Effects of ivabradine on the pulmonary vein electrical activity and modulation of pacemaker currents and calcium homeostasis

Yao Chang Chen, Kazuyoshi Suenari, Chen Chuan Cheng, Yung Kuo Lin, Yukiko Nakano, Yasuki Kihara, Shih Ann Chen, Yi Jen Chen

研究成果: 雜誌貢獻文章同行評審

34 引文 斯高帕斯(Scopus)

摘要

Effects of Ivabradine on Pulmonary Veins. Introduction: Ivabradine is a novel heart rate decreasing agent with selective and specific antagonist effects on the pacemaker current (I f). The aim of this study was to investigate the pharmacological effects of ivabradine on the pulmonary vein (PV) cardiomyocytes. Methods and Results: Whole-cell patch-clamp techniques and the indo-1 fluorimetric ratio technique were used to investigate the characteristics of the I f and intracellular calcium (Ca 2+ i) in single isolated rabbit PV cardiomyocytes with pacemaker activity before and after an ivabradine administration (0.3, 3, 10, and 30 μM). Ivabradine (0.3, 3, 10, and 30 μM) concentration dependently decreased the spontaneous activity by 6 ± 3%, 32 ± 6%, 49 ± 5%, and 85 ± 4%, and decreased the I f by 35 ± 8%, 47 ± 9%, 62 ± 5%, and 65 ± 7%, respectively, in PV cardiomyocytes. The decreased extent of the PV beating rate or I f by the different concentrations of ivabradine correlated well with the baseline PV beating rates. The IC 50 of the spontaneous activity and I f induced by ivabradine were 9.5 and 3.5 μM, respectively. Moreover, ivabradine (30 μM, but not 3 μM) decreased the Ca 2+ i transient in the PV cardiomyocytes and ivabradine (30 μM) decreased the L-type calcium current in the PV cardiomyocytes. Conclusion: Ivabradine decreased the I fs and Ca 2+ i transient in the PV cardiomyocytes, which may contribute to its inhibitory effects on the PV spontaneous activity.

原文英語
頁(從 - 到)200-206
頁數7
期刊Journal of Cardiovascular Electrophysiology
23
發行號2
DOIs
出版狀態已發佈 - 二月 2012
對外發佈Yes

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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