Pflügers Archiv

, Volume 441, Issue 1, pp 144–149

Effects of endothelin-1 on calcium and potassium currents in undiseased human ventricular myocytes

  • J. Magyar
  • N. Iost
  • Á. Körtvély
  • T. Bányász
  • L. Virág
  • P. Szigligeti
  • A. Varró
  • M. Opincariu
  • J. Szécsi
  • J.G. Papp
  • P.P. Nánási
Original Article

DOI: 10.1007/s004240000400

Cite this article as:
Magyar, J., Iost, N., Körtvély, Á. et al. Pflügers Arch - Eur J Physiol (2000) 441: 144. doi:10.1007/s004240000400

Abstract.

Endothelins have been reported to exert a wide range of electrophysiological effects in mammalian cardiac cells. These results are controversial and human data are not available. Our aim was to study the effects of endothelin-1 (ET-1, 8 nmol/l) on the L-type calcium current (ICa-L) and various potassium currents (rapid component of the delayed rectifier, IKr; transient outward current, Ito; and the inward rectifier K current, IK1) in isolated human ventricular cardiomyocytes. Cells were obtained from undiseased donor hearts using collagenase digestion via the segment perfusion technique. The whole-cell configuration of the patch-clamp technique was applied to measure ionic currents at 37°C. ET-1 significantly decreased peak ICa-L from 10.2±0.6 to 6.8±0.8 pA/pF at +5 mV (66.7% of control, P<0.05, n=5). This reduction of peak current was accompanied by a lengthening of inactivation. The voltage dependence of steady-state activation and inactivation was not altered by ET-1. IKr, measured as tail current amplitudes at –40 mV, decreased from 0.31±0.02 to 0.06±0.02 pA/pF (20.3% of control, P<0.05, n=4) after exposure to ET-1. ET-1 failed to change the peak amplitude of Ito, measured at +50 mV (9.3±4.6 and 9.0±4.4 pA/pF before and after ET-1, respectively), or steady-state IK1 amplitude, measured at the end of a 400-ms hyperpolarization to –100 mV (3.6±1.4 and 3.7±1.4 pA/pF, n=4). The present results indicate that in undiseased human ventricular myocytes ET-1 inhibits both ICa-L and IKr; however, the degree of suppression of the two currents is different.

Action potentials Calcium currents Cardiac cells Endothelins Human myocytes Potassium currents 

Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • J. Magyar
    • 1
  • N. Iost
    • 3
  • Á. Körtvély
    • 1
  • T. Bányász
    • 1
  • L. Virág
    • 2
  • P. Szigligeti
    • 1
  • A. Varró
    • 2
  • M. Opincariu
    • 4
  • J. Szécsi
    • 4
  • J.G. Papp
    • 2
  • P.P. Nánási
    • 1
  1. 1.Department of Physiology, University Medical School of Debrecen, H-4012 Debrecen, PO Box 22, HungaryHungary
  2. 2.Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6701 Szeged, PO Box 427, HungaryHungary
  3. 3.Research Unit for Cardiovascular Pharmacology, Hungarian Academy of Sciences, H-6701 Szeged, PO Box 427, HungaryHungary
  4. 4.Department of cardiac surgery, Faculty of Medicine, University of Szeged, H-6701 Szeged, PO Box 427, HungaryHungary

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