Effects of swimming training and estrogen therapy on the vascular reactivity of hypertensive ovariectomized rats: role of renin angiotensin system (706.7)

Abstract

Effects of swimming training and estrogen therapy on the vascular reactivity of hypertensive ovariectomized rats: role of renin angiotensin system Glaucia R Abreu, Nazare S Bissoli, Ana Ligia R Carvalho, Erick Roberto C Gonçalves, Patrick W Endlich: Health Science Center, Federal University of Espirito Santo, Brazil Several studies showed up regulation of Renin Angiotensin System (RAS) after menopause and the ability of physical training in reduces cardiovascular risk factors. The aim of this study was to analyze the effects of swimming training (eight weeks) and estrogen therapy (5 mg of 17β‐Estradiol, s.c.) on vascular reactivity and the expression of RAS of aorta rings in ovariectomized spontaneously hypertensive rats (SHR). The groups were divided: Sham (S), Ovariectomized (OVX), ovariectomized (OTE2), ovariectomized+swimming ON) and ovariectomized treated with E2 plus swimming (OE2+N). The systolic blood pressure was measured after the animals were sacrificed and blood was collected to measure Angiotensin II plasma levels by radioimmunoassay. Aorta reactivity we evaluated in response to Ang II and Angiotensin‐(1‐7) and RAS proteins expression were made by Western Blotting method. Both exercise and E2 increased Ang II plasma levels. However, the systolic blood pressure was attenuated by treatments. The OVX group showed increase in the constrictor response to Ang II and decrease dilatator response to Ang (1‐7), that was reverted by swimming training or E2 therapy associated to swimming. Moreover, ON and OE2+N groups showed increase in the AT2 and Mas receptor expression. On the other hand, the ON showed increase in the superoxide dismutase (SOD) anti‐oxidant enzyme and only the groups treated with E2 showed increase on eNOS expression. Then both swimming training and E2 treatment may play a non‐additive, role in the cardioprotection and the chronic physical exercise can be a feasible alternative in relation to estrogen therapy in post‐menopausal women.Grant Funding Source: Capes;CNPq