The role of the AT2 receptor in hypertension.

The renin-angiotensin system (RAS) is integrally involved in maintaining the healthy body's hemodynamic status. It is also involved in many pathogenic situations. Angiotensin II (Ang II) is the major effector hormone of this system. Ang II subtype 1 receptor blockers (ARB), like angiotensin-converting enzyme (ACE) inhibitors, modulate the potent vasoconstricting and growth-promoting effects of Ang II. Thus, it is reasonable to assume that ACE inhibitors and ARB provide similar benefits in patients with hypertension and other diseases. There are salient differences, however, in that ARB antagonize Ang II at its AT1 receptor subtype but spare its AT2 receptor subtype, which has unique-and largely oppositional- effects on the blood vessels, kidneys, and adrenals. ACE inhibitors decrease the amount of Ang II available to its AT1 and AT2 receptors alike without totally suppressing its formation. This article reviews recent findings about the role of the AT2 receptor in both health and disease and the actions of ARB mediated by this receptor.