Melzer W, Rios E, Schneider M F
Biophys J. 1984 Mar;45(3):637-41. doi: 10.1016/S0006-3495(84)84203-4.
The transient increase in free myoplasmic calcium concentration due to depolarization of a skeletal muscle fiber is the net result of the release of calcium from the sarcoplasmic reticulum (SR) and its simultaneous removal by binding to various sites and by reuptake into the SR. We present a procedure for empirically characterizing the calcium removal processes in voltage-clamped fibers and for using such characterization to determine the time course of SR calcium release during a depolarizing pulse. Our results reveal a decline of the SR calcium release rate during depolarization that was not anticipated from simple inspection of the calcium transients.
由于骨骼肌纤维去极化导致的游离肌浆钙浓度的短暂增加,是肌浆网(SR)释放钙以及通过与各种位点结合和再摄取回SR同时进行钙移除的净结果。我们提出了一种经验性地表征电压钳制纤维中钙移除过程的方法,并利用这种表征来确定去极化脉冲期间SR钙释放的时间进程。我们的结果揭示了去极化期间SR钙释放速率的下降,这是简单检查钙瞬变所无法预期的。