NGF预处理对全脑缺血再灌注沙土鼠海马CA1区神经细胞凋亡的影响

目的探讨NGF预处理对沙土鼠脑缺血再灌注后海马CA1区神经细胞凋亡的影响及最佳给药时间窗。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。NGF侧脑室注射法。蒙古种沙土鼠30只随机分为五组，每组6只：假手术组（A）、缺血再灌注损伤组（B）、NGF预处理48h、24h、12h组（C、D、E），B、C、D、E各组分别行脑缺血20min再灌注72h后处死取标本。TUNEL法观察沙土鼠脑缺血再灌注后海马CAI区神经细胞凋亡的变化。结果与缺血再灌注损伤组相比，NGF预处理各组可显著减少沙土鼠海马CA1区神经细胞凋亡数目（P〈0．05）；其中以NGF预处理48h组神经细胞凋亡指数最低。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；而以NGF预处理48h脑保护效果最好。

Effects of NGF pretreatment on apoptosis in brain hippocampus CA1 region following cerebral ischemia-reperfusion in gerbils

Objective: To investigate the effect of preconditioning with NGF on gerbils neuron apoptosis in brain hippocampus CA1 region following 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.NGF intracerebroven-tricle injection was adopted.Thirty gerbils were divided randomly into five groups,with six animals in each: sham operation control group(A),ischemia-reperfusion group(B) with a 20 min cerebral ischemia and following 72h reperfusion,NGF pretreatment 48h,24h and 12h groups(C-E) with each 20 min cerebral ischemia and following 72h reperfusion.Neural apoptosis was identified by TUNEL in brain hippocampus CA1 region.Results: Compared with ischemia-reperfusion group,the number of apoptosic cells in NGF preconditioning groups were decreased significantly(P<0.05).In each NGF preconditioning group the best protection was shown in the group given 48h before ischemia.Conclusion: NGF preconditioning can significantly decrease the neural apoptosis of the cerebral ischemia-reperfusion injury in gerbils,and the best time windows of NGF preconditioning is 48h.