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Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats
When the concentration of sodium (Na(+)) in arterial plasma (P(Na)) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In th...
Autores principales: | , , , , |
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Formato: | Texto |
Lenguaje: | English |
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The Korean Society of Electrolyte Metabolism
2010
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3041495/ https://www.ncbi.nlm.nih.gov/pubmed/21468191 http://dx.doi.org/10.5049/EBP.2010.8.1.1 |
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author | Cheema-Dhadli, Surinder Chong, Chee Keong Kim, Namhee Kamel, Kamel S Halperin, Mitchell L |
author_facet | Cheema-Dhadli, Surinder Chong, Chee Keong Kim, Namhee Kamel, Kamel S Halperin, Mitchell L |
author_sort | Cheema-Dhadli, Surinder |
collection | PubMed |
description | When the concentration of sodium (Na(+)) in arterial plasma (P(Na)) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example. |
format | Text |
id | pubmed-3041495 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | The Korean Society of Electrolyte Metabolism |
record_format | MEDLINE/PubMed |
spelling | pubmed-30414952011-04-05 Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats Cheema-Dhadli, Surinder Chong, Chee Keong Kim, Namhee Kamel, Kamel S Halperin, Mitchell L Electrolyte Blood Press Original Investigation When the concentration of sodium (Na(+)) in arterial plasma (P(Na)) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example. The Korean Society of Electrolyte Metabolism 2010-06 2010-06-30 /pmc/articles/PMC3041495/ /pubmed/21468191 http://dx.doi.org/10.5049/EBP.2010.8.1.1 Text en Copyright © 2010 The Korean Society of Electrolyte Metabolism http://creativecommons.org/licenses/by-nc/3.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Investigation Cheema-Dhadli, Surinder Chong, Chee Keong Kim, Namhee Kamel, Kamel S Halperin, Mitchell L Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats |
title | Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats |
title_full | Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats |
title_fullStr | Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats |
title_full_unstemmed | Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats |
title_short | Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats |
title_sort | importance of residual water permeability on the excretion of water during water diuresis in rats |
topic | Original Investigation |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3041495/ https://www.ncbi.nlm.nih.gov/pubmed/21468191 http://dx.doi.org/10.5049/EBP.2010.8.1.1 |
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