Renin angiotensin system and cardiac hypertrophy after sinoaortic denervation in rats

Abstract

OBJECTIVE:The aim of this study was to evaluate the role of angiotensin I, II and 1–7 on left ventricular hypertrophy of Wistar and spontaneously hypertensive rats submitted to sinoaortic denervation.METHODS:Ten weeks after sinoaortic denervation, hemodynamic and morphofunctional parameters were analyzed, and the left ventricle was dissected for biochemical analyses.RESULTS:Hypertensive groups (controls and denervated) showed an increase on mean blood pressure compared with normotensive ones (controls and denervated). Blood pressure variability was higher in denervated groups than in their respective controls. Left ventricular mass and collagen content were increased in the normotensive denervated and in both spontaneously hypertensive groups compared with Wistar controls. Both hypertensive groups presented a higher concentration of angiotensin II than Wistar controls, whereas angiotensin 1–7 concentration was decreased in the hypertensive denervated group in relation to the Wistar groups. There was no difference in angiotensin I concentration among groups.CONCLUSION:Our results suggest that not only blood pressure variability and reduced baroreflex sensitivity but also elevated levels of angiotensin II and a reduced concentration of angiotensin 1–7 may contribute to the development of left ventricular hypertrophy. These data indicate that baroreflex dysfunction associated with changes in the renin angiotensin system may be predictive factors of left ventricular hypertrophy and cardiac failure.

The nonpeptide ANG-(1–7) mimic AVE 0991 attenuates cardiac remodeling and improves baroreflex sensitivity in renovascular hypertensive rats

“…The reduced sensitivity of baroreflex control of HR is considered to be a risk factor for the development of LV hypertrophy, heart failure and sudden death (Fei et al, 1994;Piratello et al, 2010). There is a consensus, both for animals and for human patients, that hypertension is accompanied by attenuation of baroreflex sensitivity (Korner et al, 1974;McCubbin et al, 1956).…”

Cardiology in Brazilian scientific journals: an overview

“…It also improved single left ventricular myocyte contractile function, which was reversed by detraining. Piratello et al [49] evaluated the role of angiotensin I, II and 1-7 on left ventricular hypertrophy of Wistar and spontaneously hypertensive rats submitted to sinoaortic denervation and conclude that not only blood pressure variability and reduced baroreflex sensitivity but also elevated levels of angiotensin II and a reduced concentration of angiotensin 1-7 may contribute to the development of left ventricular hypertrophy. These data indicate that baroreflex dysfunction associated with changes in the renin angiotensin system may be predictive factors of left ventricular hypertrophy and cardiac failure.…”

Antihypertensive Effect of Carica papaya Via a Reduction in ACE Activity and Improved Baroreflex

“…These effects are of great importance because cardiac hypertrophy can be related to both the reduction of cardiac output and to the development of heart failure (reviewed by [24]). Additionally, the baroreflex is extremely important for the beat-to-beat control of MAP and helps reduce beatto-beat variability [25][26][27]. Hypertension [28] and the RAS [26,29,30] play important roles in the development of cardiac hypertrophy.…”