The Human cardiac transient outward potassium channel,Kv4.3:A study of its Pharmacology and modulation by Disease states

心脏的收缩是由电活动触发的。每一次心跳都会发生称为动作电位的电活动。这涉及到心脏细胞内电压的快速变化，然后必须迅速恢复到正常的静息水平或突然死亡。电流通过细胞膜时，细胞膜的快速变化（去极化）和恢复正常（复极化）都是由电流引起的。负责复极化的电流主要由钾离子携带。存在许多外向钾通道，本研究关注其中最重要的一种，称为瞬时外向电流。最近发现瞬时外向电流受疾病状态的调节，如心肌增厚和心力衰竭。它也被许多药物阻断，其中一些用于治疗心律失常。因此，临床心脏病学家对该通道特别感兴趣。过去，该通道很难研究，因为在实验中，它通常与其他几种电流混合。活的心脏细胞。编码它的基因在1996年被发现，我们现在在实验室的组织培养中有一个细胞系，它只有这个特定的通道，使我们能够系统地研究它，而不受其他电流的影响。这项研究构成了我们应用的基础。

The contraction of the heart is triggered by electrical activity.For every heart beat,electrical activity known as an action potential,occurs.This involves a rapid change in voltage inside the heart cells which must then be quickly restored to the normal resting level or sudden death ensues. Both the initial rapid change (known as depolarisation), and its restoration to normal, (repolarisation), are produced by electrical currents flowing through the cell membrane.The currents responsible for repolarisation are mainly carried by potassium ions.A number of these outward potassium channels exist and the present study is concerned with one of the most important of them, known as the transient outward current. The transient outward current has recently been found to be modulated by disease states,such as thickening of the heart muscle and heart failure.It is also known to be blocked by a number of drugs,some of which are used to treat abnormal heart rhythms.It is therefore of particular interest to clinical cardiologists This channel has been difficult to study in the past because it is usually mixed with several other currents in experiments on living heart cells.The gene which codes for it was identified in 1996 and we now have a cell-line in tissue culture in our laboratory which has only this particular channel,allowing us to study it systematically in isolation from other currents.This study forms the basis of our application.