The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1590/S0100-879X2005000700016 http://hdl.handle.net/11449/16179 |
Resumo: | We investigated the effects of bilateral injections of the GABA receptor agonists muscimol (GABA A) and baclofen (GABA B) into the nucleus tractus solitarius (NTS) on the bradycardia and hypotension induced by iv serotonin injections (5-HT, 2 µg/rat) in awake male Holtzman rats. 5-HT was injected in rats with stainless steel cannulas implanted bilaterally in the NTS, before and 5, 15, and 60 min after bilateral injections of muscimol or baclofen into the NTS. The responses to 5-HT were tested before and after the injection of atropine methyl bromide. Muscimol (50 pmol/50 nl, N = 8) into the NTS increased basal mean arterial pressure (MAP) from 115 ± 4 to 144 ± 6 mmHg, did not change basal heart rate (HR) and reduced the bradycardia (-40 ± 14 and -73 ± 26 bpm at 5 and 15 min, respectively, vs -180 ± 20 bpm for the control) and hypotension (-11 ± 4 and -14 ± 4 mmHg, vs -40 ± 9 mmHg for the control) elicited by 5-HT. Baclofen (12.5 pmol/50 nl, N = 7) into the NTS also increased basal MAP, but did not change basal HR, bradycardia or hypotension in response to 5-HT injections. Atropine methyl bromide (1 mg/kg body weight) injected iv reduced the bradycardic and hypotensive responses to 5-HT injections. The stimulation of GABA A receptors in the NTS of awake rats elicits a significant increase in basal MAP and decreases the cardiac Bezold-Jarisch reflex responses to iv 5-HT injections. |
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Repositório Institucional da UNESP |
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The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake ratsMuscimolGABA receptorsNucleus tractus solitariusParasympathetic componentBezold-Jarisch reflexAwake ratsWe investigated the effects of bilateral injections of the GABA receptor agonists muscimol (GABA A) and baclofen (GABA B) into the nucleus tractus solitarius (NTS) on the bradycardia and hypotension induced by iv serotonin injections (5-HT, 2 µg/rat) in awake male Holtzman rats. 5-HT was injected in rats with stainless steel cannulas implanted bilaterally in the NTS, before and 5, 15, and 60 min after bilateral injections of muscimol or baclofen into the NTS. The responses to 5-HT were tested before and after the injection of atropine methyl bromide. Muscimol (50 pmol/50 nl, N = 8) into the NTS increased basal mean arterial pressure (MAP) from 115 ± 4 to 144 ± 6 mmHg, did not change basal heart rate (HR) and reduced the bradycardia (-40 ± 14 and -73 ± 26 bpm at 5 and 15 min, respectively, vs -180 ± 20 bpm for the control) and hypotension (-11 ± 4 and -14 ± 4 mmHg, vs -40 ± 9 mmHg for the control) elicited by 5-HT. Baclofen (12.5 pmol/50 nl, N = 7) into the NTS also increased basal MAP, but did not change basal HR, bradycardia or hypotension in response to 5-HT injections. Atropine methyl bromide (1 mg/kg body weight) injected iv reduced the bradycardic and hypotensive responses to 5-HT injections. The stimulation of GABA A receptors in the NTS of awake rats elicits a significant increase in basal MAP and decreases the cardiac Bezold-Jarisch reflex responses to iv 5-HT injections.Universidade Estadual Paulista Faculdade de Odontologia Departamento de Ciências BásicasUniversidade Estadual Paulista Faculdade de Odontologia Departamento de Fisiologia e PatologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaUniversidade Estadual Paulista Faculdade de Odontologia Departamento de Ciências BásicasUniversidade Estadual Paulista Faculdade de Odontologia Departamento de Fisiologia e PatologiaAssociação Brasileira de Divulgação Científica (ABRADIC)Universidade Estadual Paulista (Unesp)Universidade Federal de São Paulo (UNIFESP)Callera, J. C. [UNESP]Colombari, Eduardo [UNESP]De Luca Jr., L.A. [UNESP]Menani, José Vanderlei [UNESP]2014-05-20T13:45:52Z2014-05-20T13:45:52Z2005-07-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article1123-1131application/pdfhttp://dx.doi.org/10.1590/S0100-879X2005000700016Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 38, n. 7, p. 1123-1131, 2005.0100-879Xhttp://hdl.handle.net/11449/1617910.1590/S0100-879X2005000700016S0100-879X2005000700016S0100-879X2005000700016.pdf45444500924274261023597870118105SciELOreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengBrazilian Journal of Medical and Biological Research1.492info:eu-repo/semantics/openAccess2023-11-02T06:09:01Zoai:repositorio.unesp.br:11449/16179Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462023-11-02T06:09:01Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats |
