Apelin regulates the electrophysiological characteristics of atrial myocytes

Authors

  • Chen-Chuan Cheng,

    1. Division of Cardiology, Chi-Mei Medical Center, Tainan, Taiwan
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  • Punate Weerateerangkul,

    1. Cardiac Electrophysiology Research and Training Center, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
    2. Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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  • Yen-Yu Lu,

    1. Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
    2. Division of Cardiology, Sijhih Cathay General Hospital, New Taipei City, Taiwan
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  • Yao-Chang Chen,

    1. Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
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  • Yung-Kuo Lin,

    1. Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
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  • Shih-Ann Chen,

    1. Division of Cardiology and Cardiovascular Research Center, Taipei Veterans General Hospital, Taipei, Taiwan
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  • Yi-Jen Chen

    1. Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
    2. Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
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  • C. C. Cheng and P. Weerateerangkul contributed equally to this study.

Yi-Jen Chen, Division of Cardiovascular Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, Taiwan. Tel.: 886 2 28757156; fax: 886 2 28359946; 886-2-28735656; e-mail: a9900112@ms15.hinet.net

Abstract

Eur J Clin Invest 2012

Abstract

Backgroud  Apelin, a potential agent for treating heart failure, has various ionic effects on ventricular myocytes. However, the effects of apelin on the atrium are not clear. The purpose of this study was to investigate the acute effects of apelin on the electrophysiological characteristics of atrial myocytes.

Method  Whole-cell patch-clamp techniques were used to investigate the action potential (AP) and ionic currents in isolated rabbit left atrial (LA) myocytes before and after the administration of apelin.

Result  Apelin reduced LA AP duration measured at 90%, 50% and 20% repolarization of the amplitude by 11 ± 3%, 24 ± 5%, 30 ± 7% at 1 nM (n = 11), and by 14 ± 4%, 36 ± 6% and 45 ± 5% at 10 nM (n = 11), but not at 0·1 nM. Apeline (0·1, 1, 10 nM) did not change the amplitude, or resting membrane potential in LA myocytes. Apelin (1 nM) increased sodium currents, ultra-rapid potassium currents and the reverse mode of sodium-calcium exchanger currents, but decreased late sodium currents and L-type calcium currents and did not change transient outward currents or inward rectifier potassium currents in LA myocytes.

Conclusions  Apelin significantly changed the atrial electrophysiology with a shortening of AP duration, which may be caused by its effects on multiple ionic currents.

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