NGF预处理对全脑缺血再灌注沙土鼠脑皮层神经细胞凋亡的影响

目的: 探讨神经生长因子(NGF)预处理对沙土鼠脑缺血再灌注后脑皮层神经细胞凋亡的影响.方法: 采用夹闭沙土鼠双侧颈总动脉造成全脑缺血再灌注模型.沙土鼠30只随机分为5组:假手术组(A)、缺血再灌注损伤组(B)、NGF预处理48 h、 24 h、12 h组(C、D、E),B、C、D、E各组分别行脑缺血20 min再灌注72 h后处死取标本,TUNEL法观察沙土鼠脑缺血再灌注后脑皮层神经细胞凋亡的变化.结果: 与缺血再灌注损伤组相比,NGF预处理各组沙土鼠脑皮层神经细胞凋亡数目显著减少(P＜0.05),以NGF预处理48 h组脑保护效果最好.结论: NGF预处理能明显减轻沙土鼠脑缺血再灌注引起的神经细胞凋亡,具有明显脑保护作用,以NGF预处理48 h脑保护效果最好.

Effects of Nerve Growth Factor Pretreatment on Apoptosis in Brain Cortex Following Cerebral Ischemia-reperfusion in Gerbils

Objective: To investigate the effect of preconditioning with nerve growth factor (NGF) on neuron apoptosis in brain cortex of gerbil caused by global cerebral ischemia-reperfusion injury and to explore the best time windows of NGF preconditioning. Methods: Global cerebral ischemia was induced by occlusion of bilateral carotid arteries. Thirty gerbils were divided randomly into five groups (six in each): sham operative control group (A); ischemia-reperfusion group (B) with a 20 min cerebral ischemia followed by 72h reperfusion; NGF pretreatment groups (C, D, E) of which animals received pretreatment of NGF at 48h, 24h, 12h before the 20 min of cerebral ischemia and the followed 72h reperfusion respectively; Neural apoptosis in brain cortex was identified by TUNEL. Results: compared with group B, the numbers of apoptotic cells in groups C, D, and E were significantly lower (P<0.05); The best protection was shown in group C that NGF intracerebroventricle injection was conducted in 48h before the ischemia. Conclusions: NGF preconditioning can significantly reduce the neural apoptosis of cerebral ischemia-reperfusion injury in gerbils, and the best time window of NGF preconditioning is about 48h before the ischemia.