Skip to main content
PMC home page
Biophysical Journal logoLink to Biophysical Journal
. 1982 Feb;37(2):427–431. doi: 10.1016/S0006-3495(82)84688-2

Anomalous potassium channel-gating rates as functions of calcium and potassium ion concentrations.

J F Fohlmeister, W J Adelman Jr
PMCID: PMC1328824  PMID: 6277401

Abstract

With near normal monovalent ionic concentrations, the rate of increase of the potassium conductance after a depolarizing voltage-clamp step is slowed when the external calcium concentration is increased. This trend in the rise-time with changes in calcium is reversed when the axointernal potassium concentration is reduced (150 mM) and the periaxonal concentration is increased (50 mM); that is, the rise-time decrease with increasing calcium concentration. Furthermore, the degree of sigmoidality of the K-conductance time-course always increase when the rise-times increase for a given test potential. In the case of calcium surface-charge screening, these effects may be caused by a shifted distribution of K-ions within the channels following the altered ion gradient, and by a consequent shift in the reciprocal electrostatic interactions between the ionic charges and channel-gate charges.

Full text

PDF
427

Selected References

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

  1. Adelman W. J., Jr, Fitzhugh R. Solutions of the Hodgkin-Huxley equations modified for potassium accumulation in a periaxonal space. Fed Proc. 1975 Apr;34(5):1322–1329. [PubMed] [Google Scholar]
  2. Adelman W. J., Jr, Palti Y., Senft J. P. Potassium ion accumulation in a periaxonal space and its effect on the measurement of membrane potassium ion conductance. J Membr Biol. 1973 Nov 8;13(4):387–410. doi: 10.1007/BF01868237. [DOI] [PubMed] [Google Scholar]
  3. Begenisich T. Magnitude and location of surface charges on Myxicola giant axons. J Gen Physiol. 1975 Jul;66(1):47–65. doi: 10.1085/jgp.66.1.47. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Binstock L., Goldman L. Rectification in instantaneous potassium current-voltage relations in Myxicola giant axons. J Physiol. 1971 Sep;217(3):517–531. doi: 10.1113/jphysiol.1971.sp009583. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chandler W. K., Hodgkin A. L., Meves H. The effect of changing the internal solution on sodium inactivation and related phenomena in giant axons. J Physiol. 1965 Oct;180(4):821–836. doi: 10.1113/jphysiol.1965.sp007733. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. FRANKENHAEUSER B., HODGKIN A. L. The action of calcium on the electrical properties of squid axons. J Physiol. 1957 Jul 11;137(2):218–244. doi: 10.1113/jphysiol.1957.sp005808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. FRANKENHAEUSER B., HODGKIN A. L. The after-effects of impulses in the giant nerve fibres of Loligo. J Physiol. 1956 Feb 28;131(2):341–376. doi: 10.1113/jphysiol.1956.sp005467. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. FRANKENHAEUSER B. The effect of calcium on the myelinated nerve fibre. J Physiol. 1957 Jul 11;137(2):245–260. doi: 10.1113/jphysiol.1957.sp005809. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. French R. J., Wells J. B. Sodium ions as blocking agents and charge carriers in the potassium channel of the squid giant axon. J Gen Physiol. 1977 Dec;70(6):707–724. doi: 10.1085/jgp.70.6.707. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. GRAHAME D. C. The electrical double layer and the theory of electrocapillarity. Chem Rev. 1947 Dec;41(3):441–501. doi: 10.1021/cr60130a002. [DOI] [PubMed] [Google Scholar]
  11. 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]
  12. HODGKIN A. L., HUXLEY A. F. The components of membrane conductance in the giant axon of Loligo. J Physiol. 1952 Apr;116(4):473–496. doi: 10.1113/jphysiol.1952.sp004718. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. McLaughlin S. G., Szabo G., Eisenman G. Divalent ions and the surface potential of charged phospholipid membranes. J Gen Physiol. 1971 Dec;58(6):667–687. doi: 10.1085/jgp.58.6.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Rojas E., Atwater I. An experimental approach to determine membrane charges in squid giant axons. J Gen Physiol. 1968 May;51(5 Suppl):131S+–131S+. [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES