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. 1986 Oct;50(4):677–683. doi: 10.1016/S0006-3495(86)83508-1

External [K+] and the block of the K+ inward rectifier by external Cs+ in frog skeletal muscle.

O Senyk
PMCID: PMC1329846  PMID: 2430633

Abstract

Frog skeletal muscle has a K+ channel called the inward rectifier, which passes inward current more readily than outward current. Gay and Stanfield (1977) described a voltage-dependent block of inward K+ currents through the inward rectifier by external Cs+ in frog muscle. Here, frog single muscle fibers were voltage clamped using the vaseline-gap voltage-clamp technique to study the effect of external [K+] on the voltage-dependent block of inward K+ currents through the inward rectifier by external Cs+. The block of inward K+ currents through the channel by external Cs+ was found to depend on external [K+], such that increasing the external concentration of the permeant ion K+ potentiated the block produced by the impermeant external Cs+. These findings are not consistent with a one-ion channel model for the inward rectifier. The Eyring rate theory formalism for channels, viewed as single-file multi-ion pores (Hille and Schwarz, 1978), was used to develop a two-site multi-ion model for the inward rectifier. This model successfully reproduced the experimentally observed potentiation of the Cs+ block of the channel by external K+, thus lending further support to the view of the inward rectifier as a multi-ion channel.

