Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1007/s00360-021-01396-4 http://hdl.handle.net/11449/222144 |
Resumo: | In humans, physical exercise imposes narrower limits for the heart rate (fH) response of the baroreflex, and vascular modulation becomes largely responsible for arterial pressure regulation. In undisturbed reptiles, the baroreflex-related fH alterations at the operating point (Gop) decreases at elevated body temperatures (Tb) and the vascular regulation changes accordingly. We investigated how the baroreflex of rattlesnakes, Crotalus durissus, is regulated during an activity at different Tb, expecting that activity would reduce the capacity of the cardiac baroreflex neural pathway to buffer arterial pressure fluctuations while being compensated by the vascular neural pathway regulation. Snakes were catheterized for blood pressure assessment at three different Tb: 15, 20 and 30 °C. Data were collected before and after activity at each Tb. Baroreflex gain (Gop) was assessed with the sequence method; the vascular limb, with the time constant of pressure decay (τ), using the two-element Windkessel equation. Both Gop and τ reduced when Tb increased. Activity also reduced Gop and τ in all Tb. The relationship between τ and pulse interval (τ/PI) was unaffected by the temperature at resting snakes, albeit it reduced after activity at 20 °C and 30 °C. The unchanged τ/PI and normalized Gop at different Tb indicated those variables are actively adjusted to work at different fH and pressure conditions at rest. Our data suggest that during activity, the baroreflex-related fH response is attenuated and hypertension is buffered by a disproportional increase in the rate which pressure decays during diastole. This compensation seems especially important at higher Tb where Gop is already low. |
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Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissusBaroreflex effectiveness indexOscillatory power fractionSequence methodTime constant of pressure decayWindkesselIn humans, physical exercise imposes narrower limits for the heart rate (fH) response of the baroreflex, and vascular modulation becomes largely responsible for arterial pressure regulation. In undisturbed reptiles, the baroreflex-related fH alterations at the operating point (Gop) decreases at elevated body temperatures (Tb) and the vascular regulation changes accordingly. We investigated how the baroreflex of rattlesnakes, Crotalus durissus, is regulated during an activity at different Tb, expecting that activity would reduce the capacity of the cardiac baroreflex neural pathway to buffer arterial pressure fluctuations while being compensated by the vascular neural pathway regulation. Snakes were catheterized for blood pressure assessment at three different Tb: 15, 20 and 30 °C. Data were collected before and after activity at each Tb. Baroreflex gain (Gop) was assessed with the sequence method; the vascular limb, with the time constant of pressure decay (τ), using the two-element Windkessel equation. Both Gop and τ reduced when Tb increased. Activity also reduced Gop and τ in all Tb. The relationship between τ and pulse interval (τ/PI) was unaffected by the temperature at resting snakes, albeit it reduced after activity at 20 °C and 30 °C. The unchanged τ/PI and normalized Gop at different Tb indicated those variables are actively adjusted to work at different fH and pressure conditions at rest. Our data suggest that during activity, the baroreflex-related fH response is attenuated and hypertension is buffered by a disproportional increase in the rate which pressure decays during diastole. This compensation seems especially important at higher Tb where Gop is already low.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Department of Physiological Sciences Federal University of São Carlos (UFSCar)Department of Zoology State University of São Paulo (UNESP)Department of Zoology State University of São Paulo (UNESP)FAPESP: 2016/20158-6FAPESP: 2018/05035-0FAPESP: 2019/22016-2Universidade Federal de São Carlos (UFSCar)Universidade Estadual Paulista (UNESP)Filogonio, Renato [UNESP]Neto, Antônio V. G. S.Zamponi, Mariana M.Abe, Augusto S. [UNESP]Leite, Cléo A. C.2022-04-28T19:42:40Z2022-04-28T19:42:40Z2021-09-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article917-925http://dx.doi.org/10.1007/s00360-021-01396-4Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, v. 191, n. 5, p. 917-925, 2021.0174-1578http://hdl.handle.net/11449/22214410.1007/s00360-021-01396-42-s2.0-85112069316Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengJournal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiologyinfo:eu-repo/semantics/openAccess2022-04-28T19:42:40Zoai:repositorio.unesp.br:11449/222144Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T19:12:01.124178Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus |
