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The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump

Frog sartorius muscles were made Na-rich by immersion in K-free sulfate Ringer's solution in the cold. The muscles were then loaded with Na(24) and the extracellular space cleared of radioactivity. When such Na-rich muscles were transferred to lithium sulfate Ringer's solution at 20°C, Na...

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Detalles Bibliográficos
Autores principales: Mullins, L. J., Awad, M. Z.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1965
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2213764/
https://www.ncbi.nlm.nih.gov/pubmed/14324987
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author Mullins, L. J.
Awad, M. Z.
author_facet Mullins, L. J.
Awad, M. Z.
author_sort Mullins, L. J.
collection PubMed
description Frog sartorius muscles were made Na-rich by immersion in K-free sulfate Ringer's solution in the cold. The muscles were then loaded with Na(24) and the extracellular space cleared of radioactivity. When such Na-rich muscles were transferred to lithium sulfate Ringer's solution at 20°C, Na efflux was observed to increase with time, to reach a maximum about 15 minutes after the transfer of the muscles to Li(2)SO(4), and then to decline. The decline in efflux from these muscles was proportional to ([Na](i))(8) over a considerable range of [Na](i). The membrane potential of Na-rich muscles was about -48 mv in K-free sulfate Ringer's at 4°C but changed to -76 mv in the same solution at 20°C and to -98 mv in Li(2)SO(4) Ringer's at 20°C. By contrast, muscles with a normal [Na](i) showed a fall in membrane potential when transferred from K-free sulfate Ringer's to Li(2)SO(4) Ringer's solution. The general conclusions from this study are (a) that Na extrusion is capable of generating an electrical potential, and (b) that increases in [Na](i) lead to reversible increases in P (Na) of muscle fibers.
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spelling pubmed-22137642008-04-23 The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump Mullins, L. J. Awad, M. Z. J Gen Physiol Article Frog sartorius muscles were made Na-rich by immersion in K-free sulfate Ringer's solution in the cold. The muscles were then loaded with Na(24) and the extracellular space cleared of radioactivity. When such Na-rich muscles were transferred to lithium sulfate Ringer's solution at 20°C, Na efflux was observed to increase with time, to reach a maximum about 15 minutes after the transfer of the muscles to Li(2)SO(4), and then to decline. The decline in efflux from these muscles was proportional to ([Na](i))(8) over a considerable range of [Na](i). The membrane potential of Na-rich muscles was about -48 mv in K-free sulfate Ringer's at 4°C but changed to -76 mv in the same solution at 20°C and to -98 mv in Li(2)SO(4) Ringer's at 20°C. By contrast, muscles with a normal [Na](i) showed a fall in membrane potential when transferred from K-free sulfate Ringer's to Li(2)SO(4) Ringer's solution. The general conclusions from this study are (a) that Na extrusion is capable of generating an electrical potential, and (b) that increases in [Na](i) lead to reversible increases in P (Na) of muscle fibers. The Rockefeller University Press 1965-05-01 /pmc/articles/PMC2213764/ /pubmed/14324987 Text en Copyright © 1965 by The Rockefeller Institute 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
Mullins, L. J.
Awad, M. Z.
The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump
title The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump
title_full The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump
title_fullStr The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump
title_full_unstemmed The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump
title_short The Control of the Membrane Potential of Muscle Fibers by the Sodium Pump
title_sort control of the membrane potential of muscle fibers by the sodium pump
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2213764/
https://www.ncbi.nlm.nih.gov/pubmed/14324987
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