Cargando…
Exchange Diffusion Effect and Euryhalinity in Teleosts
The sea water (SW)-adapted euryhaline Platichthys flesus, and the marine Serranus exchange about 50% of their internal sodium with the external sodium per hour. This rate of exchange decreases with decreasing salinity of the adaptation medium. When the flounder is transferred from SW to FW an instan...
Autores principales: | , , |
---|---|
Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1966
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225658/ https://www.ncbi.nlm.nih.gov/pubmed/11526837 |
_version_ | 1782149677757497344 |
---|---|
author | Motais, R. Garcia, F. Maetz, Romeu J. |
author_facet | Motais, R. Garcia, F. Maetz, Romeu J. |
author_sort | Motais, R. |
collection | PubMed |
description | The sea water (SW)-adapted euryhaline Platichthys flesus, and the marine Serranus exchange about 50% of their internal sodium with the external sodium per hour. This rate of exchange decreases with decreasing salinity of the adaptation medium. When the flounder is transferred from SW to FW an instantaneous 90% reduction of the Na and Cl outflux is observed. About 30 min later a second, progressive, reduction occurs. The outflux reductions appear to result from two types of regulatory mechanisms reducing gill permeability and preventing excessive salt loss. The first reduction corresponds to independent "Na- and Cl-free effects" as shown by transfers to artificial media containing either Na or Cl with an impermeant co-ion. The pattern of simultaneous rapid variations of Na influx and outflux for a range of salinity changes in flounder adapted to SW, ½ SW, or ¼ SW has been studied. The data are compatible with the hypothesis of an exchange diffusion mechanism characterized by a coupling of both unidirectional fluxes. The affinity of the exchange diffusion carrier for sodium has been measured (K(m) ≃ 400 mM). The delayed reduction would result from a progressive diminution of the quantity of carrier available but without modification of its affinity for sodium. When the stenohaline marine perch is transferred from SW to FW, a 40% reduction of the outflux is observed. But it is not the result of an exchange diffusion effect as it is related to the external osmolarity change and not to the NaCl concentration change. Furthermore no delayed reduction is observed after transfer into FW. This transfer is accompanied by a heavy loss of electrolytes resulting in a rapid decline of the plasma electrolyte level and death. A comparative survey of the relative importance of these regulatory mechanisms has been made. |
format | Text |
id | pubmed-2225658 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1966 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22256582008-04-23 Exchange Diffusion Effect and Euryhalinity in Teleosts Motais, R. Garcia, F. Maetz, Romeu J. J Gen Physiol Article The sea water (SW)-adapted euryhaline Platichthys flesus, and the marine Serranus exchange about 50% of their internal sodium with the external sodium per hour. This rate of exchange decreases with decreasing salinity of the adaptation medium. When the flounder is transferred from SW to FW an instantaneous 90% reduction of the Na and Cl outflux is observed. About 30 min later a second, progressive, reduction occurs. The outflux reductions appear to result from two types of regulatory mechanisms reducing gill permeability and preventing excessive salt loss. The first reduction corresponds to independent "Na- and Cl-free effects" as shown by transfers to artificial media containing either Na or Cl with an impermeant co-ion. The pattern of simultaneous rapid variations of Na influx and outflux for a range of salinity changes in flounder adapted to SW, ½ SW, or ¼ SW has been studied. The data are compatible with the hypothesis of an exchange diffusion mechanism characterized by a coupling of both unidirectional fluxes. The affinity of the exchange diffusion carrier for sodium has been measured (K(m) ≃ 400 mM). The delayed reduction would result from a progressive diminution of the quantity of carrier available but without modification of its affinity for sodium. When the stenohaline marine perch is transferred from SW to FW, a 40% reduction of the outflux is observed. But it is not the result of an exchange diffusion effect as it is related to the external osmolarity change and not to the NaCl concentration change. Furthermore no delayed reduction is observed after transfer into FW. This transfer is accompanied by a heavy loss of electrolytes resulting in a rapid decline of the plasma electrolyte level and death. A comparative survey of the relative importance of these regulatory mechanisms has been made. The Rockefeller University Press 1966-11-01 /pmc/articles/PMC2225658/ /pubmed/11526837 Text en Copyright © 1967 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 Motais, R. Garcia, F. Maetz, Romeu J. Exchange Diffusion Effect and Euryhalinity in Teleosts |
title | Exchange Diffusion Effect and Euryhalinity in Teleosts |
title_full | Exchange Diffusion Effect and Euryhalinity in Teleosts |
title_fullStr | Exchange Diffusion Effect and Euryhalinity in Teleosts |
title_full_unstemmed | Exchange Diffusion Effect and Euryhalinity in Teleosts |
title_short | Exchange Diffusion Effect and Euryhalinity in Teleosts |
title_sort | exchange diffusion effect and euryhalinity in teleosts |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225658/ https://www.ncbi.nlm.nih.gov/pubmed/11526837 |
work_keys_str_mv | AT motaisr exchangediffusioneffectandeuryhalinityinteleosts AT garciaf exchangediffusioneffectandeuryhalinityinteleosts AT maetzromeuj exchangediffusioneffectandeuryhalinityinteleosts |