Voltage-dependent ATP-sensitive potassium channels of skeletal muscle membrane
Voltage-dependent ATP-sensitive potassium channels of skeletal muscle membrane
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骨骼肌膜电压依赖性 ATP 敏感钾通道
DOI：
10.1038/316736a0
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发表时间：
1985
期刊：
影响因子：
64.8
通讯作者：
P. Stanfield
中科院分区：
文献类型：
--
作者：
A. Spruce;N. Standen;P. Stanfield
几年前就已经知道，在产生僵直的条件下，骨骼肌会产生高钾渗透性，其中ATP浓度低，细胞内Ca 2+高1。将这种高渗透性归因于由内部Ca 2+打开的K通道似乎是很自然的，特别是在肌管和成人骨骼肌的横管膜系统中已经证明了这种通道的存在2 -4。然而，正如我们在这里展示的，青蛙肌肉的表面膜含有钾通道，在低浓度的ATP（<2 mM）时打开。ATP诱导这些通道关闭而不分裂，显然将通道保持在许多关闭状态之一。通道具有至少两个开放状态，其停留时间是电压依赖性的。令人惊讶的是，我们发现这些可能是骨骼肌表面膜最常见的K通道。
It has been known for some years that skeletal muscle develops a high potassium permeability in conditions that produce rigor, where ATP concentrations are low and intracellular Ca2+ is high1. It has seemed natural to attribute this high permeability to K channels that are opened by internal Ca2+, especially as the presence of such channels has been demonstrated in myotubes and in the transverse tubular membrane system of adult skeletal muscle2–4. However, as we show here, the surface membrane of frog muscle contains potassium channels that open at low internal concentrations of ATP (<2 mM). ATP induces closing of these channels without being split, apparently holding the channels in one of a number of closed states. The channels have at least two open states whose dwell times are voltage-dependent. Surprisingly, we find that these may be the most common K channels of the surface membrane of skeletal muscle.