PMID: 9554735Apr 29, 1998Paper

Reduced inward rectifying and increased E-4031-sensitive K+ current density in arrhythmogenic subendocardial purkinje myocytes from the infarcted heart

Journal of Cardiovascular Electrophysiology
J Pinto, P A Boyden

Abstract

Subendocardial Purkinje myocytes from the 48-hour infarcted heart (IZPCs) have reduced resting potentials, possibly due to altered inwardly rectifying K+ currents IK1. Abnormal depolarization-activated outward K+ currents could contribute to long triangularly shaped action potentials of IZPCs. We used whole cell patch recordings to compare cesium-sensitive IK1 and 4-aminopyridine (4-AP)-resistant, noninactivating sustained IK between normal Purkinje myocytes (NZPCs) and IZPCs. IZPCs showed decreased net membrane currents. Two IZPC groups were distinguished, based on 4-AP-resistant outward K+ currents. IZPC-I had isochronal IK1 current-voltage relations similar to NZPCs whereas IZPC-II showed significantly reduced IK1 and increased outward plateau currents. To study the sustained IK in the presence of the Class III antiarrhythmic agent E-4031, a two-pulse protocol was used to inactivate transient outward currents, followed by step depolarizations. E-4031-sensitive currents were significantly greater in IZPCs at depolarized potentials (> 0 mV). Similar to NZPCs, IZPC E-4031 currents showed time dependence during depolarization, lack of rectification at positive steps, and voltage-dependent recovery from block. Decreased IK1 may a...Continue Reading

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Citations

Jun 22, 1999·Journal of Cardiovascular Electrophysiology·E Carmeliet
Apr 12, 2005·American Journal of Physiology. Heart and Circulatory Physiology·Wen Dun, Penelope A Boyden
May 10, 2001·Journal of Molecular and Cellular Cardiology·G N Tseng
Mar 29, 2001·Journal of Molecular and Cellular Cardiology·A N Lopatin, C G Nichols
Aug 26, 2009·Journal of Molecular and Cellular Cardiology·Justus M B Anumonwo, Anatoli N Lopatin
Dec 23, 2006·Journal of Molecular and Cellular Cardiology·Robert Dumaine, Jonathan M Cordeiro
Mar 28, 2007·Heart Failure Clinics·Luis F SantanaW Jonathan Lederer
Sep 24, 2015·Trends in Cardiovascular Medicine·Kai-Chien Yang, Jeanne M Nerbonne
Jan 26, 2010·Journal of Molecular and Cellular Cardiology·Yanggan Wang, Joseph A Hill
Sep 4, 2014·PloS One·Wen DunPenelope A Boyden
Nov 20, 2015·BioMed Research International·Benjamin R Liu, Elizabeth M Cherry
Jul 30, 2014·Journal of Cardiovascular Pharmacology·Bo-Wei Wu, Ji-Min Cao
Aug 8, 2018·Pacing and Clinical Electrophysiology : PACE·Beixin Julie HeMelvin Scheinman
Jan 15, 2000·Journal of Cardiovascular Electrophysiology·D M Roden, P M Spooner
Sep 1, 2007·Cellular Physiology and Biochemistry : International Journal of Experimental Cellular Physiology, Biochemistry, and Pharmacology·Yunlong BaiZhiguo Wang
Apr 3, 2014·Physiological Reviews·Nicole SchmittSøren-Peter Olesen
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Oct 22, 2002·American Journal of Physiology. Heart and Circulatory Physiology·Wei HanStanley Nattel

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