Objective To observe the changing pattern of fibrillation potential amplitude and positive sharp wave amplitude in a rat soleus muscle denervation model, and investigate its correlation with functional recovery of the muscle after nerve repair of different post - traumatic intervals. Methods Soleus muscle denervation model was set up in 54 male SD rats by transecting the tibial nerve. 12 rats were used to measure the amplitude of fibrillation potential and positive sharp wave of the soleus muscle after different denervation intervals, that is immediately after, 48 hours, 72 hours, 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 16 weeks after nerve transection. The other 42 rats were randomly divided into 7 groups, with 6 each. The tibial nerve was repaired 1, 2, 4, 8, 12, and 16 weeks after nerve transection respectively. 12 weeks following nerve repair, wet muscle weight and muscle fiber cross - sectional area of the soleus muscle was measured. A group without nerve repair served as control. Results After muscle denervation, positive sharp wave appeared prior to fibrillation potential. Amplitude of fibrillation potential reached peak level 1 week following denervation, maintained at this level for 4 weeks, gradually declined from 8 weeks on, and disappeared at 16 weeks after denervation. Positive sharp wave was present 48 hours following denervation, its amplitude being highest in 8 weeks. 16 weeks following denervation, positive sharp wave disappeared in half of the rats. There was no significant difference of muscle weight and fiber size among groups in which the tibial nerve was repaired within 8 weeks. Significant difference was found when the nerve was repaired after 12 weeks. Conclusions Fibrillation potential amplitude and positive sharp wave amplitude were closely correlated with recovery of muscle function. It thus can be used as a quantitative parameter to determine whether denervation atrophy of skeletal muscle is reversible or not.%目的研究大鼠腓肠肌失神经支配后纤颤电位与正尖波波幅的变化,并探讨其与在损伤后不同时期修复断伤胫神经后腓肠肌功能恢复间的相关性。方法雄性SD大鼠54只,按手术先后顺序随机分为8组。第1组12只大鼠，于切断其右侧胫神经后即刻、48 h、72 h、1周、2周、4周、8周、12周、16周,测定右侧腓肠肌的纤颤电位及正尖波。第2 ～ 7组(每组6只大鼠),分别在胫神经切断后1、2、4、8、12、16周时修复神经,各组于修复后12周取腓肠肌,测定肌湿重及肌纤维直径及截面积。第8组(6只大鼠)作为正常对照组。结果第1组的正尖波先于纤颤电位出现,纤颤电位的波幅在术后1周最高,在神经切断后4周内维持在较高水平;术后8周起其波幅呈进行性下降,16周时全部消失。正尖波于神经切断后48 h开始出现,术后8周其波幅最大,术后16周时半数大鼠的正尖波消失。于神经断伤后8周内修复的胫神经,恢复的肌肉功能与正常对照组相比,差异无显著性意义(t =1.952,P > 0.05); 神经断伤后12周以后修复组恢复的肌肉功能明显变差,与正常对照组相比差异有显著性意义(t =3.217, P < 0.05)。结论失神经支配腓肠肌纤颤电位与正尖波的波幅,与神经修复后功能恢复程度间有密切的相关性,可作为大鼠失神经骨骼肌萎缩是否可逆的一个量化指标。
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