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. 1986 Jul;83(14):5340–5344. doi: 10.1073/pnas.83.14.5340

Two types of calcium channels in guinea pig ventricular myocytes.

R Mitra, M Morad
PMCID: PMC323947  PMID: 2425366

Abstract

In cardiac muscle, Ca2+ plays a key role in regulation of numerous processes, including generation of the action potential and development of tension. The entry of Ca2+ into the cell is regulated primarily by voltage-gated channels in the membrane. Until recently, it was felt that only one type of Ca2+ channel existed in cardiac ventricular muscle. Experiments reported here suggest that in isolated guinea pig ventricular myocytes, there are two distinct types of Ca2+ channels with markedly different activation thresholds, inactivation kinetics, and sensitivities to inorganic and organic Ca2+ channel blockers. The channels were also distinguished based on their response to increased frequency of clamping such that the current through the low-threshold channel decreased while that through the high-threshold channel increased. In a few cells, the current through both channels was enhanced by isoproterenol, a beta-adrenergic agonist, but only the high-threshold channel was enhanced by the Ca2+-channel agonist Bay K 8644. Thus, isolated guinea pig ventricular myocytes appear to have two types of Ca2+ channels distinguished by various criteria.

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Selected References

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

  1. Adams D. J., Gage P. W. Characteristics of sodium and calcium conductance changes produced by membrane depolarization in an Aplysia neurone. J Physiol. 1979 Apr;289:143–161. doi: 10.1113/jphysiol.1979.sp012729. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Akaike N., Lee K. S., Brown A. M. The calcium current of Helix neuron. J Gen Physiol. 1978 May;71(5):509–531. doi: 10.1085/jgp.71.5.509. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Armstrong C. M., Matteson D. R. Two distinct populations of calcium channels in a clonal line of pituitary cells. Science. 1985 Jan 4;227(4682):65–67. doi: 10.1126/science.2578071. [DOI] [PubMed] [Google Scholar]
  4. Bean B. P. Two kinds of calcium channels in canine atrial cells. Differences in kinetics, selectivity, and pharmacology. J Gen Physiol. 1985 Jul;86(1):1–30. doi: 10.1085/jgp.86.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Beeler G. W., Jr, Reuter H. Membrane calcium current in ventricular myocardial fibres. J Physiol. 1970 Mar;207(1):191–209. doi: 10.1113/jphysiol.1970.sp009056. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Carbone E., Lux H. D. A low voltage-activated, fully inactivating Ca channel in vertebrate sensory neurones. Nature. 1984 Aug 9;310(5977):501–502. doi: 10.1038/310501a0. [DOI] [PubMed] [Google Scholar]
  7. Deitmer J. W. Evidence for two voltage-dependent calcium currents in the membrane of the ciliate Stylonychia. J Physiol. 1984 Oct;355:137–159. doi: 10.1113/jphysiol.1984.sp015411. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Fedulova S. A., Kostyuk P. G., Veselovsky N. S. Two types of calcium channels in the somatic membrane of new-born rat dorsal root ganglion neurones. J Physiol. 1985 Feb;359:431–446. doi: 10.1113/jphysiol.1985.sp015594. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Fox A. P., Krasne S. Two calcium currents in Neanthes arenaceodentatus egg cell membranes. J Physiol. 1984 Nov;356:491–505. doi: 10.1113/jphysiol.1984.sp015479. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hagiwara S., Ozawa S., Sand O. Voltage clamp analysis of two inward current mechanisms in the egg cell membrane of a starfish. J Gen Physiol. 1975 May;65(5):617–644. doi: 10.1085/jgp.65.5.617. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
