大鼠脊髓急性损伤后神经细胞凋亡及相关基因表达△

目的研究脊髓急性损伤后神经细胞的凋亡及相关基因的表达.方法大鼠脊髓(T8、T9)经中度压迫损伤后,分别在30min、2h、4h、8h、24h、48h、72h、7d、14d和21d处死取材(各时间组n=4).应用HE染色、免疫组化及凋亡细胞原位末端标记法对脊髓组织进行标记.结果损伤4h后,在损伤段及邻近段可见末端标记阳性神经元,损伤段灰质中阳性细胞数8h达高峰,24h白质中阳性胶质细胞数量达高峰.相邻节段阳性细胞数72h达高峰.损伤后P53及Bax大量表达,而Bcl-2仅少量表达.结论脊髓损伤后神经细胞的凋亡是继发损伤期的重要病理变化.

Neural cell apoptosis and correlative genes expression after acute compression injury spinal cord in rats

Objective:The characteristics of neural cells death and correlative genes expression after spinal cord compression injury were studied.Method:The spinal cord of rats were compressed at the level of T8.9 in moderate degree,rats were killed at 30min,2,4,8,24,48 or 72 hours and 7,14,21 days after injury(n=4 per group).Three segments of every spinal cord were cut for morphological studies,including hematoxylin and eosin staining,immunohistochemical staining and the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) methods.Result:After injury,TUNEL positive cells were found in the compression region and neighborhood after 4h,with a maximum presence at 8h in the compressed segment,and labeled glial cells in white matter reached a peak at 24h.The labeled cells in the adjacent segments reached a peak at 72h.After compression,P53 and Bax immunoreactivity were present in neurons and glia cells.Bcl 2 immunoreactivity was present in the lesion region with low expression.Conclusion:The data suggested that apoptosis of neural cells is an important morphological change in the secondary lesion period after spinal cord injury.