Background:Baroreceptors act as regulators of blood pressure (BP); however, its sensitivity is impaired in hypertensive patients. Among the recommendations for BP reduction, exercise training has become an important adjuvant therapy in this population. However, there are many doubts about the effects of resistance exercise training in this population.Objective:To evaluate the effect of resistance exercise training on BP and baroreceptor sensitivity in spontaneously hypertensive rats (SHR).Method:Rats SHR (n = 16) and Wistar (n = 16) at 8 weeks of age, at the beginning of the experiment, were randomly divided into 4 groups: sedentary control (CS, n = 8); trained control (CT, n = 8); sedentary SHR (HS, n = 8) and trained SHR (HT, n = 8). Resistance exercise training was performed in a stairmaster-type equipment (1.1 × 0.18 m, 2 cm between the steps, 80° incline) with weights attached to their tails, (5 days/week, 8 weeks). Baroreceptor reflex control of heart rate (HR) was tested by loading/unloading of baroreceptors with phenylephrine and sodium nitroprusside.Results:Resistance exercise training increased the soleus muscle mass in SHR when compared to HS (HS 0.027 ± 0.002 g/mm and HT 0.056 ± 0.003 g/mm). Resistance exercise training did not alter BP. On the other hand, in relation to baroreflex sensitivity, bradycardic response was improved in the TH group when compared to HS (HS -1.3 ± 0.1 bpm/mmHg and HT -2.6 ± 0.2 bpm/mmHg) although tachycardia response was not altered by resistance exercise (CS -3.3 ± 0.2 bpm/mmHg, CT -3.3 ± 0.1 bpm/mmHg, HS -1.47 ± 0.06 bpm/mmHg and HT -1.6 ± 0.1 bpm/mmHg).Conclusion:Resistance exercise training was able to promote improvements on baroreflex sensitivity of SHR rats, through the improvement of bradycardic response, despite not having reduced BP.

The activity of the ubiquitin proteasome system (UPS) and the level of oxidative stress contribute to the transition from compensated cardiac hypertrophy to heart failure in hypertension. Moreover, aerobic exercise training (AET) is an important therapy for the treatment of hypertension, but its effects on the UPS are not completely known. The aim of this study was to evaluate the effect of AET on UPS's activity and oxidative stress level in heart of spontaneously hypertensive rats (SHR). A total of 53 Wistar and SHR rats were randomly divided into sedentary and trained groups. The AET protocol was 5×/week in treadmill for 13 weeks. Exercise tolerance test, non-invasive blood pressure measurement, echocardiographic analyses, and left ventricle hemodynamics were performed during experimental period. The expression of ubiquitinated proteins, 4-hydroxynonenal (4-HNE), Akt, phospho-Akt(ser473), GSK3β, and phospho-GSK3β(ser9) were analyzed by western blotting. The evaluation of lipid hydroperoxide concentration was performed using the xylenol orange method, and the proteasomal chymotrypsin-like activity was measured by fluorimetric assay. Sedentary hypertensive group presented cardiac hypertrophy, unaltered expression of total Akt, phospho-Akt, total GSK3β and phospho-GSK3β, UPS hyperactivity, increased lipid hydroperoxidation as well as elevated expression of 4-HNE but normal cardiac function. In contrast, AET significantly increased exercise tolerance, decreased resting systolic blood pressure and heart rate in hypertensive animals. In addition, the AET increased phospho-Akt expression, decreased phospho-GSK3β, and did not alter the expression of total Akt, total GSK3β, and ubiquitinated proteins, however, significantly attenuated 4-HNE levels, lipid hydroperoxidation, and UPS's activity toward normotensive group levels. Our results provide evidence for the main effect of AET on attenuating cardiac ubiquitin proteasome hyperactivity and oxidative stress in SHR rats.

The metabolic syndrome (MetS) is a clinical manifestation strongly associated with cardiovascular disease, the main cause of death worldwide. In view of this scenario, many therapeutic proposals have appeared in order to optimize the treatment of individuals with MetS, including the practice of exercise training (ET) and the consumption of okra (O). The aim of the present study was to evaluate the effect of O consumption and/or ET in animals with MetS. In all, 32 male Zucker rats (fa/fa) at 10 weeks old were randomly distributed into four groups of 8 animals each: MetS, MetS+O, MetS+ET and MetS+ET+O, and 8 lean Zucker rats (fa/ +) comprised the control group. Okra was administered by orogastric gavage 2x/day (morning and night, 100 mg/kg), 5 days/week, for 6 weeks. The ET was performed on a treadmill 1x/day (afternoon), 5 days/week, 60 min/day, in an intensity of 70% of maximal capacity, for the same days of O treatment. It was found that, O consumption alone was able to promote improved insulin sensitivity (MetS 93.93 ± 8.54 mg/dL vs. MetS+O 69.95 ± 18.7 mg/dL, p ≤ 0.05, d = 1.65, CI = 50.32 −89.58, triglyceride reduction (MetS 492.9 ± 97.8 mg/dL vs. MetS+O 334.9 ± 98.0 mg/dL, p ≤ 0.05, d = 1.61, CI = 193.2–398.7). In addition, it promoted a reduction in systolic blood pressure (MetS 149.0 ± 9.3 mmHg vs. MetS+O 132.0 ± 11.4 mmHg, p ≤ 0.05, d = 1.63, CI = 120–140), prevented an increase in cardiac collagen (MetS 12.60 ± 2.08% vs. MetS+O 7.52 ± 0.77%, p ≤ 0.05, d = 3.24, CI = 6.56–8.49). When associated with ET, the results were similar. Thus, we conclude that O consumption combined or not with aerobic ET can have a protective effect on the cardiac tissue of rats with MetS.

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The complications of Metabolic Syndrome (MetS) include kidney disease, and most dialysis patients are diagnosed with MetS. The benefit of exercise training (ET) for MetS treatment is already well defined in the literature, but the antidiabetic and antihyperlipidemic benefits of okra (O) have been discovered only recently. The aim of this study was to evaluate the effects of O and/or ET supplementation on renal function and histology; serum urea and creatinine value; inflammation (IL-6, IL-10, TNF-α) and oxidative stress in renal tissue. For this, 32 Zucker rats (fa/fa) were randomly separated into four groups of 8 animals each: Metabolic Syndrome (MetS), MetS + Okra (MetS + O), MetS + Exercise Training (MetS + ET), and MetS + Exercise Training and Okra (MetS + ET + O), and 8 Zucker lean (fa/+) rats comprised the Control group (CTL). Okra was administered by orogastric gavage 2x/day (morning and night, 100 mg/kg) and ET performed on the treadmill, at moderate intensity, 1h/day, 5x/week for 6 weeks. Although the renal function was not altered, the animals with MetS showed greater fibrotic deposition accompanied by a worse stage of renal injury, in addition to increased kidney weight. Although all interventions were beneficial in reducing fibrosis, only ET combined with O was able to improve the degree of renal tissue impairment. ET improved the anti-inflammatory status and reduced nitrite levels, but the combination of ET and O was more beneficial as regards catalase activity. Okra consumption alone did not promote changes in inflammatory cytokines and oxidative stress in the kidney. In conclusion, ET combined or not with O seems to be beneficial in preventing the progression of renal disease when renal function is not yet altered.