REGULATION OF CALCIUM RELEASE IS GATED BY CALCIUM CURRENT, NOT GATING CHARGE, IN CARDIAC MYOCYTES
REGULATION OF CALCIUM RELEASE IS GATED BY CALCIUM CURRENT, NOT GATING CHARGE, IN CARDIAC MYOCYTES
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DOI：
10.1126/science.2543067
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发表时间：
1989-05-19
期刊：
影响因子：
56.9
通讯作者：
MORAD, M
中科院分区：
文献类型：
--
作者：
NABAUER, M;CALLEWAERT, G;MORAD, M
在骨骼肌中，膜内电荷运动启动导致钙从肌浆网释放的过程。相反，在心肌中，所产生的张力和细胞内钙瞬变的电压依赖性与钙电流的电压依赖性的相似性表明，钙电流可以门控钙的释放。然而，对于心肌，仍然假设有类似于骨骼肌的机制。通过在大鼠心室肌细胞中使用细胞外溶液的快速交换（20至50毫秒），其中测量细胞内钙瞬变或细胞缩短，现已表明，通过钙通道的钙流入是将膜去极化与钙释放偶联的过程中的强制性环节。因此，膜内电荷运动并不有助于心肌中钙的释放。
In skeletal muscle, intramembrane charge movement initiates the processes that lead to the release of calcium from the sarcoplasmic reticulum. In cardiac muscle, in contrast, the similarity of the voltage dependence of developed tension and intracellular calcium transients to that of calcium current suggests that the calcium current may gate the release of calcium. Nevertheless, a mechanism similar to that of skeletal muscle continues to be postulated for cardiac muscle. By using rapid exchange (20 to 50 milliseconds) of the extracellular solutions in rat ventricular myocytes in which the intracellular calcium transients or cell shortening were measured, it has now been show that the influx of calcium through the calcium channel is a mandatory link in the processes that couple membrane depolarization to the release of calcium. Thus, intramembrane charge movement does not contribute to the release of calcium in heart muscle.