The transient outward current in mice lacking the potassium channel geneKv1.4

Transient outward potassium current in ICC.

Interstitial cells of Cajal (ICC) are the pacemakers of the gut, initiating slow-wave activity. Several ion channels have been identified that contribute to the depolarization phase of the slow wave. Our aim was to contribute to knowledge about the identity and role of ICC potassium channels in pacemaking. Here we describe a transient outward potassium current in cell-attached patches of ICC. T...

Transient Outward Potassium Channels Dependence on Channel Inactivation Mechanisms

We carried out a systematic study on the effects of elevating [K]O on the properties of a transient outward potassium channel encoded by a cardiac cDNA (RHKI) and compared them with those on two Shaker potassium channels (H-4 and H-37). The amino acid sequences of all three channels are known, and their structure-function relations have been partially characterized. All three channels were expr...

Transient Outward Current?

To gain insight into the molecular basis of cardiac repolarization, we have expressed K' channels cloned from ventricular myocardium in Xenopus oocytes. A recently identified human cardiac K' channel isoform (human Kvl.4) has properties similar to the 4-aminopyridine-sensitive calcium-insensitive component of the cardiac transient outward current. However, these channels recovered from inactiva...

Role of the transient outward potassium current in the genesis of early afterdepolarizations in cardiac cells.

AIMS The transient outward potassium current (I(to)) plays important roles in action potential (AP) morphology and dynamics; however, its role in the genesis of early afterdepolarizations (EADs) is not well understood. We aimed to study the effects and mechanisms of I(to) on EAD genesis in cardiac cells using combined experimental and computational approaches. METHODS AND RESULTS We first car...

Novel mechanism of transient outward potassium channel current regulation in the heart: implications for cardiac electrophysiology in health and disease.