Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique

Bundles of sheep ventricular fibers were voltage-clamped utilizing a modified sucrose gap technique and intracellular voltage control. An action potential was fired off in the usual way, and the clamp circuit was switched on at preselected times during activity. Clamping the membrane back to its res...

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Detalles Bibliográficos
Autores principales: Giebisch, Gerhard, Weidmann, Silvio
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1971
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203101/
https://www.ncbi.nlm.nih.gov/pubmed/5544795
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author Giebisch, Gerhard
Weidmann, Silvio
author_facet Giebisch, Gerhard
Weidmann, Silvio
author_sort Giebisch, Gerhard
collection PubMed
description Bundles of sheep ventricular fibers were voltage-clamped utilizing a modified sucrose gap technique and intracellular voltage control. An action potential was fired off in the usual way, and the clamp circuit was switched on at preselected times during activity. Clamping the membrane back to its resting potential during the early part of an action potential resulted in a surge of inward current. The initial amplitude of this current surge decreased as the clamp was switched on progressively later during the action potential. Inward current decreasing as a function of time was also recorded if the membrane potential was clamped beyond the presumed K equilibrium potential (to -130 mv). Clamping the membrane to the inside positive range (+40 mv to +60 mv) at different times of an action potential resulted in a step of outward current which was not time-dependent. The results suggest that normal repolarization of sheep ventricle depends on a time-dependent decrease of inward current (Na, Ca) rather than on a time-dependent increase of outward current (K).
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spelling pubmed-22031012008-04-23 Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique Giebisch, Gerhard Weidmann, Silvio J Gen Physiol Article Bundles of sheep ventricular fibers were voltage-clamped utilizing a modified sucrose gap technique and intracellular voltage control. An action potential was fired off in the usual way, and the clamp circuit was switched on at preselected times during activity. Clamping the membrane back to its resting potential during the early part of an action potential resulted in a surge of inward current. The initial amplitude of this current surge decreased as the clamp was switched on progressively later during the action potential. Inward current decreasing as a function of time was also recorded if the membrane potential was clamped beyond the presumed K equilibrium potential (to -130 mv). Clamping the membrane to the inside positive range (+40 mv to +60 mv) at different times of an action potential resulted in a step of outward current which was not time-dependent. The results suggest that normal repolarization of sheep ventricle depends on a time-dependent decrease of inward current (Na, Ca) rather than on a time-dependent increase of outward current (K). The Rockefeller University Press 1971-03-01 /pmc/articles/PMC2203101/ /pubmed/5544795 Text en Copyright © 1971 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
Giebisch, Gerhard
Weidmann, Silvio
Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique
title Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique
title_full Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique
title_fullStr Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique
title_full_unstemmed Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique
title_short Membrane Currents in Mammalian Ventricular Heart Muscle Fibers Using a Voltage-Clamp Technique
title_sort membrane currents in mammalian ventricular heart muscle fibers using a voltage-clamp technique
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203101/
https://www.ncbi.nlm.nih.gov/pubmed/5544795
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