Vasopressin V2 receptor

Class

Vasopressin V2-receptor antagonist

The vasopressin V2 receptor is a G-protein-coupled receptor located mainly on the principal cells lining the kidney's collecting ducts. Its natural ligand, arginine vasopressin (also called antidiuretic hormone), binds V2 receptors to trigger insertion of water-channel proteins into the cell membrane, allowing the kidney to reabsorb water and concentrate urine. This pathway is central to the body's water balance. Blocking the V2 receptor produces the opposite effect: increased excretion of water relative to salts, a process called aquaresis. This is useful therapeutically in conditions where water is retained inappropriately, such as low blood sodium (hyponatremia) driven by excess vasopressin activity, or fluid overload states linked to heart failure. V2 receptor blockade is also explored in polycystic kidney disease, where the same signaling pathway that governs water reabsorption also promotes abnormal growth of fluid-filled cysts in kidney tissue, so dampening it may slow disease progression. Because the target sits at a single, well-defined point in water-handling physiology, antagonists of this receptor offer a relatively selective way to correct water imbalance without directly manipulating sodium or potassium handling elsewhere in the nephron.