Identification of AT2 angiotensin receptors on Swiss 3T3 cells

Swiss 3T3 cells express high-affinity receptors for angiotensin II (KD = 0.8 nM, 110,000 receptors/cell). Binding of the peptide to these receptors did not activate phosphatidylinositol 4,5 bisphosphate hydrolysis, and did not increase intracellular [Ca2+] or activate protein kinase C. The relative binding affinities of highly-selective antagonists characterised these receptors as the AT2 subtype. However, in contrast to the signalling events reported in some other cells that express AT2 receptors, AII had no apparent effect on either cyclic GMP levels or phosphotyrosine phosphatase activity in Swiss 3T3 cells. Furthermore, angiotensin II (either alone or in combination with growth factors) was not mitogenic to Swiss 3T3 cells.