Role of the Kv4.3 K+ channel in ventricular muscle - A molecular correlate for the transient outward current
Role of the Kv4.3 K+ channel in ventricular muscle - A molecular correlate for the transient outward current
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DOI：
10.1161/01.res.79.4.659
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发表时间：
1996-10-01
影响因子：
20.1
通讯作者：
McKinnon, D
中科院分区：
文献类型：
--
作者：
Dixon, JE;Shi, WM;McKinnon, D
研究了15种不同K ~+通道在犬心脏中的表达，发现了一种新的K ~+通道基因（Kv4.3），它编码一种快速失活的K ~+电流。发现Kv4.3通道具有与原生犬瞬时外向电流（I-to）相似的生物物理和药理学特性。Kv4.3基因也在人类和大鼠心脏中表达。它的结论是Kv4.3通道的基础上的大部分的I-到犬心室肌细胞，并可能在人类心肌细胞。Kv4.3和Kv4.2通道都可能参与大鼠心脏的I-to，这两个通道的差异表达可以解释在大鼠心室不同区域观察到的I-to动力学特性的差异。与大鼠心脏相比，犬心脏K+通道的表达模式存在显著差异，这种差异可能是适应不同体型哺乳动物对心脏功能的不同要求。与大鼠心脏相比，在犬心脏中观察到的心室动作电位持续时间长得多，部分原因可能是犬心脏中Kv1.2、Kv2.1和Kv4.2基因表达水平较低。
The expression of 15 different K+ channels in canine heart was examined, and a new K+ channel gene (Kv4.3), which encodes a rapidly inactivating K+ current, is described. The Kv4.3 channel was found to have biophysical and pharmacological properties similar to the native canine transient outward current (I-to). The Kv4.3 gene is also expressed in human and rat heart. It is concluded that the Kv4.3 channel underlies the bulk of the I-to in canine ventricular myocytes, and probably in human myocytes. Both the Kv4.3 and Kv4.2 channels are likely to contribute to the I-to in rat heart, and differential expression of these two channels can account for observed differences in the kinetic properties of the I-to in different regions of rat ventricle. There are significant differences in the pattern of K+ channel expression in canine heart,compared with rat heart, and these differences may be an adaptation to the different requirements for cardiac function in mammals of markedly different sizes. It is possible that the much longer ventricular action potential duration observed in canine heart compared with rat heart is due, in part, to the lower levels of Kv1.2, Kv2.1, and Kv4.2 gene expression in canine heart.