Shimojo G L, Palma R K, Brito J O, Sanches I C, Irigoyen M C, De Angelis K
Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP, Brasil.
Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil.
Braz J Med Biol Res. 2015 Jun;48(6):523-7. doi: 10.1590/1414-431X20154387. Epub 2015 Mar 27.
The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks) at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR) responses to methylatropine (3 mg/kg, iv) and propranolol (4 mg/kg, iv). Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated with decreased vagal tone. Resistance exercise trained rats had lower mean arterial pressure than untrained rats (RTHO: 159±2.2 vs SHO: 177±3.4 mmHg), as well as resting bradycardia (RTHO: 332±9.0 vs SHO: 356±5 bpm). Sympathetic tone was also lower in the trained group. Moreover, sympathetic tone was positively correlated with resting HR (r=0.7, P<0.05). The additional arterial pressure increase in hypertensive rats caused by ovarian hormone deprivation was attenuated by moderate-intensity dynamic resistance training. This benefit may be associated with resting bradycardia and reduced cardiac sympathetic tone after training, which suggests potential benefits of resistance exercise for the management of hypertension after ovarian hormone deprivation.
本研究旨在探讨抗阻运动训练对去卵巢自发性高血压大鼠血流动力学和心脏自主神经控制的影响。雌性大鼠分为4组：久坐对照组（SC）、久坐高血压组（SH）、久坐高血压去卵巢组（SHO）和抗阻训练高血压去卵巢组（RTHO）。抗阻运动训练在垂直梯上进行（每周5天，共8周），负荷为最大负荷的40%-60%。记录直接动脉压。通过心率（HR）对甲基阿托品（3mg/kg，静脉注射）和普萘洛尔（4mg/kg，静脉注射）的反应来测量迷走神经和交感神经张力。卵巢切除导致高血压大鼠血压进一步升高，并与迷走神经张力降低有关。抗阻运动训练的大鼠平均动脉压低于未训练的大鼠（RTHO：159±2.2 vs SHO：177±3.4 mmHg），静息心率也较低（RTHO：332±9.0 vs SHO：356±5次/分钟）。训练组的交感神经张力也较低。此外，交感神经张力与静息心率呈正相关（r=0.7，P<0.05）。卵巢激素剥夺导致的高血压大鼠额外动脉压升高通过中等强度动态抗阻训练得到缓解。这种益处可能与训练后静息心率减慢和心脏交感神经张力降低有关，这表明抗阻运动对卵巢激素剥夺后高血压的管理具有潜在益处。
