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Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine
The peptide uroguanylin (Ugn) is expressed at significant levels only in intestine and kidney, and is stored in both tissues primarily (perhaps exclusively) as intact prouroguanylin (proUgn). Intravascular infusion of either Ugn or proUgn evokes well‐characterized natriuretic responses in rodents. F...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4873633/ https://www.ncbi.nlm.nih.gov/pubmed/27185905 http://dx.doi.org/10.14814/phy2.12782 |
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author | Fellner, Robert C. Moss, Nicholas G. Goy, Michael F. |
author_facet | Fellner, Robert C. Moss, Nicholas G. Goy, Michael F. |
author_sort | Fellner, Robert C. |
collection | PubMed |
description | The peptide uroguanylin (Ugn) is expressed at significant levels only in intestine and kidney, and is stored in both tissues primarily (perhaps exclusively) as intact prouroguanylin (proUgn). Intravascular infusion of either Ugn or proUgn evokes well‐characterized natriuretic responses in rodents. Furthermore, Ugn knockout mice display hypertension and salt handling deficits, indicating that the Na(+) excretory mechanisms triggered when the peptides are infused into anesthetized animals are likely to operate under normal physiological conditions, and contribute to electrolyte homeostasis in conscious animals. Here, we provide strong corroborative evidence for this hypothesis, by demonstrating that U(U) (gn)V (the rate of urinary Ugn excretion) approximately doubled in conscious, unrestrained rats consuming a high‐salt diet, and decreased by ~15% after salt restriction. These changes in U(U) (gn)V were not associated with altered plasma proUgn levels (shown here to be an accurate index of intestinal proUgn secretion). Furthermore, enteric Ugn mRNA levels were unaffected by salt intake, whereas renal Ugn mRNA levels increased sharply during periods of increased dietary salt consumption. Together, these data suggest that diet‐evoked Ugn signals originate within the kidney, rather than the intestine, thus strengthening a growing body of evidence against a widely cited hypothesis that Ugn serves as the mediator of an entero‐renal natriuretic signaling axis, while underscoring a likely intrarenal natriuretic role for the peptide. The data further suggest that intrarenal Ugn signaling is preferentially engaged when salt intake is elevated, and plays only a minor role when salt intake is restricted. |
format | Online Article Text |
id | pubmed-4873633 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-48736332016-06-02 Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine Fellner, Robert C. Moss, Nicholas G. Goy, Michael F. Physiol Rep Original Research The peptide uroguanylin (Ugn) is expressed at significant levels only in intestine and kidney, and is stored in both tissues primarily (perhaps exclusively) as intact prouroguanylin (proUgn). Intravascular infusion of either Ugn or proUgn evokes well‐characterized natriuretic responses in rodents. Furthermore, Ugn knockout mice display hypertension and salt handling deficits, indicating that the Na(+) excretory mechanisms triggered when the peptides are infused into anesthetized animals are likely to operate under normal physiological conditions, and contribute to electrolyte homeostasis in conscious animals. Here, we provide strong corroborative evidence for this hypothesis, by demonstrating that U(U) (gn)V (the rate of urinary Ugn excretion) approximately doubled in conscious, unrestrained rats consuming a high‐salt diet, and decreased by ~15% after salt restriction. These changes in U(U) (gn)V were not associated with altered plasma proUgn levels (shown here to be an accurate index of intestinal proUgn secretion). Furthermore, enteric Ugn mRNA levels were unaffected by salt intake, whereas renal Ugn mRNA levels increased sharply during periods of increased dietary salt consumption. Together, these data suggest that diet‐evoked Ugn signals originate within the kidney, rather than the intestine, thus strengthening a growing body of evidence against a widely cited hypothesis that Ugn serves as the mediator of an entero‐renal natriuretic signaling axis, while underscoring a likely intrarenal natriuretic role for the peptide. The data further suggest that intrarenal Ugn signaling is preferentially engaged when salt intake is elevated, and plays only a minor role when salt intake is restricted. John Wiley and Sons Inc. 2016-05-15 /pmc/articles/PMC4873633/ /pubmed/27185905 http://dx.doi.org/10.14814/phy2.12782 Text en © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Research Fellner, Robert C. Moss, Nicholas G. Goy, Michael F. Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine |
title | Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine |
title_full | Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine |
title_fullStr | Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine |
title_full_unstemmed | Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine |
title_short | Dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine |
title_sort | dietary salt regulates uroguanylin expression and signaling activity in the kidney, but not in the intestine |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4873633/ https://www.ncbi.nlm.nih.gov/pubmed/27185905 http://dx.doi.org/10.14814/phy2.12782 |
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