Cargando…

The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria

Zinc depresses the contractile force of electrically driven rat atria logarithmically with time. The threshold concentration is about 5 x 10(-6) M zinc and the half-time for contractile depression at 10(-4) M is about 25 minutes. Zinc also depresses spontaneous activity of atria and alters the trans...

Descripción completa

Detalles Bibliográficos
Autores principales: Ciofalo, Frank R., Thomas, Lyell J.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1965
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2213758/
https://www.ncbi.nlm.nih.gov/pubmed/14324990
_version_ 1782148946085281792
author Ciofalo, Frank R.
Thomas, Lyell J.
author_facet Ciofalo, Frank R.
Thomas, Lyell J.
author_sort Ciofalo, Frank R.
collection PubMed
description Zinc depresses the contractile force of electrically driven rat atria logarithmically with time. The threshold concentration is about 5 x 10(-6) M zinc and the half-time for contractile depression at 10(-4) M is about 25 minutes. Zinc also depresses spontaneous activity of atria and alters the transmembrane potential parameters in a manner similar to quinidine. Unlike quinidine, zinc causes an elevation of the resting potential and an elevation of cellular potassium which varies with time in the same way as the resting potential. Exposure to 10(-4) M zinc for 60 minutes causes a statistically significant fall in atrial calcium content and an amount of radioactively labeled zinc is taken up which is quantitatively equal to the calcium lost. Zinc has no effect on rigor caused by iodoacetate but inhibits rigor caused by 1-fluoro-2,4 dinitrobenzene. It is postulated that zinc depression of contractile force is not due to metabolic inhibition, probably not due to quinidine-like action on the cell membrane, but may be due to an interference in the handling of calcium by the cell.
format Text
id pubmed-2213758
institution National Center for Biotechnology Information
language English
publishDate 1965
publisher The Rockefeller University Press
record_format MEDLINE/PubMed
spelling pubmed-22137582008-04-23 The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria Ciofalo, Frank R. Thomas, Lyell J. J Gen Physiol Article Zinc depresses the contractile force of electrically driven rat atria logarithmically with time. The threshold concentration is about 5 x 10(-6) M zinc and the half-time for contractile depression at 10(-4) M is about 25 minutes. Zinc also depresses spontaneous activity of atria and alters the transmembrane potential parameters in a manner similar to quinidine. Unlike quinidine, zinc causes an elevation of the resting potential and an elevation of cellular potassium which varies with time in the same way as the resting potential. Exposure to 10(-4) M zinc for 60 minutes causes a statistically significant fall in atrial calcium content and an amount of radioactively labeled zinc is taken up which is quantitatively equal to the calcium lost. Zinc has no effect on rigor caused by iodoacetate but inhibits rigor caused by 1-fluoro-2,4 dinitrobenzene. It is postulated that zinc depression of contractile force is not due to metabolic inhibition, probably not due to quinidine-like action on the cell membrane, but may be due to an interference in the handling of calcium by the cell. The Rockefeller University Press 1965-05-01 /pmc/articles/PMC2213758/ /pubmed/14324990 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
Ciofalo, Frank R.
Thomas, Lyell J.
The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria
title The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria
title_full The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria
title_fullStr The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria
title_full_unstemmed The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria
title_short The Effects of Zinc on Contractility, Membrane Potentials, and Cation Content of Rat Atria
title_sort effects of zinc on contractility, membrane potentials, and cation content of rat atria
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2213758/
https://www.ncbi.nlm.nih.gov/pubmed/14324990
work_keys_str_mv AT ciofalofrankr theeffectsofzinconcontractilitymembranepotentialsandcationcontentofratatria
AT thomaslyellj theeffectsofzinconcontractilitymembranepotentialsandcationcontentofratatria
AT ciofalofrankr effectsofzinconcontractilitymembranepotentialsandcationcontentofratatria
AT thomaslyellj effectsofzinconcontractilitymembranepotentialsandcationcontentofratatria