Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Cheema-Dhadli, Surinder, Chong, Chee Keong, Kim, Namhee, Kamel, Kamel S, Halperin, Mitchell L
Formato: Texto
Lenguaje:English
Publicado: The Korean Society of Electrolyte Metabolism 2010
Materias:
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
_version_ 1782198433485946880
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
work_keys_str_mv AT cheemadhadlisurinder importanceofresidualwaterpermeabilityontheexcretionofwaterduringwaterdiuresisinrats
AT chongcheekeong importanceofresidualwaterpermeabilityontheexcretionofwaterduringwaterdiuresisinrats
AT kimnamhee importanceofresidualwaterpermeabilityontheexcretionofwaterduringwaterdiuresisinrats
AT kamelkamels importanceofresidualwaterpermeabilityontheexcretionofwaterduringwaterdiuresisinrats
AT halperinmitchelll importanceofresidualwaterpermeabilityontheexcretionofwaterduringwaterdiuresisinrats