Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves
Main Author: | |
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Publication Date: | 2005 |
Other Authors: | , , |
Format: | Article |
Language: | eng |
Source: | Repositório Institucional da UFS |
Download full: | https://ri.ufs.br/handle/riufs/1732 |
Summary: | It has been reported that star fruit can lead to a fatal outcome in uremic patients. The intoxication syndrome consists of hiccups, mental confusion, dizziness, and vomiting. On the other hand, folk medicine uses teas and infusions of carambola leaves to treat headache, vomiting, cough, insomnia, and diabetes. This motivated us to determine if Averrhoa carambola can act on the contractility and automaticity of the guinea pig heart. We measured the atrial isometric force in stimulated left atria and determined the chronotropic changes in spontaneously beating right atria. The carambola leaf extracts (1.5 mg/ml) abolished the contractile force in a concentration-dependent manner. Among the crude, methanolic, ethanolic, aqueous, and acetic extracts, the aqueous one was the most potent (EC50 = 520 ± 94 µg/ml; flavonoids and tannins are the main constituents; Na+ and K+ contents in 1.0 mg/ml of aqueous extract were 0.12 ± 0.016 and 1.19 ± 0.15 mM, respectively). The aqueous extract abolished the positive Bowditch staircase phenomenon and reduced the inotropic response to CaCl2 (0.17-8.22 mM), events that are dependent on the cellular Ca2+ inward current. The adrenergic, muscarinic or opioid membrane receptors do not seem to participate in the mechanism of action of the cardioactive substance(s). In spontaneously beating atria, the aqueous extract promoted a negative chronotropic effect that was antagonized by 0.1 µM isoproterenol bitartrate. With this agonist, the EC50 of the aqueous extract increased from 133 ± 58 to 650 ± 100 µg/ml. These data regarding the effect of A. carambola on guinea pig atrial contractility and automaticity indicate an L-type Ca2+ channel blockade. |
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Vasconcelos, Carla Maria Lins deAraujo, Marcella Santos deSilva, Bagnolia Araujo daGarcia, Eduardo Antonio Conde2016-03-29T14:39:41Z2016-03-29T14:39:41Z2005-07VASCONCELOS, C. M. L. et al. Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 38, n. 7, jul. 2005. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000700015>. Acesso em: 29 mar. 2016.1414-431Xhttps://ri.ufs.br/handle/riufs/1732Creative Commons Attribution LicenseIt has been reported that star fruit can lead to a fatal outcome in uremic patients. The intoxication syndrome consists of hiccups, mental confusion, dizziness, and vomiting. On the other hand, folk medicine uses teas and infusions of carambola leaves to treat headache, vomiting, cough, insomnia, and diabetes. This motivated us to determine if Averrhoa carambola can act on the contractility and automaticity of the guinea pig heart. We measured the atrial isometric force in stimulated left atria and determined the chronotropic changes in spontaneously beating right atria. The carambola leaf extracts (1.5 mg/ml) abolished the contractile force in a concentration-dependent manner. Among the crude, methanolic, ethanolic, aqueous, and acetic extracts, the aqueous one was the most potent (EC50 = 520 ± 94 µg/ml; flavonoids and tannins are the main constituents; Na+ and K+ contents in 1.0 mg/ml of aqueous extract were 0.12 ± 0.016 and 1.19 ± 0.15 mM, respectively). The aqueous extract abolished the positive Bowditch staircase phenomenon and reduced the inotropic response to CaCl2 (0.17-8.22 mM), events that are dependent on the cellular Ca2+ inward current. The adrenergic, muscarinic or opioid membrane receptors do not seem to participate in the mechanism of action of the cardioactive substance(s). In spontaneously beating atria, the aqueous extract promoted a negative chronotropic effect that was antagonized by 0.1 µM isoproterenol bitartrate. With this agonist, the EC50 of the aqueous extract increased from 133 ± 58 to 650 ± 100 µg/ml. These data regarding the effect of A. carambola on guinea pig atrial contractility and automaticity indicate an L-type Ca2+ channel blockade.Associação Brasileira de Divulgação CientíficaAverrhoa carambola L.Star fruitInotropismInotropismoCronotropismoGuinea pig atriumÁtrio de cobaiaChronotropismCa2+ channel blockadeNegative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leavesinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleengreponame:Repositório Institucional da UFSinstname:Universidade Federal de Sergipe (UFS)instacron:UFSinfo:eu-repo/semantics/openAccessTHUMBNAILInotropicChronotropicEffects.pdf.jpgInotropicChronotropicEffects.pdf.jpgGenerated Thumbnailimage/jpeg1600https://ri.ufs.br/jspui/bitstream/riufs/1732/4/InotropicChronotropicEffects.pdf.jpg7c980919c1fe055b6c20ad2c30ee8b44MD54LICENSElicense.txtlicense.txttext/plain; charset=utf-81748https://ri.ufs.br/jspui/bitstream/riufs/1732/2/license.txt8a4605be74aa9ea9d79846c1fba20a33MD52ORIGINALInotropicChronotropicEffects.pdfInotropicChronotropicEffects.pdfapplication/pdf1341632https://ri.ufs.br/jspui/bitstream/riufs/1732/1/InotropicChronotropicEffects.pdfc0de7dac1680f05580b020cafd45a54dMD51TEXTInotropicChronotropicEffects.pdf.txtInotropicChronotropicEffects.pdf.txtExtracted texttext/plain34405https://ri.ufs.br/jspui/bitstream/riufs/1732/3/InotropicChronotropicEffects.pdf.txtcdef0c5e1f537517b963b24f3debb0c2MD53riufs/17322016-03-30 02:00:15.991oai:ufs.br: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Repositório InstitucionalPUBhttps://ri.ufs.br/oai/requestrepositorio@academico.ufs.bropendoar:2016-03-30T05:00:15Repositório Institucional da UFS - Universidade Federal de Sergipe (UFS)false |
