Vieira Suenimeire, Aguilar Bruno A, Veiga Ana Catarine, Philbois Stella V, Freitas Ana Caroline S, Rodrigues Karine P, Tank Jens, Souza Hugo C D
Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.
Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany.
Front Physiol. 2022 Aug 19;13:920196. doi: 10.3389/fphys.2022.920196. eCollection 2022.
Aerobic physical training reduces arterial pressure in patients with hypertension owing to integrative systemic adaptations. One of the key factors is the decrease in cardiac sympathetic influence. Thus, we hypothesized that among other causes, cardiac sympathetic influence reduction might be associated with intrinsic cardiac adaptations that provide greater efficiency. Therefore, 14 spontaneously hypertensive rats (SHR group) and 14 normotensive Wistar Kyoto rats (WKY group) were used in this study. Half of the rats in each group were trained to swim for 12 weeks. All animals underwent the following experimental protocols: double blockade of cardiac autonomic receptors with atropine and propranolol; echocardiography; and analysis of coronary bed reactivity and left ventricle contractility using the Langendorff technique. The untrained SHR group had a higher sympathetic tone, cardiac hypertrophy, and reduced ejection fraction compared with the untrained WKY group. In addition, reduced coronary bed reactivity due to increased flow, and less ventricular contractile response to dobutamine and salbutamol administration were observed. The trained SHR group showed fewer differences in echocardiographic parameters as the untrained SHR group. However, the trained SHR group showed a reduction in the cardiac sympathetic influence, greater coronary bed reactivity, and increased left intraventricular pressure. In conclusion, aerobic physical training seems to reduce cardiac sympathetic influence and increase contractile strength in SHR rats, besides the minimal effects on cardiac morphology. This reduction suggests intrinsic cardiac adaptations resulting in beneficial adjustments of coronary bed reactivity associated with greater left ventricular contraction.
有氧体育训练可通过全身性综合适应降低高血压患者的动脉压。其中一个关键因素是心脏交感神经影响的降低。因此，我们推测，除其他原因外，心脏交感神经影响的降低可能与能提高效率的心脏内在适应性有关。因此，本研究使用了14只自发性高血压大鼠（SHR组）和14只血压正常的Wistar Kyoto大鼠（WKY组）。每组一半的大鼠接受为期12周的游泳训练。所有动物均接受以下实验方案：用阿托品和普萘洛尔双重阻断心脏自主神经受体；超声心动图检查；以及使用Langendorff技术分析冠状动脉床反应性和左心室收缩性。与未训练的WKY组相比，未训练的SHR组具有更高的交感神经张力、心脏肥大和更低的射血分数。此外，观察到由于血流量增加导致冠状动脉床反应性降低，以及对多巴酚丁胺和沙丁胺醇给药的心室收缩反应减弱。训练后的SHR组与未训练的SHR组相比，超声心动图参数差异较小。然而，训练后的SHR组显示心脏交感神经影响降低、冠状动脉床反应性增强以及左心室内压升高。总之，有氧体育训练似乎能降低SHR大鼠的心脏交感神经影响并增加收缩力，同时对心脏形态的影响最小。这种降低表明心脏内在适应性导致冠状动脉床反应性的有益调整，与更大的左心室收缩相关。
