Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats

Detalhes bibliográficos
Autor(a) principal: Rambo,Angela Mara
Data de Publicação: 2022
Outros Autores: Peixoto,João Victor Capelli, Albuquerque,Rebeca Alves Lins de, Silva,Ilana Kassouf, Fogaça,Rosalvo Tadeu Hochmueller
Tipo de documento: Artigo
Idioma: eng
Título da fonte: International Journal of Cardiovascular Sciences (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2359-56472022000400459
Resumo: Abstract Background: Hyperthyroidism (Hy) is an endocrine disorder, in which the thyroid hormones markedly alter the cardiac function. Increased myocardial contractility and cardiac output, improvement in diastolic relaxation, changes in electrical activity, increments in ventricular mass, and arrhythmias have been reported. However, the influences of thyroid hormones upon molecular mechanisms of cardiac functions have not yet been fully understood. Objectives: To evaluate changes in cardiac contractile parameters and the Na+/Ca2+ exchanger (NCX) function in induced hyperthyroid rats. Methods: Hy was induced by intraperitoneal injections of T3 (15 μg/100 g) for 10 days. Contractile parameters and NCX function were evaluated in the isolated papillary muscle. Data normality was confirmed by the Shapiro-Wilk test. The comparison between groups was performed through an unpaired Student’s t-test. Results are expressed as mean ± SD. The accepted significance level was p < 0.05. Results: Our data revealed, in the Hy group, an increase of 30.98% in the maximum speed of diastolic relaxation (–284.64 ± 70.70 vs. –217.31 ± 40.30 mN/mm2/sec (p = 0.027)) and a boost of 149% in the NCX function in late phase of relaxation (20.17 ± 7.90 vs. 50.22 ± 11.94 minutes (p = 0.002)), with no changes in the maximum twitch force (p = 0.605) or maximum speed of systolic contraction (p = 0.208) when compared to the control. Conclusion: The improvement in relaxation parameters is hypothetically attributed to an increase in Sarco-Endoplasmic Reticulum Ca2+ATPase isoform 2 (SERCA2) expression and an increased calcium flow through L-type channels that boosted the NCX function.
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spelling Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of RatsHyperthyroidismThyroid HormonesPapillary MusclesRatsSodium-Calcium ExchangerMyocardial ContractionAbstract Background: Hyperthyroidism (Hy) is an endocrine disorder, in which the thyroid hormones markedly alter the cardiac function. Increased myocardial contractility and cardiac output, improvement in diastolic relaxation, changes in electrical activity, increments in ventricular mass, and arrhythmias have been reported. However, the influences of thyroid hormones upon molecular mechanisms of cardiac functions have not yet been fully understood. Objectives: To evaluate changes in cardiac contractile parameters and the Na+/Ca2+ exchanger (NCX) function in induced hyperthyroid rats. Methods: Hy was induced by intraperitoneal injections of T3 (15 μg/100 g) for 10 days. Contractile parameters and NCX function were evaluated in the isolated papillary muscle. Data normality was confirmed by the Shapiro-Wilk test. The comparison between groups was performed through an unpaired Student’s t-test. Results are expressed as mean ± SD. The accepted significance level was p < 0.05. Results: Our data revealed, in the Hy group, an increase of 30.98% in the maximum speed of diastolic relaxation (–284.64 ± 70.70 vs. –217.31 ± 40.30 mN/mm2/sec (p = 0.027)) and a boost of 149% in the NCX function in late phase of relaxation (20.17 ± 7.90 vs. 50.22 ± 11.94 minutes (p = 0.002)), with no changes in the maximum twitch force (p = 0.605) or maximum speed of systolic contraction (p = 0.208) when compared to the control. Conclusion: The improvement in relaxation parameters is hypothetically attributed to an increase in Sarco-Endoplasmic Reticulum Ca2+ATPase isoform 2 (SERCA2) expression and an increased calcium flow through L-type channels that boosted the NCX function.Sociedade Brasileira de Cardiologia2022-08-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2359-56472022000400459International Journal of Cardiovascular Sciences v.35 n.4 2022reponame:International Journal of Cardiovascular Sciences (Online)instname:Sociedade Brasileira de Cardiologia (SBC)instacron:SBC10.36660/ijcs.20210023info:eu-repo/semantics/openAccessRambo,Angela MaraPeixoto,João Victor CapelliAlbuquerque,Rebeca Alves Lins deSilva,Ilana KassoufFogaça,Rosalvo Tadeu Hochmuellereng2022-08-01T00:00:00Zoai:scielo:S2359-56472022000400459Revistahttp://publicacoes.cardiol.br/portal/ijcshttps://old.scielo.br/oai/scielo-oai.phptailanerodrigues@cardiol.br||revistaijcs@cardiol.br2359-56472359-4802opendoar:2022-08-01T00:00International Journal of Cardiovascular Sciences (Online) - Sociedade Brasileira de Cardiologia (SBC)false
