Muscle fatigue: The role of metabolism
Muscle fatigue: The role of metabolism
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DOI：
10.1139/h02-005
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发表时间：
2002-02-01
期刊：
影响因子：
--
通讯作者：
Clark, BJ
中科院分区：
文献类型：
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作者：
McCully, KK;Authier, B;Clark, BJ
本文研究了代谢物在引起肌肉疲劳中的作用。以往的研究表明，Pi（H（2）PO（4）（-），HPO（4）（-2））和H可能是引起疲劳的重要因素。一个关键问题是代谢终产物和钙相关的兴奋-收缩耦合疲劳（ECC）之间的潜在相互作用。使用体内大鼠肌肉模型来测量响应于电刺激的张力发展和代谢终产物。使用两种刺激方案，高强度刺激，然后是中等强度刺激（高组），以及低强度刺激，然后是中等强度刺激（低组）。代谢性疲劳是基于用磷磁共振光谱测量的H（2）PO（4）（-）浓度。ECC疲劳被测量为超过代谢疲劳的疲劳，以及与高刺激频率相比，低刺激频率下的力的相对下降。在初始刺激期间，高剂量组具有更大的代谢疲劳（p < 0.001）和更大的ECC疲劳（p = 0.007）。在第二个刺激期和恢复期，高剂量组在代谢疲劳（p = 0.07）和更大的ECC疲劳（p = 0.015）方面没有差异。这些结果提供了一种用于确定代谢和ECC疲劳的相对量的方法，并且表明代谢物可以增加ECC疲劳的量。
This paper examined the role of metabolites in causing muscle fatigue. Previous studies have shown that Pi (H(2)PO(4)(-), HPO(4)(-2)) and H may be important factors in causing fatigue. A key question is the potential interaction between metabolic end-products and calcium related excitation-contraction coupling fatigue (ECC). An in vivo rat muscle model was used to measure tension development and metabolic end-products in response to electrical stimulation. Two stimulation protocols were used, high intensity stimulation followed by a medium intensity stimulation (High Group), and low intensity stimulation followed by a medium intensity stimulation (Low Group). Metabolic fatigue was based on concentrations of H(2)PO(4)(-) measured with phosphorus magnetic resonance spectroscopy. ECC fatigue was measured as the fatigue in excess of metabolic fatigue, and as the relative decline of force at low compared to high stimulation frequencies. During the initial stimulation period, the High Group had greater metabolic fatigue (p < 0.001) and greater ECC fatigue (p = 0.007). During the second stimulation period and recovery, the High Group had no difference in metabolic fatigue (p = 0.07) and greater ECC fatigue (p = 0.015). These results present a method for determining the relative amounts of metabolic and ECC fatigue, and suggest that metabolites can increase the amount a ECC fatigue.