Myocardial contractility is preserved early but reduced late after ovariectomy in young female rats

Reproductive Biology and Endocrinology

Research

Dalton V Vassallo¹  Gabriel P Targueta¹  Ivanita Stefanon¹  Aurelia A Fernandes¹  Rogerio F Ribeiro Junior¹  Altemar S Paigel¹ 

[1] Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES, Brazil;

关键词: Sarcoplasmic Reticulum;    Myocardial Contractility;    Cardiac Contractility;    Inotropic Response;    Cardiac Sarcoplasmic Reticulum;   

DOI  :  10.1186/1477-7827-9-54

 received in 2011-01-03, accepted in 2011-04-23,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundOvarian sex hormones (OSHs) are implicated in cardiovascular function. It has been shown that OSHs play an important role in the long term regulation of cardiac sarcoplasmic reticulum (SR) function and contractility, although early effects of OSHs deprivation on myocardial contractility have not yet been determined. This study evaluated the early and late effects of OSHs deficiency on left ventricular contractility in rats after ovariectomy.MethodsYoung female Wistar rats were divided into 3 groups (n = 9-15): sham operated (Sham), ovariectomized (Ovx) and Ovx treated with estradiol (1 mg/kg, i.m., once a week) (Ovx+E2). After 7, 15, 30 and 60 days post Ovx, left ventricle papillary muscle was mounted for isometric tension recordings. The inotropic response to Ca2+ (0.62 to 3.75 mM) and isoproterenol (Iso 10-8 to 10-2 M) and contractility changes in response to rate changes (0.25 to 3 Hz) were assessed. Protein expression of SR Ca2+-ATPase (SERCA2a) and phospholamban (PLB) in the heart was also examined.ResultsThe positive inotropic response to Ca2+ and Iso at 7, 15, and 30 days after Ovx was preserved. However, at 60 days, the Ovx group had decreased myocardial contractility which was subsequently restored with E2 replacement. The reduction in SERCA2a and increase in PLB expression observed at 60 days after Ovx were restored with E2 replacement.ConclusionThis study demonstrated that myocardial contractility and expression of key Ca2+ handling proteins were preserved in the early phase and reduced at long-term during OSHs deprivation.

【 授权许可】

Unknown   
© Paigel et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.