PMID: 1194886Nov 1, 1975Paper

Ionic selectivity, saturation, and block in sodium channels. A four-barrier model

The Journal of General Physiology
B Hille

Abstract

Ionic fluxes in Na channels of myelinated axons show ionic competition, block, and deviations from simple flux independence. These phenomena are particularly evident when external Na+ ions are replaced by other permeant or impermeant ions. The observed currents require new flux equations not based on the concepts of free diffusion. A specific permeability model for the Na channel is developed from Eyring rate theory applied to a chain of saturable binding sites. There are four energy barriers in the pore and only one ion is allowed inside at a time. Deviations from independence arise from saturation. The model shows that ionic permeability ratios measured from zero-current potentials can differ from those measured from relative current amplitudes or conductances. The model can be fitted to experiments with various external sodium substitutes by varying only two parameters: For each ion the height of the major energy barrier (the selectivity filter) determines the biionic zero-current potential and the depth of the energy well (binding site) just external to that barrier then determines the current amplitudes. Voltage clamp measurements with myelinated nerve fibers are given showing numerous examples of deviations from independe...Continue Reading

Citations

May 1, 1980·Journal of Mathematical Biology·H H Kohler, E Vollmerhaus
Dec 29, 1977·Molecular and Cellular Biochemistry·F Hucho, W Schiebler
Dec 1, 1991·Pflügers Archiv : European journal of physiology·G Hansen, W Ulbricht
Nov 1, 1991·Pflügers Archiv : European journal of physiology·M A WatskyJ L Rae
Jul 1, 1983·Naunyn-Schmiedeberg's Archives of Pharmacology·M Kohlhardt
Sep 1, 1989·Pflügers Archiv : European journal of physiology·A Weber, D Siemen
Sep 1, 1987·Pflügers Archiv : European journal of physiology·E Sigel
Jun 1, 1984·Pflügers Archiv : European journal of physiology·B Neumcke, R Stämpfli
Dec 1, 1985·Pflügers Archiv : European journal of physiology·M F Wendt-Gallitelli, G Isenberg
Feb 1, 1983·Pflügers Archiv : European journal of physiology·G N Mozhayeva, A P Naumov
Jan 1, 1982·Neir̆ofiziologiia = Neurophysiology·P G Kostiuk, S L Mironov
Jan 1, 1982·Neir̆ofiziologiia = Neurophysiology·G N Mozhaeva, A P Naumov
Jan 1, 1982·Neir̆ofiziologiia = Neurophysiology·G N Mozhaeva, A P Naumov
Jan 1, 1985·The Journal of Membrane Biology·L C McKinneyT Begenisich
Nov 22, 1976·The Journal of Membrane Biology·S Ginsburg, D Noble
Jan 1, 1983·The Journal of Membrane Biology·D L WilsonA M Brown
Jan 1, 1986·The Journal of Membrane Biology·J B Udgaonkar, G P Hess
Jun 1, 1991·The Journal of Membrane Biology·I Benz, M Kohlhardt
Jan 1, 1975·The Journal of Membrane Biology·J H Moreno, J M Diamond
Jul 12, 1978·Biophysics of Structure and Mechanism·B Neumcke
Jun 17, 2011·European Biophysics Journal : EBJ·María Del Rocío Cantero, Horacio F Cantiello
May 11, 2011·Pflügers Archiv : European journal of physiology·Alberto RivettaClifford Slayman
Jan 1, 1978·Progress in Biophysics and Molecular Biology·D Attwell, J Jack
Jan 1, 1985·Progress in Biophysics and Molecular Biology·B I Khodorov
Jan 1, 1985·Progress in Biophysics and Molecular Biology·K CooperP Wolynes
Jan 1, 1978·Progress in Neurobiology·E M Landau
Jan 1, 1983·Progress in Neurobiology·J J McArdle

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