USMLE

V2 (Vasopressin) Receptors

1,792 views
General Pharm
  1. Gs / Gi Pathway
  2. Gq Signaling Pathway
  3. Alpha-1 (Adrenergic) Receptors
  4. Alpha-2 (Adrenergic) Receptors
  5. Beta-1 (Adrenergic) Receptors
  6. Beta-2 (Adrenergic) Receptors
  7. Beta-3 (Adrenergic) Receptors
  8. M1 (Muscarinic) Receptors
  9. M2 (Muscarinic) Receptors
  10. M3 (Muscarinic) Receptors
  11. D1 (Dopamine) Receptors
  12. D2 (Dopamine) Receptors
  13. H1 (Histamine) Receptors
  14. H2 (Histamine) Receptors
  15. V1 (Vasopressin) Receptors
  16. V2 (Vasopressin) Receptors

Summary

V2 receptors are G-protein coupled receptors that respond to vasopressin, a hormone also known as antidiuretic hormone (ADH). Binding of V2 receptors by vasopressin causes the activation of a Gs signaling pathway, which leads to different effects depending on where the receptor is bound.  In the collecting ducts of the kidney, activated V2 receptors increase surface expression of aquaporins, increasing water reabsorption and decreasing blood osmolarity. In the blood vessels, binding of V2 receptors by vasopressin increases  von Willebrand factor or VWF levels, making blood more likely to clot. Clinically, the drug desmopressin is a selective activator of V2 receptors, and it is used to treat central diabetes insipidus, as well as bleeding disorders like hemophilia A and von Willebrand deficiency.

Key Points

  • V2 (Vasopressin) Receptors
    • GPCR that responds to Vasopressin / ADH
      • Activates a Gs subunit
    • Locations
      • Kidney
      • Endothelium
    • Actions
      • Increased water reabsorption at kidney
        • Binding increases apical expression of aquaporins at distal convoluted tubules and collecting ducts
        • Implicated in SIADH and diabetes insipidus
      • Increased vWF release from endothelium
        • Desmopressin (analog of vasopressin) stimulates vWF release, which stimulates formation of platelet plugs; used to treat bleeding disorders