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The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength

The capacitance of skeletal muscle fibers was measured by recording with one microelectrode the voltage produced by a rectangular pulse of current applied with another microelectrode. The ionic strength of the bathing solution was varied by isosmotic replacement of NaCl with sucrose, the [K] [Cl] pr...

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Detalles Bibliográficos
Autores principales: Vaughan, P. C., Howell, J. N., Eisenberg, R. S.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1972
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203175/
https://www.ncbi.nlm.nih.gov/pubmed/4536730
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author Vaughan, P. C.
Howell, J. N.
Eisenberg, R. S.
author_facet Vaughan, P. C.
Howell, J. N.
Eisenberg, R. S.
author_sort Vaughan, P. C.
collection PubMed
description The capacitance of skeletal muscle fibers was measured by recording with one microelectrode the voltage produced by a rectangular pulse of current applied with another microelectrode. The ionic strength of the bathing solution was varied by isosmotic replacement of NaCl with sucrose, the [K] [Cl] product being held constant. The capacitance decreased with decreasing ionic strength, reaching a value of some 2 µF/cm(2) in solutions of 30 mM ionic strength, and not decreasing further in solutions of 15 mM ionic strength. The capacitance of glycerol-treated fibers did not change with ionic strength and was also some 2 µF/cm(2). It seems likely that lowering the ionic strength reduces the capacitance of the tubular system (defined as the charge stored in the tubular system), and that the 2 µF/cm(2) which is insensitive to ionic strength is associated with the surface membrane. The tubular system is open to the external solution in low ionic strength solutions since peroxidase is able to diffuse into the lumen of the tubules. Twitches and action potentials were also recorded from fibers in low ionic strength solutions, even though the capacitance of the tubular system was very small in these solutions. This finding can be explained if there is an action potential—like mechanism in the tubular membrane.
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spelling pubmed-22031752008-04-23 The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength Vaughan, P. C. Howell, J. N. Eisenberg, R. S. J Gen Physiol Article The capacitance of skeletal muscle fibers was measured by recording with one microelectrode the voltage produced by a rectangular pulse of current applied with another microelectrode. The ionic strength of the bathing solution was varied by isosmotic replacement of NaCl with sucrose, the [K] [Cl] product being held constant. The capacitance decreased with decreasing ionic strength, reaching a value of some 2 µF/cm(2) in solutions of 30 mM ionic strength, and not decreasing further in solutions of 15 mM ionic strength. The capacitance of glycerol-treated fibers did not change with ionic strength and was also some 2 µF/cm(2). It seems likely that lowering the ionic strength reduces the capacitance of the tubular system (defined as the charge stored in the tubular system), and that the 2 µF/cm(2) which is insensitive to ionic strength is associated with the surface membrane. The tubular system is open to the external solution in low ionic strength solutions since peroxidase is able to diffuse into the lumen of the tubules. Twitches and action potentials were also recorded from fibers in low ionic strength solutions, even though the capacitance of the tubular system was very small in these solutions. This finding can be explained if there is an action potential—like mechanism in the tubular membrane. The Rockefeller University Press 1972-03-01 /pmc/articles/PMC2203175/ /pubmed/4536730 Text en Copyright © 1972 by The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Vaughan, P. C.
Howell, J. N.
Eisenberg, R. S.
The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength
title The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength
title_full The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength
title_fullStr The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength
title_full_unstemmed The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength
title_short The Capacitance of Skeletal Muscle Fibers in Solutions of Low Ionic Strength
title_sort capacitance of skeletal muscle fibers in solutions of low ionic strength
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203175/
https://www.ncbi.nlm.nih.gov/pubmed/4536730
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