【摘要】 目的:观察脊髓损伤模型中Fas抗原及Bax蛋白在时间和空间上的表达特点以及脊髓损伤后组织形态及超微结构变化特点,探讨SCI后神经细胞的病理改变机理。方法:Wistar大鼠按Allen法建立脊髓损伤模型,分别在术后1h、8h、1d、2d、3d、7d,处死取材,每个时相点5只动物。分别在每只大鼠脊髓损伤中心区,损伤区头侧和尾侧3mm、5mm、7mm、10mm、13mm横截面处各切取3片组织。分别作Bax蛋白、Fas抗原免疫组化,HE染色,电镜下观察细胞超微结构的改变。结果:Fas抗原在损伤后8～24h,损伤区头、尾侧7mm处出现表达高峰。Bax蛋白在损伤后2～3d,损伤区头、尾侧7mm处出现高峰。电镜观察:损伤区死亡细胞呈坏死典型表现,而在非损伤区死亡细胞呈凋亡的典型表现。结论:SCI后急性损伤主要表现为细胞的坏死,继发损伤主要由细胞的凋亡引起。同时证实了凋亡的两条途径:由Fas抗原参与的死亡受体途径及Bax参与的线粒体途径均参与了SCI后细胞调亡的病理过程。更多还原

【Abstract】 Objective:The present study was designed to investigate,over an extended time period,the spatial and temporal expression features of Fas-antigen and Bax-protein as well as the pathological alterations of spinal cord under LM(light microscope)and EM(electron microscope)in a rat model of SCI Method:Taumatic injury at T10-T12level in Wistar rats(180-220g)was induced by the weight drop device(Allen method).The injuried rats were sacrificed at1h,8h,1d,2d,3d,7d after injury(n=5at each time point).A serials of10μm cross section were cut at epicenter,3mm,5mm,7mm,10mm,13mm rostral and caudal to epicenter.The immunochemistry for Fas antigen and Bax protein were performed,and HE staining were conducted.Finally,the morphological features were examined under LM and EM.Result:Fas-antigen selectively showed in both injuried and uninjuried areas.The immunoreactivity of Fas-antigen peaked at7mm caudal and rostral to epicenter8h-1d after injury.Bax protein showed similar expression pattern,but peaked at2d-3d after operation.EM showed the representative nerotic cells in lesioned areas,but the apoptotic cells at uninjuried areas.Conclusion:The data suggested that,in addition to the immediate damage,a delayed progressive destructive process causes even more severe spinal cord damage in a way of apoptosis.Fas antigen,Bax protein are possible critical factors involving in this process.更多还原