title: Cardioprotection in female rats subjected to chronic volume overload: synergistic interaction of estrogen and phytoestrogens.
abstract: Intact female rats fed a high-phytoestrogen diet are protected against adverse left ventricular (LV) remodeling induced by chronic volume overload. We hypothesized that both phytoestrogens and ovarian hormones, particularly estrogen, are necessary for this dietary-induced cardioprotection. To test this hypothesis, eight groups of female rats were studied; rats were fed either a high-phytoestrogen (+phyto) or phytoestrogen-free diet. Groups included sham-operated rats, intact rats with fistula (Fist), ovariectomized rats with fistula (Fist-OX), and Fist-OX rats treated with estrogen (EST). Myocardial function and remodeling were assessed after 8 wk of volume overload using a blood-perfused isolated heart apparatus. Fist-OX rats developed significant ventricular dilatation and increased compliance vs. intact Fist rats, which were associated with a significant decrease in contractility. Estrogen treatment prevented pulmonary edema and attenuated LV hypertrophy and dilatation but did not maintain contractility. However, dietary phytoestrogens completely prevented LV dilatation in both the Fist+phyto and Fist-OX+EST+phyto groups but had no effect on LV remodeling in the Fist-OX+phyto group. Contractility was significantly greater in the estrogen-treated rats fed the phytoestrogen diet than in those treated with estrogen alone. Dietary phytoestrogens did not affect LV or uterine mass, serum estrogen, LV estrogen receptor expression, or cardiac function in sham animals. These data indicate that estrogen is not solely responsible for the cardioprotection exhibited by intact females and that phytoestrogens can work synergistically with ovarian hormones to attenuate ventricular remodeling induced by chronic volume overload in female rats.
authors.affiliation: Department of Cell and Developmental Bioloogy and Anatomy, University of South Carolina School of Medicine, Columbia, SC 29208, USA. jgardner@gw.med.sc.edu
authors.forename: Jason D
authors.initials: JD
authors.lastname: Gardner
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Brower
authors.forename: Tetyana G
authors.initials: TG
authors.lastname: Voloshenyuk
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Janicki
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D001166:Arteriovenous Shunt, Surgical; D002302:Cardiac Output / Q000187:drug effects; D006332:Cardiomegaly / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D002908:Chronic Disease; D004032:Diet; D004195:Disease Models, Animal; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000008:administration & dosage / Q000378:metabolism*; D005260:Female; D006333:Heart Failure / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D009200:Myocardial Contraction / Q000187:drug effects; D010052:Ovariectomy; D048789:Phytoestrogens / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014684:Venae Cavae / Q000601:surgery; D016277:Ventricular Function, Left / Q000187:drug effects*; D017725:Ventricular Pressure / Q000187:drug effects; D020257:Ventricular Remodeling / Q000187:drug effects
chemical_list: D004967:Estrogens; D048789:Phytoestrogens