Calcium and sodium channels in spontaneously contracting vascular muscle cells.
Calcium and sodium channels in spontaneously contracting vascular muscle cells.
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自发收缩血管肌细胞中的钙和钠通道。
DOI：
10.1126/science.2425434
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Hermsmeyer,K
中科院分区：
文献类型：
--
作者：
Sturek,M;Hermsmeyer,K
全细胞内向电流的电生理记录显示，血管肌细胞有一种钠通道和两种钙通道。其中一种钙通道，瞬时钙通道，被微小的去极化激活，但随后迅速失活。它对钙和钡同样具有渗透性，可被镉阻断，但不能被河豚毒素阻断。另一种类型，持续钙通道，被更大的去极化激活，但失活很少；它对钡的通透性比钙更强。持续钙通道对镉的阻断比瞬时钙通道更敏感，但不被河豚毒素阻断。钠通道失活的速度是瞬时钙通道的15倍，而且在更负的电压下。这种钠通道不寻常，因为它只被很高的河豚毒素浓度(60μM)阻断，而不被镉阻断，它是第一个在血管肌肉中被表征的，与两个钙通道一起，为血管肌肉中不同的兴奋模式提供了基础。
Electrophysiological recordings of inward currents from whole cells showed that vascular muscle cells have one type of sodium channel and two types of calcium channels. One of the calcium channels, the transient calcium channel, was activated by small depolarizations but then rapidly inactivated. It was equally permeable to calcium and barium and was blocked by cadmium, but not by tetrodotoxin. The other type, the sustained calcium channel, was activated by larger depolarizations, but inactivated very little; it was more permeable to barium than calcium. The sustained calcium channel was more sensitive to block by cadmium than the transient channel, but also was not blocked by tetrodotoxin. The sodium channel inactivated 15 times more rapidly than the transient calcium channel and at more negative voltages. This sodium channel, which is unusual because it is only blocked by a very high (60 μM) tetrodotoxin concentration but not by cadmium, is the first to be characterized in vascular muscle, and together with the two calcium channels, provides a basis for different patterns of excitation in vascular muscles.