| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
Effect of angiotensin-(1-7) on reperfusion arrhythmias in isolated rat hearts
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| Data: |
1997-06-01
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| Ano: |
1997
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| Palavras-chave: |
Renin-angiotensin system
Reperfusion arrhythmias
Angiotensin-(1-7)
Coronary flow
Isolated heart
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| Resumo: |
There is increasing evidence that angiotensin-(1-7) (Ang-(1-7)) is an endogenous biologically active component of the renin-angiotensin system (RAS). In the present study, we investigated the effects of Ang-(1-7) on reperfusion arrhythmias in isolated rat hearts. Isolated rat hearts were perfused with two different media, i.e., Krebs-Ringer (2.52 mM CaCl2) and low-Ca2+ Krebs-Ringer (1.12 mM CaCl2). In hearts perfused with Krebs-Ringer, Ang-(1-7) produced a concentration-dependent (27-210 nM) reduction in coronary flow (25% reduction at highest concentration), while only slight and variable changes in contraction force and heart rate were observed. Under the same conditions, angiotensin II (Ang II; 27 and 70 nM) produced a significant reduction in coronary flow (39% and 48%, respectively) associated with a significant increase in force. A decrease in heart rate was also observed. In low-Ca2+ Krebs-Ringer solution, perfusion with Ang-(1-7) or Ang II at 27 nM concentration produced similar changes in coronary flow, contraction force and heart rate. In isolated hearts perfused with normal Krebs-Ringer, Ang-(1-7) produced a significant enhancement of reperfusion arrhythmias revealed by an increase in the incidence and duration of ventricular tachycardia and ventricular fibrillation (more than 30-min duration). The facilitation of reperfusion arrhythmias by Ang-(1-7) was associated with an increase in the magnitude of the decreased force usually observed during the post-ischemic period. The effects of Ang-(1-7) were abolished in isolated rat hearts perfused with low-Ca2+ Krebs-Ringer. The effect of Ang II (27 nM) was similar but less pronounced than that of Ang-(1-7) at the same concentration. These results indicate that the heart is a site of action for Ang-(1-7) and suggest that this heptapeptide may be involved in the mediation of the cardiac effects of the RAS
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| Tipo: |
Info:eu-repo/semantics/other
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000600016
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X1997000600016
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.30 n.6 1997
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| Direitos: |
info:eu-repo/semantics/openAccess
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