Effects of components of ischemia on the Kv4.3 current stably expressed in Chinese Hamster Ovary cells

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dc.contributor.author Singarayar, S
dc.contributor.author Singleton, C
dc.contributor.author Tie, H
dc.contributor.author Wyse, K
dc.contributor.author Bursill, J
dc.contributor.author Bauskin, A
dc.contributor.author Wu, W
dc.contributor.author Valenzuela, S
dc.contributor.author Breit, S
dc.contributor.author Campbell, T
dc.date.accessioned 2010-05-28T09:49:27Z
dc.date.issued 2002-02-01
dc.identifier.citation Journal of Molecular and Cellular Cardiology, 2002, 34 (2), pp. 197 - 207
dc.identifier.issn 0022-2828
dc.identifier.other C1UNSUBMIT en_US
dc.identifier.uri http://hdl.handle.net/10453/9414
dc.description.abstract We investigated the effects of three components of ischemia: external acidosis (pH = 6.0), extracellular hyperkalemia ([K+] = 20 mmol/l), and resting membrane depolarization to -60 mV. on Kv4.3 current stably expressed in Chinese Hamster Ovary cells. We used single electrode whole cell patch clamp techniques to study changes in the current elicited. External acidosis caused a positive shift in the steady state activation curve from -13.4±2.1 mV to -3.3±1.5 mV (n = 8, P = 0.004) and the steady state inactivation curve from -56.5±0.4 mV to -46.7±0.5 mV (n = 14, P<0.0001). Acidosis also caused an acceleration of recovery from inactivation with the t1/2 decreasing from 306 ms (95% CI 287-327 ms) to 194 ms (95% CI 182-207 ms), (n = 14, P<0.05). Hyperkalemia did not affect any of these parameters. Combined acidosis and hyperkalemia produced effects similar to those seen with acidosis. Changing the holding potential from -90 mV to -60 mV with test potentials of +5 and +85 mV decreased the peak currents by 34.1% and 32.4% respectively (n = 14). However, in the presence of external acidosis the decrease in peak currents induced by changing the holding potential was less marked. In acidotic bath the peak current at -60 mV was reduced by only 13.6% at a test potential of +5 mV and 12.3% at a test potential of +85 mV (n = 14). Taken together our data suggest that the membrane depolarization and changes in pH which occur under ischemic conditions would be accompanied by relative preservation of Kv4.3 currents and provide a molecular basis for the observation of preserved epicardial Ito and epicardial action potential duration (APD) shortening in ischemia. © 2002 Elsevier Science Ltd.
dc.language eng
dc.relation.isbasedon 10.1006/jmcc.2001.1502
dc.subject Acidosis, Hyperkalemia, Ischemia, Kv4.3, Transient outward current, Animals, CHO Cells, Myocardial Ischemia, Ischemia, Acidosis, Hyperkalemia, Potassium Channels, Potassium Channels, Voltage-Gated, Gene Transfer Techniques, Transfection, Shal Potassium Channels, Membrane Potentials, Cricetinae, Acidosis, Animals, CHO Cells, Cricetinae, Gene Transfer Techniques, Hyperkalemia, Ischemia, Membrane Potentials, Myocardial Ischemia, Potassium Channels, Potassium Channels, Voltage-Gated, Shal Potassium Channels, Transfection, Kv4.3, Transient outward current, Ischemia, Acidosis, Hyperkalemia., Cardiovascular System & Hematology
dc.subject Acidosis; Hyperkalemia; Ischemia; Kv4.3; Transient outward current; Animals; CHO Cells; Myocardial Ischemia; Ischemia; Acidosis; Hyperkalemia; Potassium Channels; Potassium Channels, Voltage-Gated; Gene Transfer Techniques; Transfection; Shal Potassium Channels; Membrane Potentials; Cricetinae; Acidosis; Animals; CHO Cells; Cricetinae; Gene Transfer Techniques; Hyperkalemia; Ischemia; Membrane Potentials; Myocardial Ischemia; Potassium Channels; Potassium Channels, Voltage-Gated; Shal Potassium Channels; Transfection; Kv4.3, Transient outward current, Ischemia, Acidosis, Hyperkalemia.; Cardiovascular System & Hematology
dc.title Effects of components of ischemia on the Kv4.3 current stably expressed in Chinese Hamster Ovary cells
dc.type Journal Article
dc.parent Journal of Molecular and Cellular Cardiology
dc.journal.volume 2
dc.journal.volume 34
dc.journal.number 2 en_US
dc.publocation USA en_US
dc.identifier.startpage 197 en_US
dc.identifier.endpage 207 en_US
dc.cauo.name SCI.Medical and Molecular Biosciences en_US
dc.conference Verified OK en_US
dc.for 0304 Medicinal and Biomolecular Chemistry
dc.for 0306 Physical Chemistry (Incl. Structural)
dc.for 1004 Medical Biotechnology
dc.personcode 0000031940 en_US
dc.personcode 0000031941 en_US
dc.personcode 0000031942 en_US
dc.personcode 0000031943 en_US
dc.personcode 0000031944 en_US
dc.personcode 0000030023 en_US
dc.personcode 0000030024 en_US
dc.personcode 010690 en_US
dc.personcode X000028 en_US
dc.personcode 0000016340 en_US
dc.percentage 50 en_US
dc.classification.name Medical Biotechnology en_US
dc.classification.type FOR-08 en_US
dc.edition en_US
dc.custom en_US
dc.date.activity en_US
dc.location.activity en_US
dc.description.keywords Kv4.3, Transient outward current, Ischemia, Acidosis, Hyperkalemia. en_US
dc.description.keywords Kv4.3, Transient outward current, Ischemia, Acidosis, Hyperkalemia.
dc.description.keywords Animals
dc.description.keywords CHO Cells
dc.description.keywords Myocardial Ischemia
dc.description.keywords Ischemia
dc.description.keywords Acidosis
dc.description.keywords Hyperkalemia
dc.description.keywords Potassium Channels
dc.description.keywords Potassium Channels, Voltage-Gated
dc.description.keywords Gene Transfer Techniques
dc.description.keywords Transfection
dc.description.keywords Shal Potassium Channels
dc.description.keywords Membrane Potentials
dc.description.keywords Cricetinae
dc.description.keywords Acidosis
dc.description.keywords Hyperkalemia
dc.description.keywords Ischemia
dc.description.keywords Kv4.3
dc.description.keywords Transient outward current
dc.description.keywords Acidosis
dc.description.keywords Hyperkalemia
dc.description.keywords Ischemia
dc.description.keywords Kv4.3
dc.description.keywords Transient outward current
pubs.embargo.period Not known
pubs.organisational-group /University of Technology Sydney
pubs.organisational-group /University of Technology Sydney/Faculty of Science
pubs.organisational-group /University of Technology Sydney/Strength - Health Technologies


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