Calcium channels in excitable cell membranes.
Calcium channels in excitable cell membranes.
复制标题
可兴奋细胞膜中的钙通道。
DOI：
10.1146/annurev.ph.45.030183.002013
复制
发表时间：
1983
影响因子：
18.2
通讯作者：
R. Tsien
中科院分区：
文献类型：
--
作者：
R. Tsien
钙离子通透性在可兴奋细胞中的存在已经被认识了30年(3 I)--几乎从我们知道电压依赖的钠和钾的通透性开始(46，47)。然而，直到今天，我们对钙通道的了解远远落后于我们对钠通道或钾通道的了解。这种情况具有讽刺意味，因为钙通道分布广泛，在生物功能的多样性上可与特征更好的通道相媲美。钙通道在膜兴奋与细胞反应(如分泌或收缩)之间起着至关重要的作用。它们主要负责一些特殊但非常有趣的兴奋性形式--例如在心脏的结节区(14，76)，草履虫的纤毛(11，12)，或某些神经元的树突()或生长锥(6)。与钠通道不同，钙通道通常受激素和神经递质的调节。多年来，钙通道的生物物理或生化分析一直受到实验问题的严重阻碍(例如42，81)。没有哪种药物像鱿鱼轴突和河豚毒素对钠通道那样适用于钙通道，也没有哪种药物像它对钠通道那样特异。但最近，随着记录钙通道活动的强大方法的发展，以及以有效和特定的方式阻断可能与钙通道相互作用的药物的发展，最先进的技术已经有所改善。我们现在知道，钙通道是孔，能够每秒传输数百万离子，其电压依赖的性质明显地将它们与本卷其他地方描述的泵或交换机制区分开来。越来越多的人意识到钙通道可以
The existence of calcium permeability in excitable cells has been appreciated for 30 years (3 I)-almost as long as we have known about voltage-depend ent permeabilities to sodium and potassium (46, 47). Yet, to this day, our understanding of Ca channels has lagged far behind our knowledge of Na or K channels. This situation is ironic because Ca channels are widely distributed and rival their better-characterized counterparts in diversity of biological function (42). Ca channels play a crucial role in coupling mem brane excitation to cellular responses such as secretion or contraction. They are primarily responsible for some specialized but very interesting forms of excitability-e.g. in the nodal regions of the heart (14, 76), the cilia of Paramecium (11, 12), or the dendrites (64) or growth cones (6) of certain neurons. Unlike Na channels, Ca channels are often modulated by hor mones and neurotransmitters. For many years, biophysical or biochemical analysis of Ca channels has been seriously hampered by experimental problems (e.g. 42, 81). No prepa ration has been as suitable and no drug as specific for Ca channels as the squid axon and tetrodotoxin are for Na channels. But the state of the art has improved recently with the development of powerful methods for recording Ca channel activity and of blocking drugs that may interact with Ca channels in a potent and specific manner. We now know that Ca channels are pores, capable of transferring millions of permeant ions per second, whose voltage-dependent properties clearly distinguish them from pumps or exchange mechanisms described elsewhere in this volume. There is growing appreciation that Ca channels can be