The rate of force generation by the myocardium is not influenced by afterload
Autor(a) principal: | |
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Data de Publicação: | 1997 |
Outros Autores: | , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1590/S0100-879X1997001200015 http://hdl.handle.net/11449/28054 |
Resumo: | The influence of afterload on the rate of force generation by the myocardium was investigated using two types of preparations: the in situ dog heart (dP/dt) and isolated papillary muscle of rats (dT/dt). Thirteen anesthetized, mechanically ventilated and thoracotomized dogs were submitted to pharmacological autonomic blockade (3.0 mg/kg oxprenolol plus 0.5 mg/kg atropine). A reservoir connected to the left atrium permitted the control of left ventricular end-diastolic pressure (LVEDP). A mechanical constriction of the descending thoracic aorta allowed to increase the systolic pressure in two steps of 20 mmHg (conditions H1 and H2) above control values (condition C). After arterial pressure elevations (systolic pressure C: 119 ± 8.1; H1: 142 ± 7.9; H2 166 ± 7.7 mmHg; P<0.01), there were no significant differences in heart rate (C: 125 ± 13.9; H1: 125 ± 13.5; H2: 123 ± 14.1 bpm; P>0.05) or LVEDP (C: 6.2 ± 2.48; H1: 6.3 ± 2.43; H2: 6.1 ± 2.51 mmHg; P>0.05). The values of dP/dt did not change after each elevation of arterial pressure (C: 3,068 ± 1,057; H1: 3,112 ± 996; H2: 3,086 ± 980 mmHg/s; P>0.05). In isolated rat papillary muscle, an afterload corresponding to 50% and 75% of the maximal developed tension did not alter the values of the maximum rate of tension development (100%: 78 ± 13; 75%: 80 ± 13; 50%: 79 ± 11 g mm-2 s-1, P>0.05). The results show that the rise in afterload per se does not cause changes in dP/dt or dT/dt |
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Repositório Institucional da UNESP |
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The rate of force generation by the myocardium is not influenced by afterloadventricular functionafterloaddP/dtdT/dtpapillary muscleisometric contractionsThe influence of afterload on the rate of force generation by the myocardium was investigated using two types of preparations: the in situ dog heart (dP/dt) and isolated papillary muscle of rats (dT/dt). Thirteen anesthetized, mechanically ventilated and thoracotomized dogs were submitted to pharmacological autonomic blockade (3.0 mg/kg oxprenolol plus 0.5 mg/kg atropine). A reservoir connected to the left atrium permitted the control of left ventricular end-diastolic pressure (LVEDP). A mechanical constriction of the descending thoracic aorta allowed to increase the systolic pressure in two steps of 20 mmHg (conditions H1 and H2) above control values (condition C). After arterial pressure elevations (systolic pressure C: 119 ± 8.1; H1: 142 ± 7.9; H2 166 ± 7.7 mmHg; P<0.01), there were no significant differences in heart rate (C: 125 ± 13.9; H1: 125 ± 13.5; H2: 123 ± 14.1 bpm; P>0.05) or LVEDP (C: 6.2 ± 2.48; H1: 6.3 ± 2.43; H2: 6.1 ± 2.51 mmHg; P>0.05). The values of dP/dt did not change after each elevation of arterial pressure (C: 3,068 ± 1,057; H1: 3,112 ± 996; H2: 3,086 ± 980 mmHg/s; P>0.05). In isolated rat papillary muscle, an afterload corresponding to 50% and 75% of the maximal developed tension did not alter the values of the maximum rate of tension development (100%: 78 ± 13; 75%: 80 ± 13; 50%: 79 ± 11 g mm-2 s-1, P>0.05). The results show that the rise in afterload per se does not cause changes in dP/dt or dT/dtA01Universidade Estadual PaulistaUniversidade Estadual PaulistaAssociação Brasileira de Divulgação Científica (ABRADIC)Universidade Estadual Paulista (Unesp)Fioretto, J.R.Okoshi, M.P. [UNESP]Okoshi, Katashi [UNESP]Cicogna, A.C. [UNESP]Bonatto, R.C.Padovani, C.R. [UNESP]Tucci, P.J.F. [UNESP]2014-05-20T15:11:30Z2014-05-20T15:11:30Z1997-12-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article1471-1477application/pdfhttp://dx.doi.org/10.1590/S0100-879X1997001200015Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 30, n. 12, p. 1471-1477, 1997.0100-879Xhttp://hdl.handle.net/11449/2805410.1590/S0100-879X1997001200015S0100-879X1997001200015S0100-879X1997001200015.pdf44631386719984321590971576309420941897010356413702463913032413760000-0002-0648-876XSciELOreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengBrazilian Journal of Medical and Biological Research1.492info:eu-repo/semantics/openAccess2023-12-18T06:14:44Zoai:repositorio.unesp.br:11449/28054Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462023-12-18T06:14:44Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
