Noninvasive measurements of activity-induced changes in muscle metabolism.
Noninvasive measurements of activity-induced changes in muscle metabolism.
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DOI：
10.1016/0021-9290(91)90385-z
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发表时间：
1991
影响因子：
2.4
通讯作者：
K. McCully;Hiroomi Kakihira;K. Vandenborne;J. Kent‐Braun
中科院分区：
文献类型：
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作者：
K. McCully;Hiroomi Kakihira;K. Vandenborne;J. Kent‐Braun
两种非侵入性测量技术被用来监测活动引起的人类骨骼肌的变化。磷磁共振波谱（P-MRS）用于测量能量代谢的变化，方法是在30 cm内径、1.9特斯拉磁体中，在腕屈肌稳定水平工作期间测量无机磷酸盐与磷酸肌酸（Pi PCr）的比值，并在76 cm内径、1.8特斯拉磁体中，测量小腿肌肉运动后PCr的恢复率。近红光谱（NRS）被用来测量运动中和运动后血红蛋白和肌红蛋白的氧饱和度的变化。14天的腕关节屈曲运动导致肌肉代谢的显着改善MRS测量。这种改善消失后35天的不活动。在训练过程中的肌肉应力，如肌肉酸痛和最大力量下降的迹象与静息Pi PCr的增加。使用跖屈运动的类似训练方案导致PCr再合成率提高，在训练停止后42天恢复到对照值。NRS测量的腕屈肌肌肉在斜坡运动协议表明，血红蛋白-肌红蛋白的氧饱和度从60%，在休息到15%，在最高的工作水平。在年轻和老年受试者中，氧饱和度恢复的半衰期均快于PCr，支持了健康个体在次极量运动中氧输送不是速率限制的假设。
Two noninvasive measurement techniques were used to monitor activity-induced changes in skeletal muscle in humans. Phosphorus magnetic resonance spectroscopy (P-MRS) was used to measure changes in energy metabolism by measuring the ratio of inorganic phosphate to phosphocreatine (Pi PCr) during steady level work in the wrist flexor muscles in a 30 cm bore, 1.9 Telsa magnet, and the rate of PCr recovery from exercise in the calf muscles in a 76 cm bore, 1.8 Tesla magnet. Near red spectroscopy (NRS) was used to measure changes in oxygen saturation of hemoglobin and myoglobin during and after exercise. Fourteen days of wrist flexion exercise resulted in significant improvement in muscle metabolism as measured by MRS. This improvement disappeared after 35 days of inactivity. Indications of muscle stress during training such as muscle soreness and decreased maximum strength were associated with increases in resting Pi PCr. A similar training protocol using plantar flexion exercise resulted in an improved rate of PCr resynthesis, which returned to control values 42 days after training stopped. NRS measurements of the wrist flexor muscles during a ramp exercise protocol demonstrated a decrease in the oxygen saturation of hemoglobin-myoglobin from 60% at rest to 15% at the highest work levels. The half time of recovery of oxygen saturation was faster than that of PCr in both young and old subjects, supporting the hypothesis that oxygen delivery is not rate limiting in submaximal exercise in healthy individuals.