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. 1987 Oct;52(4):519–525. doi: 10.1016/S0006-3495(87)83241-1

Background K+ current in isolated canine cardiac Purkinje myocytes.

A K Shah 1, I S Cohen 1, N B Datyner 1
PMCID: PMC1330042  PMID: 2445390

Abstract

The current-voltage (I-V) relation of the background current, IK1, was studied in isolated canine cardiac Purkinje myocytes using the whole-cell, patch-clamp technique. Since Ba2+ and Cs+ block IK1, these cations were used to separate the I-V relation of IK1 from that of the whole cell. The I-V relation of IK1 was measured as the difference between the I-V relations of the cell in normal Tyrode (control solution) and in the presence of either Ba2+ (1 mM) or Cs+ (10 mM). Our results indicate that IK1 is an inwardly rectifying K+ current whose conductance depends on extracellular potassium concentration. In different [K+]0's the I-V relations of IK1 exhibit crossover. In addition the I-V relation of IK1 contains a region of negative slope (even when that of the whole cell does not). We also examined the relationship between the resting potential of the myocyte, Vm, and [K+]0 and found that it exhibits the characteristic anomalous behavior first reported in Purkinje strands (Weidmann, S., 1956, Elektrophysiologie der Herzmuskelfaser, Med. Verlag H. Huber), where lowering [K+]0 below 4 mM results in a depolarization.

