The cardiovascular and other actions of the vasoconstricting peptide angiotensin II are mediated by the type 1 and type 2 angiotensin II receptors (AT1 and AT2), which are seven transmembrane glycoproteins with 30% sequence similarity. AT1 receptors (Bergsma DJ et al, 1992) couple to G(q/11), and signal through phospholipases A, C, D, inositol phosphates, calcium channels, and a variety of serine/threonine and tyrosine kinases. The AT2 receptor (Tsuzuki S et al, 1994) is expressed mainly during fetal development. It is much less abundant in adult tissues and is up-regulated in pathological conditions. Its signaling pathways include serine and tyrosine phosphatases, phospholipase A2, nitric oxide, and cyclic guanosine monophosphate. The AT2 receptor counteracts several of the growth responses initiated by the AT1 and growth factor receptors.