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Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei
The penetration of (14)C-labeled erythritol, mannitol, and sucrose through the axolemma was determined in medium sized paired axons, one at rest and the other stimulated 25 times per sec. The resting permeabilities, in 10(-7) cm/sec, are erythritol, 2.9 ± 0.3 (mean ± SEM); mannitol, 2.3 ± 0.4; and s...
Autores principales: | , , , , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
1966
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225629/ https://www.ncbi.nlm.nih.gov/pubmed/5971032 |
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author | Villegas, Raimundo Villegas, Gloria M. Blei, Margarita Herrera, Francisco C. Villegas, Jorge |
author_facet | Villegas, Raimundo Villegas, Gloria M. Blei, Margarita Herrera, Francisco C. Villegas, Jorge |
author_sort | Villegas, Raimundo |
collection | PubMed |
description | The penetration of (14)C-labeled erythritol, mannitol, and sucrose through the axolemma was determined in medium sized paired axons, one at rest and the other stimulated 25 times per sec. The resting permeabilities, in 10(-7) cm/sec, are erythritol, 2.9 ± 0.3 (mean ± SEM); mannitol, 2.3 ± 0.4; and sucrose 0.9 ± 0.1. In the stimulated axons they are: erythritol, 5.2 ± 0.3; mannitol, 4.0 ± 0.5; and sucrose, 1.8 ± 0.3. Thus, the calculated permeabilities during activity (1 msec per impulse), in the same units, are: 100, 75, and 38, respectively. These changes in permeability are reversible. The effects of external potassium and sodium concentrations on erythritol penetration were also studied. At rest, erythritol penetration is independent of potassium and sodium concentrations. In the stimulated axons, erythritol penetration decreases when the extracellular sodium is diminished. Sodium influx (not the efflux) decreases during rest and activity when the extracellular sodium is diminished. The diminution during activity of erythritol and sodium entries in low sodium solutions may be related to a decrease of a drag effect of sodium ions on the nonelectrolyte molecules or to independent effects of the sodium concentration on sodium influx and the nonelectrolyte pathways. The axolemma discriminates among erythritol, mannitol, sucrose, and the different ionic species during rest and activity. |
format | Text |
id | pubmed-2225629 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1966 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22256292008-04-23 Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei Villegas, Raimundo Villegas, Gloria M. Blei, Margarita Herrera, Francisco C. Villegas, Jorge J Gen Physiol Article The penetration of (14)C-labeled erythritol, mannitol, and sucrose through the axolemma was determined in medium sized paired axons, one at rest and the other stimulated 25 times per sec. The resting permeabilities, in 10(-7) cm/sec, are erythritol, 2.9 ± 0.3 (mean ± SEM); mannitol, 2.3 ± 0.4; and sucrose 0.9 ± 0.1. In the stimulated axons they are: erythritol, 5.2 ± 0.3; mannitol, 4.0 ± 0.5; and sucrose, 1.8 ± 0.3. Thus, the calculated permeabilities during activity (1 msec per impulse), in the same units, are: 100, 75, and 38, respectively. These changes in permeability are reversible. The effects of external potassium and sodium concentrations on erythritol penetration were also studied. At rest, erythritol penetration is independent of potassium and sodium concentrations. In the stimulated axons, erythritol penetration decreases when the extracellular sodium is diminished. Sodium influx (not the efflux) decreases during rest and activity when the extracellular sodium is diminished. The diminution during activity of erythritol and sodium entries in low sodium solutions may be related to a decrease of a drag effect of sodium ions on the nonelectrolyte molecules or to independent effects of the sodium concentration on sodium influx and the nonelectrolyte pathways. The axolemma discriminates among erythritol, mannitol, sucrose, and the different ionic species during rest and activity. The Rockefeller University Press 1966-09-01 /pmc/articles/PMC2225629/ /pubmed/5971032 Text en Copyright © 1967 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 Villegas, Raimundo Villegas, Gloria M. Blei, Margarita Herrera, Francisco C. Villegas, Jorge Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei |
title | Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei
|
title_full | Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei
|
title_fullStr | Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei
|
title_full_unstemmed | Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei
|
title_short | Nonelectrolyte Penetration and Sodium Fluxes through the Axolemma of Resting and Stimulated Medium Sized Axons of the Squid Doryteuthis plei
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title_sort | nonelectrolyte penetration and sodium fluxes through the axolemma of resting and stimulated medium sized axons of the squid doryteuthis plei |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225629/ https://www.ncbi.nlm.nih.gov/pubmed/5971032 |
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