Role of calcium stores and phosphate channels in muscle fatigue

当剧烈运动时，肌肉会变得虚弱；这就是常见的肌肉疲劳。我们正在研究肌肉疲劳的机制，并认为这是由于肌肉中储存的钙的耗尽造成的。我们怀疑钙的储存减少是因为作为肌肉新陈代谢的产物的磷酸盐进入了钙储存并以磷酸钙的形式沉淀。目前，我们正试图通过研究磷酸盐从肌肉细胞进入钙库的通道来证明这一假说并扩展它。有可能找到或设计出最大限度地减少磷酸盐通过这一通道的移动的药物，这种药物可能会减少由这种机制引起的疲劳成分。这种药物可能会使那些正常活动受到肌肉疲劳限制的患者受益；这包括患有任何致残性肌肉疾病的患者，如肌肉营养不良或中风，以及心力衰竭患者。此外，老年人的肌肉体积减少，剩余的肌肉容易疲劳，导致失去行动能力和独立性；因此，老年人也可能从这种药物中受益。

Muscles become weaker when ever they are used intensively; this is the familiar muscle fatigue. We are studying the mechanism of muscle fatigue and believe it is caused by depletion of a store of calcium inside the muscle. We suspect the store of calcium declines because phosphate, which is a product of muscle metabolism, enters the calcium store and precipitates as calcium phosphate. Currently we are trying to prove this hypothesis and extend it by studying the channels through which phosphate passes from the muscle cell into the calcium store. It may be possible to find or design drugs which minimise the movement of phosphate through this channel and such a drug might reduce the component of fatigue caused by this mechanism. Such a drug might benefit patients whose normal activities are limited by muscle fatigue; this includes patients with any disabling muscle disease, such as muscular dystrophy or stroke, and patients with heart failure. In addition elderly people suffer a loss of muscle bulk and the remaining muscle is easily fatigued causing loss of mobility and independence; so the elderly might also benefit from such a drug.