Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1977 Jul;268(3):575–611. doi: 10.1113/jphysiol.1977.sp011874

Regenerative repolarization of the frog ventricular action potential: a time and voltage-dependent phenomenon.

Y Goldman, M Morad
PMCID: PMC1283681  PMID: 301932

Abstract

1. The regenerative repolarization process has been examined in frog ventricular myocardium using a single sucrose gap voltage clamp technique. 2. Application of brief (30-150 msec) anodal voltage clamp pulses during the plateau of the action potential revealed a 'threshold' potential region for immediate repolarization. The response to anodal clamp pulses was not all-or-none but was graded. 3. The threshold potential was strongly dependent on the duration of the test voltage clamp pulses and was more negative for shorter clamps. 4. Regenerative repolarization was also observed in the presence of tetrodotoxin. 5. No threshold for immediate repolarization was observed with very short clamps (2-20 msec in duration). Instead the membrane depolarized upon release of each clamp pulse. 6. Theoretical showed that the de- and repolarizations observed after test clamp steps are not due to geometrical properties or inhomogeneous potential distributions. 7. The results suggest that the instantaneous I-V relation of the membrane during the plateau may be linear.

Full text

PDF
575

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Beeler G. W., Jr, Reuter H. Voltage clamp experiments on ventricular myocarial fibres. J Physiol. 1970 Mar;207(1):165–190. doi: 10.1113/jphysiol.1970.sp009055. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Brady A. J., Woodbury J. W. The sodium-potassium hypothesis as the basis of electrical activity in frog ventricle. J Physiol. 1960 Dec;154(2):385–407. doi: 10.1113/jphysiol.1960.sp006586. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. CRANEFIELD P. F., HOFFMAN B. F. Propagated repolarization in heart muscle. J Gen Physiol. 1958 Mar 20;41(4):633–649. doi: 10.1085/jgp.41.4.633. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Cole K. S., Curtis H. J. ELECTRIC IMPEDANCE OF THE SQUID GIANT AXON DURING ACTIVITY. J Gen Physiol. 1939 May 20;22(5):649–670. doi: 10.1085/jgp.22.5.649. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dudel J., Peper K., Rüdel R., Trautwein W. The effect of tetrodotoxin on the membrane current in cardiac muscle (Purkinje fibers). Pflugers Arch Gesamte Physiol Menschen Tiere. 1967;295(3):213–226. doi: 10.1007/BF01844101. [DOI] [PubMed] [Google Scholar]
  6. Goldman Y., Morad M. Ionic membrane conductance during the time course of the cardiac action potential. J Physiol. 1977 Jul;268(3):655–695. doi: 10.1113/jphysiol.1977.sp011876. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Goldman Y., Morad M. Measurement of transmembrane potential and current in cardiac muscle: a new voltage clamp method. J Physiol. 1977 Jul;268(3):613–654. doi: 10.1113/jphysiol.1977.sp011875. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. HALL A. E., HUTTER O. F., NOBLE D. Current-voltage relations of Purkinje fibres in sodium-deficient solutions. J Physiol. 1963 Apr;166:225–240. doi: 10.1113/jphysiol.1963.sp007102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. HODGKIN A. L., HUXLEY A. F. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952 Aug;117(4):500–544. doi: 10.1113/jphysiol.1952.sp004764. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hagiwara S., Nakajima S. Differences in Na and Ca spikes as examined by application of tetrodotoxin, procaine, and manganese ions. J Gen Physiol. 1966 Mar;49(4):793–806. doi: 10.1085/jgp.49.4.793. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. McGuigan J. A. Some limitations of the double sucrose gap, and its use in a study of the slow outward current in mammalian ventricular muscle. J Physiol. 1974 Aug;240(3):775–806. doi: 10.1113/jphysiol.1974.sp010634. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Morad M., Orkand R. K. Excitation-concentration coupling in frog ventricle: evidence from voltage clamp studies. J Physiol. 1971 Dec;219(1):167–189. doi: 10.1113/jphysiol.1971.sp009656. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. NOBLE D. A modification of the Hodgkin--Huxley equations applicable to Purkinje fibre action and pace-maker potentials. J Physiol. 1962 Feb;160:317–352. doi: 10.1113/jphysiol.1962.sp006849. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. NOBLE D. The voltage dependence of the cardiac membrane conductance. Biophys J. 1962 Sep;2:381–393. doi: 10.1016/s0006-3495(62)86862-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. New W., Trautwein W. Inward membrane currents in mammalian myocardium. Pflugers Arch. 1972;334(1):1–23. doi: 10.1007/BF00585997. [DOI] [PubMed] [Google Scholar]
  16. Noble D., Hall A. E. The Conditions for Initiating "All-or-Nothing" Repolarization in Cardiac Muscle. Biophys J. 1963 Jul;3(4):261–274. doi: 10.1016/s0006-3495(63)86820-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Page S. G., Niedergerke R. Structures of physiological interest in the frog heart ventricle. J Cell Sci. 1972 Jul;11(1):179–203. doi: 10.1242/jcs.11.1.179. [DOI] [PubMed] [Google Scholar]
  18. Sommer J. R., Johnson E. A. Cardiac muscle. A comparative ultrastructural study with special reference to frog and chicken hearts. Z Zellforsch Mikrosk Anat. 1969;98(3):437–468. [PubMed] [Google Scholar]
  19. Staley N. A., Benson E. S. The ultrastructure of frog ventricular cardiac muscle and its relationship to mechanism of excitation-contraction coupling. J Cell Biol. 1968 Jul;38(1):99–114. doi: 10.1083/jcb.38.1.99. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Tarr M., Trank J. Equivalent circuit of frog atrial tissue as determined by voltage clamp-unclamp experiments. J Gen Physiol. 1971 Nov;58(5):511–522. doi: 10.1085/jgp.58.5.511. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Vassalle M. Analysis of cardiac pacemaker potential using a "voltage clamp" technique. Am J Physiol. 1966 Jun;210(6):1335–1341. doi: 10.1152/ajplegacy.1966.210.6.1335. [DOI] [PubMed] [Google Scholar]
  22. WEIDMANN S. Effect of current flow on the membrane potential of cardiac muscle. J Physiol. 1951 Oct 29;115(2):227–236. doi: 10.1113/jphysiol.1951.sp004667. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES