Water reabsorption in the kidney represents a critical physiologic event in the maintenance
of body water homeostasis. This highly regulated process relies largely on vasopressin (VP)
action and on the VP-sensitive water channel that is aquaporin-1 (AQP2) expressed in
principal cells of the kidney collecting duct. Defects in the VP signaling pathway and/or in
AQP2 cell surface expression can lead to an inappropriate reduction in renal water
reabsorption and the development of nephrogenic diabetes insipidus, a disease …