ABSTRACT
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 (Nâ¯=â¯48) were divided into two groups, at 10â¯weeks of life: early ovarian hormones deprivation by ovariectomy (OVX; Nâ¯=â¯24) and sham (SHAM; Nâ¯=â¯24). Between weeks 62 and 82, 12 animals of each group underwent aerobic training (OVX-T and SHAM-T, Nâ¯=â¯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 (Δâ¯=â¯101⯱â¯4.7â¯mmHg) showed higher values for maximal left intraventricular pressure in response to dobutamine, when compared to SHAM group (Δâ¯=â¯55⯱â¯11.8â¯mmHg). Both OVX-T (Δâ¯=â¯70⯱â¯4.0â¯mmHg) and SHAM-T (Δâ¯=â¯22⯱â¯6.6â¯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¯0.02â¯AU) and OVX-T (0.29⯱â¯0.01â¯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.