Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis

Detalhes bibliográficos
Autor(a) principal: Davila, Diego F.
Data de Publicação: 1995
Outros Autores: Gotterberg, Carlos F., Torres, Argenis, Holzhaker, Geza, Barrios, Richard, Ramoni, Paolo, Donis, José H.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Revista do Instituto de Medicina Tropical de São Paulo
Texto Completo: https://www.revistas.usp.br/rimtsp/article/view/29252
Resumo: To clarify the mechanism responsible for the transient sinus tachycardia in rats with acute chagasic myocarditis, we have examined the cardiac sympathetic-parasympathetic balance of 29 rats inoculated with 200,000 parasites (Trypanosoma cruzi). Sixteen infected animals and 8 controls were studied between days 18 and 21 after inoculation (acute stage). The remaining 13 infected animals and 9 controls were studied between days 60 and 70 after inoculation (sub-acute stage). Under anesthesia (urethane 1.25 g/kg), all animals received intravenous atenolol (5 mg/kg) and atropine (10 mg/kg). Acute stage: The baseline heart rate of the infected animals was significantly higher than that of the controls (P < 0.0001). The magnitude of the negative chronotropic response to atenolol was 4 times that of the controls (P < 0.00001). This response correlated with the baseline heart rate (r= - 0.72, P < 0.001). The heart rate responses to the beta-blocker and to atropine, of the infected animals studied during the sub-acute stage, were not different from controls. These findings suggest that cardiac sympathetic activity is transiently enhanced and cardiac parasympathetic activity is not impaired, in rats with acute chagasic myocarditis. The transient predominance of cardiac sympathetic activity could explain, in part, the sinus tachycardia observed in the acute stage of experimentally-induced chagasic myocarditis.
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spelling Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis O balanço autonômico cardíaco nas ratas com miocardite chagásica aguda experimental MyocarditisChagas diseaseCardiac Autonomic SystemAtropineBeta-Blockers To clarify the mechanism responsible for the transient sinus tachycardia in rats with acute chagasic myocarditis, we have examined the cardiac sympathetic-parasympathetic balance of 29 rats inoculated with 200,000 parasites (Trypanosoma cruzi). Sixteen infected animals and 8 controls were studied between days 18 and 21 after inoculation (acute stage). The remaining 13 infected animals and 9 controls were studied between days 60 and 70 after inoculation (sub-acute stage). Under anesthesia (urethane 1.25 g/kg), all animals received intravenous atenolol (5 mg/kg) and atropine (10 mg/kg). Acute stage: The baseline heart rate of the infected animals was significantly higher than that of the controls (P < 0.0001). The magnitude of the negative chronotropic response to atenolol was 4 times that of the controls (P < 0.00001). This response correlated with the baseline heart rate (r= - 0.72, P < 0.001). The heart rate responses to the beta-blocker and to atropine, of the infected animals studied during the sub-acute stage, were not different from controls. These findings suggest that cardiac sympathetic activity is transiently enhanced and cardiac parasympathetic activity is not impaired, in rats with acute chagasic myocarditis. The transient predominance of cardiac sympathetic activity could explain, in part, the sinus tachycardia observed in the acute stage of experimentally-induced chagasic myocarditis. Com a finalidade de pesquisar o mecanismo responsável pela taquicardia sinusal transitória que ocorre nas ratas com miocardite chagásica aguda, foi estudado o balanço autonômico cardíaco em 16 ratas inoculadas com Trypanosoma cruzi por via intraperitoneal. Oito animais foram estudados aos 18 e 21 dias após-inoculação (Estádio agudo); os oito animais restantes foram estudados entre os dias 60 a 70 após inoculação (Estádio sub-agudo). Todos os animais em estudo bem como os controles receberam atenolol e atropina. No estádio agudo, a frequência cardíaca basal dos animais infectados foi significativamente maior que a dos controles. A resposta cronotrópica negativa pela administração de atenolol foi quatro vezes maior nos animais infectados. No estádio sub-agudo, a frequência cardíaca basal e a resposta cronotrópica ao atenolol e atropina foi similar nos dois grupos do estudo. Os nossos resultados sugerem que no estádio agudo da miocardite chagásica experimental, a atividade simpática encontra-se periodicamente aumentada. Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo1995-04-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://www.revistas.usp.br/rimtsp/article/view/29252Revista do Instituto de Medicina Tropical de São Paulo; Vol. 37 No. 2 (1995); 155-159 Revista do Instituto de Medicina Tropical de São Paulo; Vol. 37 Núm. 2 (1995); 155-159 Revista do Instituto de Medicina Tropical de São Paulo; v. 37 n. 2 (1995); 155-159 1678-99460036-4665reponame:Revista do Instituto de Medicina Tropical de São Pauloinstname:Instituto de Medicina Tropical (IMT)instacron:IMTenghttps://www.revistas.usp.br/rimtsp/article/view/29252/31109Copyright (c) 2018 Revista do Instituto de Medicina Tropical de São Pauloinfo:eu-repo/semantics/openAccessDavila, Diego F.Gotterberg, Carlos F.Torres, ArgenisHolzhaker, GezaBarrios, RichardRamoni, PaoloDonis, José H.2012-07-02T01:39:57Zoai:revistas.usp.br:article/29252Revistahttp://www.revistas.usp.br/rimtsp/indexPUBhttps://www.revistas.usp.br/rimtsp/oai||revimtsp@usp.br1678-99460036-4665opendoar:2022-12-13T16:51:00.167954Revista do Instituto de Medicina Tropical de São Paulo - Instituto de Medicina Tropical (IMT)true
dc.title.none.fl_str_mv Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
O balanço autonômico cardíaco nas ratas com miocardite chagásica aguda experimental
title Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
spellingShingle Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
Davila, Diego F.
