Exercise induces the synthesis of estrogen in ovariectomized Sprague–Dawley rats ventricular myocardium trough increase expression of CYP19aromatase

摘要

Introduction Postmenopausal women have complex health problems related to hormonal status. Recently there are controversial issues about hormonal therapy for heart diseases. Another alternative to overcome heart disease in postmenopause is exercise. Several studies have reported that exercise can induce estrogen synthesis in the extragonadal organs. The aim of this study is to know the estrogen synthesis process by aromatization in the ventricular myocardium of ovariectomized rats after exercise.Methods The research design of this study was experimental with post-test only control group design for the tissue levels of estrogen and testosterone as well as CYP19aromatase and COX2 expression. The subjects of this study were 68 healthy female Sprague-Dawley rats aged 4–5 weeks given exercise using a rat treadmill for 12 weeks, 5×/week by graded exercise at 17–23 m/min for 10–60 min with 5–10% inclination. Tissue estrogen and testosterone levels were determined using ECLIA, and to determine CYP19aromatase and COX2 expression using IHC method.Results The ovariectomized and exercised groups lead to higher tissue estrogen levels (36.67 +- 9.23 compared to 24.56 +- 3.33 pg/dL), higher CYP19aromatase expression (44.43 +- 5.56 %) compared to group without exercise (34.09 +- 2.62 %), as well as COX2 47.34 +- 1.86 % compared to 32.02 + 2.81 %. No significant difference was found in tissue testosterone levels. We analyze the data with multiple regressions to determine the influence of these three variables. Tissue estrogen levels were predictable from CYP19aromatase and COX2 expression but not tissue testosterone levels. Multiple regressions r square showed that 51.2 % of the total variation in estrogen tissue levels could be accounted for by CYP19aromatase and COX2 expression.Conclusion The present study found that 12-week exercise with treadmill prevents ovariectomized-induced deterioration of ventricular myocardium estrogen levels of rats. It is likely that the beneficial effects of exercise were exerted through the increase of expression of CYP19aromatase and COX2 in ventricular myocardium ovariectomized rats. Nevertheless, the precise mechanisms by which exercise prevents deterioration of estrogen levels in ventricular myocardium, which have consequences in the prevention of heart disease, require further investigations. Exercise of postovariectomized rat leads to the ventricular myocardium estrogen synthesis through the increase of CYP19aromatase and COX2 expression.