Neto Octávio Barbosa, de Sordi Carla Cristina, da Mota Gustavo Ribeiro, Marocolo Moacir, Chriguer Rosângela Soares, da Silva Valdo José Dias
Human Performance and Sport Research Group, Department of Sport Sciences, Federal University of Triângulo Mineiro, Uberaba, Brazil; Department of Physiology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Brazil.
Department of Endocrinology and Metabolism, Postgraduate Course on Health Science, Federal University of Triângulo Mineiro, Uberaba, Brazil.
Auton Neurosci. 2017 Dec;208:66-72. doi: 10.1016/j.autneu.2017.09.012. Epub 2017 Sep 14.
We examined the vagal transfer function of autonomic heart rate (HR) control in anesthetized sedentary and exercise-trained Spontaneously Hypertensive Rats (SHR). To this end, male SHR and Wystar-Kyoto (WKY) rats with 48-50weeks of age-old were divided into 4 groups: sedentary (SHR, n=12) and trained (SHR, n=14) hypertensive rats, sedentary (WKY, n=13) and trained (WKY, n=13) normotensive rats. The trained groups were submitted to swimming protocol for 9weeks. Blood pressure (BP), HR, HR variability (HRV), BP variability (BPV), baroreflex sensitivity and cardiac tonus were recorded in baseline conditions. Following, electric stimulation of peripheral vagus nerve was performed in anesthetized conditions. Resting bradycardia was observed in SHR and WKY when compared to their respective sedentary groups (p<0.001). The BP was lower in SHR than in SHR (p<0.001). The SHR and WKY rats showed higher baroreflex-mediated tachycardia values when compared to their respective sedentary counterparts (p<0.001). Baroreflex bradycardic response in SHR was higher than in SHR (p<0.005). The SHR and WKY rats showed a decreased sympathetic activity in comparison to their respective sedentary groups (p<0.05). The cardiac vagal tonus was higher in SHR than in SHR (p<0.05). Regarding the dynamic transducer properties of peripheral vagus nerve to the heart no difference was observed among the groups. In conclusion, our results demonstrate that exercise training decreased BP in SHR and improved cardiovascular autonomic balance to the heart without changes in transduction properties of peripheral cardiac vagus nerve.
我们研究了麻醉状态下久坐不动和经过运动训练的自发性高血压大鼠（SHR）自主心率（HR）控制的迷走神经传递功能。为此，将48 - 50周龄的雄性SHR和Wistar - Kyoto（WKY）大鼠分为4组：久坐不动的高血压大鼠（SHR，n = 12）和经过训练的高血压大鼠（SHR，n = 14），久坐不动的正常血压大鼠（WKY，n = 13）和经过训练的正常血压大鼠（WKY，n = 13）。训练组进行为期9周的游泳训练方案。在基线条件下记录血压（BP）、心率（HR）、心率变异性（HRV）、血压变异性（BPV）、压力反射敏感性和心脏张力。随后，在麻醉状态下对周围迷走神经进行电刺激。与各自久坐不动的组相比，SHR和WKY均出现静息心动过缓（p < 0.001）。SHR的血压低于SHR（p < 0.001）。与各自久坐不动的对应组相比，SHR和WKY大鼠的压力反射介导的心动过速值更高（p < 0.001）。SHR的压力反射性心动过缓反应高于SHR（p < 0.005）。与各自久坐不动的组相比，SHR和WKY大鼠的交感神经活动降低（p < 0.05）。SHR的心脏迷走神经张力高于SHR（p < 0.05）。关于周围迷走神经对心脏的动态转换特性，各组之间未观察到差异。总之，我们的结果表明，运动训练可降低SHR的血压并改善心脏的心血管自主神经平衡，而周围心脏迷走神经的转换特性无变化。