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Selected References

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

  1. Baumgarten C. M., Isenberg G. 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. doi: 10.1007/BF01063450. [DOI] [PubMed] [Google Scholar]
  2. Callewaert G., Carmeliet E., Vereecke J. Single cardiac Purkinje cells: general electrophysiology and voltage-clamp analysis of the pace-maker current. J Physiol. 1984 Apr;349:643–661. doi: 10.1113/jphysiol.1984.sp015179. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Carmeliet E. Induction and removal of inward-going rectification in sheep cardiac Purkinje fibres. J Physiol. 1982 Jun;327:285–308. doi: 10.1113/jphysiol.1982.sp014232. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Carmeliet E., Mubagwa K. Changes by acetylcholine of membrane currents in rabbit cardiac Purkinje fibres. J Physiol. 1986 Feb;371:201–217. doi: 10.1113/jphysiol.1986.sp015969. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Carmeliet E., Mubagwa K. Characterization of the acetylcholine-induced potassium current in rabbit cardiac Purkinje fibres. J Physiol. 1986 Feb;371:219–237. doi: 10.1113/jphysiol.1986.sp015970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Carmeliet E., Mubagwa K. Desensitization of the acetylcholine-induced increase of potassium conductance in rabbit cardiac Purkinje fibres. J Physiol. 1986 Feb;371:239–255. doi: 10.1113/jphysiol.1986.sp015971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Carmeliet E., Ramon J. Effect of acetylcholine on time-independent currents in sheep cardiac Purkinje fibers. Pflugers Arch. 1980 Sep;387(3):207–216. doi: 10.1007/BF00580972. [DOI] [PubMed] [Google Scholar]
  8. Cleemann L., Morad M. Potassium currents in frog ventricular muscle: evidence from voltage clamp currents and extracellular K accumulation. J Physiol. 1979 Jan;286:113–143. doi: 10.1113/jphysiol.1979.sp012609. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Cohen I. S., Datyner N. B., Gintant G. A., Mulrine N. K., Pennefather P. Properties of an electrogenic sodium-potassium pump in isolated canine Purkinje myocytes. J Physiol. 1987 Feb;383:251–267. doi: 10.1113/jphysiol.1987.sp016407. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Cohen I. S., Falk R. T., Mulrine N. K. Actions of barium and rubidium on membrane currents in canine Purkinje fibres. J Physiol. 1983 May;338:589–612. doi: 10.1113/jphysiol.1983.sp014691. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Cohen I., Kline R. K+ fluctuations in the extracellular spaces of cardiac muscle. Evidence from the voltage clamp and extracellular K+ - selective microelectrodes. Circ Res. 1982 Jan;50(1):1–16. [PubMed] [Google Scholar]
  12. Datyner N. B., Gintant G. A., Cohen I. S. Versatile temperature controlled tissue bath for studies of isolated cells using an inverted microscope. Pflugers Arch. 1985 Mar;403(3):318–323. doi: 10.1007/BF00583607. [DOI] [PubMed] [Google Scholar]
  13. DiFrancesco D., Ferroni A., Visentin S. Barium-induced blockade of the inward rectifier in calf Purkinje fibres. Pflugers Arch. 1984 Dec;402(4):446–453. doi: 10.1007/BF00583946. [DOI] [PubMed] [Google Scholar]
  14. Eisenberg B. R., Cohen I. S. The ultrastructure of the cardiac Purkinje strand in the dog: a morphometric analysis. Proc R Soc Lond B Biol Sci. 1983 Jan 22;217(1207):191–213. doi: 10.1098/rspb.1983.0006. [DOI] [PubMed] [Google Scholar]
  15. Eisner D. A., Lederer W. J., Vaughan-Jones R. D. The dependence of sodium pumping and tension on intracellular sodium activity in voltage-clamped sheep Purkinje fibres. J Physiol. 1981 Aug;317:163–187. doi: 10.1113/jphysiol.1981.sp013819. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Ellis D. The effects of external cations and ouabain on the intracellular sodium activity of sheep heart Purkinje fibres. J Physiol. 1977 Dec;273(1):211–240. doi: 10.1113/jphysiol.1977.sp012090. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Gintant G. A., Datyner N. B., Cohen I. S. Gating of delayed rectification in acutely isolated canine cardiac Purkinje myocytes. Evidence for a single voltage-gated conductance. Biophys J. 1985 Dec;48(6):1059–1064. doi: 10.1016/S0006-3495(85)83869-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. HODGKIN A. L., KATZ B. The effect of sodium ions on the electrical activity of giant axon of the squid. J Physiol. 1949 Mar 1;108(1):37–77. doi: 10.1113/jphysiol.1949.sp004310. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Haas H. G., Kern R. Potassium fluxes in voltage clamped Purkinje fibres. Pflugers Arch Gesamte Physiol Menschen Tiere. 1966;291(1):69–84. doi: 10.1007/BF00362653. [DOI] [PubMed] [Google Scholar]
  20. Isenberg G. Cardiac Purkinje fibers: cesium as a tool to block inward rectifying potassium currents. Pflugers Arch. 1976 Sep 30;365(2-3):99–106. doi: 10.1007/BF01067006. [DOI] [PubMed] [Google Scholar]
  21. KHAIRALLAH P. A., MOMMAERTS W. F. H. M. Nucleotide metabolism in cardiac activity. I. Methods. Circ Res. 1953 Jan;1(1):8–11. doi: 10.1161/01.res.1.1.8. [DOI] [PubMed] [Google Scholar]
  22. Kameyama M., Kakei M., Sato R., Shibasaki T., Matsuda H., Irisawa H. Intracellular Na+ activates a K+ channel in mammalian cardiac cells. Nature. 1984 May 24;309(5966):354–356. doi: 10.1038/309354a0. [DOI] [PubMed] [Google Scholar]
  23. Kline R. P., Cohen I. S. Extracellular [K+] fluctuations in voltage-clamped canine cardiac Purkinje fibers. Biophys J. 1984 Nov;46(5):663–668. doi: 10.1016/S0006-3495(84)84065-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Kurachi Y. Voltage-dependent activation of the inward-rectifier potassium channel in the ventricular cell membrane of guinea-pig heart. J Physiol. 1985 Sep;366:365–385. doi: 10.1113/jphysiol.1985.sp015803. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Lee C. O., Dagostino M. Effect of strophanthidin on intracellular Na ion activity and twitch tension of constantly driven canine cardiac Purkinje fibers. Biophys J. 1982 Dec;40(3):185–198. doi: 10.1016/S0006-3495(82)84474-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Noma A. ATP-regulated K+ channels in cardiac muscle. Nature. 1983 Sep 8;305(5930):147–148. doi: 10.1038/305147a0. [DOI] [PubMed] [Google Scholar]
  27. Sakmann B., Noma A., Trautwein W. Acetylcholine activation of single muscarinic K+ channels in isolated pacemaker cells of the mammalian heart. Nature. 1983 May 19;303(5914):250–253. doi: 10.1038/303250a0. [DOI] [PubMed] [Google Scholar]
  28. Sakmann B., Trube G. Conductance properties of single inwardly rectifying potassium channels in ventricular cells from guinea-pig heart. J Physiol. 1984 Feb;347:641–657. doi: 10.1113/jphysiol.1984.sp015088. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Trube G., Hescheler J. Inward-rectifying channels in isolated patches of the heart cell membrane: ATP-dependence and comparison with cell-attached patches. Pflugers Arch. 1984 Jun;401(2):178–184. doi: 10.1007/BF00583879. [DOI] [PubMed] [Google Scholar]
  30. Vereecke J., Isenberg G., Carmeliet E. K efflux through inward rectifying K channels in voltage clamped Purkinje fibers. Pflugers Arch. 1980 Apr;384(3):207–217. doi: 10.1007/BF00584555. [DOI] [PubMed] [Google Scholar]

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