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Updated: May 26, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
TASK-1 channels may modulate action potential duration of human atrial cardiomyocytes
Sven H Limberg1, Michael F Netter, Caroline Rolfes
1Institut für Physiologie und Pathophysiologie, Abteilung vegetative Physiologie, Universität Marburg, Deutschhausstraße 1-2, Marburg, Germany.
Background/Aims:
Atrial fibrillation is the most common arrhythmia in the elderly, and potassium channels with atrium-specific expression have been discussed as targets to treat atrial fibrillation. Our aim was to characterize TASK-1 channels in human heart and to functionally describe the role of the atrial whole cell current I(TASK-1).
Methods And Results:
Using quantitative PCR, we show that TASK-1 is predominantly expressed in the atria, auricles and atrio-ventricular node of the human heart. Single channel recordings show the functional expression of TASK-1 in right human auricles. In addition, we describe for the first time the whole cell current carried by TASK-1 channels (I(TASK-1)) in human atrial tissue. We show that I(TASK-1) contributes to the sustained outward current I(Ksus) and that I(TASK-1) is a major component of the background conductance in human atrial cardiomyocytes. Using patch clamp recordings and mathematical modeling of action potentials, we demonstrate that modulation of I(TASK-1) can alter human atrial action potential duration.
Conclusion:
Due to the lack of ventricular expression and the ability to alter human atrial action potential duration, TASK-1 might be a drug target for the treatment of atrial fibrillation.
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