The site of action of vasopressin antagonist in kidney
V2 receptors are located on medullary collecting ducts. drugs acting on V2 receptor antagonists are vaptans like convivaptan and tolvaptan Ref: Goodman Gillman 12th ed pg 707
Medullary Collecting duct
Coical collecting duct
Proximal convoluted tubule
Distal convoluted tubule
Kidney