Pflügers Archiv

, Volume 395, Issue 1, pp 78–80 | Cite as

Magnesium restores high K-induced inactivation of the fast Na channel in guinea pig ventricular muscle

  • Tatsuto Kiyosue
  • Makoto Arita
Excitable Tissues and Central Nervous Physiology Letters and Notes


The effect of extracellular magnesium concentration (Mgo) on the upstroke of the action potential was studied in guinea pig ventricular muscle under various K+ concentrations (2.7–19mM). Increased Mgo shifted the steady state inactivation curve of the fast Na channel in the depolarizing direction and this effect was concentration-dependent (0–20mM). Such an effect could explain the Mg-induced increase in maximum rate of rise of the action potential which Späh and Fleckenstein (1979) proposed to be due to a “Mg channel”.

Key words

Magnesium Ventricular muscle Maximum rate of rise Na inactivation curve Surface charge 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Arita, M., Kiyosue, T.: Effect of isoproterenol on “residual fast channel dependent slow conduction” produced in guinea pig ventricular muscle. Am. J. Cardiol. 47: 475 (1981)Google Scholar
  2. Beeler, G. W., Reuter, H.: Reconstruction of the action potential of ventricular myocardial fibers. J. Physiol. 268: 177–210 (1977)Google Scholar
  3. Cohen, I., Attwell, D., Strichartz, G.: The dependence of the maximum rate of rise of the action potential upstroke on membrane properties, Proc. R. Soc. Lond. 214: 85–98 (1981)Google Scholar
  4. Frankenhaeuser, B., Hodgkin, A. L.: The action of calcium on the electrical properties of squid axon. J. Physiol. 137: 218–244 (1957)Google Scholar
  5. Hogan, P. M., Spitzer, K. W.: Manganese and electrogenic phenomena in canine Purkinje fibers. Circ. Res. 36: 377–391 (1975)Google Scholar
  6. Schauf, C. L.: The interactions of calcium withMyxicola giant axons and a description in terms of a simple surface charge model. J. Physiol. 248: 613–624 (1975)Google Scholar
  7. Schneider, J. A., Sperelakis, N.: The demonstration of energy dependence of the isoproterenol-induced transcellular calcium current in isolated perfused guinea pig hearts-An explanation for mechanical failure. J. Surg. Res. 16: 389–403 (1974)Google Scholar
  8. Späh, F., Fleckenstein A.: Evidence of a new, preferentially Mg-carring, transport system besides the fast Na and slow Ca channels in the excited myocardial sarcolemma membrane. J. Mol. Cell. Cardiol. 11: 1109–1127 (1979)Google Scholar
  9. Walton, M., Fozzard, H. A.: The relation of\(\dot V_{max}\) to INa,\(\bar G_{Na}\) and h in a model of the cardiac Purkinje fiber. Biophys. J. 25: 407–420 (1979)Google Scholar
  10. Weidmann, S.: Effects of calcium ions and local anaesthetics on electrical properties of Purkinje fibers. J. Physiol. 129: 568–582 (1955)Google Scholar
  11. Windisch, H., Tritthart, H. A.: Calcium ion effects on the rising phase of action potentials obtained from guinea-pig papillary muscle at different potassium concentrations. J. Mol. Cell. Cardiol. 13: 457–469 (1981)Google Scholar
  12. Wit, A. L., Rosen, M. R., Hoffman, B. F.: Electrophysiology and pharmacology of cardiac arrhythmias. II. Relationship of normal and abnormal electrical activity of cardiac fibers to the genesis of arrhythmia. A. Automaticity. Am. Heart. J. 88: 515–524 (1974)Google Scholar

Copyright information

© Springer-Verlag 1982

Authors and Affiliations

  • Tatsuto Kiyosue
    • 1
  • Makoto Arita
    • 1
  1. 1.Department of PhysiologyFaculty of Medicine Medical College of OitaOitaJapan

Personalised recommendations