The present study was to investigate the effects of prehypertesive exercise on the cardiac hypertrophy, the expression of angiotensin converting enzyme(ACE) and ACE2 and the levels of angiotensin II (AngII) and angiotensin-(1–7) [Ang-(1–7)] in the heart of the young spontaneously hypertensive rats (SHR).Design and Method:
Male 5-wk SHR and normotensive Wistar kyoto (WKY) rats were randomly divided into sedentary (S) and exercise training(E) groups, n = 10 for each group. Rats run on a treadmill based on a exercise regimen (18–20 m/s, 60 min/d, 5 d/wk) for 8 weeks.Real time PCR and Western blotting were used to detect the mRNA and protein expression, respectively. The levels of cardiac Ang II and Ang-(1–7) were measured using a ELISA method.Results:
As shown in table1, exercise training prevented a increase in the left ventricular mass index(LVMI) and the left ventricular end diastolic pressure (LVEDP) and a decrease in–dp/dt max in SHR.Exercise training did not induce physiological myocardial hypertrophy in WKY. Furthermore, exercise training normalized cardiac mRNA and protein expressions of ACE as well as myocardial AngII level in SHR, but up-regulated cardiac mRNA expressions of ACE2 alone. Exercise training had no effects on cardiac ACE2 protein expressions and Ang-(1–7) levels in SHR.Conclusions:
Exercise training prevents cardiac hypertrophy in the young SHR, which may be associated with a decrease in Ang II caused by the downregulation of ACE expression.