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Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors

The influence of polyvalent cations on the activation of end plate receptors has been studied in vitro on the sartorius muscle of the frog. In the absence of extracellular calcium, the sensitivity of the receptors to depolarizing quaternary ammonium salts was markedly reduced. Maximum receptor activ...

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Detalles Bibliográficos
Autores principales: Lambert, Donald H., Parsons, Rodney L.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1970
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225958/
https://www.ncbi.nlm.nih.gov/pubmed/5476386
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author Lambert, Donald H.
Parsons, Rodney L.
author_facet Lambert, Donald H.
Parsons, Rodney L.
author_sort Lambert, Donald H.
collection PubMed
description The influence of polyvalent cations on the activation of end plate receptors has been studied in vitro on the sartorius muscle of the frog. In the absence of extracellular calcium, the sensitivity of the receptors to depolarizing quaternary ammonium salts was markedly reduced. Maximum receptor activation occurred in those fibers equilibrated in 1.8 mM calcium Ringer solution, with the response being reduced as the calcium concentration was raised or lowered. Magnesium was less efficient than calcium in regulating the sensitivity of the end plate receptors, the maximum receptor response occurring in those fibers equilibrated in 8 mM magnesium Ringer solution. In the presence of lanthanum the end plate response to carbamylcholine or acetylcholine was enhanced. Lanthanum increased the conductance change produced by carbamylcholine both in polarized and in potassium-depolarized fibers. The application of 10(-2) mM lanthanum to the end plate increased MEPP's amplitude, rise time, and half-fall time by 19, 54, and 45%, respectively. The results suggest that polyvalent cations influence postjunctional membrane receptor processes in addition to their well-documented prejunctional action.
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spelling pubmed-22259582008-04-23 Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors Lambert, Donald H. Parsons, Rodney L. J Gen Physiol Article The influence of polyvalent cations on the activation of end plate receptors has been studied in vitro on the sartorius muscle of the frog. In the absence of extracellular calcium, the sensitivity of the receptors to depolarizing quaternary ammonium salts was markedly reduced. Maximum receptor activation occurred in those fibers equilibrated in 1.8 mM calcium Ringer solution, with the response being reduced as the calcium concentration was raised or lowered. Magnesium was less efficient than calcium in regulating the sensitivity of the end plate receptors, the maximum receptor response occurring in those fibers equilibrated in 8 mM magnesium Ringer solution. In the presence of lanthanum the end plate response to carbamylcholine or acetylcholine was enhanced. Lanthanum increased the conductance change produced by carbamylcholine both in polarized and in potassium-depolarized fibers. The application of 10(-2) mM lanthanum to the end plate increased MEPP's amplitude, rise time, and half-fall time by 19, 54, and 45%, respectively. The results suggest that polyvalent cations influence postjunctional membrane receptor processes in addition to their well-documented prejunctional action. The Rockefeller University Press 1970-09-01 /pmc/articles/PMC2225958/ /pubmed/5476386 Text en Copyright © 1970 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
Lambert, Donald H.
Parsons, Rodney L.
Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors
title Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors
title_full Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors
title_fullStr Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors
title_full_unstemmed Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors
title_short Influence of Polyvalent Cations on the Activation of Muscle End Plate Receptors
title_sort influence of polyvalent cations on the activation of muscle end plate receptors
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225958/
https://www.ncbi.nlm.nih.gov/pubmed/5476386
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