Relationship of muscular fatigue to pH and diprotonated Pi in humans: a 31P-NMR study.
Relationship of muscular fatigue to pH and diprotonated Pi in humans: a 31P-NMR study.
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人类肌肉疲劳与 pH 值和二质子化 Pi 的关系：31P-NMR 研究。
DOI：
10.1152/jappl.1988.64.6.2333
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Chance,B
中科院分区：
文献类型：
--
作者：
Wilson,JR;McCully,KK;Mancini,DM;Boden,B;Chance,B
17名正常受试者进行最大屈腕运动，连续监测前臂肌肉的pH值和H_2PO_4-，用31P核磁共振测量，并监测肌肉疲劳，以最大发育力下降的百分比表示。4分钟的运动(屈膝持续时间=1 S)使最大发育力从10 0%下降到74+/-9%，pH从6.99+/-0.0 4下降到6.17+/-0.33，H_2O_4~-增加到静息水平的927+/-401%。在所有受试者中，发育力与pH呈线性关系(r=0.90+/-0.08)，与H_2PO_4-呈线性关系(r=-0.89+/-0.08)。将收缩时间增加一倍至2 S，发育力、pH和H_2PO_4-的变化更快，但力与pH和H_2PO_4-的关系没有变化。最大运动量前两分钟的次极量运动可显著降低pH值和升高H_2PO_4~-。在随后的最大运动中，发展的力量与H_2PO_4-的关系保持不变。相反，发育力和pH之间的关系向左移动；在最大限度的运动中，肌肉的pH值保持较低，而发育力与对照组运动中的结果相当。这些观察表明，短期高强度运动中的肌肉疲劳主要是由肌肉内H_2PO_4的增加引起的，而不是由于肌肉内pH的降低。
Seventeen normal subjects performed maximal wrist flexion exercise with continuous monitoring of forearm muscle pH and H2PO4-, measured with 31P nuclear magnetic resonance, and muscle fatigue, expressed as a percentage of decline in maximal developed force. Four minutes of exercise (flexion duration = 1 s) reduced maximal developed force from 100 to 74 +/- 9% and pH from 6.99 +/- 0.04 to 6.17 +/- 0.33 and increased H2PO4- to 927 +/- 401% of resting levels. In all subjects, linear relationships were noted between developed force and pH (r = 0.90 +/- 0.08) and between developed force and H2PO4- (r = -0.89 +/- 0.08). Doubling the contraction duration to 2 s produced more rapid changes in developed force, pH, and H2PO4- but no change in the relationship of force to pH and H2PO4-. Two minutes of submaximal exercise before maximal exercise significantly reduced pH and increased H2PO4-. During subsequent maximal exercise, the relationship between developed force and H2PO4- remained unchanged. In contrast, the relationship between developed force and pH was shifted leftward; muscle pH remained lower throughout maximal exercise, and developed force remained comparable to that noted during control exercise. These observations suggest that muscle fatigue during intense short-term exercise is primarily caused by an increase in intramuscular H2PO4- rather than by a decrease in intramuscular pH.