Differential effects of ivabradine and ryanodine on pacemaker activity in canine sinus node and purkinje fibers.

Journal of Cardiovascular Electrophysiology
Eugene A Sosunov, Evgeny P Anyukhovsky

Abstract

It is generally accepted that at least 2 major mechanisms contribute to sinus node (SN) pacemaking: a membrane voltage (mainly I(f) ) clock and a calcium (Ca) clock (localized submembrane sarcoplasmic reticulum Ca(2+) release during late diastolic depolarization). The aim of this study was to compare the contributions of each mechanism to pacemaker activity in SN and Purkinje fibers (PFs) exhibiting normal or abnormal automaticity. Conventional microelectrodes were used to record action potentials in isolated spontaneously beating canine SN and free running PF in control and in the presence of 0.1 μM isoproterenol. Ryanodine (0.1-3 μM) and ivabradine (3 μM) were used to inhibit sarcoplasmic reticulum Ca(2+) release or I(f), respectively. To induce automaticity at low membrane potentials, PFs were superfused with BaCl(2). In SN, ivabradine reduced the rate whereas ryanodine had no effect. Isoproterenol significantly accelerated automatic rate, which was decreased by ivabradine and ryanodine. In normally polarized PFs, ryanodine had no effects on the automatic rate in the absence or presence of isoproterenol, whereas ivabradine inhibited both control and isoproterenol-accelerated automaticity. In PF depolarized with BaCl(2), ivab...Continue Reading

References

Jul 1, 1976·Circulation Research·W T WoodsT N James
Sep 1, 1987·Pflügers Archiv : European journal of physiology·P LippL Pott
Mar 1, 1973·Circulation Research·T N James
Apr 1, 1981·Journal of Molecular and Cellular Cardiology·W T WoodsT N James
Dec 1, 1980·The American Journal of Cardiology·K H Dangman, B F Hoffman
Sep 1, 1994·Journal of Cardiovascular Pharmacology·E P Anyukhovsky, M R Rosen
May 23, 2001·Circulation Research·M Shigekawa, T Iwamoto
Jul 1, 1962·The Anatomical Record·T N JAMES
Feb 18, 2006·The Journal of Physiology·A BucchiD DiFrancesco
Apr 28, 2006·Pharmacological Research : the Official Journal of the Italian Pharmacological Society·J P Vilaine
Apr 28, 2006·Pharmacological Research : the Official Journal of the Italian Pharmacological Society·Dario DiFrancesco
Apr 11, 2007·Circulation·Halina DobrzynskiRobert H Anderson
Feb 5, 2008·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Alexei N PlotnikovMichael R Rosen
Feb 20, 2010·Circulation Research·Dario DiFrancesco
Mar 18, 2010·Journal of Cardiovascular Electrophysiology·Antonella SetteLeonardo Calò
Apr 13, 2010·Journal of Molecular and Cellular Cardiology·Zhan GaoMark E Anderson
Jul 27, 2010·Journal of Cardiovascular Electrophysiology·Shomu BohoraApurva Vasavda
Oct 12, 2010·Advances in Pharmacology·Catherine Thollon, Jean-Paul Vilaine

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Citations

Jan 18, 2016·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Penelope A BoydenRichard B Robinson
May 8, 2013·Journal of Cardiovascular Electrophysiology·Lucas F SobradoRichard L Verrier
Nov 19, 2013·Journal of Cardiovascular Electrophysiology·Jason T JacobsonJeffrey J Goldberger
Oct 15, 2011·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Michael R RosenGuy Salama
Jun 21, 2019·The Journal of General Physiology·Richard Z LinIra S Cohen
Oct 26, 2018·Circulation·Ming LeiChristopher L-H Huang

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