乐果诱导的大鼠迟发性神经病电生理变化的研究

Experimental study of electrophysiology of dimethoate induced delayed neurotoxicity in rats

目的通过建立乐果诱导的迟发性神经毒性的大鼠模型,探讨乐果所致迟发性神经病的电生理变化特点,为疾病的早期诊断提供理论依据。方法健康雄性SD大鼠60只,随机分成3组。观察染毒后中毒症状。电子显微镜下观察周围神经的病理变化。测定大鼠摆尾温度阈值(tailflick threshold temperature,TTT);检测胫神经、腓肠神经的运动神经传导速度(motor nerve conduct velocity,MNCV)、感觉神经传导速度(sense nerve conduct velocity,SNCV)、潜伏期(latency,LAT)、波幅(amlitude,AMP)和肌电图等电生理变化。结果神经病理改变:透射电子显微镜下可见,髓鞘普遍疏楹,可见部分髓鞘缺失。神经传导速度和肌电图的变化;第2周时染毒组波幅明显降低,与对照组相比差异有统计学意义。染毒后第4周时,高、低剂量组胫神经运动神经传导速度下降了,波幅的变化与运动传导速度一致。潜伏期增加差异有统计学意义。与对照组比腓肠神经与胫神经变化一致,但幅度较胫神经变化大。肌电图检查结果在实验2周时,高剂量组和低剂量组的大鼠小腿肌肌电图上观察到了纤颤电位,而到4周时,纤颤电位、正锐波更加频繁。结论用大鼠建立乐果迟发性神经病的动物模型是可行的;电生理检查可以作为早期诊断迟发性多发神经病的一个重要指标。

Objective To explore the eletronic physiology characteristic in the processiong of delayed polyneuropathy（ OPIDP）. Methods 60 healthy male SD rats were divided into 3 groups randomly, sense function was measured by the tests of the tailflick threshold temperature. The change of electrophysiology of motor nerve conduct velocity, sense nerve conduct velocity and electromyography of tibial nerve and sural nerve were measured by using electromyography. Results The results of electrophysiology ： At 2 week, Compared with the control group, the amplitude decreased obviously in dimethoate groups, and there was significant difference. At 4 week, the speed of conduct of tibial nerve slowed in high dose group and low dose group, and the changes of the amplitude is similar to conduct speed. The latency prolonged. Compared with control group, sural nerve＇s conduct speed and the amplitude decreased and latency prolonged, all these changes were more obvious the changes of the tibial nerve＇ s changes. The results of electrophysiology： At 2 week denervated potential was appeared in dimethoate groups in the electromyogram（fibrillation potential and positive sharp wave）. At 4 week all these changes were more obvious than before. Conclusion Electrophysiology is important to the early diagnose of OPIDP.