Workman, Antony J and Marshall, Gillian E and Rankin, Andrew C and Smith, Godfrey L and Dempster, John (2012) Transient outward K+ current (ITO) reduction prolongs action potentials and promotes afterdepolarisations : a dynamic-clamp study in human and rabbit cardiac atrial myocytes. Journal of Physiology. (In Press)
Full text not available in this repository. (Request a copy from the Strathclyde author)Abstract
Background & aim. Human atrial transient outward K+ current (ITO) is decreased in a variety of cardiac pathologies, but how ITO reduction alters action potentials (AP) and arrhythmia mechanisms is poorly understood, owing to non-selectivity of ITO blockers. Aim: to investigate effects of selective ITO changes on AP shape and duration (APD), and on afterdepolarisations or abnormal automaticity with beta-adrenergic-stimulation, using the dynamic-clamp technique in atrial cells. Methods & Results. Human and rabbit atrial cells were isolated by enzymatic dissociation, and electrical activity recorded by whole-cell-patch clamp (35-37oC). Dynamic-clamp-simulated ITO reduction or block slowed AP phase 1 and elevated the plateau, significantly prolonging APD, in both species. In human atrial cells, ITO block (100% ITO subtraction) increased APD50 by 31%, APD90 by 17%, and APD-61mV (reflecting cellular effective refractory period) by 22% (P
| Item type: | Article |
|---|---|
| ID code: | 40252 |
| Keywords: | K+ current, cardiac atrial myocytes, ion current, dynamic clamp, atrial cells, Pharmacy and materia medica |
| Subjects: | Medicine > Pharmacy and materia medica |
| Department: | Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences |
| Related URLs: | |
| Depositing user: | Pure Administrator |
| Date Deposited: | 29 Jun 2012 10:59 |
| Last modified: | 29 Jun 2012 10:59 |
| URI: | http://strathprints.strath.ac.uk/id/eprint/40252 |
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