Regulation of glycogen breakdown and its consequences for skeletal muscle function after training
Regulation of glycogen breakdown and its consequences for skeletal muscle function after training
复制标题
DOI：
10.1007/s00335-014-9519-x
复制
发表时间：
2014-10-01
期刊：
影响因子：
2.5
通讯作者：
Westerblad, Hakan
中科院分区：
文献类型：
--
作者：
Katz, Abram;Westerblad, Hakan
反复进行体育锻炼，即，训练，诱导线粒体生物合成，并导致改善的身体表现和次极量运动期间糖原分解的衰减。已经提出，由于线粒体体积增加，较低程度的代谢应激（例如，ADP和P-i的较小增加）是在相同绝对强度的运动期间在训练状态下维持线粒体呼吸所必需的。据信P-i积累程度较低是导致糖原分解减少的原因，因为P-i是糖原磷酸化酶（糖原分解的限速酶）的底物。然而，在这篇综述中，我们提出了一个替代的解释减少糖原分解。因此，训练后较低程度的代谢应激也与AMP（特定细胞内位点收缩期间的游离浓度）的较小增加相关，这导致磷酸化酶B（磷酸化酶的非磷酸化形式）的较少活化，从而导致糖原分解减少。同时，干扰跨桥功能和细胞内Ca 2+处理的P1的较小积累有助于增加的抗疲劳性。糖原消耗的延迟也有助于在长时间运动期间通过作为能量储备来增强性能。
Repeated bouts of physical exercise, i.e., training, induce mitochondrial biogenesis and result in improved physical performance and attenuation of glycogen breakdown during submaximal exercise. It has been suggested that as a consequence of the increased mitochondrial volume, a smaller degree of metabolic stress (e.g., smaller increases in ADP and P-i) is required to maintain mitochondrial respiration in the trained state during exercise at the same absolute intensity. The lower degree of P-i accumulation is believed to account for the diminished glycogen breakdown, since P-i is a substrate for glycogen phosphorylase, the rate-limiting enzyme for glycogenolysis. However, in this review, we present an alternative explanation for the diminished glycogen breakdown. Thus, the lower degree of metabolic stress after training is also associated with smaller increases in AMP (free concentration during contraction at specific intracellular sites) and this results in less activation of phosphorylase b (the non-phosphorylated form of phosphorylase), resulting in diminished glycogen breakdown. Concomitantly, the smaller accumulation of P-i, which interferes with cross-bridge function and intracellular Ca2+ handling, contributes to the increased fatigue resistance. The delay in glycogen depletion also contributes to enhanced performance during prolonged exercise by functioning as an energy reserve.