Hypertension (H) is a multifactorial disease characterized by high and sustained levels of blood pressure (BP), classified as primary and secondary H. Dexamethasone (DEX) is a synthetic glucocorticoid with potent anti-allergic and anti-inflammatory effects and H is one of its unwanted side-effect. Spontaneously hypertensive rats (SHR) treated with DEX may have higher mortality risk due to H exacerbation. Microcirculation rarefaction is present in primary H (SHR) and in DEX induced H and is associated with angiogenic and apoptotic pathways alterations. More recently, miRNAs has being considered important in primary H genesis; however, its role in SHR treated with DEX has not yet being investigated. On the other hand, physical training (T) has been recommended crucial strategy to control hypertension. The aim of this study is to investigate if T is able to attenuate BP exacerbation in SHR treated with DEX and if this effect is associated with microcirculation miRNAs expression. Normotensive (Wistar) and hypertensive rats (SHR) will be submitted to eight weeks of T on a treadmill (60% of maximum physical capacity, 5 days a week, one hour per day) or kept sedentary. During 14 days, after eight weeks of T, animals will be treated with DEX (50µg/kg per day, s.c.) or saline. Body weight will be measured weekly during the T and daily during DEX treatment. Resting BP and arterial stiffness will be measured after DEX treatment. Subsequently, tibialis anterior muscle and left ventricle will be removed and processed for capillary density and capillary-to-fiber ratio, as well as, for VEGF, PI3K, eNOS, Bcl-2 and caspase-3-cleaved proteins production and miRNAs-16, -21, -126, -155, -205, -221 and -222 gene expression evaluations. Results will be presented as mean ± mean standard error. ANOVA two way and Tukey post-hoc will be performed for comparison among groups (p <0.05).
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