Is the change in intracellular pH during fatigue large enough to be the main cause of fatigue?
Is the change in intracellular pH during fatigue large enough to be the main cause of fatigue?
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疲劳时细胞内pH值的变化是否大到足以成为疲劳的主要原因？
DOI：
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发表时间：
1986
影响因子：
2.1
通讯作者：
G. W. Mainwood
中科院分区：
文献类型：
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作者：
J. Renaud;Y. Allard;G. W. Mainwood
暴露于细胞外 pH 8.0（25 mM HCO3-，1% CO2）的青蛙缝匠肌的细胞内 pH 为 6.9-7.1。经过疲劳刺激期（每秒一次强直性收缩，持续 3 分钟）后，细胞内 pH 值为 6.5-6.7。当用暴露于 pH 6.4（2mM HCO3-，1% CO2）的青蛙缝匠肌重复类似实验时，细胞内 pH 值在休息时为 6.8-6.9，在疲劳后为 6.3-6.4。因此，在这两个实验中，疲劳期间细胞内 pH 值降低了 0.4-0.5 个 pH 单位。当沐浴液的CO2浓度从1%增加到30%时，静息肌肉的细胞内pH值从7.0下降到6.2-6.3。虽然CO2对细胞内pH值的影响大于疲劳效应，但CO2对强直力的降低小于40%，而疲劳期间强直力至少降低70%。因此，在青蛙缝匠肌中，疲劳期间强直力的降低超过了细胞内 pH 值变化所预期的降低。
The intracellular pH of frog sartorius muscles exposed to an extracellular pH 8.0 (25 mM HCO3-, 1% CO2) was 6.9-7.1. Following a fatiguing stimulation period (one tetanic contraction per second for 3 min), the intracellular pH was 6.5-6.7. When similar experiments were repeated with frog sartorius muscles exposed to pH 6.4 (2mM HCO3-, 1% CO2), the intracellular pH was 6.8-6.9 at rest and 6.3-6.4 following fatigue. So, in both experiments the intracellular pH decreased by 0.4-0.5 pH unit during fatigue. When the CO2 concentration of the bathing solution was increased from 1 to 30%, the intracellular pH of resting muscles decreased from 7.0 to 6.2-6.3. Although the effect of CO2 on the intracellular pH was greater than the fatigue effect, the decrease in tetanic force with CO2 was less than 40%, while during fatigue the tetanic force decreased by at least 70%. Therefore in frog sartorius muscle the decrease in tetanic force during fatigue exceeds the decrease that is expected from just a change in intracellular pH.