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Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes
Infection of human erythrocytes with the malaria parasite Plasmodium falciparum induces new permeability pathways (NPPs) in the host cell membrane. Isotopic flux measurements demonstrated that the NPP are permeable to a wide variety of molecules, thus allowing uptake of nutrients and release of wast...
Autores principales: | , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
2004
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217455/ https://www.ncbi.nlm.nih.gov/pubmed/15051807 http://dx.doi.org/10.1085/jgp.200308919 |
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author | Duranton, Christophe Huber, Stephan M. Tanneur, Valerie Brand, Verena B. Akkaya, Canan Shumilina, Ekaterina V. Sandu, Ciprian D. Lang, Florian |
author_facet | Duranton, Christophe Huber, Stephan M. Tanneur, Valerie Brand, Verena B. Akkaya, Canan Shumilina, Ekaterina V. Sandu, Ciprian D. Lang, Florian |
author_sort | Duranton, Christophe |
collection | PubMed |
description | Infection of human erythrocytes with the malaria parasite Plasmodium falciparum induces new permeability pathways (NPPs) in the host cell membrane. Isotopic flux measurements demonstrated that the NPP are permeable to a wide variety of molecules, thus allowing uptake of nutrients and release of waste products. Recent patch-clamp recordings demonstrated the infection-induced up-regulation of an inwardly and an outwardly rectifying Cl(−) conductance. The present experiments have been performed to explore the sensitivity to cell volume and the organic osmolyte permeability of the two conductances. It is shown that the outward rectifier has a high relative lactate permeability (P(lactate)/P(Cl) = 0.4). Sucrose inhibited the outward-rectifier and abolished the infection-induced hemolysis in isosmotic sorbitol solution but had no or little effect on the inward-rectifier. Furosemide and NPPB blocked the outward-rectifying lactate current and the sorbitol hemolysis with IC(50)s in the range of 0.1 and 1 μM, respectively. In contrast, the IC(50)s of NPPB and furosemide for the inward-rectifying current were >10 μM. Osmotic cell-shrinkage inhibited the inwardly but not the outwardly rectifying conductance. In conclusion, the parasite-induced outwardly-rectifying anion conductance allows permeation of lactate and neutral carbohydrates, whereas the inward rectifier seems largely impermeable to organic solutes. All together, these data should help to resolve ongoing controversy regarding the number of unique channels that exist in P. falciparum–infected erythrocytes. |
format | Text |
id | pubmed-2217455 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2004 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22174552008-03-21 Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes Duranton, Christophe Huber, Stephan M. Tanneur, Valerie Brand, Verena B. Akkaya, Canan Shumilina, Ekaterina V. Sandu, Ciprian D. Lang, Florian J Gen Physiol Article Infection of human erythrocytes with the malaria parasite Plasmodium falciparum induces new permeability pathways (NPPs) in the host cell membrane. Isotopic flux measurements demonstrated that the NPP are permeable to a wide variety of molecules, thus allowing uptake of nutrients and release of waste products. Recent patch-clamp recordings demonstrated the infection-induced up-regulation of an inwardly and an outwardly rectifying Cl(−) conductance. The present experiments have been performed to explore the sensitivity to cell volume and the organic osmolyte permeability of the two conductances. It is shown that the outward rectifier has a high relative lactate permeability (P(lactate)/P(Cl) = 0.4). Sucrose inhibited the outward-rectifier and abolished the infection-induced hemolysis in isosmotic sorbitol solution but had no or little effect on the inward-rectifier. Furosemide and NPPB blocked the outward-rectifying lactate current and the sorbitol hemolysis with IC(50)s in the range of 0.1 and 1 μM, respectively. In contrast, the IC(50)s of NPPB and furosemide for the inward-rectifying current were >10 μM. Osmotic cell-shrinkage inhibited the inwardly but not the outwardly rectifying conductance. In conclusion, the parasite-induced outwardly-rectifying anion conductance allows permeation of lactate and neutral carbohydrates, whereas the inward rectifier seems largely impermeable to organic solutes. All together, these data should help to resolve ongoing controversy regarding the number of unique channels that exist in P. falciparum–infected erythrocytes. The Rockefeller University Press 2004-04 /pmc/articles/PMC2217455/ /pubmed/15051807 http://dx.doi.org/10.1085/jgp.200308919 Text en Copyright © 2004, 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 Duranton, Christophe Huber, Stephan M. Tanneur, Valerie Brand, Verena B. Akkaya, Canan Shumilina, Ekaterina V. Sandu, Ciprian D. Lang, Florian Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes |
title | Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes |
title_full | Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes |
title_fullStr | Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes |
title_full_unstemmed | Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes |
title_short | Organic Osmolyte Permeabilities of the Malaria-induced Anion Conductances in Human Erythrocytes |
title_sort | organic osmolyte permeabilities of the malaria-induced anion conductances in human erythrocytes |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217455/ https://www.ncbi.nlm.nih.gov/pubmed/15051807 http://dx.doi.org/10.1085/jgp.200308919 |
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