Dupont Salter Anne-Caroline, Richmond Frances J R, Loeb Gerald E
Queen's University, Kingston, ON K7L 3N6, Canada.
IEEE Trans Neural Syst Rehabil Eng. 2003 Sep;11(3):209-17. doi: 10.1109/TNSRE.2003.817675.
Previous studies have shown that immobilization causes muscle atrophy and that the rate of atrophy depends on the length at which the muscle is immobilized. However, most studies have been carried out in neurologically intact animals that were capable of generating at least some voluntary muscle activation. In this study, tetrodotoxin was applied chronically to the rat sciatic nerve to produce complete paralysis of distal muscles for seven days, and the ankle was immobilized to hold the muscles at long or short lengths. Paralysis without immobilization resulted in relative weight losses of 36% for soleus, 19% for tibialis anterior (TA), and 17% for lateral gastrocnemius (LG) muscles. Casting the ankle in plantarflexion stretched TA and reduced its weight loss to 10%. Soleus and LG were shortened by this intervention and had increased losses of 43% and 28%, respectively. Fixing the limb in dorsiflexion resulted in a posture similar to that adopted by the unrestrained rats and had no significant effect on the amount of muscle atrophy compared to that in unrestrained paralyzed animals.
先前的研究表明，固定会导致肌肉萎缩，且萎缩速率取决于肌肉被固定时的长度。然而，大多数研究是在神经功能完整、能够产生至少一些自主肌肉激活的动物身上进行的。在本研究中，将河豚毒素长期应用于大鼠坐骨神经，以使远端肌肉完全麻痹7天，并固定踝关节以使肌肉保持长或短的长度。不进行固定的麻痹导致比目鱼肌相对重量损失36%，胫前肌（TA）相对重量损失19%，外侧腓肠肌（LG）相对重量损失17%。将踝关节固定于跖屈位会拉伸TA，并将其重量损失降至10%。比目鱼肌和LG因该干预而缩短，重量损失分别增加至43%和28%。将肢体固定于背屈位导致姿势与未受约束的大鼠相似，与未受约束的麻痹动物相比，对肌肉萎缩量无显著影响。
