Vasopressin (AVP), the antidiuretic hormone, is a cyclic nonapeptide involved in the homeostasis of body fluid, blood volume, vascular tone, and blood pressure. AVP also belongs to the family of vasoactive and mitogenic peptides involved in physiological and pathological cell growth and differentiation.
AVP exerts its actions through binding to specific V_1A, V_1B, and V₂, membrane receptors coupled to distinct second messengers.