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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...
Autores principales: | , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1972
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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. |
format | Text |
id | pubmed-2203175 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1972 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
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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