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Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin

In laboratory animals and in human, centrally penetrant ghrelin receptor agonists, given systemically or orally, cause defecation. Animal studies show that the effect is due to activation of ghrelin receptors in the spinal lumbosacral defecation centers. However, it is not known whether there is a p...

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Autores principales: Pustovit, Ruslan V, Callaghan, Brid, Ringuet, Mitchell T, Kerr, Nicole F, Hunne, Billie, Smyth, Ian M, Pietra, Claudio, Furness, John B.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5555902/
https://www.ncbi.nlm.nih.gov/pubmed/28801520
http://dx.doi.org/10.14814/phy2.13385
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author Pustovit, Ruslan V
Callaghan, Brid
Ringuet, Mitchell T
Kerr, Nicole F
Hunne, Billie
Smyth, Ian M
Pietra, Claudio
Furness, John B.
author_facet Pustovit, Ruslan V
Callaghan, Brid
Ringuet, Mitchell T
Kerr, Nicole F
Hunne, Billie
Smyth, Ian M
Pietra, Claudio
Furness, John B.
author_sort Pustovit, Ruslan V
collection PubMed
description In laboratory animals and in human, centrally penetrant ghrelin receptor agonists, given systemically or orally, cause defecation. Animal studies show that the effect is due to activation of ghrelin receptors in the spinal lumbosacral defecation centers. However, it is not known whether there is a physiological role of ghrelin or the ghrelin receptor in the control of defecation. Using immunohistochemistry and immunoassay, we detected and measured ghrelin in the stomach, but were unable to detect ghrelin by either method in the lumbosacral spinal cord, or other regions of the CNS. In rats in which the thoracic spinal cord was transected 5 weeks before, the effects of a ghrelin agonist on colorectal propulsion were significantly enhanced, but defecation caused by water avoidance stress (WAS) was reduced. In knockout rats that expressed no ghrelin and in wild‐type rats, WAS‐induced defecation was reduced by a ghrelin receptor antagonist, to similar extents. We conclude that the ghrelin receptors of the lumbosacral defecation centers have a physiological role in the control of defecation, but that their role is not dependent on ghrelin. This implies that a transmitter other than ghrelin engages the ghrelin receptor or a ghrelin receptor complex.
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spelling pubmed-55559022017-08-16 Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin Pustovit, Ruslan V Callaghan, Brid Ringuet, Mitchell T Kerr, Nicole F Hunne, Billie Smyth, Ian M Pietra, Claudio Furness, John B. Physiol Rep Original Research In laboratory animals and in human, centrally penetrant ghrelin receptor agonists, given systemically or orally, cause defecation. Animal studies show that the effect is due to activation of ghrelin receptors in the spinal lumbosacral defecation centers. However, it is not known whether there is a physiological role of ghrelin or the ghrelin receptor in the control of defecation. Using immunohistochemistry and immunoassay, we detected and measured ghrelin in the stomach, but were unable to detect ghrelin by either method in the lumbosacral spinal cord, or other regions of the CNS. In rats in which the thoracic spinal cord was transected 5 weeks before, the effects of a ghrelin agonist on colorectal propulsion were significantly enhanced, but defecation caused by water avoidance stress (WAS) was reduced. In knockout rats that expressed no ghrelin and in wild‐type rats, WAS‐induced defecation was reduced by a ghrelin receptor antagonist, to similar extents. We conclude that the ghrelin receptors of the lumbosacral defecation centers have a physiological role in the control of defecation, but that their role is not dependent on ghrelin. This implies that a transmitter other than ghrelin engages the ghrelin receptor or a ghrelin receptor complex. John Wiley and Sons Inc. 2017-08-11 /pmc/articles/PMC5555902/ /pubmed/28801520 http://dx.doi.org/10.14814/phy2.13385 Text en © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American 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
Pustovit, Ruslan V
Callaghan, Brid
Ringuet, Mitchell T
Kerr, Nicole F
Hunne, Billie
Smyth, Ian M
Pietra, Claudio
Furness, John B.
Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin
title Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin
title_full Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin
title_fullStr Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin
title_full_unstemmed Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin
title_short Evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin
title_sort evidence that central pathways that mediate defecation utilize ghrelin receptors but do not require endogenous ghrelin
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5555902/
https://www.ncbi.nlm.nih.gov/pubmed/28801520
http://dx.doi.org/10.14814/phy2.13385
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