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Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol
The contractility of the frog sartorius muscle was suppressed after treatment with a Ringer solution added with ethylene glycol (EGR). No contraction was elicited by nerve stimulation when the muscle was brought back to normal Ringer solution after having been soaked in 876 mM EGR for 4 hr or in 109...
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1972
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226067/ https://www.ncbi.nlm.nih.gov/pubmed/4340279 |
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author | Sevcik, Carlos Narahashi, Toshio |
author_facet | Sevcik, Carlos Narahashi, Toshio |
author_sort | Sevcik, Carlos |
collection | PubMed |
description | The contractility of the frog sartorius muscle was suppressed after treatment with a Ringer solution added with ethylene glycol (EGR). No contraction was elicited by nerve stimulation when the muscle was brought back to normal Ringer solution after having been soaked in 876 mM EGR for 4 hr or in 1095 mM EGR for 2 hr. However, the action potential of normal amplitude was generated and followed by a depolarizing afterpotential. The resting membrane potential was slightly decreased from the mean normal value of –91.1 mv to –78.8 mv when 1095 mM EGR was used, and to –82.3 mv when 876 mM EGR was used, but remained almost constant for as long as 2 hr. The afterpotential that follows a train of impulses and a slow change in membrane potential produced by a step hyperpolarizing current (so-called "creep") were suppressed after treatment with ethylene glycol. The specific membrane capacity decreased to about 50% of the control values while the specific membrane resistance increased to about twice the control values Therefore, the membrane time constant remained essentially unchanged. The water content of the muscle decreased by about 30% during a 2 hr immersion in 1095 mM EGR, and increased by about 30% beyond the original control level after bringing the muscle back to normal Ringer. The intracellular potassium content did not change significantly during these procedures. Some differences between the present results and those obtained with glycerol are discussed. |
format | Text |
id | pubmed-2226067 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1972 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22260672008-04-23 Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol Sevcik, Carlos Narahashi, Toshio J Gen Physiol Article The contractility of the frog sartorius muscle was suppressed after treatment with a Ringer solution added with ethylene glycol (EGR). No contraction was elicited by nerve stimulation when the muscle was brought back to normal Ringer solution after having been soaked in 876 mM EGR for 4 hr or in 1095 mM EGR for 2 hr. However, the action potential of normal amplitude was generated and followed by a depolarizing afterpotential. The resting membrane potential was slightly decreased from the mean normal value of –91.1 mv to –78.8 mv when 1095 mM EGR was used, and to –82.3 mv when 876 mM EGR was used, but remained almost constant for as long as 2 hr. The afterpotential that follows a train of impulses and a slow change in membrane potential produced by a step hyperpolarizing current (so-called "creep") were suppressed after treatment with ethylene glycol. The specific membrane capacity decreased to about 50% of the control values while the specific membrane resistance increased to about twice the control values Therefore, the membrane time constant remained essentially unchanged. The water content of the muscle decreased by about 30% during a 2 hr immersion in 1095 mM EGR, and increased by about 30% beyond the original control level after bringing the muscle back to normal Ringer. The intracellular potassium content did not change significantly during these procedures. Some differences between the present results and those obtained with glycerol are discussed. The Rockefeller University Press 1972-08-01 /pmc/articles/PMC2226067/ /pubmed/4340279 Text en Copyright © 1972 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 Sevcik, Carlos Narahashi, Toshio Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol |
title | Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol |
title_full | Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol |
title_fullStr | Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol |
title_full_unstemmed | Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol |
title_short | Electrical Properties and Excitation-Contraction Coupling in Skeletal Muscle Treated with Ethylene Glycol |
title_sort | electrical properties and excitation-contraction coupling in skeletal muscle treated with ethylene glycol |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226067/ https://www.ncbi.nlm.nih.gov/pubmed/4340279 |
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