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 ß-adrenergic receptor expression quantification. RESULTS: Echocardiography showed slight changes in morphology between OVX and SHAM groups. OVX group (Δ = 101 ±â€¯4.7 mmHg) showed higher values for maximal left intraventricular pressure in response to dobutamine, when compared to SHAM group (Δ = 55 ±â€¯11.8 mmHg). Both OVX-T (Δ = 70 ±â€¯4.0 mmHg) and SHAM-T (Δ = 22 ±â€¯6.6 mmHg) groups showed a reduction in this response. While, ß-adrenergic receptor expression was not different between the untrained groups, SHAM-T (0.23 ±â€¯0.02 AU) and OVX-T (0.29 ±â€¯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 ß-adrenergic receptors expression, influencing the cardiac contractility.