Role of the angiotensin AT2 receptor in blood pressure regulation and therapeutic implications

The angiotensin (ANG) Type 2 (AT(2)) receptor is one of two major ANG II receptors that have been identified, cloned, and sequenced. Most of the biologic actions of ANG II are thought to be mediated by the AT(1) receptor, but evidence is beginning to emerge that the AT(2) receptor has a significant role in the regulation of blood pressure. In the adult rat, the AT(2) receptor is expressed, albeit in low concentrations in kidney, mesenteric blood vessels, and heart. Most of the evidence suggests that the AT(2) receptor stimulates a vasodilator signaling cascade that includes bradykinin, nitric oxide, and guanosine cyclic 3 ' ,5 ' -monophosphate. At lease some of the beneficial actions of A(1) receptor blockade are mediated by the AT(2) receptor through this pathway. Several recent studies suggest that AT(2) receptors may mediate vasodilation and hypotension. The AT(2) receptor represents a potential therapeutic target for agonist action and a candidate molecule in the pathophysiology of hypertension. Am J Hypertens 2001;14: 98S-102S (C) 2001 American Journal of Hypertension, Ltd.