The activity of AVPR1A is mediated by G proteins which stimulate a phosphatidylinositol-calcium second messenger system. AVPR1A receptor belongs to the same subfamily of G-protein coupled receptors of AVPR1B, V2R and OTR receptors. The receptor mediates several actons, such as cell contraction and proliferation, platelet aggregation, release of coagulation factor and glycogenolysis. V1A is coupled to Gq/11 proteins and it appears in a high density on smooth muscle cells. It plays an important role in regulation of blood pressure through arterial vasoconstriction and it stimulates VEGF secretion. AVPR1A also appears in the brain, palying important roles in social behaviours, including affiliation and attachment and related to diseases as autism. HiTSeeker AVPR1A Cell Line from Innoprot allows the measurement of the activity and potency of ligands; such as AVP.