Overview of the Renin-Angiotensin System

ABSTRACT

Angiotensin II is an octapeptide hormone of the renin-angiotensin system (RAS), and it regulates a wide variety of physiological responses including salt and water balance, the blood pressure and the vascular tone. Clinical trials with angiotensin-converting enzyme (ACE) inhibitors have demonstrated survival benefits in subjects with congestive heart failure and myocardial infarction, and this support the importance of angiotensin II in the pathogenesis of cardiovascular diseases. Through activation of small G proteins such as Ras, Rho, and Rac, angiotensin II induces remodeling of vascular smooth muscle cells (VSMC), including proliferation, migration, hypertrophy and inflammation. Angiotensin (1-7) appears to be the main effector peptide of ACE2 with vasodilatory, natriuretic and antiinflammatory properties. The cross-talk between the angiotensin II receptors may play an important role in maintaining cardiovascular homeostasis.