Prevention of angiotensin II-induced cardiac remodeling by angiotensin-(1–7)

JL Grobe, AP Mecca, M Lingis… - American Journal …, 2007 - journals.physiology.org
JL Grobe, AP Mecca, M Lingis, V Shenoy, TA Bolton, JM Machado, RC Speth, MK Raizada
American Journal of Physiology-Heart and Circulatory Physiology, 2007journals.physiology.org
Cardiac remodeling, which typically results from chronic hypertension or following an acute
myocardial infarction, is a major risk factor for the development of heart failure and,
ultimately, death. The renin-angiotensin system (RAS) has previously been established to
play an important role in the progression of cardiac remodeling, and inhibition of a
hyperactive RAS provides protection from cardiac remodeling and subsequent heart failure.
Our previous studies have demonstrated that overexpression of angiotensin-converting …
Cardiac remodeling, which typically results from chronic hypertension or following an acute myocardial infarction, is a major risk factor for the development of heart failure and, ultimately, death. The renin-angiotensin system (RAS) has previously been established to play an important role in the progression of cardiac remodeling, and inhibition of a hyperactive RAS provides protection from cardiac remodeling and subsequent heart failure. Our previous studies have demonstrated that overexpression of angiotensin-converting enzyme 2 (ACE2) prevents cardiac remodeling and hypertrophy during chronic infusion of angiotensin II (ANG II). This, coupled with the knowledge that ACE2 is a key enzyme in the formation of ANG-(1–7), led us to hypothesize that chronic infusion of ANG-(1–7) would prevent cardiac remodeling induced by chronic infusion of ANG II. Infusion of ANG II into adult Sprague-Dawley rats resulted in significantly increased blood pressure, myocyte hypertrophy, and midmyocardial interstitial fibrosis. Coinfusion of ANG-(1–7) resulted in significant attenuations of myocyte hypertrophy and interstitial fibrosis, without significant effects on blood pressure. In a subgroup of animals also administered [d-Ala7]-ANG-(1–7) (A779), an antagonist to the reported receptor for ANG-(1–7), there was a tendency to attenuate the antiremodeling effects of ANG-(1–7). Chronic infusion of ANG II, with or without coinfusion of ANG-(1–7), had no effect on ANG II type 1 or type 2 receptor binding in cardiac tissue. Together, these findings indicate an antiremodeling role for ANG-(1–7) in cardiac tissue, which is not mediated through modulation of blood pressure or altered cardiac angiotensin receptor populations and may be at least partially mediated through an ANG-(1–7) receptor.
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