dc.title.pt_BR.fl_str_mv |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves |
title |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves |
spellingShingle |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves Vasconcelos, Carla Maria Lins de Averrhoa carambola L. Star fruit Inotropism Inotropismo Cronotropismo Guinea pig atrium Átrio de cobaia Chronotropism Ca2+ channel blockade |
title_short |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves |
title_full |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves |
title_fullStr |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves |
title_full_unstemmed |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves |
title_sort |
Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves |
author |
Vasconcelos, Carla Maria Lins de |
author_facet |
Vasconcelos, Carla Maria Lins de Araujo, Marcella Santos de Silva, Bagnolia Araujo da Garcia, Eduardo Antonio Conde |
author_role |
author |
author2 |
Araujo, Marcella Santos de Silva, Bagnolia Araujo da Garcia, Eduardo Antonio Conde |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Vasconcelos, Carla Maria Lins de Araujo, Marcella Santos de Silva, Bagnolia Araujo da Garcia, Eduardo Antonio Conde |
dc.subject.por.fl_str_mv |
Averrhoa carambola L. Star fruit Inotropism Inotropismo Cronotropismo Guinea pig atrium Átrio de cobaia Chronotropism Ca2+ channel blockade |
topic |
Averrhoa carambola L. Star fruit Inotropism Inotropismo Cronotropismo Guinea pig atrium Átrio de cobaia Chronotropism Ca2+ channel blockade |
description |
It has been reported that star fruit can lead to a fatal outcome in uremic patients. The intoxication syndrome consists of hiccups, mental confusion, dizziness, and vomiting. On the other hand, folk medicine uses teas and infusions of carambola leaves to treat headache, vomiting, cough, insomnia, and diabetes. This motivated us to determine if Averrhoa carambola can act on the contractility and automaticity of the guinea pig heart. We measured the atrial isometric force in stimulated left atria and determined the chronotropic changes in spontaneously beating right atria. The carambola leaf extracts (1.5 mg/ml) abolished the contractile force in a concentration-dependent manner. Among the crude, methanolic, ethanolic, aqueous, and acetic extracts, the aqueous one was the most potent (EC50 = 520 ± 94 µg/ml; flavonoids and tannins are the main constituents; Na+ and K+ contents in 1.0 mg/ml of aqueous extract were 0.12 ± 0.016 and 1.19 ± 0.15 mM, respectively). The aqueous extract abolished the positive Bowditch staircase phenomenon and reduced the inotropic response to CaCl2 (0.17-8.22 mM), events that are dependent on the cellular Ca2+ inward current. The adrenergic, muscarinic or opioid membrane receptors do not seem to participate in the mechanism of action of the cardioactive substance(s). In spontaneously beating atria, the aqueous extract promoted a negative chronotropic effect that was antagonized by 0.1 µM isoproterenol bitartrate. With this agonist, the EC50 of the aqueous extract increased from 133 ± 58 to 650 ± 100 µg/ml. These data regarding the effect of A. carambola on guinea pig atrial contractility and automaticity indicate an L-type Ca2+ channel blockade. |
publishDate |
2005 |
dc.date.issued.fl_str_mv |
2005-07 |
dc.date.accessioned.fl_str_mv |
2016-03-29T14:39:41Z |
dc.date.available.fl_str_mv |
2016-03-29T14:39:41Z |
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.citation.fl_str_mv |
VASCONCELOS, C. M. L. et al. Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 38, n. 7, jul. 2005. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000700015>. Acesso em: 29 mar. 2016. |
dc.identifier.uri.fl_str_mv |
https://ri.ufs.br/handle/riufs/1732 |
dc.identifier.issn.none.fl_str_mv |
1414-431X |
dc.identifier.license.pt_BR.fl_str_mv |
Creative Commons Attribution License |
identifier_str_mv |
VASCONCELOS, C. M. L. et al. Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 38, n. 7, jul. 2005. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000700015>. Acesso em: 29 mar. 2016. 1414-431X Creative Commons Attribution License |
url |
https://ri.ufs.br/handle/riufs/1732 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Associação Brasileira de Divulgação Científica |
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Associação Brasileira de Divulgação Científica |
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Universidade Federal de Sergipe (UFS) |
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UFS |
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Repositório Institucional da UFS |
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