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PMID: 571107 Published · ppublish English Journal Article Research Support, U.S. Gov't, P.H.S.

The steady state TTX-sensitive ("window") sodium current in cardiac Purkinje fibres.

Pflugers Archiv : European journal of physiology ·Vol. 379 ·No. 2 ·1979-03-16 ·Pages 137-42

Attwell D, Cohen I, Eisner D, Ohba M, Ojeda C

Abstract

Voltage clamp experiments on isolated sheep Purkinje fibres showed an increase of the steady state outward membrane current, over the potential range -65mV to -15 mV, in the presence of tetrodotoxin (TTX, 3.10(-5 M). This "window" current is considered to be the steady state component of the fast sodium current (INa), resulting from the crossover of the activation and inactivation curves which govern the opening of the sodium channel. TTX had no significant effect on the reversal potential, activation curve, kinetics or instantaneous I-V relationship of the pacemaker current IK2. The window found in these experiments extends to potentials well into the range of the action potential plateau. Consequently small changes of the steady state INa might have large effects on the action potential duration. The effects of TTX and local anaesthetics are discussed in this context.

MeSH Terms
Action Potentials/drug effects Animals Computers Heart Conduction System/drug effects,physiology Ion Channels/drug effects,physiology Kinetics Models, Biological Sheep Tetrodotoxin/pharmacology
Chemicals
Ion Channels Tetrodotoxin
Authors & Affiliations
5 authors, click to expand affiliations / ORCID
Attwell D
Cohen I
Eisner D
Ohba M
Ojeda C
References (24)
24 references, click to expand
  1. Shortening effect of tetrodotoxin on action potentials of the conducting system in the dog heart [proceedings].
    J Physiol. 1978 Jul;280:24P PMID: 690871
  2. Effects of calcium ions and local anesthetics on electrical properties of Purkinje fibres.
    J Physiol. 1955 Sep 28;129(3):568-82 PMID: 13264118
  3. Depletion and accumulation of potassium in the extracellular clefts of cardiac Purkinje fibers during voltage clamp hyperpolarization and depolarization.
    Pflugers Arch. 1977 Mar 11;368(1-2):19-31 PMID: 558594
  4. Voltage-dependent action of tetrodotoxin in mammalian cardiac muscle.
    Nature. 1976 Sep 23;263(5575):344-5 PMID: 958493
  5. Some effects of prolonged polarization on membrane currents in bullfrog atrial muscle.
    J Membr Biol. 1973;11(4):331-52 PMID: 4544319
  6. The effects of potassium and temperature on the pace-maker current, iK2, in Purkinje fibres.
    J Physiol. 1976 Aug;260(1):55-74 PMID: 966178
  7. On the voltage-dependent action of tetrodotoxin.
    Biophys J. 1977 Mar;17(3):275-9 PMID: 843585
  8. Two levels of resting potential in cardiac Purkinje fibers.
    J Gen Physiol. 1977 Dec;70(6):725-46 PMID: 591921
  9. Reconstruction of the electrical activity of cardiac Purkinje fibres.
    J Physiol. 1975 Sep;251(1):1-59 PMID: 1185607
  10. Reconstruction of the repolarization process in cardiac Purkinje fibres based on voltage clamp measurements of membrane current.
    J Physiol. 1969 Jan;200(1):233-54 PMID: 5761948
  11. The effect of tetrodotoxin on the membrane current in cardiac muscle (Purkinje fibers).
    Pflugers Arch Gesamte Physiol Menschen Tiere. 1967;295(3):213-26 PMID: 5241427
  12. Electrophysiological actions of lidocaine on canine ventricular muscle and Purkinje fibers.
    Circ Res. 1969 May;24(5):639-55 PMID: 5770253
  13. Incomplete inactivation of the slow inward current in cardiac Purkinje fibres [proceedings].
    J Physiol. 1976 Dec;263(1):127P-128P PMID: 1011098
  14. VOLTAGE CLAMP TECHNIQUE IN MAMMALIAN CARDIAC FIBRES.
    Pflugers Arch Gesamte Physiol Menschen Tiere. 1964 Jun 9;280:50-62 PMID: 14251605
  15. The effect of lidocaine on diastolic transmembrane currents determining pacemaker depolarization in cardiac Purkinje fibers.
    Circ Res. 1976 Mar;38(3):203-8 PMID: 1248069
  16. Voltage and time dependence of excitatory sodium current in cooled sheep Purkinje fibres.
    Pflugers Arch. 1970;315(2):136-58 PMID: 5460932
  17. TETRODOTOXIN BLOCKAGE OF SODIUM CONDUCTANCE INCREASE IN LOBSTER GIANT AXONS.
    J Gen Physiol. 1964 May;47:965-74 PMID: 14155438
  18. The kinetics and rectifier properties of the slow potassium current in cardiac Purkinje fibres.
    J Physiol. 1968 Mar;195(1):185-214 PMID: 5639799
  19. Manganese amd electrogenic phenomena in canine Purkinje fibers.
    Circ Res. 1975 Mar;36(3):377-91 PMID: 1111996
  20. Molecular mechanisms of nerve block by local anesthetics.
    Anesthesiology. 1976 Oct;45(4):421-41 PMID: 9844
  21. Late sodium current in the node of Ranvier.
    Pflugers Arch. 1975;357(1-2):145-8 PMID: 1080274
  22. The time and voltage dependence of the slow outward current in cardiac Purkinje fibres.
    J Physiol. 1966 Oct;186(3):632-62 PMID: 5972158
  23. Heart: excitation and contraction.
    Annu Rev Physiol. 1971;33:479-532 PMID: 4951054
  24. Slow inward current and contraction of sheep cardiac Purkinje fibers.
    J Gen Physiol. 1975 Mar;65(3):367-84 PMID: 1117286
Article Info
Journal
Pflugers Archiv : European journal of physiology
Abbr.
Pflugers Arch
ISSN
0031-6768
DOI
10.1007/BF00586939
Published
1979-03-16
Pages
137-42
Language
English
Region
Germany
NLM ID
0154720
Subset
IM
External Links
PubMed source DOI: 10.1007/BF00586939 View journal details
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