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Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis

The duration of ciliary reversal of Paramecium caudatum in response to changes in external ionic factors was determined with various ionic compositions of both equilibration and stimulation media. The reversal response was found to occur when calcium ions bound by an inferred cellular cation exchang...

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Detalles Bibliográficos
Autor principal: Naitoh, Yutaka
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1968
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2201152/
https://www.ncbi.nlm.nih.gov/pubmed/4966766
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author Naitoh, Yutaka
author_facet Naitoh, Yutaka
author_sort Naitoh, Yutaka
collection PubMed
description The duration of ciliary reversal of Paramecium caudatum in response to changes in external ionic factors was determined with various ionic compositions of both equilibration and stimulation media. The reversal response was found to occur when calcium ions bound by an inferred cellular cation exchange system were liberated in exchange for externally applied cations other than calcium. Factors which affect the duration of the response were (a) initial amount of calcium bound by the cation exchange system, (b) final amount of calcium bound by the system after equilibration with the stimulation medium, and (c) concentration of calcium ions in the stimulation medium. An empirical equation is presented which relates the duration of the response to these three factors. On the basis of these and previously published data, the following hypothesis is proposed for the mechanism underlying ciliary reversal in response to cationic stimulation: Ca(++) liberated from the cellular cation exchange system activates a contractile system which is energized by ATP. Contraction of this component results in the reversal of effective beat direction of cilia by a mechanism not yet understood. The duration of reversal in live paramecia is related to the time course of bound calcium release.
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spelling pubmed-22011522008-04-23 Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis Naitoh, Yutaka J Gen Physiol Article The duration of ciliary reversal of Paramecium caudatum in response to changes in external ionic factors was determined with various ionic compositions of both equilibration and stimulation media. The reversal response was found to occur when calcium ions bound by an inferred cellular cation exchange system were liberated in exchange for externally applied cations other than calcium. Factors which affect the duration of the response were (a) initial amount of calcium bound by the cation exchange system, (b) final amount of calcium bound by the system after equilibration with the stimulation medium, and (c) concentration of calcium ions in the stimulation medium. An empirical equation is presented which relates the duration of the response to these three factors. On the basis of these and previously published data, the following hypothesis is proposed for the mechanism underlying ciliary reversal in response to cationic stimulation: Ca(++) liberated from the cellular cation exchange system activates a contractile system which is energized by ATP. Contraction of this component results in the reversal of effective beat direction of cilia by a mechanism not yet understood. The duration of reversal in live paramecia is related to the time course of bound calcium release. The Rockefeller University Press 1968-01-01 /pmc/articles/PMC2201152/ /pubmed/4966766 Text en Copyright © 1968 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
Naitoh, Yutaka
Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis
title Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis
title_full Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis
title_fullStr Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis
title_full_unstemmed Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis
title_short Ionic Control of the Reversal Response of Cilia in Paramecium caudatum : A calcium hypothesis
title_sort ionic control of the reversal response of cilia in paramecium caudatum : a calcium hypothesis
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2201152/
https://www.ncbi.nlm.nih.gov/pubmed/4966766
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