Angiotensin receptors: distribution, signalling and function

Angiotensin II (Ang II) is a multi-functional hormone that plays a major ro le in regulating blood pressure and cardiovascular homoeostasis. The action s of Ang II are mediated by at least two receptor subtypes, designated AT(1 ) and AT(2). In addition, other angiotensin receptors have been identified which may recognize other angiotensin peptide fragments; however, until now only the AT(1) and AT(2) receptor have been cloned in animals or humans. M ost of the well-described actions of Ang II, such as vasoconstriction, faci litation of sympathetic transmission, stimulation of aldosterone release an d promotion of cellular growth are all mediated by the AT(1) receptor. Much less is known about the function of the AT(2) receptor, but recent studies suggest that it may play a role in mediating anti-proliferation, cellular differentiation, apoptosis and vasodilatation. In this review, we discuss r ecent advances in our understanding of Ang II receptors, in particular, the ir distribution, signalling and function.