A NOVEL TYPE OF CARDIAC CALCIUM-CHANNEL IN VENTRICULAR CELLS
A NOVEL TYPE OF CARDIAC CALCIUM-CHANNEL IN VENTRICULAR CELLS
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DOI：
10.1038/316443a0
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发表时间：
1985-01-01
期刊：
影响因子：
64.8
通讯作者：
TSIEN, RW
中科院分区：
文献类型：
--
作者：
NILIUS, B;HESS, P;TSIEN, RW
钙离子内流对心脏活动的几个方面至关重要，因此询问心脏细胞是否具有单一或多种类型的钙离子通道非常重要。在单一电流1 -3的膜片钳研究中仅鉴定出一种Ca通道类型，尽管心脏细胞4 - 6的全细胞记录和其他细胞7，8的单一记录的建议相反。在这里，我们描述了一种新类型的心脏钙通道与几个属性，区分它从迄今为止确定的钙通道在心脏细胞。在等渗Ba中，它的电导很小（8 pS），在Ba中并不比在Ca中大。它在相对负的电位下激活和失活，并在贴片切除后长时间保持功能。它是不敏感的二氢吡啶类药物，如尼莫地平和钙激动剂湾K 8644，是更耐外部镉比先前描述的类型的心脏钙通道阻断。
Calcium influx is vital for several aspects of cardiac activity, so it is important to ask if heart cells possess a single or multiple types of Ca channel. Only one Ca channel type has been identified in patch-clamp studies of unitary current1–3, despite suggestions to the contrary from whole-cell recordings in heart cells4–6and unitary recordings from other cells7,8. Here we describe a novel type of cardiac Ca channel with several properties that distinguish it from the hitherto-identified Ca channel in heart cells. Its conductance in isotonic Ba is small (8 pS), and is no larger in Ba than in Ca. It activates and inactivates at relatively negative potentials and remains functional long after patch excision. It is insensitive to dihydropyridines such as nimodipine and the Ca agonist Bay K 8644, and is more resistant to block by external Cd than the previously described type of cardiac Ca channel.