PET/CT imaging of age- and task-associated differences in muscle activity during fatiguing contractions.
PET/CT imaging of age- and task-associated differences in muscle activity during fatiguing contractions.
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疲劳收缩期间肌肉活动的 PET/CT 成像与年龄和任务相关的差异。
DOI：
10.1152/japplphysiol.01439.2012
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Enoka,RogerM
中科院分区：
文献类型：
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作者：
Rudroff,Thorsten;Kalliokoski,KariK;Block,DerekE;Gould,JeffreyR;Klingensmith3rd,WilliamC;Enoka,RogerM
该研究比较了骨骼肌摄取[18 F]-2-氟-2-脱氧-d-葡萄糖（[18 F]-FDG）的正电子发射断层扫描/计算机断层扫描（PET/CT），以及年轻人和老年人进行疲劳等长收缩（需要力量或位置控制）时表面肌电图（EMG）记录显示的肌肉活动量。本文记录了6名青年男子（26 ± 6岁）和6名老年男子（77 ± 6岁）在膝关节伸肌疲劳收缩时的大腿肌电信号。任务失败后立即进行PET/CT扫描。在24条腿部肌肉中的葡萄糖摄取量，量化为标准化摄取值，在力量任务后，老年男性的葡萄糖摄取量更大，而年轻男性的葡萄糖摄取量在不同任务中有所不同（力0.64 ± 0.3g/ml;位置0.73 ± 0.3g/ml），而老年人则无（力，0.84 ± 0.3g/ml;位置，0.79 ± 0.26g/ml）（年龄×任务交互作用;P< 0.001）。相比之下，年轻男性在两次收缩期间激动肌的EMG振幅增加率更大，并且两组受试者在两项任务中的EMG振幅增加率没有差异。葡萄糖摄取的成像估计表明疲劳收缩期间骨骼肌摄取[18 F]-FDG的空间分布存在年龄和任务依赖性差异。研究结果表明，PET/CT对[18F]-FDG摄取的成像，而不是表面EMG记录，检测到了年轻人而不是老年人在疲劳任务中肌肉活动的调节。
The study compared positron emission tomography/computed tomography (PET/CT) of [18F]-2-fluoro-2-deoxy-d-glucose ([18F]-FDG) uptake by skeletal muscles and the amount of muscle activity as indicated by surface electromyographic (EMG) recordings when young and old men performed fatiguing isometric contractions that required either force or position control. EMG signals were recorded from thigh muscles of six young men (26 ± 6 yr) and six old men (77 ± 6 yr) during fatiguing contractions with the knee extensors. PET/CT scans were performed immediately after task failure. Glucose uptake in 24 leg muscles, quantified as standardized uptake values, was greater for the old men after the force task and differed across tasks for the young men (force, 0.64 ± 0.3 g/ml; position, 0.73 ± 0.3 g/ml), but not the old men (force, 0.84 ± 0.3 g/ml; position, 0.79 ± 0.26 g/ml) (age × task interaction;P< 0.001). In contrast, the rate of increase in EMG amplitude for the agonist muscles was greater for the young men during the two contractions and there was no difference for either group of subjects in the rate of increase in EMG amplitude across the two tasks. The imaging estimates of glucose uptake indicated age- and task-dependent differences in the spatial distribution of [18F]-FDG uptake by skeletal muscles during fatiguing contractions. The findings demonstrate that PET/CT imaging of [18F]-FDG uptake, but not surface EMG recordings, detected the modulation of muscle activity across the fatiguing tasks by the young men but not the old men.