神经节苷脂对6-OHDA损毁交感神经末梢的对抗作用

RESISTANT ACTION OF GANGLIOSIDES ON THE 6-OHDA INJURED SYMPATHETIC NERVES

单次6-OHDA (15mg/kg.i.p.)注射后24h,可使雌性成年小鼠颌下腺内儿茶酚胺荧光神经末梢几乎完全消失;同时用 HPLC 测得腺体内去甲肾上腺素(NA)和多巴胺(DA)的含量下降至正常值的3—4%以下。随着受损交感神经末梢再生过程,NA 和 DA 水平有缓慢的恢复。在损毁2周时 NA 和 DA 含量分别达到正常水平的50%和28%,且在4周时完全恢复。在注射6-OHDA 的同时,和在损伤后12h 内给动物注射4次神经节苷脂(每次50mg/kg.i.p.)并在其后的一周內每天注射一次,可使颌下腺内 NA 含量维持在正常水平;在损毁后4h 及损毁前4d 开始施用神经节苷脂,也可不同程度地对抗交感神经末梢损伤,但作用强度不如前者。实验结果提示:(1)神经节苷脂通过减弱6-OHDA 及其代谢产物的损伤效应能够保护交感神经末梢膜,它可能还有促损伤末梢再生性长芽的作用;(2)损伤后神经节苷脂处理得越早,其效果越好。

A single dose of 6—OHDA(15 mg/kg i.p.)would cause an almost completedisappearance of catecholamine fluorescence in histological preparation of sub-mandibular glands(SMG)24 hours after injection.Recovery of NA and DA le-vels went on slowly along with the course of regeneration of the lesioned sympatheticnerve terminals.The NA and the DA contents reached 50% and 28% respectivelytwo weeks after lesion and fully recovered by the end of the fourth week.Gangliosides mixture(GM)(50 mg/kg i.p.)given 0,4,8,and 12 hours after6-OHDA injection could prevent the injury action of NA and DA for at least 24hours.If this treatment was followed by daily injection for one week,the NAcontents remained normal by the end of two weeks.GM treat ments beginningeither 4 days before or 4 hours after 6-OHDA injection could lessen the extent ofdecrease of NA and DA by 6-OHDA.The results suggest that:a)GM is effective in protecting the membrane ofsympathetic terminals from the injureous effect of 6-OHDA or 6-OHDA metabo-lites and promoting the regeneration of the lesioned terminals.b)The earlier theGM treatments are given,the better will be the effects.