Arginine Vasopressin 1A receptor belongs to the same subfamily of G-protein coupled receptors of AVPR1B, V2R and OTR receptors. The activity of Arginine Vasopressin receptor 1A (AVPR1A) mediated by Gq/G11, stimulates a phosphatidylinositol-calcium second messenger system. V1A Vasopressin Receptor Assay from Innoprot allows the measurement of AVPR1A receptor activation by Calcium concentration increase in the cytosol.