地塞米松治疗坐骨神经非冻结性冷损伤的实验研究  

Experimental Study of Dexamethasone Treating in Non-freezing Cold Injury of Sciatic Nerves

作　　者：李浩[1] 徐敏[2] 

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

出　　处：《华西医学》2014年第2期219-222,共4页West China Medical Journal

基　　金：四川省医学会"施慧达"科研课题(SHD12-21);宜宾市卫生局医学科研项目~~

摘　　要：目的观察地塞米松治疗坐骨神经非冻结性冷损伤的显微结构变化，探讨其保护作用。方法12只雄性Wistar大鼠随机分成低温组与干预组：低温组一侧坐骨神经予以3～5℃持续低温2h；干预组一侧坐骨神经予以相同低温2h，完毕后立即腹腔注射地塞米松。对侧坐骨神经作为对照。冷损伤后24h观察坐骨神经结构变化。结果①光学显微镜下发现：对照侧坐骨神经仅少量有髓纤维出现空或暗轴索，伴随正常的神经内膜毛细血管。低温组冷损伤后24h，许多有髓纤维出现轴索退变，神经内膜毛细血管管腔狭窄。干预组治疗后，有髓纤维仍可见轴索退变，但神经内膜血管管腔未见狭窄。②电子显微镜下发现：对照侧24h时仅少量有髓纤维轻微板层松散，无髓纤维与神经内膜血管基本正常。低温组冷损伤后24h，有髓纤维出现髓鞘板层结构松散，乃至于结构完全消失；轴索轻则微丝溶解，重则结构消失。无髓纤维基本正常。神经内膜血管内皮细胞增生。紧密连接未见破坏。干预组治疗后，有髓纤维病变未见缓解，但内皮细胞未见增生。结论地塞米松治疗坐骨神经非冻结性冷损伤后，神经内膜血管病变得到明显改善，但有髓纤维病变并未缓解。提示地塞米松对冷损伤的治疗作用可能仅限于血管系统。Objective To observe the changes of microstructure of rats＇ sciatic nerves with non-freezing cold injury after treated with dexamethasone. Methods Twelve male Wistar rats were randomly divided into cooling group and treating group. Unilateral sciatic nerves of the rats in the cooling group received cooling treatment with 3-5℃ for 2 hours; while unilateral sciatic nerves of the rats in the treating group received cooling treatment with 3-5℃ for 2 hours and underwent the celiac injection with dexamethasone in addition. The other sciatic nerves were exposed, as the control. The bilateral sciatic nerves of rats in each group were harvested after 24 hours. The microstructure of nerves was examined under the light microscope and electron microscope. Results Light microscopic examination revealed extensive myelinated fibre degeneration in form of giant empty axons or shrunken dark axons on the first day after cooled. And the endoneurial capillary lumen was narrowed because of swollen endothelial cells. After the treatment, myelinated fibre degeneration was still similar to that before the treatment, but the endoneurial capillary lumen and endothelial cells were normal. By electron microscopy, sciatic nerves showed extensive myelinated fiber degeneration, and swollen endothelial cells. But unmyelinated fibers and tight junction were preserved on the first days after cooled. Aggregated red cells and platelet thrombus were not found. After the treatment, myelinated fibre degeneration was still similar to that before the treatment. Unmyelinated fibers and tight junction were preserved. The endoneurial capillary lumen and endothelial cells were normal. Conclusions After the treatment, the damage of endoneurial capillary had improved, but myelinated fiber degeneration was similar to that before the treatment. It suggested that dexamethasone may only improve the vascular system in non-freezing cold injury of sciatic nerve.

关 键 词：非冻结性冷损伤 坐骨神经 地塞米松 大鼠 

分 类 号：R745.42[医药卫生—神经病学与精神病学]