神经节苷脂对大鼠坐骨神经变性的影响及其机制的研究

Effect of gangliosides on the occurrence of degeneration of rat sciatic nerves and its mechanism

目的：观察预防性给与神经节苷脂对大鼠坐骨神经切断后华勒氏变性的影响，并对其机制进行研究。方法：连续８ｄ给大鼠ｉｐ５０和８０ｍｇ·ｋｇ－１·ｄ－１神经节苷脂，第９天将大鼠坐骨神经切断，切断后分别于第７天，第１１天和第１６天用图象分析仪检查该神经远段内有髓神经纤维变性情况。结果：无论于第７天还是于第１１天观察，坐骨神经内均出现完整髓鞘神经纤维，而生理盐水对照组神经纤维全部崩解。前者各自的第７天组坐骨神经内神经纤维数均比第１１天组多，有显著性差异（Ｐ＜０．００１）；８０ｍｇ·ｋｇ－１组坐骨神经内神经纤维数与５０ｍｇ·ｋｇ－１组相比，无论于第７天还是于第１１天均无显著性差异（Ｐ＞０．０５）。以上各组神经纤维轴突直径，神经纤维直径以及它们之间的比值均与正常坐骨神经内有髓神经纤维相似（Ｐ＞０．０５）。无论是５０ｍｇ·ｋｇ－１组还是８０ｍｇ·ｋｇ－１组，于第１６天坐骨神经内均无完整髓鞘神经纤维。坐骨神经切断前后均用５０ｍｇ·ｋｇ－１，各组于切断后第７天、第１１天和第１６天坐骨神经内均保留有完整髓鞘神经纤维，其中第７天组与只在损伤前给５０ｍｇ·ｋｇ－１和８０ｍｇ·ｋｇ－１第７天两组相比无显著性差异（Ｐ＞０．０５）；而第１１?

OBJECTIVE: To study the effect of pretreated gangliosides (GLS) on the occurrence of wallerian degeneration of rat sciatic nerves after nerve cutting and its mechanism. METHODS: Rats were treated intraperitonealy with 50 and 80 mg·kg -1 ·d -1 of a ganglioside mixture respectively for 8 days. The sciatic nerve of the rats was cut on day 9. On day 7, 11 and 16 after nerve cutting, histological evaluation of the sciatic nerve transverse sections 1 cm distal to the cutting site was performed by an image analyzer, and the number of nerve fibers, axon diameter, fiber diameter and their ratio were determined. RESULTS: There were nerve fibers in the GLS pretreated groups on day 7 and 11, and all fibers in the control group (physiological saline treated) disintegrated. The number of nerve fibers on day 7 was greater than that on day 11 in the former groups. The difference between the number of nerve fibers in 80 mg·kg -1 GLS groups and that of 50 mg·kg -1 groups on either day 7 or 11 were not statistically significant. The axon diameter, fiber diameter and their ratio of the above groups were similar to normal nerve fibers (P>0.05). There were no normal nerve fibers on day 16 in either 50 mg·kg -1 or 80 mg·kg -1 GLS pretreated groups. CONCLUSION: Some pretreated GLS can to some extent prevent the degeneration of nerve fibers after nerve cutting. The pretreated GLS are stored in the dynamic GLS pool in the body. When the nerves are damaged, these GLS can nourish the nerves, join the process of nerve repair, and prevent nerve degeneration. The preventive effect of pretreated GLS on the nerve degeneration is not infinite.