| Texto completo | |
| Autor(es): Mostrar menos - |
Becari, Christiane
;
Durand, Marina T.
;
Guimaraes, Alessander O.
;
Lataro, Renata M.
;
Prado, Cibele M.
;
de Oliveira, Mauro
;
Candido, Sarai C. O.
;
Pais, Paloma
;
Ribeiro, Mauricio S.
;
Bader, Michael
;
Pesquero, Joao B.
;
Salgado, Maria C. O.
;
Salgado, Helio C.
Número total de Autores: 13
|
| Tipo de documento: | Artigo Científico |
| Fonte: | FRONTIERS IN PHYSIOLOGY; v. 8, MAR 23 2017. |
| Citações Web of Science: | 2 |
| Resumo | |
In vitro and ex vivo experiments indicate that elastase-2 (ELA-2), a chymotrypsin-serine protease elastase family member 2A, is an alternative pathway for angiotensin II (Ang II) generation. However, the role played by ELA-2 in vivo is unclear. We examined ELA-2 knockout (ELA-2K0) mice compared to wild-type (WT) mice and determined whether ELA-2 played a role in hemodynamics {[}arterial pressure (AP) and heart rate (HR)], cardiocirculatory sympathovagal balance and baroreflex sensitivity. The variability of systolic arterial pressure (SAP) and pulse interval (PI) for evaluating autonomic modulation was examined for time and frequency domains (spectral analysis), whereas a symbolic analysis was also used to evaluate PI variability. In addition, baroreflex sensitivity was examined using the sequence method. Cardiac function was evaluated echocardiographically under anesthesia. The AP was normal whereas the HR was reduced in ELA-2K0 mice (425 +/- 17 vs. 512 +/- 13 bpm from WT). SAP variability and baroreflex sensitivity were similar in both strains. The LF power from the PI spectrum (33.6 +/- 5 vs. 51.8 +/- 4.8 nu from WT) and the LF/HF ratio (0.60 +/- 0.1 vs. 1.45 +/- 0.3 from WT) were reduced, whereas the HF power was increased (66.4 +/- 5 vs. 48.2 +/- 4.8 nu from WI) in ELA-2K0 mice, indicating a shift toward parasympathetic modulation of HR. Echocardiographic examination showed normal fractional shortening and an ejection fraction in ELA-2K0 mice; however, the cardiac output, stroke volume, and ventricular size were reduced. These findings provide the first evidence that ELA-2 acts on the sympathovagal balance of the heart, as expressed by the reduced sympathetic modulation of HR in ELA-2K0 mice. (AU) | |
| Processo FAPESP: | 09/50548-7 - Caracterizacao da elastase-2, enzima formadora de angiotensina ii, em camundongos. |
| Beneficiário: | Christiane Becari |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 13/20549-7 - Avanços na regulação cardiocirculatória em condições fisiológica e fisiopatológica |
| Beneficiário: | Helio Cesar Salgado |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |