大鼠脑创伤后细胞凋亡的变化规律研究  

Spatial and temporal profile of apoptosis following lateral fluid percussion brain injury in rat

作　　者：骆纯[1] 朱诚[1] 卢亦成[1] 江基尧[1] 张光霁[1] 

机构地区：[1]第二军医大学附属长征医院,200003

出　　处：《上海医学》2002年第2期77-79,T001,共4页Shanghai Medical Journal

摘　　要：目的　探讨大鼠脑创伤后细胞凋亡的时空变化规律。方法　采用凋亡原位末端标记、电镜超微结构、DNA凝胶电泳观察脑创伤后细胞凋亡的形态和生化特征。结果　皮质细胞凋亡在伤后 2 4h已十分明显 ,伤后 7d到达顶峰。白质细胞凋亡发生最早 ,伤后 7d出现高峰。伤后第 2、3天海马CA3区凋亡细胞数目和密度最高 ,第 7天开始减少 ,但第 14天时凋亡细胞数仍在较高水平。伤侧丘脑凋亡细胞出现最晚 ,伤后 3d逐渐增多 ,伤后 2周出现高峰。伤后 2个月各脑区凋亡细胞数恢复到术前水平。损伤后 1d、3dDNA电泳出现了凋亡特征性梯状带。结论　创伤性脑损伤后各个脑区的细胞凋亡反应不同 ,这种差异表明细胞凋亡与急性和延迟性细胞死亡均有关。Objective To investigate the spatial and temporal profile of apoptotic neural cells apoptosis following TBI. Methods In addition to morphological evidence of apoptosis, TUNEL histochemistry was used to identify DNA fragmentation in situ at both light and electronmicroscopic levels, whereas characteristic internucleosomal DNA fragmentation of apoptosis was demonstrated by DNA gel electrophoresis. Results Using TUNEL method, we detected massive cells with extensive DNA fragmentation in different regions of the brains of rats subjected to experimental traumatic brain injury. Compared with the sham controls, in the injured cortex, the apoptotic cells were detectable for up to 24 h and reached a peak 1 week after injury. The number of apoptotic cells in the white matter had a significant increase as early as 12h after injury and with a peak at 1 week. An increase in apoptotic cells was observed in the hippocampus at 48 h, whereas in the thalamus, the apoptotic response was delayed, peaking at 2 weeks after injury. By 2 months, the number of apoptotic cells in most regions had returned to uninjured levels. Gel electrophoresis of DNA extracted from affected areas of the injured brain revealed only internucleosomal fragmentation at 185 bp intervals, a feature originally described in apoptotic cell death. And no DNA ladder was detectable in the cortex and hippocampus contralateral to the injured hemisphere. Conclusion These data suggest that, in addition to the well described necrotic cell death, a temporal course of apoptotic cell death is initiated after brain trauma in selected brain regions. The apoptotic response to trauma is regionally distinct and may be involved in both acute and delayed patterns of cell death after TBI.

关 键 词：细胞凋亡 创伤性脑损伤 液压伤 大鼠 变化规律 

分 类 号：R363[医药卫生—病理学]