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Rectification of oxygen transfer through the rat colonic epithelium

AIM: To assess whether higher sensitivity of colonic epithelium to hypoxia at the serosal side is associated with oxygen transfer asymmetry. METHODS: Rats were fed either with normal chow or a low-sodium diet. Tissues were mounted as flat sheets in a modified, airtight Ussing chamber with oxygen met...

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Autores principales: Saraví, Fernando D, Carra, Graciela E, Matus, Daniel A, Ibáñez, Jorge E
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Baishideng Publishing Group Inc 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5437503/
https://www.ncbi.nlm.nih.gov/pubmed/28573068
http://dx.doi.org/10.4291/wjgp.v8.i2.59
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author Saraví, Fernando D
Carra, Graciela E
Matus, Daniel A
Ibáñez, Jorge E
author_facet Saraví, Fernando D
Carra, Graciela E
Matus, Daniel A
Ibáñez, Jorge E
author_sort Saraví, Fernando D
collection PubMed
description AIM: To assess whether higher sensitivity of colonic epithelium to hypoxia at the serosal side is associated with oxygen transfer asymmetry. METHODS: Rats were fed either with normal chow or a low-sodium diet. Tissues were mounted as flat sheets in a modified, airtight Ussing chamber with oxygen meters in each hemichamber. Mucosal samples from normal diet animals were studied under control conditions, in low-chloride solution and after adding chloride secretion inhibitors and chloride secretagogues. Samples from sodium-deprived rats were studied before and after ouabain addition. In separate experiments, the correlation between short-circuit current and oxygen consumption was analyzed. Finally, hypoxia was induced in one hemichamber to assess the relationship between its oxygen content and the oxygen pressure difference between both hemichambers. RESULTS: In all studied conditions, oxygen consumption was larger in the serosal hemichamber than in the mucosal one (P = 0.0025 to P < 0.0001). Short-circuit current showed significant correlation with both total oxygen consumption (r = 0.765; P = 0.009) in normoxia and oxygen consumption in the serosal hemichamber (r = 0.754; P = 0.011) during mucosal hypoxia, but not with oxygen consumption in the mucosal hemichamber. When hypoxia was induced in the mucosal hemichamber, an oxygen pressure difference of 13 kPa with the serosal hemichamber was enough to keep its oxygen content constant. However, when hypoxia was induced in the serosal hemichamber, the oxygen pressure difference with the mucosal hemichamber necessary to keep its oxygen content constant was 40 kPa (P < 0.0001). CONCLUSION: Serosal oxygen supply is more readily available to support short-circuit current. This may be partly due to a rectifying behavior of transepithelial oxygen transfer.
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spelling pubmed-54375032017-06-01 Rectification of oxygen transfer through the rat colonic epithelium Saraví, Fernando D Carra, Graciela E Matus, Daniel A Ibáñez, Jorge E World J Gastrointest Pathophysiol Basic Study AIM: To assess whether higher sensitivity of colonic epithelium to hypoxia at the serosal side is associated with oxygen transfer asymmetry. METHODS: Rats were fed either with normal chow or a low-sodium diet. Tissues were mounted as flat sheets in a modified, airtight Ussing chamber with oxygen meters in each hemichamber. Mucosal samples from normal diet animals were studied under control conditions, in low-chloride solution and after adding chloride secretion inhibitors and chloride secretagogues. Samples from sodium-deprived rats were studied before and after ouabain addition. In separate experiments, the correlation between short-circuit current and oxygen consumption was analyzed. Finally, hypoxia was induced in one hemichamber to assess the relationship between its oxygen content and the oxygen pressure difference between both hemichambers. RESULTS: In all studied conditions, oxygen consumption was larger in the serosal hemichamber than in the mucosal one (P = 0.0025 to P < 0.0001). Short-circuit current showed significant correlation with both total oxygen consumption (r = 0.765; P = 0.009) in normoxia and oxygen consumption in the serosal hemichamber (r = 0.754; P = 0.011) during mucosal hypoxia, but not with oxygen consumption in the mucosal hemichamber. When hypoxia was induced in the mucosal hemichamber, an oxygen pressure difference of 13 kPa with the serosal hemichamber was enough to keep its oxygen content constant. However, when hypoxia was induced in the serosal hemichamber, the oxygen pressure difference with the mucosal hemichamber necessary to keep its oxygen content constant was 40 kPa (P < 0.0001). CONCLUSION: Serosal oxygen supply is more readily available to support short-circuit current. This may be partly due to a rectifying behavior of transepithelial oxygen transfer. Baishideng Publishing Group Inc 2017-05-15 2017-05-15 /pmc/articles/PMC5437503/ /pubmed/28573068 http://dx.doi.org/10.4291/wjgp.v8.i2.59 Text en ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved. http://creativecommons.org/licenses/by-nc/4.0/ Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
spellingShingle Basic Study
Saraví, Fernando D
Carra, Graciela E
Matus, Daniel A
Ibáñez, Jorge E
Rectification of oxygen transfer through the rat colonic epithelium
title Rectification of oxygen transfer through the rat colonic epithelium
title_full Rectification of oxygen transfer through the rat colonic epithelium
title_fullStr Rectification of oxygen transfer through the rat colonic epithelium
title_full_unstemmed Rectification of oxygen transfer through the rat colonic epithelium
title_short Rectification of oxygen transfer through the rat colonic epithelium
title_sort rectification of oxygen transfer through the rat colonic epithelium
topic Basic Study
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5437503/
https://www.ncbi.nlm.nih.gov/pubmed/28573068
http://dx.doi.org/10.4291/wjgp.v8.i2.59
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