实验性糖尿病大鼠的单纤维肌电图研究

Single-fiber Electromyography in Exprimental Diabetic Rats

目的:分析链脲佐菌素(STZ)诱导的糖尿病大鼠坐骨神经的神经传导速度和腓肠肌单纤维肌电图的特点,评价两种检查方法对糖尿病多发性神经病早期诊断的价值。方法:健康雄性SD大鼠经腹腔注射STZ60mg·kg-1诱导成1型糖尿病大鼠模型(糖尿病组),在注射STZ后4、6、8、10和12周进行坐骨神经神经传导检查和腓肠肌单纤维肌电图的检测,并与正常对照组相比,然后观察大鼠胫神经的超微结构变化。结果:与正常对照组相比,糖尿病组大鼠6周起出现坐骨神经运动传导速度下降(P<0.05),运动波幅下降不明显(P>0.05);单纤维肌电图检查可发现糖尿病组大鼠4周起纤维密度明显增高(P<0.05),而Jitter值变化不明显。胫神经病理上出现典型的脱髓鞘、轴突变性和轴突再生性的改变与电生理的改变相一致。结论:糖尿病组大鼠6周起出现传导速度下降等周围神经病变的改变,而单纤维肌电图从4周起就显示纤维密度较对照组增高。神经传导速度和纤维密度检查都可用于糖尿病多发性神经病的早期诊断,纤维密度较神经传导速度更为敏感。

Aim：To investigate the nerve conduction studies and the single-fiber electromyography in streptozotocin（STZ）-induced diabetic rats and assess the value of these two methods in the diagnosis of diabetic polyneuropathy （DPN）. Methods：Healthy male SD rats were intraperitoneal injected with STZ （60 mg·g-1） to induce type 1 diabetes mellitus models. The diabetic rats were examed the motor nerve conduction velocity（MCV） in the sciatic nerve and the single-fiber electromyography of gastrocnemius every two week after 4 weeks of STZ injection until 12 weeks and compared with the normal control group. After electrophysiologic examination,the pathologic changes of posterior tibial nerve were observed. Results：Compared with the normal control group,MCV of the diabetic group rats decreased significantly（P0.05） at 6 weeks after STZ injection,but the amplitude of compound muscle action potential was just a little lower than the control,showed no significant differences（P0.05）. The fiber density of single-fiber electromyography of the diabetic rats was much higher than the control（P0.05） at 4 weeks after STZ injection and the Jitter of both the group rats was the same. Pathological examination showed typical changes of demyelination,axonal degeneration and regeneration,which confirmed the findings of NCS and SFEMG.