Ein Vergleich zwischen Fluxmessungen und elektrischen Messungen am Myokard

  • H. G. Haas


1. On the basis of preceeding measurements of the K and Na transmembrane fluxes in resting frog atria and of membrane potential and intracellular K and Na concentrations, the K and Na conductances and permeabilities of resting fibres are calculated. It is assumed that a) the K and Na fluxes are purely passive in the direction of the gradient of the electrochemical potential but composed of an active and a passive part in the opposite direction, and b) there is an independence between passive influx and efflux.

2. The conductances calculated in this manner markedly differ from the conductances determined on the basis of electrophysiological measurements. The K conductance based on tracer experiments is much smaller than the K conductance based on electrical methods; and further, the ratio K: Na conductance calculated from flux measurements is much lower than to be expected from electrical determinations.

3. Possible explanations for this discrepancy are discussed. It is suggested that a correction of the above basic assumptions on the ionic movements could reconcile the results of the flux measurements and the electrical methods: If there is exchange diffusion for Na ions as proposed by Ussing (1949b), and if there is interaction between the passive K influx and efflux hindering each another, the K and Na conductances calculated from the fluxes approach the electrical values.


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  1. Brady, A. J., and J. W. Woodbury: The sodium-potassium hypothesis as the basis of electrical activity in frog ventricle. J. Physiol. (Lond.) 154, 385 (1960).Google Scholar
  2. Burrows, R., and J. F. Lamb: Sodium and potassium fluxes in cells cultured from chick embryo heart muscle. J. Physiol. (Lond.) 162, 510 (1962).Google Scholar
  3. Carmeliet, E. E.: Chloride and potassium permeability in cardiac Purkinje fibres. Brüssel: ARSCIA S.A. (1961).Google Scholar
  4. Conn, H. L., and J. C. Wood: Sodium exchange and distribution in the isolated heart of the normal dog. Amer. J. Physiol. 197, 631 (1959).Google Scholar
  5. Deck, K. A., and W. Trautwein: Ionic currents in cardiac excitation. Pflügers Arch. ges. Physiol. 280, 63 (1964).Google Scholar
  6. Goldman, D. E.: Potential, impedance, and rectification in membranes. J. gen. Physiol. 27, 37 (1943).Google Scholar
  7. Haas, H. G., u. H. G. Glitsch: Kalium-Fluxe am Vorhof des Froschherzens. Pflügers Arch. ges. Physiol. 275, 358 (1962).Google Scholar
  8. —— —— u. R. Kern: Zum Problem der gegenseitigen Beeinflussung der Ionenfluxe am Myokard. Pflügers Arch. ges. Physiol. 281, 282 (1964).Google Scholar
  9. —— —— u. W. Trautwein: Natrium-Fluxe am Vorhof des Froschherzens. Pflügers Arch. ges. Physiol. 277, 36 (1963).Google Scholar
  10. Hodgkin, A. L., and P. Horowicz: Movements of Na and K in single muscle fibres. J. Physiol. (Lond.) 145, 405 (1959a).Google Scholar
  11. —— —— The influence of potassium and chloride ions on the membrane potential of single muscle fibres. J. Physiol. (Lond.) 148, 127 (1959b).Google Scholar
  12. ——, and B. Katz: The effect of sodium ions on the electrical activity of the giant axon of the Squid. J. Physiol. (Lond.) 108, 37 (1949).Google Scholar
  13. ——, and R. D. Keynes: Active transport of actions in giant axons from Sepia and Loligo. J. Physiol. (Lond.) 128, 28 (1955a).Google Scholar
  14. —— —— The potassium permeability of a giant nerve fibre. J. Physiol. (Lond.) 128, 61 (1955b).Google Scholar
  15. Keynes, R. D.: The ionic movements during nervous activity. J. Physiol. (Lond.) 114, 119 (1951).Google Scholar
  16. —— The ionic fluxes in frog muscle. Proc. roy. Soc. B 142, 359 (1954).Google Scholar
  17. ——, and R. C. Swan: The effect of external sodium concentration on the sodium fluxes in frog skeletal muscle. J. Physiol. (Lond.) 147, 591 (1959).Google Scholar
  18. Teorell, T.: Membrane electrophoresis in relation to bio-electrical polarization effects. Arch. Sci. physiol. 3, 205 (1949).Google Scholar
  19. Trautwein, W., S. W. Kuffler, and C. Edwards: Changes in membrane characteristics of heart muscle during inhibition. J. gen. Physiol. 40, 135 (1956).Google Scholar
  20. Ussing, H. H.: The distinction by means of tracers between active transport and diffusion. Acta physiol. scand. 19, 43 (1949a).Google Scholar
  21. —— Transport of ions across cellular membranes. Physiol. Rev. 29, 127 (1949b).Google Scholar
  22. Weidmann, S.: The electrical constants of Purkinje fibres. J. Physiol. (Lond.) 118, 348 (1952).Google Scholar
  23. Wood, J. C., and H. L. Conn: Potassium transfer kinetics in the isolated dog heart. Influence of contraction rate, ventricular fibrillation, high serum potassium, and acetylcholine. Amer. J. Physiol. 195, 451 (1958).Google Scholar

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© Springer-Verlag 1964

Authors and Affiliations

  • H. G. Haas
    • 1
  1. 1.Aus dem Physiologischen Institut der Universität HeidelbergGermany

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