The rate of force generation by the myocardium is not influenced by afterload |
title |
The rate of force generation by the myocardium is not influenced by afterload |
spellingShingle |
The rate of force generation by the myocardium is not influenced by afterload Fioretto, J.R. ventricular function afterload dP/dt dT/dt papillary muscle isometric contractions |
title_short |
The rate of force generation by the myocardium is not influenced by afterload |
title_full |
The rate of force generation by the myocardium is not influenced by afterload |
title_fullStr |
The rate of force generation by the myocardium is not influenced by afterload |
title_full_unstemmed |
The rate of force generation by the myocardium is not influenced by afterload |
title_sort |
The rate of force generation by the myocardium is not influenced by afterload |
author |
Fioretto, J.R. |
author_facet |
Fioretto, J.R. Okoshi, M.P. [UNESP] Okoshi, Katashi [UNESP] Cicogna, A.C. [UNESP] Bonatto, R.C. Padovani, C.R. [UNESP] Tucci, P.J.F. [UNESP] |
author_role |
author |
author2 |
Okoshi, M.P. [UNESP] Okoshi, Katashi [UNESP] Cicogna, A.C. [UNESP] Bonatto, R.C. Padovani, C.R. [UNESP] Tucci, P.J.F. [UNESP] |
author2_role |
author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Fioretto, J.R. Okoshi, M.P. [UNESP] Okoshi, Katashi [UNESP] Cicogna, A.C. [UNESP] Bonatto, R.C. Padovani, C.R. [UNESP] Tucci, P.J.F. [UNESP] |
dc.subject.por.fl_str_mv |
ventricular function afterload dP/dt dT/dt papillary muscle isometric contractions |
topic |
ventricular function afterload dP/dt dT/dt papillary muscle isometric contractions |
description |
The influence of afterload on the rate of force generation by the myocardium was investigated using two types of preparations: the in situ dog heart (dP/dt) and isolated papillary muscle of rats (dT/dt). Thirteen anesthetized, mechanically ventilated and thoracotomized dogs were submitted to pharmacological autonomic blockade (3.0 mg/kg oxprenolol plus 0.5 mg/kg atropine). A reservoir connected to the left atrium permitted the control of left ventricular end-diastolic pressure (LVEDP). A mechanical constriction of the descending thoracic aorta allowed to increase the systolic pressure in two steps of 20 mmHg (conditions H1 and H2) above control values (condition C). After arterial pressure elevations (systolic pressure C: 119 ± 8.1; H1: 142 ± 7.9; H2 166 ± 7.7 mmHg; P<0.01), there were no significant differences in heart rate (C: 125 ± 13.9; H1: 125 ± 13.5; H2: 123 ± 14.1 bpm; P>0.05) or LVEDP (C: 6.2 ± 2.48; H1: 6.3 ± 2.43; H2: 6.1 ± 2.51 mmHg; P>0.05). The values of dP/dt did not change after each elevation of arterial pressure (C: 3,068 ± 1,057; H1: 3,112 ± 996; H2: 3,086 ± 980 mmHg/s; P>0.05). In isolated rat papillary muscle, an afterload corresponding to 50% and 75% of the maximal developed tension did not alter the values of the maximum rate of tension development (100%: 78 ± 13; 75%: 80 ± 13; 50%: 79 ± 11 g mm-2 s-1, P>0.05). The results show that the rise in afterload per se does not cause changes in dP/dt or dT/dt |
publishDate |
1997 |
dc.date.none.fl_str_mv |
1997-12-01 2014-05-20T15:11:30Z 2014-05-20T15:11:30Z |
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/10.1590/S0100-879X1997001200015 Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 30, n. 12, p. 1471-1477, 1997. 0100-879X http://hdl.handle.net/11449/28054 10.1590/S0100-879X1997001200015 S0100-879X1997001200015 S0100-879X1997001200015.pdf 4463138671998432 1590971576309420 9418970103564137 0246391303241376 0000-0002-0648-876X |
url |
http://dx.doi.org/10.1590/S0100-879X1997001200015 http://hdl.handle.net/11449/28054 |
identifier_str_mv |
Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 30, n. 12, p. 1471-1477, 1997. 0100-879X 10.1590/S0100-879X1997001200015 S0100-879X1997001200015 S0100-879X1997001200015.pdf 4463138671998432 1590971576309420 9418970103564137 0246391303241376 0000-0002-0648-876X |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Brazilian Journal of Medical and Biological Research 1.492 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
1471-1477 application/pdf |
dc.publisher.none.fl_str_mv |
Associação Brasileira de Divulgação Científica (ABRADIC) |
publisher.none.fl_str_mv |
Associação Brasileira de Divulgação Científica (ABRADIC) |
dc.source.none.fl_str_mv |
SciELO 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 |
|
_version_ |
1803047001228574720 |