title |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus |
spellingShingle |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus Filogonio, Renato [UNESP] Baroreflex effectiveness index Oscillatory power fraction Sequence method Time constant of pressure decay Windkessel |
title_short |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus |
title_full |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus |
title_fullStr |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus |
title_full_unstemmed |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus |
title_sort |
Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus |
author |
Filogonio, Renato [UNESP] |
author_facet |
Filogonio, Renato [UNESP] Neto, Antônio V. G. S. Zamponi, Mariana M. Abe, Augusto S. [UNESP] Leite, Cléo A. C. |
author_role |
author |
author2 |
Neto, Antônio V. G. S. Zamponi, Mariana M. Abe, Augusto S. [UNESP] Leite, Cléo A. C. |
author2_role |
author author author author |
dc.contributor.none.fl_str_mv |
Universidade Federal de São Carlos (UFSCar) Universidade Estadual Paulista (UNESP) |
dc.contributor.author.fl_str_mv |
Filogonio, Renato [UNESP] Neto, Antônio V. G. S. Zamponi, Mariana M. Abe, Augusto S. [UNESP] Leite, Cléo A. C. |
dc.subject.por.fl_str_mv |
Baroreflex effectiveness index Oscillatory power fraction Sequence method Time constant of pressure decay Windkessel |
topic |
Baroreflex effectiveness index Oscillatory power fraction Sequence method Time constant of pressure decay Windkessel |
description |
In humans, physical exercise imposes narrower limits for the heart rate (fH) response of the baroreflex, and vascular modulation becomes largely responsible for arterial pressure regulation. In undisturbed reptiles, the baroreflex-related fH alterations at the operating point (Gop) decreases at elevated body temperatures (Tb) and the vascular regulation changes accordingly. We investigated how the baroreflex of rattlesnakes, Crotalus durissus, is regulated during an activity at different Tb, expecting that activity would reduce the capacity of the cardiac baroreflex neural pathway to buffer arterial pressure fluctuations while being compensated by the vascular neural pathway regulation. Snakes were catheterized for blood pressure assessment at three different Tb: 15, 20 and 30 °C. Data were collected before and after activity at each Tb. Baroreflex gain (Gop) was assessed with the sequence method; the vascular limb, with the time constant of pressure decay (τ), using the two-element Windkessel equation. Both Gop and τ reduced when Tb increased. Activity also reduced Gop and τ in all Tb. The relationship between τ and pulse interval (τ/PI) was unaffected by the temperature at resting snakes, albeit it reduced after activity at 20 °C and 30 °C. The unchanged τ/PI and normalized Gop at different Tb indicated those variables are actively adjusted to work at different fH and pressure conditions at rest. Our data suggest that during activity, the baroreflex-related fH response is attenuated and hypertension is buffered by a disproportional increase in the rate which pressure decays during diastole. This compensation seems especially important at higher Tb where Gop is already low. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-09-01 2022-04-28T19:42:40Z 2022-04-28T19:42:40Z |
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/10.1007/s00360-021-01396-4 Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, v. 191, n. 5, p. 917-925, 2021. 0174-1578 http://hdl.handle.net/11449/222144 10.1007/s00360-021-01396-4 2-s2.0-85112069316 |
url |
http://dx.doi.org/10.1007/s00360-021-01396-4 http://hdl.handle.net/11449/222144 |
identifier_str_mv |
Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, v. 191, n. 5, p. 917-925, 2021. 0174-1578 10.1007/s00360-021-01396-4 2-s2.0-85112069316 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
917-925 |
dc.source.none.fl_str_mv |
Scopus 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 |
|
_version_ |
1808129032029470720 |