Early Exercise Training Postpones Hypertension Progression via Activation of Central ACE2‐Ang(1–7)‐Mas Axis in Prehypertensive Rats

Abstract

ObjectivesTo investigate the effects of exercise training on the development of hypertension in spontaneously hypertensive rats (SHR) and explore the underlying mechanisms by focusing on the central ACE2‐Ang (1–7)‐MAS axis.MethodsThe male SHR (n=20, 5 weeks old) and 20 normotensive Wistar Kyoto rats (WKY) were randomly assigned to sedentary (Sed) group or exercise training (ExT) group. The trained rats run on a treadmill in 20 m/min, 30 min/day, 5 day/week for 20 weeks. Systolic blood pressure (SBP) were measured by a tail‐cuff method. The baroreflex sensitivity (BRS) was assessed by intravenous injection of phenylephrine under anesthesia. The expression of ACE2 and MAS receptors mRNA and protein in the cardiovascular centers was determined by real‐time PCR and Western blot. Alterations in the BRS were evaluated before and after intracerebroventricular injection of MAS receptor agonist Ang (1–7) and its antagonist A779, respectively.Results(1) Exercise training significantly postponed the development of hypertension in SHR and decreased SBP in both SHR and WKY as compared with Sed groups (P<0.01 and P<0.05). (2) Exercise training enhanced blood pressure regulation and improved the BRS in the SHR (P<0.01). (3) The expression of ACE2 and MAS receptor mRNA and protein in rostral ventrolateral medulla (RVLM), nucleus tract solitarius (NTS), and paraventricular nucleus (PVN) was up‐regulated in SHR+ExT group (P<0.05, P<0.01). (4) Central administration of A779 abolished the benefits of exercise‐induced improvement of BRS in the SHR+ExT rats (P<0.01). In contrast, Ang (1–7) improved the BRS in both SHR+Sed group and SHR +ExT group (P<0.05).ConclusionExercise training postpones hypertension progression and improves blood pressure regulation, which is associated with the enhancement of central ACE2‐Ang(1–7)‐Mas axis.Support or Funding InformationNational Natural Science Foundation of China (No. 81372111) and Natural Science Foundation of Fujian Province of China (No. 2014J01339)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.