脑缺血再灌注后海马谷氨酸和神经生长因子的表达

Expression of glutamate and nerve growth factor in hippocampus after cerebral ischemic reperfusion

[目的]揭示谷氨酸和神经生长因子的表达变化在迟发性神经元死亡(delayedneuronaldeathDND)过程中的意义。[方法]用免疫组织化学方法检测脑缺血再灌注后1、2和7d后海马CA1、CA3神经元及齿状回颗粒细胞(DGCs)的谷氨酸和神经生长因子表达。并用电镜观察神经元超微结构变化。[结果]脑缺血再灌注后第1和第2天,海马CA1神经元谷氨酸表达的辉度值分别为60.67±3.18和81.22±7.12,明显高于对照组的42.25±2.79(P<0.01),且第2天的表达明显高于第1天(P<0.01);神经生长因子表达的辉度值分别为34.95±2.80和28.83±1.82,明显低于对照组的49±2.38(P<0.01),且第2天表达明显低于第1天(P<0.05)。脑缺血再灌注后第7天神经元脱失仅见于海马CA1区。[结论]短暂缺血性损伤时出现的持续性的谷氨酸上调和神经生长因子表达下调可能参与DND的形成。

[Objective] To unclose the significance of expression changes of glutamate and nerve growth factor (NGF)in delayed neuronal death (DND). [Method] To detect expressions of glutamate and NGF in CA1、CA3 neurons and DGCs of hippocampus on 1、2 and 7 days after cerebral ischemic reperfusion immunohistoche- mically, and observe neuronal ultrastructural change with electron microscope. [Results] On the first day and second day after cerebral ischemic reperfusion expression of glutamate in CA1 neuron of hippocampus were 60.67 ±3.18 and 81.22±7.12; respectively both of which were significantly higher than that of control group being 42.25±2.79,P<0.01,the expression on the second day was significantly higher than that on the first day,P <0.01; expression of NGF were 34.95±2.80 and 28.83±1.82 respectively both of which were significantly lower than that of control group being 49±2.38,P<0.01,expression on the second day was significantly lower than that on the first day,P<0.05. Neuronal disappearance was only observed in CA1 of hippocampus on the seventh day after cerebral ischemic reperfusion. [Conclusion] The persistent up-regulation of glutamate and down- regulation of expression of NGF following transient ischemic injury may participate in formation of DND.