Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.3389/fphys.2018.00134 http://hdl.handle.net/11449/163913 |
Resumo: | Exposure to chronic sustained hypoxia (SH), as experienced in high altitudes, elicits an increase in ventilation, named ventilatory acclimatization to hypoxia (VAH). We previously showed that rats exposed to short-term(24 h) SH exhibit enhanced abdominal expiratory motor activity at rest, accompanied by augmented baseline sympathetic vasoconstrictor activity. In the present study, we investigated whether the respiratory and sympathetic changes elicited by short-term SH are accompanied by carotid body chemoreceptor sensitization. Juvenile male Holtzman rats (60-80 g) were exposed to SH (10% O-2 for 24 h) or normoxia (control) to examine basal and hypoxic-induced ventilatory parameters in unanesthetized conditions, as well as the sensory response of carotid body chemoreceptors in artificially perfused in situ preparations. Under resting conditions (normoxia/normocapnia), SH rats (n = 12) exhibited higher baseline respiratory frequency, tidal volume, and minute ventilation compared to controls (n = 11, P < 0.05). SH group also showed greater hypoxia ventilatory response than control group (P < 0.05). The in situ preparations of SH rats (n = 8) exhibited augmented baseline expiratory and sympathetic activities under normocapnia, with additional bursts in abdominal and thoracic sympathetic nerves during late expiratory phase that were not seen in controls (n = 8, P < 0.05). Interestingly, basal and potassium cyanide-induced afferent activity of carotid sinus nerve (CSN) was similar between SH and control rats. Our findings indicate that the maintenance of elevated resting ventilation, baseline sympathetic overactivity, and enhanced ventilatory responses to hypoxia in rats exposed to 24 h of SH are not dependent on increased basal and sensorial activity of carotid body chemoreceptors. |
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Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Ratsactive expirationcarotid bodychemoreceptorhypoxic ventilatory responsesympathetic activityventilatory acclimatizationExposure to chronic sustained hypoxia (SH), as experienced in high altitudes, elicits an increase in ventilation, named ventilatory acclimatization to hypoxia (VAH). We previously showed that rats exposed to short-term(24 h) SH exhibit enhanced abdominal expiratory motor activity at rest, accompanied by augmented baseline sympathetic vasoconstrictor activity. In the present study, we investigated whether the respiratory and sympathetic changes elicited by short-term SH are accompanied by carotid body chemoreceptor sensitization. Juvenile male Holtzman rats (60-80 g) were exposed to SH (10% O-2 for 24 h) or normoxia (control) to examine basal and hypoxic-induced ventilatory parameters in unanesthetized conditions, as well as the sensory response of carotid body chemoreceptors in artificially perfused in situ preparations. Under resting conditions (normoxia/normocapnia), SH rats (n = 12) exhibited higher baseline respiratory frequency, tidal volume, and minute ventilation compared to controls (n = 11, P < 0.05). SH group also showed greater hypoxia ventilatory response than control group (P < 0.05). The in situ preparations of SH rats (n = 8) exhibited augmented baseline expiratory and sympathetic activities under normocapnia, with additional bursts in abdominal and thoracic sympathetic nerves during late expiratory phase that were not seen in controls (n = 8, P < 0.05). Interestingly, basal and potassium cyanide-induced afferent activity of carotid sinus nerve (CSN) was similar between SH and control rats. Our findings indicate that the maintenance of elevated resting ventilation, baseline sympathetic overactivity, and enhanced ventilatory responses to hypoxia in rats exposed to 24 h of SH are not dependent on increased basal and sensorial activity of carotid body chemoreceptors.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)NIHSao Paulo State Univ, Dept Physiol & Pathol, Araraquara, BrazilUniv Fed Goias, Dept Physiol Sci, Goiania, Go, BrazilSao Paulo State Univ, Dept Physiol & Pathol, Araraquara, BrazilFAPESP: 2013/17.251-6FAPESP: 2015/23.568-8CNPq: 302892/2014-1NIH: R01AT008632Frontiers Media SaUniversidade Estadual Paulista (Unesp)Universidade Federal de Goiás (UFG)Flor, Karine C. [UNESP]Silva, Elaine F.Menezes, Miguel F. [UNESP]Pedrino, Gustavo R.Colornbari, Eduardo [UNESP]Zoccal, Daniel R. [UNESP]2018-11-26T17:48:23Z2018-11-26T17:48:23Z2018-02-27info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article12application/pdfhttp://dx.doi.org/10.3389/fphys.2018.00134Frontiers In Physiology. Lausanne: Frontiers Media Sa, v. 9, 12 p., 2018.1664-042Xhttp://hdl.handle.net/11449/16391310.3389/fphys.2018.00134WOS:000426217400001WOS000426217400001.pdfWeb of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengFrontiers In Physiologyinfo:eu-repo/semantics/openAccess2023-11-03T06:07:46Zoai:repositorio.unesp.br:11449/163913Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T16:47:14.742405Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats |
