An Exploratory Study on Two Exogenous Estrogenic Metabolites (EDMs): Their Effects In Vitro and on Oophorectomized...

Background: For a long time, it was thought that estrogen degradation metabolites (EDMs) had no role in the female body, but this view has changed. Despite the progress, there are still unknowns about EDMs and the heart. We found that EDMs affect isolated cardiac mitochondria, which may impact heart function. Therefore, our objective was to explore the effect of two EDMs, Met A (2-hydroxyestrone) and Met D (17β-estradiol-3-methyl-ether), on two experimental models: rat H9c2 cardiomyoblast cells exposed for increasing times to different concentrations of each EDM, and, also, the effects of each metabolite on heart function in intact and oophorectomized (Oopho) rats. Methods: The cell viability, mitochondrial potential, and oxidative stress were assayed in H9c2 cells. Echocardiographic analyses, histological analyses, and an assessment of cardiac damage and oxidative stress in intact and Oopho rats were tested. Results: The strongest negative effects were seen with Met D, where antioxidant capacity decreased and oxidative stress increased significantly. Upon further analysis of the effects of each metabolite on heart function, echocardiographic analysis revealed that cardiac function had not changed in either group, although clear signs of cardiac hypertrophy and fibrosis were observed. Conclusions: Our results suggest EDMs have specific effects on female rats. This study emphasizes the need to thoroughly investigate EDMs' side effects and impact on the heart.