不同时段缺血对SD大鼠周围神经超微结构的影响

Ultrastructure Changement in Peripheral Nerve on Different Ischemia Period in SD Rat

目的 探讨缺血对 SD大鼠周围神经组织超微结构的影响。 方法 采用两步冷冻法 ,以 1 5 % DMSO为低温保护剂 ,对 30只 SD大鼠股前神经进行缺血冷藏和常温缺血实验 ,时间为 1 ,2 ,3,4 ,5 ,6和 8h,- 5 0℃冷冻温度预处理 ,液氮保存 1周 ,透射电镜观察。 结果 缺血 1～ 2 h,冷藏组个别髓鞘轻度水肿 ,常温组髓鞘增厚 ,雪旺细胞水肿 ;缺血 3～ 4 h,冷藏组个别轴索内线粒体轻度肿胀 ,常温组少数神经纤维脱髓鞘现象 ;缺血 5～ 6 h,冷藏组部分髓鞘不规则 ,排列疏松 ,常温组神经纤维脱髓鞘增多 ,雪旺细胞及轴索内线粒体水肿明显 ;缺血 8h,冷藏组少数神经纤维脱髓鞘 ,部分雪旺细胞水肿 ,常温组轴索明显萎缩 ,少数雪旺细胞破坏。 结论 缺血 8h冷藏神经组织 ,其超微结构仍较好 。

Objective To investigate the changement of the ultrastructure on peripheral nerve ischemia of SD rat. Methods To adopt two steps frozon methods with 15%DMSO for low temperature protective reagent, the cold storage ischemia and normal temperature ischemia samples were checked at 1, 2, 3, 4, 5, 6 and 8 h. The nerve tissue with -50 ℃ of preliminary treatment temperature was preserved in liquid nitrogen for one week. The tissue was sliced and studied by using transmission electrical microscope(TEM). Results During 1~2 hr, cold storaged groups showed a little dropsy, the normal temperature groups myelin showed incrassation and Schwann's cell dropsy. At 3~4 hr, cold storage groups showed a little dropsy in axis cylinder, the normal temperature groups showed nerve demyelination. At 5~6 hr, the cold storage groups showed arranged sparseness and abnormity of myelin, the normal temperature groups showed demyelination and manifold, the mitochondria obvious dropsy in Schwann's cell and axis cylinder. At 8 hr, the cold storage groups showed demyelination and Schwann's cell dropsy, in the normal temperature groups the axis cylinder were obvious atrophy and Schwann's cell damnify. Frozon at 8 hr, the ultrastructure of peripheral nerve maintains a good protective condition, the cold storage could prolong the duration of nerve tissue for ischemia.;