Road J D, Jiang T X
Department of Medicine, University of British Columbia, Vancouver, Canada.
Mol Cell Biochem. 1998 Feb;179(1-2):81-6. doi: 10.1023/a:1006855819966.
Limb muscles can be injured during and after vigourous contractions. However, this injury is most evident under specific conditions. The strength and type of muscle contraction as well as the contractile status of the muscle are important determinants of injury. The initiating event leading to muscle injury is not clearly understood but there are several leading theories. The respiratory muscles are of obvious importance to survival, and fatigue or injury to them has been hypothesized to be prevented by various mechanisms. One such mechanism is reduced activation by the central nervous system. In this review information on the neural activation of the breathing muscles during inspiratory loading is discussed and reveals that neural activation to the diaphragm, the main inspiratory muscle, is high. Previous studies investigating the presence of muscle fatigue immediately after such inspiratory loading have shown little evidence of it. However, based on information from limb muscles, delayed or secondary muscle injury might occur and could produce deleterious effects on respiratory muscle function. Recent evidence shows that chronic low intensity inspiratory loading can produce diaphragmatic injury (Reid et al.) and secondary or delayed muscle injury can occur three days after an acute period of high intensity inspiratory loading. The results reviewed in this article suggest that the respiratory muscles, specifically the diaphragm, are not spared from injury or the results of muscle injury. Diaphragmatic function during the period of secondary muscle injury is markedly impaired and thus respiratory muscle injury is a phenomenon that warrants further investigation.
肢体肌肉在剧烈收缩期间及之后可能会受伤。然而，这种损伤在特定条件下最为明显。肌肉收缩的强度和类型以及肌肉的收缩状态是损伤的重要决定因素。导致肌肉损伤的起始事件尚不清楚，但有几种主要理论。呼吸肌对生存显然至关重要，并且已假设通过各种机制可预防其疲劳或损伤。一种这样的机制是中枢神经系统减少激活。在本综述中，讨论了吸气负荷期间呼吸肌神经激活的信息，并表明对主要吸气肌膈肌的神经激活很高。先前研究此类吸气负荷后立即出现肌肉疲劳情况的研究几乎没有发现相关证据。然而，根据来自肢体肌肉的信息，可能会发生延迟性或继发性肌肉损伤，并可能对呼吸肌功能产生有害影响。最近的证据表明，慢性低强度吸气负荷可导致膈肌损伤（里德等人），继发性或延迟性肌肉损伤可在高强度吸气负荷急性期三天后发生。本文综述的结果表明，呼吸肌，特别是膈肌，也不能免于损伤或肌肉损伤的后果。继发性肌肉损伤期间的膈肌功能明显受损，因此呼吸肌损伤是一种值得进一步研究的现象。
