X线照射对大鼠脊髓损伤模型轴索和髓鞘的作用

目的 探讨Ｘ射线对脊髓轴索和髓鞘的作用。方法 Ｗｉｓｔａｒ大鼠６０只,将其胸部脊髓半横断,制作成脊髓损伤模型;随机分成实验组（ｎ＝３０）和对照组（ｎ＝３０）,实验组为胸部脊髓半横断加Ｘ射线照射,对照组为单纯胸部脊髓半横断。实验组术后次日行Ｘ射线照射,剂量为３５Ｇｙ;术后２４周对所有实验动物的损伤脊髓组织行免疫组化和超微结构观察。结果 实验组脊髓损伤上、下段髓鞘均减少,损伤下段神经纤维阳性轴索数量增

Changes in myelin sheath and axon of spinal cord in X-irradiation injured rats

Objective To investigate the X irradiation effect on the myelin sheath and axon of the spinal cord. Methods 60 Wistar adult rats receiving hemisection in the thoracic spinal cord were made into models of spinal injury.Among these rats,30 in the test group received X irradiation of 35 Gy the day after operation, while 30 in the control group only received hemisecton. Operative spinal cord was subjected to immunohistochemistry and hypermicroscopic observation. Results In the test group, injury to the myelin sheath of the upper and lower lesion and the number of neurofibrotic positive axon increbsed. In the control group the number of myelin sheath below the injured section decreased. Under electronic microscope,demyelination was found in the spinal cord and new born tiny neurofibrotic tracts were seen below the lesion. Conclusions X irradiation can make spinal cord demyelinate and promote the increase of neurofibrotic positive axon.