坐骨神经非冻结性冷损伤时血神经屏障损害的研究  

The study of blood-nerve barriers in non-freezing cold injury of the sciatic nerves

作　　者：李浩[1] 张磊[2] 徐敏[3] 

机构地区：[1]宜宾市第一人民医院神经内科,四川宜宾644000 [2]宜宾市第一人民医院药剂科,四川宜宾644000 [3]首都医科大学宣武医院神经内科,北京100053

出　　处：《中风与神经疾病杂志》2016年第2期104-108,共5页Journal of Apoplexy and Nervous Diseases

基　　金：四川省医学会"施慧达"课题(SHD12-21)

摘　　要：目的使用大鼠坐骨神经制造周围神经非冻结性冷损伤模型,观察非冻结性冷损伤时神经内部的水肿变化,研究冷损伤时血神经屏障功能的损害情况及相应的病理改变。方法 48只雄性Wistar随机分成冷损伤后1 d组、3 d组和5 d组。每只大鼠一侧坐骨神经予以3℃~5℃持续低温2 h;以对侧坐骨神经作为对照。每组大鼠在相应的时间点取下坐骨神经进行观察：静脉注射伊文思蓝后1 h,测量坐骨神经中伊文思蓝浓度;静脉注射伊文思蓝后1 h,坐骨神经包埋制片,在荧光显微镜下观察伊文思蓝的分布;坐骨神经包埋制片,在光学显微镜及电子显微镜下观察有髓纤维、无髓纤维及毛细血管的状况。结果冷损伤后1 d,多数有髓纤维出现以＂空、暗＂为形式的轴索退变;无髓纤维和紧密连接完好;神经内膜毛细血管管腔狭窄;冷损伤后3~5 d,有髓纤维病变继续加重;神经内膜毛细血管管腔仍然狭窄,内皮细胞间的紧密连接开放;冷损伤后1 d,冷损伤侧坐骨神经中的伊文思蓝浓度与对照侧相比有显著升高;在正常的坐骨神经内,伊文思蓝红色荧光局限于神经内膜的血管腔内,未渗漏至血管外;在冷损伤后1 d,坐骨神经的一些受冷部位出现了神经内膜弥漫性红色荧光;类似荧光也出现冷损伤后3 d与5 d的坐骨神经中,但是其荧光强度有所下降。结论坐骨神经非冻结性冷损伤可以导致血神经屏障功能破坏,引起神经内膜水肿;非冻结性冷损伤早期主要选择性损害有髓纤维,而对无髓纤维损伤极轻。Objective To make the model of non-freezing cold injury in peripheral nerves,observe edema in endoneurium in non-freezing cold injury,and study the effect of barrier function and corresponding pathological changes.Methods Male Wistar rats were randomly divided into the 1st group,3rd group and 5th group. One side of sciatic nerves wastreated at 3 ℃ ~ 5 ℃ for 2 hours,the other side was as control. The bilateral sciatic nerves of each group were harvested on the 1st,3rd and 5th day after cooling. The structure of nerves and blood-nerve barrier were examined. Results On the1 st day,most of the myelinated fibres in sciatic nerves showed＂empty or dark＂axons,with normal unmyelinated fibres and tight junction. Endoneurial capillary lumen was seriously narrowed. From the 3rd day to 5th day,myelinated fibre degeneration became more widespread and unmyelinated fibres also began to degenerate. The vasculature was similar to that of the1 st day,with tight junction open. There was significant difference between the cooled group and control group in the 1st day.Normal rat sciatic nerve showed a bright red fluorescence confined to the lumen of endoneurial blood vessels and none appeared outside the vascular walls. The segments at the cooling sites of sciatic nerves were examined on 1st day after the cooled injury,the sciatic nerve showed intense red fluorescence in endoneurium,outside the vascular. On the 3rd and 5th day after nerve cooled,the red fluorescence was also seen,but the intensity decreased. Conclusion Non-freezing cold injury to rat sciatic nerve could resulted in breakdown of the blood-nerve barrier function,causing endoneurial edema. Myelinated fibers were mainly selectively damaged,but unmyelinated fibers were preserved.

关 键 词：非冻结性冷损伤 血神经屏障 坐骨神经 神经变性 

分 类 号：R745[医药卫生—神经病学与精神病学]