模拟失重对人体骨骼肌体积和肌内乙酰胆碱/肌酸比值的影响及等张运动对肌萎缩的作用

目的：研究模拟失重对人体骨骼肌体积和肌内乙酰胆碱／肌酸（Cho/Cr)比值的影响，并观察卧床期等张肌肉锻炼的抗肌萎缩作用。方法：10名健康青年男性志愿者，进行卧床3周的模拟失重试验，将其随机分为卧床对照组（5人）和卧床运动训练组（5人）。使用核磁共振成像和磁共振波谱观察卧床前后右侧大腿骨骼肌体积，肌四头肌体积和比目鱼肌内Cho/Cr的变化，使用REV9000等速测力系统测试其膝关节伸肌相对峰力矩的变化。结果：两组受试者卧床后右侧大腿骨骼肌体积、肌四头肌体积和膝关节伸肌相对峰力矩除Cho/Cr外均较卧床前显著下降，以股四头肌体积变化最显著。对照组与训练组间差异无显著性意义。结论：模拟失重对人体下肢骨骼肌短期内即可出现以伸肌为主的萎缩和膝关节伸肌相对峰力矩的下降。本组数据未能显示出等张运动对抗肌萎缩有显著的作用。

Changes of human skeletal muscle volume and cholin/creatin ratio under simulated weightlessness condition and the effect of exercise in muscle atrophy

Objective To observe the changes of human skeletal muscle volume and cholin/creatin ratio (Cho/Cr) under weightlessness condition, and the effect of isotonic exercise against amyotrophy. Method Ten healthy young male volunteers underwent bed rest for 3 weeks and were randomly divided into control group and exercise group. Muscle volume of the right thigh skeletal muscle and quadriceps of thigh, the Cho/Cr of the soleus muscle were measured by magnetic resonance image and proton spectroscopy. Knee joint extensor muscle's relative ptagon/bt was measured by REV9000 isovelocity loading ergometer. Results Except Cho/Cr of soleus muscle, all the indexes mentioned above decreased significantly after 21 days bed rest. There was no significant difference between control group and exercise group. Conclusion Under short term weightlessness, skeletal muscle atrophy acompanied by knee joint extensor muscle's relative ptagon/bt decrease may appear in lower limb, especially in extensor muscle groups.This experiment didn't show significant anti amyotrophy effect of exercise.