Estrogen modulates cardiac growth through an estrogen receptor alpha-dependent mechanism in healthy ovariectomized mice

Abstract

The modulation of cardiac growth by estrogen in healthy mice is not completely understood. The aim was to investigate the effects of estrogen on cardiac growth in healthy mice lacking either estrogen receptor (ER) alpha or beta. Wild-type (WT), ER alpha knockout (ERKO) and ER beta knockout (BERKO) 2-month-old mice were ovariectomized and randomly assigned to groups receiving an estradiol (E2)-containing or soy-free (control, CON) diet (n = 5-7/group). After three months of E2 administration, WT and BERKO mice had significantly lower body weight, higher relative uterus and heart weight than CON mice, while there was no major E2 effect in ERKO mice. Furthermore, there was a higher concentration of E2-responsive genes Igf1 and Myocd in WT and BERKO but not in ERKO mice. Together, these findings indicate that the estrogenic regulation of cardiac growth in healthy mice is primarily mediated through ER alpha and not ER beta. (C) 2013 Elsevier Ireland Ltd. All rights reserved.