大鼠椎管减压与细胞凋亡的相关性研究

目的:观察在大鼠脊髓压迫性损伤后椎管减压与神经细胞凋亡的关系.方法:健康成年SD大鼠36只,随机分为两组:(1)椎管减压组30只,每组10只,采用自制压迫装置于L_1水平制做椎管减压模型;(2)假手术组6只,只做全椎板切除不做脊髓压迫.用HE、Nissl、TUNEL、免疫组化和Western blot等方法,分别于脊髓压迫6、12 h和24 h后去除压迫装置,观察减压段脊髓组织病理变化、细胞凋亡与caspase-3的表达变化情况.结果:TUNEL(+)细胞数于6 h减压时开始增高(9.62±3.54),24 h减压时达峰值(26.09±4.11),与假手术组(3.38±1.04)相比具有显著性差异(P<0.05);各减压组间比较有显著性差异(P<0.05).caspase-3免疫反应与TUNEL(+)细胞数量表达变化相符.结论:大鼠脊髓损伤后,神经细胞凋亡的改变与脊髓受压时间长度相关;早期进行椎管减压可减少继发性神经细胞凋亡,加快神经功能恢复.

A correlative study between early vertebral canal decompression and apoptosis following spinal cord injury in the rats

Objective: To investigate whether spinal cord decompression is related to neural cell apoptosis after spinal cord injury.Methods: The spinal cord was compressed posteriorly at L_1 level using a self-designed compression device for 6,12 h and 24 h,followed by decompression by removal of the screw. Apoptosis and cellular damage were assessed by the staining of HE、Nissl、terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)and immunostaining of easpase-3.Results: Compared with shame-operation group,the number of TUNEL positive cells was significantly higher in the decompression at 6、12、24h after spinal cord injury.which was consistent with immunoreactive to caspase-3(P<0.05).Conclusion: The results indicate that the dynamic change of apoptosis was correlated with duration of spinal compression.Early decompression could reduce neural cell apoptosis following secondary spinal cord injury.