Volume overload influence on hypertrophied myocardium function


Autoria(s): Cicogna, Antonio Carlos; Matsubara, Beatriz Bojikian; Matsubara, Luiz Shiguero; Okoshi, Katashi; Gut, Ana Lúcia; Padovani, Carlos Roberto; Meyer, M. M.; Okoshi, Marina Politi
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

20/05/2014

20/05/2014

01/11/2002

Resumo

The aim of this study was to demonstrate that hypertrophied cardiac muscle is more sensitive to volume-overload than normal cardiac muscle. We assessed the mechanical function of isolated left ventricular papillary muscle from male spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats (WKY) Submitted to volume overload caused by aortocaval fistula (ACF) for 30 days. Muscles were perfused with Krebs-Henseleit solution at 28degreesC and Studied isometrically at a Stimulation rate of 0.2 Hz. The ACF increased the right and left ventricular weight-to-body weight ratio in WKY rats; it also promoted right ventricular hypertrophy and further increased the basal hypertrophy in the left ventricle from SHR. The arterial systolic pressure was greater in SHR than in WKY rats, and decreased with ACF in both groups. Developed tension (DT) and maximum rate of DT (+dT/dt) were greater in the SHR-control than in the WKY-control (P<0.05); the time from peak tension to 50% relaxation (RT1/2) was similar in these animals. ACE did not change any parameters ill the SHR group and increased the resting tension in the WKY group. However, the significant difference observed between myocardial contraction performance in WKY-controls and SHR-controls disappeared when the SHR-ACF and WKY-controls were compared. Furthermore, RT1/2 increased significantly ill the SHR-ACF in relation to the WKY-controls. In conclusion, the data lead LIS to infer that volume-overload for 30 days promotes more mechanical functional changes in hypertrophied muscle than in normal cardiac muscle.

Formato

689-695

Identificador

http://dx.doi.org/10.1536/jhj.43.689

Japanese Heart Journal. Tokyo: Japan Heart Journal, Second Dept of Internal Med, v. 43, n. 6, p. 689-695, 2002.

0021-4868

http://hdl.handle.net/11449/37115

10.1536/jhj.43.689

WOS:000180562900011

WOS000180562900011.pdf

Idioma(s)

eng

Publicador

Japan Heart Journal, Second Dept of Internal Med

Relação

Japanese Heart Journal

Direitos

closedAccess

Palavras-Chave #spontaneously hypertensive rats #volume overload #myocardium function #isolated muscle
Tipo

info:eu-repo/semantics/article