Renal aquaporins: key roles in water balance and water balance disorders.

The discovery of a family of molecular water channels, aquaporins, by Agre and co-workers has shed light on the long-standing biophysical question of how water traverses biological membranes, and has provided detailed molecular insight into the fundamental physiology of water balance and the pathophysiology of water balance disorders. In this review, we focus mainly on the vasopressin-regulated water channel, aquaporin 2, and its critical role in acute and chronic regulation of body water balance, as well as in multiple water balance disorders.