REVIEW Overview of the Renin-Angiotensin System

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 con-gestive 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 inflam-mation. 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. (Korean Circulation J 2007;37:91-96) KEY WORDS：Renin；Angiotensin II；Angiotensin-converting enzyme inhibitors；Angiotensin II receptor； Angiotensin-converting enzyme 2