Glycolytic regulation during an aerobic rest-to-work transition in dog gracilis muscle.
Glycolytic regulation during an aerobic rest-to-work transition in dog gracilis muscle.
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DOI：
10.1152/jappl.1987.63.6.2366
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发表时间：
1987-12
影响因子：
3.3
通讯作者：
R. Connett
中科院分区：
文献类型：
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作者：
R. Connett
糖原磷酸化酶活性和几个糖酵解中间体进行了测量，在休息和5，10，15，30，60和180秒的抽搐刺激后，在4赫兹的快速冷冻样品的股薄肌。在糖酵解的初始爆发（0-5秒）期间，只有3-磷酸甘油酸和乳酸积累。这些变化在低糖酵解通量期间（5-30 s）被逆转。在糖酵解的第二次爆发（30-60秒）期间，大多数糖酵解中间产物增加。糖原磷酸化酶a的水平与糖酵解的初始爆发平行变化，但在整个第二次爆发中保持在静息水平。在糖酵解的初始爆发过程中，磷酸甘油酸变位酶-烯醇化酶步骤偏离平衡，表明了短暂的限速作用。使用磷酸果糖激酶动力学模型的分析表明，细胞溶质pH（R。J. Connett，J.Appl.Physiol.63：2360-2365，1987）和游离[ADP]和[AMP]可以解释糖酵解的初始爆发。糖酵解的第二次爆发需要其他调节因子。它的结论是，初始碱化是一个主要的调节因素，在早期爆发糖酵解在休息到工作的过渡在红肌肉。
Glycogen phosphorylase activity and several glycolytic intermediates were measured at rest and after 5, 10, 15, 30, 60, and 180 s of twitch stimulation at 4 Hz in fast-frozen samples of gracilis muscle. During an initial burst of glycolysis (0-5 s) only 3-phosphoglycerate and lactate accumulate. These changes are reversed during the period of low glycolytic flux (5-30 s). During a second burst of glycolysis (30-60 s) most glycolytic intermediates increase. The levels of glycogen phosphorylase a changes in parallel with the initial burst of glycolysis but remain at resting levels throughout the second burst. The phosphoglycerate mutase-enolase steps deviate from equilibrium during the initial burst of glycolysis, suggesting a transiently rate-limiting role. Analysis using a model of phosphofructokinase kinetics indicates that combined changes in cytosolic pH (R. J. Connett, J. Appl. Physiol. 63: 2360-2365, 1987) and free [ADP] and [AMP] can account for the initial burst of glycolysis. The second burst of glycolysis requires other regulatory factors. It is concluded that an initial alkalization is a major regulatory factor in the early burst of glycolysis during a rest-to-work transition in red muscle.