Abstract 645: Aerobic Vs. Resistance Exercise Training In Ovariectomized Hypertensive Rats: Cardiovascular And Oxidative Stress Evaluations

Abstract

Hypertension becomes more prevalent in menopause women. Aerobic exercise has been indicated as a nonpharmacological treatment for hypertension, however the benefits of resistance exercise are not well know. The purpose of the present study was to investigate the effects of aerobic or resistance exercise training on cardiovascular autonomic control and oxidative stress profile in ovariectomized hypertensive rats. Female spontaneously hypertensive rats (SHR) were divided into 4 groups (n=8 each): sedentary (HS), sedentary ovariectomized(HSO), aerobic trained ovariectomized (HATO) and resistance trained ovoriectomized (HRTO). The moderate intensity aerobic training (AT) was performed on a treadmill (8 weeks) and the moderate intensity resistance exercise training (RT) was performed on a vertical ladder with weights attached to the rat tail (8 weeks). Arterial pressure (AP) and heart rate (HR) were directly recorded and baroreflex sensitivity was evaluated by bradycardic (BR) and tachycardic responses (TR). Oxidative stress was evaluated in cardiac tissue by chemiluminescence, the ratio of glutathione reductase/glutathione oxidized (GSSG-GSH) and superoxide dismutase (SOD) and glutathione peroxidase (GPx) antioxidant enzyme activities. The exercise training induced a reduction in mean AP in trained groups compared to sedentary groups. HR was similar between groups. The AT increased TR in relation to other groups (HATO:-2.74±0.15 vs. HRTO: -1.42±0.2, HSO: -1.4±0.17 e HS -1.91±0.2 bpm/mmHg).However, BR was improved in both HATO (-1.38±0.07 bpm/mmHg) and HRTO (-1.34±0.05 bpm/mmHg) in relation to HS and HSO groups (-1.12±0.1 and -1.01±0.09 bpm/mmHg). Lipid peroxidation was reduced in trained groups in relation to sedentary groups (HRTO: 3538±168 and HATO: 4485±310 vs. HSO: 6514±547 and HS: 6661±566 cps/mg prot). The ratio GSSG-GSH did not differ between groups, however GSSG was higher in HATO group as compared to other groups (HATO: 346±14.5 vs. HRTO: 260±12, HSO:271±12, HS:234±11 μmol/g tissue) and GSH was lower in HRTO group as compared to HATO (HRTO:19±2 vs. HATO: 26±0.7 μmol/g tissue). SOD increased in HRTO in relation to sedentary groups (HRTO: 16.86±0.56 vs. HS:11.47±0.41, HSO: 11.17±0.41 USOD/mg prot) and GPx was higher in HRTO in relation to HSO (HRTO: 60±2.8 vs. HSO: 38.5±1.67 nmol/min/mg prot). In conclusion, aerobic or resistance exercise training induced a reduction in AP, associated with attenuation of baroreflex dysfunction and improvement in oxidative profile in cardiac tissue in ovariectomized hypertensive rats, suggesting a positive role of these nonpharmacological approachs in the management of cardiovascular risk in hypertension after hormones deprivation. Financial Support: FAPESP(2011/16441-0, 2011/15828-9,2010/17188-4)