Vasopressin receptor 1A, Vasopressin receptor 1B, Vasopressin receptor 2 (V1A (AVPR1A), V1B (AVPR1B), V2 (AVPR2))

Vasopressin receptors 1A, 1B, and 2 are **G protein-coupled receptors** for arginine vasopressin, mediating its diverse physiological actions. Vasopressin receptor 1A (AVPR1A) is primarily expressed in vascular smooth muscle, liver, brain, and other tissues, mediating vasoconstriction and modulating social and stress-related behaviors. Vasopressin receptor 1B (AVPR1B) is mainly located in the anterior pituitary and some brain regions, where it regulates the stress response by stimulating ACTH release as part of the HPA axis. Vasopressin receptor 2 (AVPR2) is highly expressed in the renal collecting ducts and mediates antidiuretic effects by promoting water reabsorption, as well as in some extrarenal tissues. Dysfunction in these receptors is associated with a range of diseases including diabetes insipidus, SIADH, cardiovascular diseases, and some behavioral and neuropsychiatric disorders. Various antagonists and agonists for these receptors are in clinical use or development.

Other names

V1a receptorAVPR1AArginine vasopressin receptor 1AAntidiuretic hormone receptor 1AV1-vascular vasopressin receptorV1b receptorAVPR1BArginine vasopressin receptor 1BPituitary vasopressin receptorV3 receptorV2 receptorAVPR2Arginine vasopressin receptor 2Renal vasopressin receptor

Vasopressin receptor antagonists block binding of vasopressin/ADH, thereby inhibiting downstream G protein pathways—leading to aquaresis (water excretion without sodium loss) or suppression of ACTH or vasoconstriction, depending on the receptor expressed. Agonists mimic vasopressin action, enhancing water reabsorption (V2), increasing vasoconstriction (V1A), or stimulating ACTH release (V1B).