Lieber R L, Johansson C B, Vahlsing H L, Hargens A R, Feringa E R
Exp Neurol. 1986 Mar;91(3):423-34. doi: 10.1016/0014-4886(86)90041-5.
Contractile properties of rat soleus and extensor digitorum longus muscles were studied 1 year after complete thoracic spinal cord transection (spinal cord level T9). Force-generating capacity and contraction speed were unchanged in the extensor digitorum longus 1 year after transection. However, the rate of contraction and relaxation increased in the soleus as reflected by a decrease in time-to-peak tension and increase in fusion frequency. Additionally, the soleus muscle cross-sectional area decreased significantly (50%) while generating the same absolute tension. Thus, a large increase in soleus specific tension (force per unit area) was observed. These data, in conjunction with the increase in contractile speeds, suggest soleus slow-to-fast fiber type conversion secondary to cordotomy. Discriminant analysis of the contractile properties yields fusion frequency as the best discriminator between muscle groups. Thus, following cordotomy, predominantly slow muscles are affected to a greater extent than fast muscles.
在完全性胸段脊髓横断（脊髓水平T9）1年后，对大鼠比目鱼肌和趾长伸肌的收缩特性进行了研究。横断1年后，趾长伸肌的力量产生能力和收缩速度没有变化。然而，比目鱼肌的收缩和舒张速率增加，表现为达到峰值张力的时间缩短和融合频率增加。此外，比目鱼肌的横截面积显著减小（50%），而产生的绝对张力相同。因此，观察到比目鱼肌的比张力（每单位面积的力）大幅增加。这些数据，结合收缩速度的增加，提示脊髓切开术后比目鱼肌发生了慢肌纤维向快肌纤维的类型转换。对收缩特性进行判别分析得出，融合频率是区分不同肌肉群的最佳指标。因此，脊髓切开术后，主要的慢肌比快肌受到的影响更大。