title |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats |
spellingShingle |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats Callera, J. C. [UNESP] Muscimol GABA receptors Nucleus tractus solitarius Parasympathetic component Bezold-Jarisch reflex Awake rats |
title_short |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats |
title_full |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats |
title_fullStr |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats |
title_full_unstemmed |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats |
title_sort |
The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats |
author |
Callera, J. C. [UNESP] |
author_facet |
Callera, J. C. [UNESP] Colombari, Eduardo [UNESP] De Luca Jr., L.A. [UNESP] Menani, José Vanderlei [UNESP] |
author_role |
author |
author2 |
Colombari, Eduardo [UNESP] De Luca Jr., L.A. [UNESP] Menani, José Vanderlei [UNESP] |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) Universidade Federal de São Paulo (UNIFESP) |
dc.contributor.author.fl_str_mv |
Callera, J. C. [UNESP] Colombari, Eduardo [UNESP] De Luca Jr., L.A. [UNESP] Menani, José Vanderlei [UNESP] |
dc.subject.por.fl_str_mv |
Muscimol GABA receptors Nucleus tractus solitarius Parasympathetic component Bezold-Jarisch reflex Awake rats |
topic |
Muscimol GABA receptors Nucleus tractus solitarius Parasympathetic component Bezold-Jarisch reflex Awake rats |
description |
We investigated the effects of bilateral injections of the GABA receptor agonists muscimol (GABA A) and baclofen (GABA B) into the nucleus tractus solitarius (NTS) on the bradycardia and hypotension induced by iv serotonin injections (5-HT, 2 µg/rat) in awake male Holtzman rats. 5-HT was injected in rats with stainless steel cannulas implanted bilaterally in the NTS, before and 5, 15, and 60 min after bilateral injections of muscimol or baclofen into the NTS. The responses to 5-HT were tested before and after the injection of atropine methyl bromide. Muscimol (50 pmol/50 nl, N = 8) into the NTS increased basal mean arterial pressure (MAP) from 115 ± 4 to 144 ± 6 mmHg, did not change basal heart rate (HR) and reduced the bradycardia (-40 ± 14 and -73 ± 26 bpm at 5 and 15 min, respectively, vs -180 ± 20 bpm for the control) and hypotension (-11 ± 4 and -14 ± 4 mmHg, vs -40 ± 9 mmHg for the control) elicited by 5-HT. Baclofen (12.5 pmol/50 nl, N = 7) into the NTS also increased basal MAP, but did not change basal HR, bradycardia or hypotension in response to 5-HT injections. Atropine methyl bromide (1 mg/kg body weight) injected iv reduced the bradycardic and hypotensive responses to 5-HT injections. The stimulation of GABA A receptors in the NTS of awake rats elicits a significant increase in basal MAP and decreases the cardiac Bezold-Jarisch reflex responses to iv 5-HT injections. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-07-01 2014-05-20T13:45:52Z 2014-05-20T13:45:52Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1590/S0100-879X2005000700016 Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 38, n. 7, p. 1123-1131, 2005. 0100-879X http://hdl.handle.net/11449/16179 10.1590/S0100-879X2005000700016 S0100-879X2005000700016 S0100-879X2005000700016.pdf 4544450092427426 1023597870118105 |
url |
http://dx.doi.org/10.1590/S0100-879X2005000700016 http://hdl.handle.net/11449/16179 |
identifier_str_mv |
Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 38, n. 7, p. 1123-1131, 2005. 0100-879X 10.1590/S0100-879X2005000700016 S0100-879X2005000700016 S0100-879X2005000700016.pdf 4544450092427426 1023597870118105 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Brazilian Journal of Medical and Biological Research 1.492 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
1123-1131 application/pdf |
dc.publisher.none.fl_str_mv |
Associação Brasileira de Divulgação Científica (ABRADIC) |
publisher.none.fl_str_mv |
Associação Brasileira de Divulgação Científica (ABRADIC) |
dc.source.none.fl_str_mv |
SciELO reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
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1799964791459020800 |