Ren J M, Chasiotis D, Bergström M, Hultman E
qepartment of Clinical Chemistry II, Karolinska Institutet, Huddinge University Hospital, Sweden.
Acta Physiol Scand. 1988 May;133(1):101-7. doi: 10.1111/j.1748-1716.1988.tb08387.x.
Phosphorylase activity, glycogenolytic and glucolytic rates were estimated in human quadriceps muscle during electrical stimulation at 20 Hz. Two stimulation periods of 10 s duration were separated by a pause of 60 s. The blood circulation to the leg was intact or occluded during the experiment. ATP turnover rates and force production were of the same order during the two contraction periods both with and without intact blood flow. Also the increase in phosphorylase a activity (from approximately 30% to approximately 65%) was the same during the contraction periods. Glycogenolytic and glucolytic rates were however about 30% higher (P less than 0.05) during the second contraction compared with the first when circulation was occluded, but similar when the circulation was intact. During the 60 s rest period, the phosphocreatine (PCr) was maintained at a low level and inorganic phosphate (Pi) remained increased under occluded circulation while PCr was resynthesized in the rest period with intact circulation. We conclude that the increased glycogenolytic rate observed during the second contraction with occluded blood circulation was due to the high [Pi] in the muscle and that the increased glucolytic rate was caused by high [Pi] and low [PCr]. In the rest period with anoxia the glycogenolysis was completely inhibited and glucolysis was inhibited by 95% in spite of the changes in [PCr] and [Pi].
在20Hz电刺激期间，对人体股四头肌的磷酸化酶活性、糖原分解率和糖酵解率进行了评估。两个持续10秒的刺激期之间间隔60秒。实验过程中，腿部的血液循环保持正常或被阻断。在有和没有完整血流的两个收缩期，ATP周转率和力量产生处于同一水平。在收缩期，磷酸化酶a活性的增加（从约30%增至约65%）也是相同的。然而，当血液循环被阻断时，与第一次收缩相比，第二次收缩期间的糖原分解率和糖酵解率约高30%（P<0.05），而当血液循环正常时，两者相似。在60秒的休息期，当血液循环被阻断时，磷酸肌酸（PCr）维持在低水平，无机磷酸盐（Pi）持续升高，而当血液循环正常时，PCr在休息期重新合成。我们得出结论，在血液循环被阻断的第二次收缩期间观察到的糖原分解率增加是由于肌肉中高浓度的[Pi]，而糖酵解率增加是由高浓度的[Pi]和低浓度的[PCr]引起的。在缺氧的休息期，尽管[PCr]和[Pi]发生了变化，但糖原分解被完全抑制，糖酵解被抑制了95%。