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Selected References

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

  1. ADRIAN R. H., FREYGANG W. H. Potassium conductance of frog muscle membrane under controlled voltage. J Physiol. 1962 Aug;163:104–114. doi: 10.1113/jphysiol.1962.sp006960. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Adrian R. H., Chandler W. K., Hodgkin A. L. Voltage clamp experiments in striated muscle fibres. J Physiol. 1970 Jul;208(3):607–644. doi: 10.1113/jphysiol.1970.sp009139. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Almers W. Potassium conductance changes in skeletal muscle and the potassium concentration in the transverse tubules. J Physiol. 1972 Aug;225(1):33–56. doi: 10.1113/jphysiol.1972.sp009928. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Almers W. The decline of potassium permeability during extreme hyperpolarization in frog skeletal muscle. J Physiol. 1972 Aug;225(1):57–83. doi: 10.1113/jphysiol.1972.sp009929. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Begenisich T. B., Cahalan M. D. Sodium channel permeation in squid axons. I: Reversal potential experiments. J Physiol. 1980 Oct;307:217–242. doi: 10.1113/jphysiol.1980.sp013432. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Begenisich T., De Weer P. Potassium flux ratio in voltage-clamped squid giant axons. J Gen Physiol. 1980 Jul;76(1):83–98. doi: 10.1085/jgp.76.1.83. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Blatz A. L. Asymmetric proton block of inward rectifier K channels in skeletal muscle. Pflugers Arch. 1984 Aug;401(4):402–407. doi: 10.1007/BF00584343. [DOI] [PubMed] [Google Scholar]
  8. Ciani S., Krasne S., Hagiwara S. A model for the effects of potential and external K+ concentration on the Cs+ blocking of inward rectification. Biophys J. 1980 Apr;30(1):199–204. doi: 10.1016/S0006-3495(80)85089-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Constanti A., Galvan M. Fast inward-rectifying current accounts for anomalous rectification in olfactory cortex neurones. J Physiol. 1983 Feb;335:153–178. doi: 10.1113/jphysiol.1983.sp014526. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Gay L. A., Stanfield P. R. Cs(+) causes a voltage-dependent block of inward K currents in resting skeletal muscle fibres. Nature. 1977 May 12;267(5607):169–170. doi: 10.1038/267169a0. [DOI] [PubMed] [Google Scholar]
  11. HODGKIN A. L., KEYNES R. D. The potassium permeability of a giant nerve fibre. J Physiol. 1955 Apr 28;128(1):61–88. doi: 10.1113/jphysiol.1955.sp005291. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. HOROWICZ P., GERBER C. J. EFFECTS OF EXTERNAL POTASSIUM AND STROPHANTHIDIN ON SODIUM FLUXES IN FROG STRIATED MUSCLE. J Gen Physiol. 1965 Jan;48:489–514. doi: 10.1085/jgp.48.3.489. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hagiwara S., Miyazaki S., Rosenthal N. P. Potassium current and the effect of cesium on this current during anomalous rectification of the egg cell membrane of a starfish. J Gen Physiol. 1976 Jun;67(6):621–638. doi: 10.1085/jgp.67.6.621. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Hagiwara S., Takahashi K. The anomalous rectification and cation selectivity of the membrane of a starfish egg cell. J Membr Biol. 1974;18(1):61–80. doi: 10.1007/BF01870103. [DOI] [PubMed] [Google Scholar]
  15. Hestrin S. The interaction of potassium with the activation of anomalous rectification in frog muscle membrane. J Physiol. 1981 Aug;317:497–508. doi: 10.1113/jphysiol.1981.sp013839. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Hille B., Campbell D. T. An improved vaseline gap voltage clamp for skeletal muscle fibers. J Gen Physiol. 1976 Mar;67(3):265–293. doi: 10.1085/jgp.67.3.265. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Hille B., Schwarz W. Potassium channels as multi-ion single-file pores. J Gen Physiol. 1978 Oct;72(4):409–442. doi: 10.1085/jgp.72.4.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Horowicz P., Gage P. W., Eisenberg R. S. The role of the electrochemical gradient in determining potassium fluxes in frog striated muscle. J Gen Physiol. 1968 May;51(5 Suppl):193S+–193S+. [PubMed] [Google Scholar]
  19. Kovács L., Schneider M. F. Contractile activation by voltage clamp depolarization of cut skeletal muscle fibres. J Physiol. 1978 Apr;277:483–506. doi: 10.1113/jphysiol.1978.sp012286. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Leech C. A., Stanfield P. R. Inward rectification in frog skeletal muscle fibres and its dependence on membrane potential and external potassium. J Physiol. 1981;319:295–309. doi: 10.1113/jphysiol.1981.sp013909. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Nelson P. G., Frank K. Anomalous rectification in cat spinal motoneurons and effect of polarizing currents on excitatory postsynaptic potential. J Neurophysiol. 1967 Sep;30(5):1097–1113. doi: 10.1152/jn.1967.30.5.1097. [DOI] [PubMed] [Google Scholar]
  22. Noble D., Tsien R. W. The kinetics and rectifier properties of the slow potassium current in cardiac Purkinje fibres. J Physiol. 1968 Mar;195(1):185–214. doi: 10.1113/jphysiol.1968.sp008454. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Ohmori H. Inactivation kinetics and steady-state current noise in the anomalous rectifier of tunicate egg cell membranes. J Physiol. 1978 Aug;281:77–99. doi: 10.1113/jphysiol.1978.sp012410. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Sanchez J. A., Stefani E. Inward calcium current in twitch muscle fibres of the frog. J Physiol. 1978 Oct;283:197–209. doi: 10.1113/jphysiol.1978.sp012496. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Schwarz W., Neumcke B., Palade P. T. K-current fluctuations in inward-rectifying channels of frog skeletal muscle. J Membr Biol. 1981;63(1-2):85–92. doi: 10.1007/BF01969449. [DOI] [PubMed] [Google Scholar]
  26. Spalding B. C., Senyk O., Swift J. G., Horowicz P. Unidirectional flux ratio for potassium ions in depolarized frog skeletal muscle. Am J Physiol. 1981 Jul;241(1):C68–C75. doi: 10.1152/ajpcell.1981.241.1.C68. [DOI] [PubMed] [Google Scholar]
  27. Standen N. B., Stanfield P. R. Potassium depletion and sodium block of potassium currents under hyperpolarization in frog sartorius muscle. J Physiol. 1979 Sep;294:497–520. doi: 10.1113/jphysiol.1979.sp012943. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Standen N. B., Stanfield P. R. Rubidium block and rubidium permeability of the inward rectifier of frog skeletal muscle fibres. J Physiol. 1980 Jul;304:415–435. doi: 10.1113/jphysiol.1980.sp013333. [DOI] [PMC free article] [PubMed] [Google Scholar]

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