神经节苷脂对大鼠坐骨神经损伤后神经纤维变化的作用研究

The Effect of Gangliosides on Rat Sciatic Nerves After Nerve Injury

连续8d每天给大鼠ip10，20和50mg／kg神经节苷脂，d9将大鼠坐骨神经损伤，损伤后d7用图象分析仪检查该神经内有髓神经纤维变性情况。其中50mg／kg组有髓神经纤维华勒氏变性程度与对照组（ip生理盐水）相比大幅度减小；10mg／kg组无效；20mg／kg组有轻度减轻作用。以上各组中的有髓神经纤维轴突直径和神经纤维直径以及G值与正常有髓神经纤维相似，P＞0．05。正常大鼠坐骨神经损伤后d15观察发现其内的再生有髓神经纤维数约为正常坐骨神经的三分之一，其中的轴突直径和神经纤维直径均较大，约为正常有髓神经纤维的二倍，G值则较小，P＜0．05。结果提示，大鼠神经损伤前预防性给予的神经节苷脂能储存于机体内，在神经损伤后，它们迅速释放并参与神经的营养与生长修复工作，主要起到防止神经纤维华勒氏变性的作用，而不是促进变性的神经纤维再生。同时也说明，神经损伤之前机体内储存足量神经节苷脂对于预防神经华勒氏变性是重要的。

Rats were treated intraperitonealy with 10, 20 and 50 mg/kg of a ganglioside mixture respec tively everyday for 8 d, then the sciatic nerve of the rats was crushed using a standardized procedure.In the d7 after nerve damage, histological evaluation of the sciatic nerve transverse sections 1 cm distul to the nerve crush was performed by means of an image analyzer, and the number of nerve fibbers, axon diameter, fibber diameter and their ratio (G ratio) determined. In another group(nerve fibber re generation group) sciatic nerve of the rats was crushed using the above procedure, in d15 was ana lyzed using the same methods.It was found that the number of fibbers was obviously higher in the 50 mg/kg gangliosides treated group than in the control group(physiological saline treated); 20 mg/kg gangliocides had a smaller ef fect in the prevention of wallerian degeneration than 50 mg/kg gangliosides. The 10 mg/kg ganglio sides had no effect. The axon diameter, fibber diameter and G ratio of the above groups were similar to normal nerve fibbers(P＞ 0. 05). In the nerve fibber regeneration group, the axon diameter and fib ber diameter were greater than normal fibbers, P＜0. 001. G ratio was smaller than normal fibbers, P ＜0. 05. These results suggested that the fibbers of sciatic nerve in the gangliosides pretreated groups were normal nerve fibbers. The above results also mean that gangliosides which was injected into rats before nerve damage could be stored in a dynamic gangliosides pool in the body. When the nerves were damaged, those gangliosides could nourish the nerves, join the process of nerve repair, and prevent the nerve degeneration. Giving enough amount of gang1isides be fore nerve crush had some effect on the prevention of nerve degeneration.