dc.title.none.fl_str_mv Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
title Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
spellingShingle Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
Rambo,Angela Mara
Hyperthyroidism
Thyroid Hormones
Papillary Muscles
Rats
Sodium-Calcium Exchanger
Myocardial Contraction
title_short Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
title_full Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
title_fullStr Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
title_full_unstemmed Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
title_sort Effects of Hyperthyroidism on Contractility and Na+/Ca2+ Exchanger Activity in the Isolated Papillary Muscle of Rats
author Rambo,Angela Mara
author_facet Rambo,Angela Mara
Peixoto,João Victor Capelli
Albuquerque,Rebeca Alves Lins de
Silva,Ilana Kassouf
Fogaça,Rosalvo Tadeu Hochmueller
author_role author
author2 Peixoto,João Victor Capelli
Albuquerque,Rebeca Alves Lins de
Silva,Ilana Kassouf
Fogaça,Rosalvo Tadeu Hochmueller
author2_role author
author
author
author
dc.contributor.author.fl_str_mv Rambo,Angela Mara
Peixoto,João Victor Capelli
Albuquerque,Rebeca Alves Lins de
Silva,Ilana Kassouf
Fogaça,Rosalvo Tadeu Hochmueller
dc.subject.por.fl_str_mv Hyperthyroidism
Thyroid Hormones
Papillary Muscles
Rats
Sodium-Calcium Exchanger
Myocardial Contraction
topic Hyperthyroidism
Thyroid Hormones
Papillary Muscles
Rats
Sodium-Calcium Exchanger
Myocardial Contraction
description Abstract Background: Hyperthyroidism (Hy) is an endocrine disorder, in which the thyroid hormones markedly alter the cardiac function. Increased myocardial contractility and cardiac output, improvement in diastolic relaxation, changes in electrical activity, increments in ventricular mass, and arrhythmias have been reported. However, the influences of thyroid hormones upon molecular mechanisms of cardiac functions have not yet been fully understood. Objectives: To evaluate changes in cardiac contractile parameters and the Na+/Ca2+ exchanger (NCX) function in induced hyperthyroid rats. Methods: Hy was induced by intraperitoneal injections of T3 (15 μg/100 g) for 10 days. Contractile parameters and NCX function were evaluated in the isolated papillary muscle. Data normality was confirmed by the Shapiro-Wilk test. The comparison between groups was performed through an unpaired Student’s t-test. Results are expressed as mean ± SD. The accepted significance level was p < 0.05. Results: Our data revealed, in the Hy group, an increase of 30.98% in the maximum speed of diastolic relaxation (–284.64 ± 70.70 vs. –217.31 ± 40.30 mN/mm2/sec (p = 0.027)) and a boost of 149% in the NCX function in late phase of relaxation (20.17 ± 7.90 vs. 50.22 ± 11.94 minutes (p = 0.002)), with no changes in the maximum twitch force (p = 0.605) or maximum speed of systolic contraction (p = 0.208) when compared to the control. Conclusion: The improvement in relaxation parameters is hypothetically attributed to an increase in Sarco-Endoplasmic Reticulum Ca2+ATPase isoform 2 (SERCA2) expression and an increased calcium flow through L-type channels that boosted the NCX function.
publishDate 2022
dc.date.none.fl_str_mv 2022-08-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2359-56472022000400459
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2359-56472022000400459
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.36660/ijcs.20210023
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Sociedade Brasileira de Cardiologia
publisher.none.fl_str_mv Sociedade Brasileira de Cardiologia
dc.source.none.fl_str_mv International Journal of Cardiovascular Sciences v.35 n.4 2022
reponame:International Journal of Cardiovascular Sciences (Online)
instname:Sociedade Brasileira de Cardiologia (SBC)
instacron:SBC
instname_str Sociedade Brasileira de Cardiologia (SBC)
instacron_str SBC
institution SBC
reponame_str International Journal of Cardiovascular Sciences (Online)
collection International Journal of Cardiovascular Sciences (Online)
repository.name.fl_str_mv International Journal of Cardiovascular Sciences (Online) - Sociedade Brasileira de Cardiologia (SBC)
repository.mail.fl_str_mv tailanerodrigues@cardiol.br||revistaijcs@cardiol.br
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