神经生长因子预处理对大鼠脑缺血再灌注损伤保护作用机制的研究

The Protection Mechanism of Nerve Growth Factor Pretreatment to Iischemia-reperfusion Caused Injury in Global Cerebral of Rats

目的:探讨神经生长因子(NGF)预处理对大鼠脑缺血再灌注损伤保护作用的机制。方法:采用四动脉阻断(4VO)法制作大鼠全脑缺血模型。18只大鼠随机分为3组,每组6只。对照组:只分离翼小孔和颈总动脉,未予脑缺血处理;缺血组:未行NGF预处理,只行脑缺血再灌注处理;NGF预处理组:全脑缺血前12 h脑室内注射NGF 20 U,所有大鼠缺血20 m in再灌注24 h后取脑组织。采用TUNEL法原位标记DNA片段,观察海马CA1区神经细胞凋亡的变化。结果:NGF预处理组海马CA1区TUNEL阳性神经细胞为(10.83±2.84)细胞/视野,与缺血组(17.69±3.79)细胞/视野比较显著减少(P<0.05)。结论:NGF预处理通过抑制神经细胞凋亡对大鼠全脑缺血再灌注损伤有保护作用。

Objective： To investigate the protection mechanism of nerve growth factor （NGF） pretreatment to ischemia-reperfusion caused injury in global cerebral of rats. Methods： Global ischemia in Wistar rats was induced by four-vessel occlusion. Eighteen rats were randomly divicled into three groups （six in each） ： the control group （sham operation）, ischemic group （received operation but not NGF pretreatment） and NGF-pretreated group （received operation and NGF pretreatment in 12 hours before the operation）, Brains of the rats were taken out in 24 hours of reperfusion that followed 20 minutes of ischemia, and the apoptotic changes in hippocampal CA1 were observed through terminal deoxynucleotidyl transferase mediated d-UTP-biotion nick endlabeling （TUNEL） of DNA fragments. Resuits： The number of TUNEL positive ceils was markedly reduced in NGF-pretreated group when compared with ischemic group （P 〈 0.05）. Conclusion： NGF pretreatment can protect neural ceils from damage during cerebral ischemia-reperfusion by suppressing the apoptosis in rats.