Vasopressin receptor 2

AVPR2 is expressed in the kidney tubule, predominantly in the membrane of cells of the distal convoluted tubule and collecting ducts, in fetal lung tissue and lung cancer, the last two being associated with alternative splicing. AVPR2 is also expressed outside the kidney in vascular endothelium. Stimulation causes the release of von Willebrand factor and factor VIII from the endothelial cells. Because von Willebrand factor helps stabilize circulating levels of factor VIII, the vasopressin analog desmopressin can be used to stimulate the AVPR2 receptor and increase levels of circulating factor VIII. This is useful in the treatment of hemophilia A as well as Von Willebrand disease.

In the kidney, AVPR2's primary property is to respond to arginine vasopressin by stimulating mechanisms that concentrate the urine and maintain water homeostasis in the organism. When the function of AVPR2 is lost, the disease nephrogenic diabetes insipidus (NDI) results.

Antagonists

Vasopressin receptor antagonists that are selective for the V2 receptor include:

• Tolvaptan (FDA-approved)
• Lixivaptan
• Mozavaptan
• Satavaptan

Their main uses are in hyponatremia, such as that caused by syndrome of inappropriate antidiuretic hormone (SIADH) and heart failure, however these agents should be avoided in patients with cirrhosis.

Demeclocycline and lithium carbonate act as indirect antagonists of renal vasopressin V₂ receptors by inhibiting activation of the second messenger cascade of the receptors.