Wackerhage H, Mueller K, Hoffmann U, Leyk D, Essfeld D, Zange J
Department of Physiology, German Sports University, Cologne, Germany.
MAGMA. 1996 Sep-Dec;4(3-4):151-5. doi: 10.1007/BF01772002.
In an oxygen-depleted muscle, glycolytically produced ATP is inversely related to the ([ATP]+ creatine phosphate [PCr]) decrease because ATP, PCr, and glycolysis are virtually the only energy sources under these conditions. In particular, the onset of glycolysis or any appreciable increase in the rate of glycolytic ATP production will lead to a slower rate of ([ATP]+ [PCr]) breakdown at a given energy consumption. To quantify this relationship, endurance athletes performed isometric foot plantar flexion (20% of a test force [TF], n = 10; 50% TF, n = 5) during local arterial occlusion. Parameters of energy metabolism were measured with 31P magnetic resonance spectroscopy (31P-MRS). During exercise, [PCr] decreased to 80 +/- 10 (20% TF) and 11 +/- 4% (50% TF) of its resting concentration, and pH dropped from 7.04 +/- 0.01 to 6.98 +/- 0.10 (20% TF) and from 7.03 +/- 0.02 to 6.70 +/- 0.10 (50% TF). In both experiments, two phases of ([ATP]+ [PCr]) decrease were observed: an initial faster decrease was followed by a slower decline. The latter phase started at about the time when the pH began to drop. The difference between a line extrapolated from the slope of the initial phase and the measured ([ATP]+[PCr]) decrease was used as an estimate for glycolytically produced ATP. This estimate and pH were significantly correlated with r = -0.97 (20% TF) and r = -0.99 (50% TF). These results indicate that glycolytically produced ATP can be estimated from the ([ATP]+ [PCr]) decrease during exercise.
在缺氧的肌肉中，糖酵解产生的ATP与（[ATP]+磷酸肌酸[PCr]）的减少呈负相关，因为在这些条件下，ATP、PCr和糖酵解几乎是唯一的能量来源。特别是，糖酵解的开始或糖酵解产生ATP的速率的任何显著增加，将导致在给定能量消耗下（[ATP]+[PCr]）分解的速率变慢。为了量化这种关系，耐力运动员在局部动脉闭塞期间进行了等长足底屈肌运动（测试力[TF]的20%，n = 10；50%TF，n = 5）。用31P磁共振波谱（31P-MRS）测量能量代谢参数。运动期间，[PCr]降至其静息浓度的80±10（20%TF）和11±4%（50%TF），pH从7.04±0.01降至6.98±0.10（20%TF），从7.03±0.02降至6.70±0.10（50%TF）。在两个实验中，均观察到（[ATP]+[PCr]）减少的两个阶段：最初较快的减少之后是较慢的下降。后一阶段大约在pH开始下降时开始。从初始阶段斜率外推的直线与测量的（[ATP]+[PCr]）减少之间的差异用作糖酵解产生的ATP的估计值。该估计值与pH显著相关，r = -0.97（20%TF）和r = -0.99（50%TF）。这些结果表明，运动期间糖酵解产生的ATP可以根据（[ATP]+[PCr]）的减少来估计。
