[Role of chlorine transporters and water channels in autosomal dominant polycystic kidneys].

The molecular identification of several transporters has allowed a better understanding of the mechanism involved in cyst fluid accumulation in the autosomal dominant polycystic kidney disease (ADPKD). This fluid secretion is mediated by Cl- secretion, the latter process being stimulated by cyclic AMP. At the cellular level, Cl- secretion is carried out by a basolateral, bumetanide-sensitive cotransporter, organized in series with an apical CFTR channel. The accumulation of Cl- in the cyst lumen attracts Na+ (electric coupling) and water (osmotic coupling), the movement of the latter being partially mediated by aquaporins. The understanding of cyst fluid secretion mechanisms will be helpful to elaborate new therapeutic strategies aiming at slowing cyst expansion and preserving renal function.