 1-30 s groups. Conclusion Ischemic postconditioning attenustes the brain injury induced by focal cerebral ischemia and reperfusion.