Abstract 507: Combined Exercise Training Induces Additional Cardiovascular Autonomic Benefits in Comparison to Dynamic Resistance Training in Ovariectomized Diabetic Rats
The purpose of this study was to compare the cardiovascular autonomic effects between dynamic aerobic, resistance and combined exercise training in ovariectomized diabetic female rats. Female Wistar rats (200-220g) were divided into 4 ovariectomized (bilateral ovaries removal) diabetic (streptozotocin, 50mg/kg, iv) groups: sedentary (DOS) and trained by an aerobic protocol on a treadmill (DOTA), by a resistance protocol in ladder (DOTR), or by a combined protocol in ladder+treadmill on alternate days (DOTC). After 8 weeks of training, the animals were cannulated to arterial pressure (AP) recording and baroreflex sensitivity (BS) evaluation. Heart rate (HR) and systolic AP variabilities were analyzed in the time and frequency domains. Exercise training induced an increase of 77% in the run capacity in the DOTA group (DOS: 8.6±0.6; DOTA: 15.3±0.4; DOTR: 11.5±1.6; DOTC: 15.0±0.2 min), 60% in the maximum load in DOTR group (DOS: 179.7±11.0; DOTA: 167.3±1.5; DOTR: 288.4±7.5; DOTC: 284.6±10.2 % of body weight), and increases in both exercise tests in DOTC (75% and 58%, respectively). All trained animals showed normalization of diabetic induced-resting hypotension and bradycardia, associated with increased HR variance (DOS: 39.6±2.6; DOTA: 71.2±7.2; DOTR: 70.9±12.1; DOTC: 65.7±6.1 ms2) and normalization of the LF band of pulse interval (DOS: 2.7±0.3; DOTA: 5.3±0.4; DOTR: 7.2±1.5; DOTC: 6.8±0.8 ms2) (vs. DOS). The DOTA and DOTC groups (but not DOTR) had higher BS (tachycardic and bradycardic responses), and attenuation in SAP variability (DOS: 7.4±0.8; DOTA: 12.7±1.1; DOTR: 8.9±1.0; DOTC: 13.3±1.0 mmHg2) in relation to DOS. Mortality was higher in DOS group when compared to trained group. In conclusion, the results showed that dynamic aerobic, resistance or combined exercise training induced benefits in physical capacity, hemodynamic and autonomic parameters after ovarian hormone deprivation in diabetic rats. However, the combined exercise training promoted additional effects than aerobic or resistance training in this condition.
- © 2013 by American Heart Association, Inc.