椎管减压对大鼠内质网跨膜蛋白Ire1α与细胞凋亡的影响

Effects of vertebral canal decompression on Ire1α expression and apoptosis following spinal cord injury in the rats

目的观察椎管减压对于大鼠脊髓内质网跨膜蛋白Ire1α与细胞凋亡表达变化的影响。方法健康成年SD大鼠60只,随机分为:1)椎管减压组(模型组)40只,每个时相点10只,采用压迫装置制备椎管减压模型;2)对照组10只,行脊髓持续压迫;3)假手术组10只,只做椎板切除。模型组分别于脊髓受压0.5、3、6、12h后解除压迫。采用免疫组化、Tunel染色观察压迫段脊髓内Ire1α的表达变化及细胞凋亡情况。结果细胞凋亡数与Ire1α阳性细胞数均于0.5h减压时开始增高,二者随减压时间的延迟而不断增加。假手术组与对照组、各减压组之间相比均有显著性差异(P<0.05)。结论大鼠脊髓压迫性损伤,尽早进行椎管减压,能够减轻内质网应激反应,减少Ire1α的表达与细胞凋亡的发生,促进神经功能恢复。

Objective To investigate the effects of vertebral canal decompression on Ire1α expression and apoptosis following spinal cord injury in the rats.Methods Sixty adult SD rats（250±20 g）were randomly divided into consistently compressive group（control group,n=10）decompressive groups（n=40）and shame-operation group（n=10）.The spinal cord was compressed posteriorly at the level of the first lumbar vertebra with a custom-made screw for 0.5,3,6 and 12 hours respectively,followed by decompression by removal of the screw.The sections were detected by immunohistochemistry and TUNEL staining.Results TUNEL-and Ire1α-positive cells were increased at 0.5 hour after decompression,and gradually elevated with the delay of decompression.The number of Ire1α-positive neurons was significantly lower than that of the control group（P0.05）.Conclusion The results indicate that the dynamic changes of Ire1α and apoptosis were correlated to decompression.Early decompression could reduce Ire1α expression and relieve the apoptosis following secondary spinal cord injury.