兔坐骨神经高速弹丸震荡伤后腰段脊髓运动神经元及胶质细胞凋亡规律

Apoptosis regulations of motoneurons and glial cells of lumbar spinal cord following sciatic nerve injury by high speed firearms in rabbits

目的 探讨坐骨神经高速弹丸震荡伤后腰段脊髓运动神经元及胶质细胞凋亡规律。方法 6 5只大耳白兔分为正常对照组、高速弹丸震荡伤组 (震荡伤组 )和切割伤组。震荡伤组致伤靶点为兔右大腿外侧坐骨神经体表投影线中点 ,切割伤组在同一水平切断右坐骨神经。应用DNA电泳、原位末端标记法 (TUNEL)染色和流式细胞仪进行细胞凋亡定性定量检测。 结果 震荡伤组伤后 2周运动神经元数明显减少 ;伤后 1,2周 ,可见TUNEL阳性运动神经元及胶质细胞 ,DNA电泳出现凋亡梯形带 ,流式细胞仪检测可见亚二倍体峰 ;震荡伤组伤后 1,2周 ,细胞凋亡百分比分别为 10 .6 %和 2 6 .4 %。切割伤组仅在 4周时有少量阳性运动神经元。 结论 与切割伤组比较 ,震荡伤组细胞凋亡发生早、数量多 。

Objective To explore the apoptosis regulations of motoneurons and glial cells of the lumbar spinal cord after sciatic nerve injury by high speed firearms in rabbits. Methods Sixty five rabbits were divided into normal control, firearms group and cut group. In the firearms group, the target was the midpoint of the lateral body surface projection of the right sciatic nerve. The right sciatic nerve was cut at the same level in the cut group. The survived motoneurons were counted, and the apoptosis regulations of motoneurons and glial cells e detected by means of DNA gel electrophoresis,flow cytometry and TUNEL staining. Results The number of motoneurons decreased significantly after 2 weeks in the firearms group. At the 1st and 2nd weeks after injury, positive TUNEL staining motoneurons and glial cells were found. Cell apoptosis was confirmed by gel electrophoresis and flow cytometry too. Apoptosis ratios of motoneurons and glial cells were 10.6% and 26.4% respectively at the 1st and 2nd weeks. Only a few positive motoneurons were observed in the 4th week in the cut group. Conclusions Compared with the cut group, cell apoptosis occurs earlier, and the number of apoptotic cells is more in the firearms group. Apoptosis is the main mechanism for the decrease of motoneurons posterior to firearms injury.