【摘要】 目的:观测大鼠脊神经前根撕脱伤对盆底肌运动神经元的存活及神经元中一氧化氮合酶(NOS)和N-甲基-D-天冬氨酸型受体(NMDAR)表达的影响。方法:取雄性SD大鼠25只,背部切口显露脊髓,拨断一侧L6￣S2脊神经前根。动物分为5组,分别于术后第3、7、14、21、28天,取腰骶段脊髓进行还原型烟酰腺嘌呤二核苷酸(NADPH-d)组织化学、中性红复染和NMDA受体免疫组织化学染色观察及定量分析。结果:术后第3、7、14、21、28天,与对侧比较术侧前角运动神经元存活率分别为96%、85%、50%、35%和20%;术后第7d开始出现NOS阳性神经元,其标记率分别为6%、40%、62%和41%。与对侧比较,术侧前角运动神经元NMDA受体亚单位表达改变,其中NMDAR1受体亚单位表达明显减少,NMDAR2B表达显著增高,NMDAR2A表达无明显变化。结论:前根撕脱伤可导致盆底肌运动神经元进行性死亡,NOS持续表达和NMDA受体亚单位的表达变化可能是导致神经元死亡的重要原因。更多还原

【Abstract】 Objective:To investigate the survival and NMDA expression of pelvic motoneurons in adult rats following lumbosacral ventral root avulsion.Method:25 adult male Sprague-Dawley rats were divided into 5 groups,the lumbar laminectomy was performed in adult rats.Under a surgical microscope,the dura mater was opened and L6-S2 ventral roots on the right side were avulsed individually.The animals were allowed to survive for 3,7,14,21,or 28 days postoperatively.The positive neurons were counted after NADPH-diaphoase histochemistry,neutral red counterstaining and NMDA receptor immunohistochemistry.Result:After different living periods,the survival rate of motoneurons were 96%,85%,50%,35% and 20% respectively,about 0%,6%,40%,62% and 41% of motoneurons expressed NOS.A decrease in NMDAR1 immunolabeling and a increase in NMDAR2B immunolabeling ipsilateral to the lesion were observed,but no change was detectable in NMDAR2A immunolabeling.Conclusion:Lumbosacral ventral root avulsion progressively deplete pelvic motoneurons.The different expressions of NOS and NMDA receptor subunits may be an important mechanism contributing toward the death of the injured neurons.更多还原