THE CONTROL OF CALCIUM-RELEASE IN HEART-MUSCLE
THE CONTROL OF CALCIUM-RELEASE IN HEART-MUSCLE
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DOI：
10.1126/science.7754384
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发表时间：
1995-05-19
期刊：
影响因子：
56.9
通讯作者：
LEDERER, WJ
中科院分区：
文献类型：
--
作者：
CANNELL, MB;CHENG, H;LEDERER, WJ
用共聚焦显微镜和电压钳技术研究了心肌细胞内钙库（肌浆网）释放钙的控制。去极化通过改变被称为“钙火花”的基本钙释放事件的空间和时间总和的程度来诱发分级的钙释放。这些诱发的火花是由局部L型钙通道电流以随机方式触发的，在不同的电位下是相似的，并且类似于自发的钙火花。一旦触发，钙火花期间从肌浆网释放的钙是独立的触发钙内流的持续时间。这些结果被用来开发一个统一的模型，心脏兴奋-收缩耦合，解释了大（但矛盾的稳定）放大触发钙内流的数字和模拟行为的组合。
The control of calcium release from intracellular stores (the sarcoplasmic reticulum) in cardiac muscle was examined with the use of a confocal microscope and voltage clamp techniques. Depolarization evoked graded calcium release by altering the extent of spatial and temporal summation of elementary calcium release events called ''calcium sparks.'' These evoked sparks were triggered by local L-type calcium channel currents in a stochastic manner, were similar at different potentials, and resembled spontaneous calcium sparks. Once triggered, the calcium release from the sarcoplasmic reticulum during a calcium spark was independent of the duration of the triggering calcium influx. These results were used to develop a unifying model for cardiac excitation-contraction coupling that explains the large (but paradoxically stable) amplification of the trigger calcium influx by a combination of digital and analog behavior.