Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae

Detalhes bibliográficos
Autor(a) principal: Zena, Lucas A. [UNESP]
Data de Publicação: 2016
Outros Autores: Dantonio, Valter [UNESP], Gargaglioni, Luciane H. [UNESP], Andrade, Denis V. [UNESP], Abe, Augusto S. [UNESP], Bicego, Kenia C. [UNESP]
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://dx.doi.org/10.1242/jeb.129130
http://hdl.handle.net/11449/161249
Resumo: Baroreflex regulation of blood pressure is important for maintaining appropriate tissue perfusion. Although temperature affects heart rate (f(H)) reflex regulation in some reptiles and toads, no data are available on the influence of temperature-independent metabolic states on baroreflex. The South American tegu lizard Salvator merianae exhibits a clear seasonal cycle of activity decreasing f(H) along with winter metabolic downregulation, independent of body temperature. Through pharmacological interventions (phenylephrine and sodium nitroprusside), the baroreflex control of f(H) was studied at similar to 25 degrees C in spring-summer-and winter-acclimated tegus. In winter lizards, resting and minimum fH were lower than in spring-summer animals (respectively, 13.3 +/- 0.82 versus 10.3 +/- 0.81 and 11.2 +/- 0.65 versus 7.97 +/- 0.88 beats min(-1)), while no acclimation differences occurred in resting blood pressure (5.14 +/- 0.38 versus 5.06 +/- 0.56 kPa), baroreflex gain (94.3 +/- 10.7 versus 138.7 +/- 30.3% kPa(-1)) or rate-pressure product (an index ofmyocardial activity). Vagal tone exceeded the sympathetic tone of f(H), especially in the winter group. Therefore, despite the lower f(H), winter acclimation does not diminish the f(H) baroreflex responses or rate-pressure product, possibly because of increased stroke volume that may arise because of heart hypertrophy. Independent of acclimation, f(H) responded more to hypotension than to hypertension. This should imply that tegus, which have no pressure separation within the single heart ventricle, must have other protection mechanisms against pulmonary hypertension or oedema, presumably through lymphatic drainage and/or vagal vasoconstriction of pulmonary artery. Such a predominant f(H) reflex response to hypotension, previously observed in anurans, crocodilians and mammals, may be a common feature of tetrapods.
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spelling Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianaeAdrenergic receptorsBaroreceptorBlood pressureCholinergic toneHibernationSeasonal changesBaroreflex regulation of blood pressure is important for maintaining appropriate tissue perfusion. Although temperature affects heart rate (f(H)) reflex regulation in some reptiles and toads, no data are available on the influence of temperature-independent metabolic states on baroreflex. The South American tegu lizard Salvator merianae exhibits a clear seasonal cycle of activity decreasing f(H) along with winter metabolic downregulation, independent of body temperature. Through pharmacological interventions (phenylephrine and sodium nitroprusside), the baroreflex control of f(H) was studied at similar to 25 degrees C in spring-summer-and winter-acclimated tegus. In winter lizards, resting and minimum fH were lower than in spring-summer animals (respectively, 13.3 +/- 0.82 versus 10.3 +/- 0.81 and 11.2 +/- 0.65 versus 7.97 +/- 0.88 beats min(-1)), while no acclimation differences occurred in resting blood pressure (5.14 +/- 0.38 versus 5.06 +/- 0.56 kPa), baroreflex gain (94.3 +/- 10.7 versus 138.7 +/- 30.3% kPa(-1)) or rate-pressure product (an index ofmyocardial activity). Vagal tone exceeded the sympathetic tone of f(H), especially in the winter group. Therefore, despite the lower f(H), winter acclimation does not diminish the f(H) baroreflex responses or rate-pressure product, possibly because of increased stroke volume that may arise because of heart hypertrophy. Independent of acclimation, f(H) responded more to hypotension than to hypertension. This should imply that tegus, which have no pressure separation within the single heart ventricle, must have other protection mechanisms against pulmonary hypertension or oedema, presumably through lymphatic drainage and/or vagal vasoconstriction of pulmonary artery. Such a predominant f(H) reflex response to hypotension, previously observed in anurans, crocodilians and mammals, may be a common feature of tetrapods.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Sao Paulo State Univ, Dept Anim Morphol & Physiol, Coll Agr & Veterinarian Sci, BR-14884900 Sao Paulo, BrazilNatl Inst Sci & Technol Comparat Physiol INCT Fis, BR-14884900 Sao Paulo, BrazilSao Paulo State Univ, Inst Biosci, Dept Zool, BR-13506900 Sao Paulo, BrazilSao Paulo State Univ, Dept Anim Morphol & Physiol, Coll Agr & Veterinarian Sci, BR-14884900 Sao Paulo, BrazilSao Paulo State Univ, Inst Biosci, Dept Zool, BR-13506900 Sao Paulo, BrazilCNPq: 573921/2008-3FAPESP: 07/54113-0FAPESP: 09/00806-0FAPESP: 10/05063-2FAPESP: 12/17379-0Company Of Biologists LtdUniversidade Estadual Paulista (Unesp)Natl Inst Sci & Technol Comparat Physiol INCT FisZena, Lucas A. [UNESP]Dantonio, Valter [UNESP]Gargaglioni, Luciane H. [UNESP]Andrade, Denis V. [UNESP]Abe, Augusto S. [UNESP]Bicego, Kenia C. [UNESP]2018-11-26T16:27:45Z2018-11-26T16:27:45Z2016-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article725-733application/pdfhttp://dx.doi.org/10.1242/jeb.129130Journal Of Experimental Biology. Cambridge: Company Of Biologists Ltd, v. 219, n. 5, p. 725-733, 2016.0022-0949http://hdl.handle.net/11449/16124910.1242/jeb.129130WOS:000371134700021WOS000371134700021.pdfWeb of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengJournal Of Experimental Biology1,611info:eu-repo/semantics/openAccess2024-06-06T18:41:31Zoai:repositorio.unesp.br:11449/161249Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T15:41:43.577657Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
title Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
spellingShingle Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
Zena, Lucas A. [UNESP]
Adrenergic receptors
Baroreceptor
Blood pressure
Cholinergic tone
Hibernation
Seasonal changes
title_short Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
title_full Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
title_fullStr Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
title_full_unstemmed Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
title_sort Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae
author Zena, Lucas A. [UNESP]
author_facet Zena, Lucas A. [UNESP]
Dantonio, Valter [UNESP]
Gargaglioni, Luciane H. [UNESP]
Andrade, Denis V. [UNESP]
Abe, Augusto S. [UNESP]
Bicego, Kenia C. [UNESP]
author_role author
author2 Dantonio, Valter [UNESP]
Gargaglioni, Luciane H. [UNESP]
Andrade, Denis V. [UNESP]
Abe, Augusto S. [UNESP]
Bicego, Kenia C. [UNESP]
author2_role author
author
author
author
author
dc.contributor.none.fl_str_mv Universidade Estadual Paulista (Unesp)
Natl Inst Sci & Technol Comparat Physiol INCT Fis
dc.contributor.author.fl_str_mv Zena, Lucas A. [UNESP]
Dantonio, Valter [UNESP]
Gargaglioni, Luciane H. [UNESP]
Andrade, Denis V. [UNESP]
Abe, Augusto S. [UNESP]
Bicego, Kenia C. [UNESP]
dc.subject.por.fl_str_mv Adrenergic receptors
Baroreceptor
Blood pressure
Cholinergic tone
Hibernation
Seasonal changes
topic Adrenergic receptors
Baroreceptor
Blood pressure
Cholinergic tone
Hibernation
Seasonal changes
description Baroreflex regulation of blood pressure is important for maintaining appropriate tissue perfusion. Although temperature affects heart rate (f(H)) reflex regulation in some reptiles and toads, no data are available on the influence of temperature-independent metabolic states on baroreflex. The South American tegu lizard Salvator merianae exhibits a clear seasonal cycle of activity decreasing f(H) along with winter metabolic downregulation, independent of body temperature. Through pharmacological interventions (phenylephrine and sodium nitroprusside), the baroreflex control of f(H) was studied at similar to 25 degrees C in spring-summer-and winter-acclimated tegus. In winter lizards, resting and minimum fH were lower than in spring-summer animals (respectively, 13.3 +/- 0.82 versus 10.3 +/- 0.81 and 11.2 +/- 0.65 versus 7.97 +/- 0.88 beats min(-1)), while no acclimation differences occurred in resting blood pressure (5.14 +/- 0.38 versus 5.06 +/- 0.56 kPa), baroreflex gain (94.3 +/- 10.7 versus 138.7 +/- 30.3% kPa(-1)) or rate-pressure product (an index ofmyocardial activity). Vagal tone exceeded the sympathetic tone of f(H), especially in the winter group. Therefore, despite the lower f(H), winter acclimation does not diminish the f(H) baroreflex responses or rate-pressure product, possibly because of increased stroke volume that may arise because of heart hypertrophy. Independent of acclimation, f(H) responded more to hypotension than to hypertension. This should imply that tegus, which have no pressure separation within the single heart ventricle, must have other protection mechanisms against pulmonary hypertension or oedema, presumably through lymphatic drainage and/or vagal vasoconstriction of pulmonary artery. Such a predominant f(H) reflex response to hypotension, previously observed in anurans, crocodilians and mammals, may be a common feature of tetrapods.
publishDate 2016
dc.date.none.fl_str_mv 2016-03-01
2018-11-26T16:27:45Z
2018-11-26T16:27:45Z
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/10.1242/jeb.129130
Journal Of Experimental Biology. Cambridge: Company Of Biologists Ltd, v. 219, n. 5, p. 725-733, 2016.
0022-0949
http://hdl.handle.net/11449/161249
10.1242/jeb.129130
WOS:000371134700021
WOS000371134700021.pdf
url http://dx.doi.org/10.1242/jeb.129130
http://hdl.handle.net/11449/161249
identifier_str_mv Journal Of Experimental Biology. Cambridge: Company Of Biologists Ltd, v. 219, n. 5, p. 725-733, 2016.
0022-0949
10.1242/jeb.129130
WOS:000371134700021
WOS000371134700021.pdf
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Journal Of Experimental Biology
1,611
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 725-733
application/pdf
dc.publisher.none.fl_str_mv Company Of Biologists Ltd
publisher.none.fl_str_mv Company Of Biologists Ltd
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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