大鼠脊髓急性损伤后神经细胞的凋亡

Apoptosis of neural cells after acute spinal cord injury in rats

目的 研究脊髓急性损伤后神经细胞的凋亡及其分布特点。 方法 44只大鼠分为对照组 (4只 )和损伤组 (4 0只 )。损伤组脊髓 (T8,9)经中度压迫致伤后 ,分别在伤后 30min、2 ,4,8,2 4,48,72h和 7,14,2 1d处死取材 (每时相点鼠数 =4只 )。应用HE、尼氏染色及凋亡细胞原位末端标记法对脊髓组织进行细胞检测。 结果 伤后 4h ,损伤段及邻近段可见末端标记阳性神经细胞 ;伤后 8h ,损伤段灰质中阳性细胞数达高峰 ;伤后 2 4h ,白质中阳性胶质细胞数达高峰 ;伤后72h ,相邻节段阳性细胞数达高峰。阳性细胞以白质中胶质细胞为主 ,主要分布于相邻节段。

Objective To study the characteristics of apoptotic death of neural cells after acute spinal cord injury. Methods Forty four rats were divided into a control group and an injury group. After moderate degree compression injury to the lower thoracic spinal cord (T 8,9 )in the injury group, the rats were sacrificed at 30 min,2,4,8,24,48 and 72 h and 7,14,21 days (n=4 for each time point).Three segments of every spinal cord were cut for morphological studies, including hematoxylin and eosin staining, Nissl staining and the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL). Results TUNEL positive cells were found in the compression region and neighboring regions 4 h after injury, with a maximum presence at 8 h in the compressed segment, and labeled glial cells in white matter reached a peak at 24 h after injury, but the labeled cells in the neighboring segments reached a peak at 72 h after injury. Most of the TUNEL positive cells were glial cells in the neighboring white matter. Conclusions Apoptosis of neural cells is an important morphological change in the secondary lesion period after spinal cord injury.