Swimming Exercise Ameliorates Elevated Blood Pressure and Vascular Endothelial Dysfunction in Old Rats

摘要

Background and Aim: Advancing age increases the risk of cardiovascular diseases, resulting in higher rates of morbidity and mortality. We tested the hypothesis that habitual swimming exercise would reverse age-related systolic hypertension, vascular dysfunction, hyperactivity of sympathetic nervous system, dyslipidemia, and oxidative stress. Methods: Thirty male Wistar albino rats were used in the present study. Rats were divided (10/group) into young (3-4 months), old sedentary (22-24 months), and old exercised (6 weeks swimming protocol) rats. Systolic blood pressure (SBP), endothelial function, sensitivity of sympathetic nervous system, and renal artery Doppler flowmetry were evaluated. Serum lipids, renal biomarkers and oxidant-antioxidant status were assessed.Results: SBP was significantly higher (100 ± 4.83 vs 80 ± 3.34 mmHg) in old sedentary when compared to young rats, and was associated with reduced endothelial-dependent dilation (EDD), increased sympathetic adrenergic vasoconstriction, dyslipidemia, reduced renal artery blood flow velocity (RBFV), and increased renal artery resistance (RAR). Swimming exercise restored SBP, EDD, sympathetic adrenergic vasoconstriction, serum lipids, RBFV, RAR, to levels almost comparable to young rats. Swimming increased significantly total antioxidant capacity in old exercised rats (2.37 ± 0.33 vs. 1.92 ± 0.44 mM /L), while serum malondialdhyde was decreased (2.58 ± 0.23 vs. 4.42 ± 0.14 ηM/L), when compared to old sedentary rats. All results were statistically significant (p < 0.05).Conclusion: We report here that habitual swimming ameliorates age-dependent systolic hypertension and endothelial dysfunction possibly by anti-oxidant mechanism.