银杏叶提取物减轻臂丛根性撕脱后脊髓运动神经元超微结构的损伤

Extracts of Ginkgo Biloba 761 alleviates ultrastructural injury of motor neurons following brachial roots avulsion

目的：研究银杏叶提取物(EGb761)对臂丛撕脱后运动神经元超微结构的保护作用。方法：显微镜下撕脱大鼠臂丛 C_5～T_(?)神经根,术后实验大鼠腹腔注射100 mg·kg^(-1)·d^(-1)EGb761,透射电镜观察损伤 C_7节段运动神经元的超微结构。结果：神经根撕脱6～8周,运动神经元胞体体积缩小、胞核染色质裂解、浓缩异染色质增多；粗面内质网和游离核糖体减少、线粒体减少、嵴肿胀；神经髓鞘不完整、呈空泡状变性。EGb761治疗后,胞体体积基本正常,偶见浓缩异染色质；粗面内质网减少不显著；游离核糖体数量明显增多；线粒体形态正常；髓鞘完整呈同心圆包绕在轴索周围。结论：EGb761能减轻运动神经元超微结构的损伤,减少臂丛根性撕脱诱导的运动神经元凋亡。

Objective： To study the protective effect of extracts of Ginkgo Biloba 761 （EGb761） on injured motor neurons following brachial root avulsion. Methods： The nerve roots （C5-T1） of right brachial plexus of male adult Sprague-Dawley rats were isolated and avulsed under the microscope; The injured rats were randomly divided into normal saline, EGb761 100 mg/kg · d treated and sham groups. The injured rats were intraperitoneally injected with lml normal saline or 100 mg/kg aqueous solution every day. After 6 and 8 weeks, all rats were killed and the ultra structure of injured C7 spinal segments were observed by transmission electron microscope. Results. In normal saline group, the bodies of motor neurons were shrunk. The nuclear chromatin curdled at the edge of nuclear membrane was splitting, divergent but the nuclear membrane was integrated. The amount of rough endoplasmic reticula and the free ribosomes were decreased. Mitochondria and its spines were all swollen. The lamellar appearance of myelin sheath disappeared and became vacuolar. In EGb761 treated groups, there was less curdled nuclear chromatin. The cell membranes of injured motor neurons were also integrated but without shrunk nuclear membranes. The amount of rough endoplasmic reticula and the free ribosome were more than that in normal saline group. The shape of mitochondria and its spines remained normal. The lamellar appearance of myelin sheath was clear and complete. Conclusion：EGb761 is effective in preventing some subcellular organelles deterioration in root avulsion-induced spinal motor neuron neuropathy.