Influence of ovariectomy in the right ventricular contractility in heart failure rats.
Arch Med Res
; 38(2): 170-5, 2007 Feb.
Article
em En
| MEDLINE
| ID: mdl-17227725
BACKGROUND: Clinical studies in postmenopausal women suggest that female hormones play an important role in maintaining healthy cardiovascular conditions. The objective of this study was to evaluate the influence of ovarian hormones in the right ventricle contractility in heart failure (HF) rats following myocardial infarction (MI). METHODS: Female Wistar rats were divided into four groups: healthy ovariectomized (OVX), ovariectomized with HF (OVX-HF), HF, and sham operated (SHAM). Ovariectomy was performed in 10-week-old rats, and MI was induced 1 week later. Eight weeks after MI, right ventricular (RV) performance was analyzed using RV strip preparations. RESULTS: Ovariectomy did not change the infarct size (HF: 42 +/- 3.5 vs. OVX-HF: 39 +/- 1.5%). In the presence of isoproterenol (ISO) and calcium, the isometric force was reduced in both HF groups. Ovariectomy did not modify the positive inotropic parameter in the control and in HF rats. Time to peak tension (TPT) was prolonged in both ovariectomized groups compared to SHAM (ISO 10(-7) M OVX: 125 +/- 12( *); SHAM: 81 +/- 4; HF: 87 +/- 4; OVX-HF: 102 +/- 6( *) msec, ( *)p <0.01 vs. SHAM), and relaxation time (RT) was prolonged in OVX (270 +/- 16( *) msec) and OVX-HF (241 +/- 10( *) msec) vs. SHAM (197 +/- 6 msec; ( *)p <0.01 vs. SHAM). CONCLUSIONS: We conclude that the absence of female ovarian hormones during nine weeks does not influence the right ventricle positive inotropic response, but it prolongs the time of contraction and relaxation in normal and in HF rats following MI.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Baixo Débito Cardíaco
/
Disfunção Ventricular Direita
/
Estrogênios
/
Contração Miocárdica
/
Infarto do Miocárdio
Tipo de estudo:
Etiology_studies
Limite:
Animals
Idioma:
En
Revista:
Arch Med Res
Assunto da revista:
MEDICINA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos