Vasopressin antagonist acts on which pa of the nephron?
(A) Proximal convoluted tubule (B) Distal convoluted tubule (C) Coical collecting tubule (D) Medullary collecting duct
(D) Answer- D (Medullary collecting duct)'The mechanism by which vasopressin exes its anti-diuretic effect is activated by V2 receptors and involves the inseion of aquaporin-2 into the apical (luminal) membranes at the principle cells of the collecting duct.'