title |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats |
spellingShingle |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats Flor, Karine C. [UNESP] active expiration carotid body chemoreceptor hypoxic ventilatory response sympathetic activity ventilatory acclimatization |
title_short |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats |
title_full |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats |
title_fullStr |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats |
title_full_unstemmed |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats |
title_sort |
Short-Term Sustained Hypoxia Elevates Basal and Hypoxia-Induced Ventilation but Not the Carotid Body Chemoreceptor Activity in Rats |
author |
Flor, Karine C. [UNESP] |
author_facet |
Flor, Karine C. [UNESP] Silva, Elaine F. Menezes, Miguel F. [UNESP] Pedrino, Gustavo R. Colornbari, Eduardo [UNESP] Zoccal, Daniel R. [UNESP] |
author_role |
author |
author2 |
Silva, Elaine F. Menezes, Miguel F. [UNESP] Pedrino, Gustavo R. Colornbari, Eduardo [UNESP] Zoccal, Daniel R. [UNESP] |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) Universidade Federal de Goiás (UFG) |
dc.contributor.author.fl_str_mv |
Flor, Karine C. [UNESP] Silva, Elaine F. Menezes, Miguel F. [UNESP] Pedrino, Gustavo R. Colornbari, Eduardo [UNESP] Zoccal, Daniel R. [UNESP] |
dc.subject.por.fl_str_mv |
active expiration carotid body chemoreceptor hypoxic ventilatory response sympathetic activity ventilatory acclimatization |
topic |
active expiration carotid body chemoreceptor hypoxic ventilatory response sympathetic activity ventilatory acclimatization |
description |
Exposure to chronic sustained hypoxia (SH), as experienced in high altitudes, elicits an increase in ventilation, named ventilatory acclimatization to hypoxia (VAH). We previously showed that rats exposed to short-term(24 h) SH exhibit enhanced abdominal expiratory motor activity at rest, accompanied by augmented baseline sympathetic vasoconstrictor activity. In the present study, we investigated whether the respiratory and sympathetic changes elicited by short-term SH are accompanied by carotid body chemoreceptor sensitization. Juvenile male Holtzman rats (60-80 g) were exposed to SH (10% O-2 for 24 h) or normoxia (control) to examine basal and hypoxic-induced ventilatory parameters in unanesthetized conditions, as well as the sensory response of carotid body chemoreceptors in artificially perfused in situ preparations. Under resting conditions (normoxia/normocapnia), SH rats (n = 12) exhibited higher baseline respiratory frequency, tidal volume, and minute ventilation compared to controls (n = 11, P < 0.05). SH group also showed greater hypoxia ventilatory response than control group (P < 0.05). The in situ preparations of SH rats (n = 8) exhibited augmented baseline expiratory and sympathetic activities under normocapnia, with additional bursts in abdominal and thoracic sympathetic nerves during late expiratory phase that were not seen in controls (n = 8, P < 0.05). Interestingly, basal and potassium cyanide-induced afferent activity of carotid sinus nerve (CSN) was similar between SH and control rats. Our findings indicate that the maintenance of elevated resting ventilation, baseline sympathetic overactivity, and enhanced ventilatory responses to hypoxia in rats exposed to 24 h of SH are not dependent on increased basal and sensorial activity of carotid body chemoreceptors. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-11-26T17:48:23Z 2018-11-26T17:48:23Z 2018-02-27 |
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/10.3389/fphys.2018.00134 Frontiers In Physiology. Lausanne: Frontiers Media Sa, v. 9, 12 p., 2018. 1664-042X http://hdl.handle.net/11449/163913 10.3389/fphys.2018.00134 WOS:000426217400001 WOS000426217400001.pdf |
url |
http://dx.doi.org/10.3389/fphys.2018.00134 http://hdl.handle.net/11449/163913 |
identifier_str_mv |
Frontiers In Physiology. Lausanne: Frontiers Media Sa, v. 9, 12 p., 2018. 1664-042X 10.3389/fphys.2018.00134 WOS:000426217400001 WOS000426217400001.pdf |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Frontiers In Physiology |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
12 application/pdf |
dc.publisher.none.fl_str_mv |
Frontiers Media Sa |
publisher.none.fl_str_mv |
Frontiers Media Sa |
dc.source.none.fl_str_mv |
Web of Science 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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1808128700833595392 |