大鼠液压脑损伤导致皮质神经细胞的早期凋亡

Early apoptosis of cortical neurons after fluid-percussion brain injury in rats

目的:观察大鼠脑损伤后神经细胞的早期凋亡及其动态变化。方法:利用液压脑损伤致伤仪制作SD大鼠左顶叶中度脑损伤模型,对照组埋打击管但不致伤。动物致伤后分别于伤后6h、24h和48h,采用流式细胞仪和电子显微镜,对大鼠液压脑损伤后神经细胞凋亡的动态过程进行观察。结果:流式细胞术检测结果显示大鼠液压脑损伤后6h左侧顶叶皮质神经细胞即可出现早期凋亡现象。伤后6h神经细胞的早期凋亡率为21.97%(P<0.01),伤后24h达高峰,为65.90%(P<0.01),伤后48h与伤后24h比较无显著性差异。电镜观察发现伤后24h可出现早期凋亡。结论:大鼠液压脑损伤后6h即可出现神经细胞的早期凋亡,较以往报道的伤后神经细胞凋亡出现的时间更早。

Objective：To observe the early apoptosis and its dynamic changes after traumatic brain injury（TBI） in Sprague- Dawley rats. Methods： The moderate brain injury model was established by a fluid-percussion brain injury device; animals in control group were only cannulated but not injured. Then the injured animals were sacrificed 6, 24 and 48 hours after injury. Flow cytometer and electron microscope were used to observe the apoptosis of nerve cells. Results： Flow cytometer showed that the early apoptosis of nerve cells occurred in left parietal cortex 6 hours after TBI, with an apoptotic ratio being 21.97%, significantly higher than that in the control group at the same time point（P〈0.01）. The apoptosis reached its peak 24 hours after TBI, with an apoptotic ratio being 65. 90%, significantly higher than that in the control group at the same time point（P〈 0.01）; there was no significant difference between those of 24 hours and 48 hours after TBI（P〉0.05）. Electron microscope showed apoptosis of nerve cells in the left parietal cortex 24 hours after TBI. Conclusion： Early apoptosis of nerve cells may occur 6 hours after TBI, which is earlier than previously reported