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Sodium efflux in Myxicola giant axons
Several properties of the Na pump in giant axons from the marine annelid Myxicola infundibulum have been determined in an attempt to characterize this preparation for membrane transport studies. Both NaO and KO activated the Na pump of normal microinjected Myxicola axons. In this preparation, the KO...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1977
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2215339/ https://www.ncbi.nlm.nih.gov/pubmed/894242 |
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collection | PubMed |
description | Several properties of the Na pump in giant axons from the marine annelid Myxicola infundibulum have been determined in an attempt to characterize this preparation for membrane transport studies. Both NaO and KO activated the Na pump of normal microinjected Myxicola axons. In this preparation, the KO activation was less and the NaO activation much greater than that found in the squid giant axon. However, when the intracellular ATP:ADP ratio of the Myxicola axon was elevated by injection of an extraneous phosphagen system, the K sensitivity of Na efflux increased to the magnitude characteristic of squid axons and the activating effect of NaO disappeared. Several axons were injected with Na2SO4 in order to determine the effect of elevated Nai on the Na efflux. Increasing Nai enhanced a component of Na efflux which was insensitive to ouabain and dependent on [Ca] in Na-free (Li) seawater. After subtracting the CaO-dependent fraction, Na efflux was related linearly to [Na]i in all solutions except in K-free (Li) seawater, where it appeared to reach saturation at high [Na]i. |
format | Text |
id | pubmed-2215339 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1977 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22153392008-04-23 Sodium efflux in Myxicola giant axons J Gen Physiol Articles Several properties of the Na pump in giant axons from the marine annelid Myxicola infundibulum have been determined in an attempt to characterize this preparation for membrane transport studies. Both NaO and KO activated the Na pump of normal microinjected Myxicola axons. In this preparation, the KO activation was less and the NaO activation much greater than that found in the squid giant axon. However, when the intracellular ATP:ADP ratio of the Myxicola axon was elevated by injection of an extraneous phosphagen system, the K sensitivity of Na efflux increased to the magnitude characteristic of squid axons and the activating effect of NaO disappeared. Several axons were injected with Na2SO4 in order to determine the effect of elevated Nai on the Na efflux. Increasing Nai enhanced a component of Na efflux which was insensitive to ouabain and dependent on [Ca] in Na-free (Li) seawater. After subtracting the CaO-dependent fraction, Na efflux was related linearly to [Na]i in all solutions except in K-free (Li) seawater, where it appeared to reach saturation at high [Na]i. The Rockefeller University Press 1977-06-01 /pmc/articles/PMC2215339/ /pubmed/894242 Text en 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 | Articles Sodium efflux in Myxicola giant axons |
title | Sodium efflux in Myxicola giant axons |
title_full | Sodium efflux in Myxicola giant axons |
title_fullStr | Sodium efflux in Myxicola giant axons |
title_full_unstemmed | Sodium efflux in Myxicola giant axons |
title_short | Sodium efflux in Myxicola giant axons |
title_sort | sodium efflux in myxicola giant axons |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2215339/ https://www.ncbi.nlm.nih.gov/pubmed/894242 |