Myocarditis
Chagas disease
Cardiac Autonomic System
Atropine
Beta-Blockers
title_short Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
title_full Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
title_fullStr Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
title_full_unstemmed Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
title_sort Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
author Davila, Diego F.
author_facet Davila, Diego F.
Gotterberg, Carlos F.
Torres, Argenis
Holzhaker, Geza
Barrios, Richard
Ramoni, Paolo
Donis, José H.
author_role author
author2 Gotterberg, Carlos F.
Torres, Argenis
Holzhaker, Geza
Barrios, Richard
Ramoni, Paolo
Donis, José H.
author2_role author
author
author
author
author
author
dc.contributor.author.fl_str_mv Davila, Diego F.
Gotterberg, Carlos F.
Torres, Argenis
Holzhaker, Geza
Barrios, Richard
Ramoni, Paolo
Donis, José H.
dc.subject.por.fl_str_mv Myocarditis
Chagas disease
Cardiac Autonomic System
Atropine
Beta-Blockers
topic Myocarditis
Chagas disease
Cardiac Autonomic System
Atropine
Beta-Blockers
description To clarify the mechanism responsible for the transient sinus tachycardia in rats with acute chagasic myocarditis, we have examined the cardiac sympathetic-parasympathetic balance of 29 rats inoculated with 200,000 parasites (Trypanosoma cruzi). Sixteen infected animals and 8 controls were studied between days 18 and 21 after inoculation (acute stage). The remaining 13 infected animals and 9 controls were studied between days 60 and 70 after inoculation (sub-acute stage). Under anesthesia (urethane 1.25 g/kg), all animals received intravenous atenolol (5 mg/kg) and atropine (10 mg/kg). Acute stage: The baseline heart rate of the infected animals was significantly higher than that of the controls (P < 0.0001). The magnitude of the negative chronotropic response to atenolol was 4 times that of the controls (P < 0.00001). This response correlated with the baseline heart rate (r= - 0.72, P < 0.001). The heart rate responses to the beta-blocker and to atropine, of the infected animals studied during the sub-acute stage, were not different from controls. These findings suggest that cardiac sympathetic activity is transiently enhanced and cardiac parasympathetic activity is not impaired, in rats with acute chagasic myocarditis. The transient predominance of cardiac sympathetic activity could explain, in part, the sinus tachycardia observed in the acute stage of experimentally-induced chagasic myocarditis.
publishDate 1995
dc.date.none.fl_str_mv 1995-04-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://www.revistas.usp.br/rimtsp/article/view/29252
url https://www.revistas.usp.br/rimtsp/article/view/29252
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv https://www.revistas.usp.br/rimtsp/article/view/29252/31109
dc.rights.driver.fl_str_mv Copyright (c) 2018 Revista do Instituto de Medicina Tropical de São Paulo
info:eu-repo/semantics/openAccess
rights_invalid_str_mv Copyright (c) 2018 Revista do Instituto de Medicina Tropical de São Paulo
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo
publisher.none.fl_str_mv Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo
dc.source.none.fl_str_mv Revista do Instituto de Medicina Tropical de São Paulo; Vol. 37 No. 2 (1995); 155-159
Revista do Instituto de Medicina Tropical de São Paulo; Vol. 37 Núm. 2 (1995); 155-159
Revista do Instituto de Medicina Tropical de São Paulo; v. 37 n. 2 (1995); 155-159
1678-9946
0036-4665
reponame:Revista do Instituto de Medicina Tropical de São Paulo
instname:Instituto de Medicina Tropical (IMT)
instacron:IMT
instname_str Instituto de Medicina Tropical (IMT)
instacron_str IMT
institution IMT
reponame_str Revista do Instituto de Medicina Tropical de São Paulo
collection Revista do Instituto de Medicina Tropical de São Paulo
repository.name.fl_str_mv Revista do Instituto de Medicina Tropical de São Paulo - Instituto de Medicina Tropical (IMT)
repository.mail.fl_str_mv ||revimtsp@usp.br
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