Effects of Ivabradine on the Pulmonary Vein Electrical Activity and Modulation of Pacemaker Currents and Calcium Homeostasis

Kazuyoshi Suenari, Yukiko Nakano, Yasuki Kihara, Kazuyoshi Suenari, Yao Chang Chen, Yi Jen Chen, Shih Ann Chen

Research output: Contribution to journalArticle

Abstract

Introduction: Ivabradine is a novel heart rate decreasing agent with selective and specific antagonist effects on the pacemaker current (If). The aim of this study was to investigate the pharmacological effects of ivabradine on the pulmonary vein (PV) cardiomyocytes. Methods: Whole-cell patch clamp techniques and the indo-1 fluorimetric ratio technique were used to investigate the characteristics of the If and intracellular calcium (Ca2+i) in single isolated rabbit PV cardiomyocytes with pacemaker activity before and after an ivabradine administration (0.3, 3, 10, and 30 μM). Results: Ivabradine concentration-dependently decreased the spontaneous activity and the If in PV cardiomyocytes. The decreased extent of the PV beating rate or If by the different concentrations of ivabradine correlated well with the baseline PV beating rates. The IC50 of the spontaneous activity and If induced by ivabradine were 9.5μM and 3.5μM, respectively. Moreover, ivabradine (30uM, but not 3uM) decreased the Ca2+i transient in the PV cardiomyocytes and ivabradine (30 uM) decreased the L-type calcium current in the PV cardiomyocytes. Conclusion: Ivabradine decreased the pacemaker currents and Ca2+i transient in the PV cardiomyocytes, which may contribute to its inhibitory effects on the PV spontaneous activity.

Original languageEnglish
Pages (from-to)263
Number of pages1
JournalJournal of Arrhythmia
Volume27
Issue number4
DOIs
Publication statusPublished - 2011
Externally publishedYes

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ivabradine
Pulmonary Veins
Homeostasis
Calcium
Cardiac Myocytes
Patch-Clamp Techniques

Keywords

  • atrial fibrillation
  • pacemaker current
  • pulmonary vein

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Cite this

Effects of Ivabradine on the Pulmonary Vein Electrical Activity and Modulation of Pacemaker Currents and Calcium Homeostasis. / Suenari, Kazuyoshi; Nakano, Yukiko; Kihara, Yasuki; Suenari, Kazuyoshi; Chen, Yao Chang; Chen, Yi Jen; Chen, Shih Ann.

In: Journal of Arrhythmia, Vol. 27, No. 4, 2011, p. 263.

Research output: Contribution to journalArticle

Suenari, Kazuyoshi ; Nakano, Yukiko ; Kihara, Yasuki ; Suenari, Kazuyoshi ; Chen, Yao Chang ; Chen, Yi Jen ; Chen, Shih Ann. / Effects of Ivabradine on the Pulmonary Vein Electrical Activity and Modulation of Pacemaker Currents and Calcium Homeostasis. In: Journal of Arrhythmia. 2011 ; Vol. 27, No. 4. pp. 263.
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AU - Chen, Yao Chang

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AU - Chen, Shih Ann

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