Early ovarian hormone deprivation increases cardiac contractility in old female rats—Role of physical training

Objectives: We investigated the effects of early ovarian hormones deprivation on morphology and cardiac function and the effects of aerobic training on these parameters, in old rats. Methods: Female Wistar rats (N = 48) were divided into two groups, at 10 weeks of life: early ovarian hormones deprivation by ovariectomy (OVX; N = 24) and sham (SHAM; N = 24). Between weeks 62 and 82, 12 animals of each group underwent aerobic training (OVX-T and SHAM-T, N = 12). At the end of week 82, all were evaluated by echocardiography, cardiac function (Langendorff technique) and cardiac β-adrenergic receptor expression quantification. Results: Echocardiography showed slight changes in morphology between OVX and SHAM groups. OVX group (Δ = 101 ± 4.7 mmHg) showed higher values for maximal left intraventricular pressure in response to dobutamine, when compared to SHAM group (Δ = 55 ± 11.8 mmHg). Both OVX-T (Δ = 70 ± 4.0 mmHg) and SHAM-T (Δ = 22 ± 6.6 mmHg) groups showed a reduction in this response. While, β-adrenergic receptor expression was not different between the untrained groups, SHAM-T (0.23 ± 0.02 AU) and OVX-T (0.29 ± 0.01 AU), showed decreased expression of these receptors. Conclusion: Early ovarian hormones deprivation associated with aging, promotes discrete changes in cardiac morphology and increasing cardiac contractility. Aerobic training decreases β-adrenergic receptors expression, influencing the cardiac contractility.