Exercise training attenuates hypertension and cardiac hypertrophy via time‐related regulation on ACE and ACE2 axes

Abstract

Appropriate exercise training (ExT) has been shown to lower high blood pressure. However, prehypertension ExT has rarely been concerned. This study tested whether prehypertension ExT protects against hypertension and cardiac remodeling in spontaneously hypertensive rats (SHR), and explored the underlying mechanisms by examining cardiac angiotensin converting enzyme (ACE) and ACE2 axes. Low-intensity ExT was started in male SHR and control Wistar-Kyoto rats prior to the onset of hypertension, and lasted for either 8 or 16 weeks. Blood pressure (BP) was measured biweekly by the tail-cuff method. Cardiac function and remodeling were assessed, and ACE and ACE2 axes were determined after the final ExT. The results showed that prehypertension ExT slowed down the onset and progression of hypertension in SHR. In parallel, the hypertrophy in hypertensive heart was attenuated, myocardial fibrosis was reduced, and the impairment of left ventricular diastolic function was relieved. In SHR myocardium, the elements of ACE-AngII-AT1 axis were homogeneously and progressively increased, whereas those of ACE2-Ang(1–7)-MAS axis were heterogeneously decreased. Different time-related responses were observed for the key effecters, Ang II and Ang(1–7). Myocardial Ang II was increased progressively in SHR, and was reduced consistently by ExT. In contrast, Ang(1–7) was decreased only after 16-week sedentariness, which was abolished by ExT. Besides, 16-week ExT increased Ang(1–7) in normotensive control rats. In summary, prehypertension ExT attenuates hypertension and cardiac remodeling. Down-regulation of Ang II seems to serve as a protective mechanism throughout ExT, while up-regulation of Ang(1–7) is involved after a relatively long period of ExT. Support or Funding Information This work was supported by the National Natural Science Foundation of China (No. 81372111, 81670295), and the Natural Science Foundation of Fujian Province of China (No. 2014J01339). mRNA and protein levels of ACE and AT1 in left ventricles of WKY and SHR after 8 or 16 weeks of exercise training. mRNA and protein Expression of ACE2 and MAS receptor in left ventricles of WKY and SHR after 8 or 16 weeks of exercise training. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.