Hegedus J, Putman C T, Gordon T
Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada.
Muscle Nerve. 2009 Mar;39(3):318-27. doi: 10.1002/mus.21160.
We examined whether there are gender differences in the progressive loss of functional motor units in SOD1(G93A) transgenic mice. Isometric muscle and motor unit twitch contractions were recorded in fast- and slow-twitch muscles in response to stimulation of the sciatic nerve. Using a modified motor unit number estimation technique (ITS-MUNE), we found that motor unit numbers declined rapidly from 40 to 90 days of age during the asymptomatic phase of ALS in fast- but not slow-twitch hindlimb muscles of both male and female mice. There was a corresponding decline in twitch and tetanic contractile forces of the fast-twitch muscles. Gender did not affect the progressive loss of motor units and associated decline in force production. We conclude that gender does not alter progressive, muscle-specific motor unit loss in ALS, even though gender does influence disease onset.
我们研究了超氧化物歧化酶1（G93A）转基因小鼠功能性运动单位的渐进性丧失是否存在性别差异。记录了坐骨神经刺激后快肌和慢肌的等长肌肉及运动单位抽搐收缩情况。使用改良的运动单位数量估计技术（ITS-MUNE），我们发现，在雄性和雌性小鼠的无症状期，即40至90日龄期间，快速收缩而非慢速收缩的后肢肌肉中，运动单位数量迅速下降。快速收缩肌肉的抽搐和强直收缩力也相应下降。性别并不影响运动单位的渐进性丧失以及相关的力量产生下降。我们得出结论，尽管性别确实会影响疾病发病，但在肌萎缩侧索硬化症中，性别不会改变渐进性、肌肉特异性的运动单位丧失。
