Argov Z, Nagle D, Giger U, Leigh J S
Department of Biochemistry/Biophysics, University of Pennsylvania School of Medicine, Philadelphia 19104.
Eur J Appl Physiol Occup Physiol. 1989;58(8):808-15. doi: 10.1007/BF02332211.
In vivo phosphorus nuclear magnetic resonance spectroscopy of muscle was performed at rest, during work and during postexercise recovery in rats injected with iodo-acetate (IA) (35-40 mg.kg-1, intra-arterially), in order to follow bio-energetic changes in muscle with acute glycolytic block. Three animals with contracture had very low ratios of phosphocreatine:inorganic phosphate (PCr:Pi) at rest (0.5-0.9). The PCr:Pi were normal at rest (6.9 +/- 2.0, +/- 2 SD) in all other rats. Exercise-induced continuous accumulation of phosphomonoesters (PME), the characteristic finding of glycolytic block, was observed. The end-exercise levels of PME correlated with the degree of block measured in vitro. During steady-state work, induced by nerve stimulation at four frequencies, PCr:Pi values were significantly lower (p less than 0.02) than the control values at 0.25, 1.0 and 2.0 Hz. The ATP levels fell during exercise to reach 75% +/- 7% of initial values. The recovery of PCr:Pi from exercise and the disappearance of PME were slow. Two animals which survived the IA injection demonstrated much lower PME accumulation 18 h later. It is concluded that in acute muscle glycolytic block: (1) energy metabolism is impaired during exercise and also at rest, (2) accumulating PME can serve as an indicator of the degree of glycolytic block, (3) ATP levels fall during work, and (4) postexercise recovery is slow. The findings are compared with 31P-NMR observations in chronic muscle glycolytic disorders.
对经动脉注射碘乙酸（IA）（35 - 40 mg·kg⁻¹）的大鼠，在静息、工作期间以及运动后恢复过程中进行肌肉的活体磷核磁共振波谱分析，以追踪急性糖酵解受阻时肌肉中的生物能量变化。三只出现挛缩的动物在静息时磷酸肌酸与无机磷酸的比率（PCr:Pi）非常低（0.5 - 0.9）。所有其他大鼠静息时的PCr:Pi正常（6.9 ± 2.0，± 2标准差）。观察到运动诱导的磷酸单酯（PME）持续积累，这是糖酵解受阻的特征性表现。运动结束时PME的水平与体外测量的受阻程度相关。在由四种频率的神经刺激诱导的稳态工作期间，在0.25、1.0和2.0 Hz时，PCr:Pi值显著低于对照值（p < 0.02）。运动期间ATP水平下降至初始值的75% ± 7%。运动后PCr:Pi的恢复以及PME的消失缓慢。两只在IA注射后存活的动物在18小时后PME积累明显更低。结论是，在急性肌肉糖酵解受阻时：（1）运动期间以及静息时能量代谢受损，（2）积累的PME可作为糖酵解受阻程度的指标，（3）工作期间ATP水平下降，（4）运动后恢复缓慢。将这些发现与慢性肌肉糖酵解紊乱的³¹P - NMR观察结果进行了比较。
