Noninvasive measurement of phosphocreatine recovery kinetics in single human muscles.
Noninvasive measurement of phosphocreatine recovery kinetics in single human muscles.
复制标题
无创测量单个人体肌肉中磷酸肌酸恢复动力学。
DOI：
10.1152/ajpcell.1997.272.2.c525
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Leigh,JS
中科院分区：
文献类型：
--
作者：
Walter,G;Vandenborne,K;McCully,KK;Leigh,JS
运动后磷酸肌酸（PCr）再合成的速率与肌肉氧化能力（Vmax）有关。与使用一维图像引导，本地化的核磁共振波谱技术，PCr动力学监测后，在内侧腓肠肌的8名健康受试者自愿，短时间，最大速率运动。每6秒获得一次局部光谱，其中来自非选择区域的污染<5%。最大速率运动引起接近最大至最大的肌肉激活，如高PCr水解速率（2.26 +/-0.07 mM/s）和广泛的PCr消耗所示。在最大速率运动9秒结束时，PCr消耗61.4 +/-2.4%，细胞内pH为7.04 +/-0.03。最大速率运动9 s后，PCr恢复，速率常数（kPCr）为1.87 +/-0.15 min（-1），Vmax为67.2 +/-6.0 mM/min。与先前活动无关，有氧ATP合成速率在9 s内达到48.6 +/-4.9 mM/min。将最大速率运动延长至30 s导致92.0 +/-1.2%PCr消耗和6.45 +/-0.07的细胞内pH。细胞内酸中毒分离kPCr和肌肉Vmax之间的直接关系，但不影响初始PCr再合成率。
The rate at which phosphocreatine (PCr) is resynthesized after exercise is related to muscle oxidative capacity (Vmax). With the use of a one-dimensional image-guided, localized nuclear magnetic resonance spectroscopy technique, PCr kinetics were monitored in the medial gastrocnemius of eight healthy subjects after voluntary, short duration, maximal rate exercise. Localized spectra were obtained every 6 s with <5% contamination from nonselected regions. Maximal rate exercise elicited near-maximal to maximal muscle activation, as indicated by the high-PCr hydrolysis rate (2.26 +/- 0.07 mM/s) and extensive PCr depletion. At the end of 9 s of maximal rate exercise, PCr was depleted by 61.4 +/- 2.4% and intracellular pH was 7.04 +/- 0.03. After 9 s of maximal rate exercise, PCr recovered with a rate constant (kPCr) of 1.87 +/- 0.15 min(-1) and a Vmax of 67.2 +/- 6.0 mM/min. Independent of prior activity, aerobic ATP synthesis rates reached 48.6 +/- 4.9 mM/min within 9 s. Extending maximal rate exercise to 30 s resulted in 92.0 +/- 1.2% PCr depletion and an intracellular pH of 6.45 +/- 0.07. The intracellular acidosis separated the direct relationship between kPCr and muscle Vmax but did not affect the initial PCr resynthesis rate.