Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis
Autor(a) principal: | |
---|---|
Data de Publicação: | 1995 |
Outros Autores: | , , , , , |
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. |
id |
IMT-1_a2167b6a402bef911dec4e6625d4303a |
---|---|
oai_identifier_str |
oai:revistas.usp.br:article/29252 |
network_acronym_str |
IMT-1 |
network_name_str |
Revista do Instituto de Medicina Tropical de São Paulo |
repository_id_str |
|
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 |
_version_ |
1798951641134661632 |