The main physiological role of vasopressin (ADH) is the reduction of free-water clearance by the kidney to produce concentrated urine. Vasopressin acts on the distal nephron to increase water permeability of the tubular cell so that solute-free water may pass along the osmotic gradient from the lumen of the nephron to the renal interstitial medulla.
See later:
•ÊOther Effects of Vasopressin
ΓÇó Regulation of Vasopressin Secretion
ΓÇó Osmoregulation of Vasopressin Secretion and Thirst