  12. Heyer C. B., Lux H. D. Properties of a facilitating calcium current in pace-maker neurones of the snail, Helix pomatia. J Physiol. 1976 Nov;262(2):319–348. doi: 10.1113/jphysiol.1976.sp011598. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Irisawa H., Kokubun S. Modulation by intracellular ATP and cyclic AMP of the slow inward current in isolated single ventricular cells of the guinea-pig. J Physiol. 1983 May;338:321–337. doi: 10.1113/jphysiol.1983.sp014675. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Isenberg G., Klöckner U. Calcium currents of isolated bovine ventricular myocytes are fast and of large amplitude. Pflugers Arch. 1982 Oct;395(1):30–41. doi: 10.1007/BF00584965. [DOI] [PubMed] [Google Scholar]
  15. Lee K. S., Tsien R. W. Reversal of current through calcium channels in dialysed single heart cells. Nature. 1982 Jun 10;297(5866):498–501. doi: 10.1038/297498a0. [DOI] [PubMed] [Google Scholar]
  16. Lux H. D., Eckert R. Inferred slow inward current in snail neurones. Nature. 1974 Aug 16;250(467):574–576. doi: 10.1038/250574a0. [DOI] [PubMed] [Google Scholar]
  17. Mascher D., Peper K. Two components of inward current in myocardial muscle fibers. Pflugers Arch. 1969;307(3):190–203. doi: 10.1007/BF00592084. [DOI] [PubMed] [Google Scholar]
  18. Matsuda H., Noma A. Isolation of calcium current and its sensitivity to monovalent cations in dialysed ventricular cells of guinea-pig. J Physiol. 1984 Dec;357:553–573. doi: 10.1113/jphysiol.1984.sp015517. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Mitra R., Morad M. A uniform enzymatic method for dissociation of myocytes from hearts and stomachs of vertebrates. Am J Physiol. 1985 Nov;249(5 Pt 2):H1056–H1060. doi: 10.1152/ajpheart.1985.249.5.H1056. [DOI] [PubMed] [Google Scholar]
  20. Morad M., Goldman Y. E., Trentham D. R. Rapid photochemical inactivation of Ca2+-antagonists shows that Ca2+ entry directly activates contraction in frog heart. Nature. 1983 Aug 18;304(5927):635–638. doi: 10.1038/304635a0. [DOI] [PubMed] [Google Scholar]
  21. Morad M., Trautwein W. The effect of the duration of the action potential on contraction in the mammalian heart muscle. Pflugers Arch Gesamte Physiol Menschen Tiere. 1968;299(1):66–82. doi: 10.1007/BF00362542. [DOI] [PubMed] [Google Scholar]
  22. Nilius B., Hess P., Lansman J. B., Tsien R. W. A novel type of cardiac calcium channel in ventricular cells. Nature. 1985 Aug 1;316(6027):443–446. doi: 10.1038/316443a0. [DOI] [PubMed] [Google Scholar]
  23. Noma A., Morad M., Irisawa H. Does the "pacemaker current" generate the diastolic depolarization in the rabbit SA node cells? Pflugers Arch. 1983 May;397(3):190–194. doi: 10.1007/BF00584356. [DOI] [PubMed] [Google Scholar]
  24. Reuter H. The dependence of slow inward current in Purkinje fibres on the extracellular calcium-concentration. J Physiol. 1967 Sep;192(2):479–492. doi: 10.1113/jphysiol.1967.sp008310. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Rougier O., Vassort G., Garnier D., Gargouil Y. M., Coraboeuf E. Existence and role of a slow inward current during the frog atrial action potential. Pflugers Arch. 1969;308(2):91–110. doi: 10.1007/BF00587018. [DOI] [PubMed] [Google Scholar]
  26. Schramm M., Thomas G., Towart R., Franckowiak G. Novel dihydropyridines with positive inotropic action through activation of Ca2+ channels. Nature. 1983 Jun 9;303(5917):535–537. doi: 10.1038/303535a0. [DOI] [PubMed] [Google Scholar]
  27. Smith S. J., Zucker R. S. Aequorin response facilitation and intracellular calcium accumulation in molluscan neurones. J Physiol. 1980 Mar;300:167–196. doi: 10.1113/jphysiol.1980.sp013157. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Tillotson D., Horn R. Inactivation without facilitation of calcium conductance in caesium-loaded neurones of Aplysia. Nature. 1978 May 25;273(5660):312–314. doi: 10.1038/273312a0. [DOI] [PubMed] [Google Scholar]
  29. Zipes D. P., Fischer J. C. Effects of agents which inhibit the slow channel on sinus node automaticity and atrioventricular conduction in the dog. Circ Res. 1974 Feb;34(2):184–192. doi: 10.1161/01.res.34.2.184. [DOI] [PubMed] [Google Scholar]

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