The nanopeptide hormone vasopressin is a new player in the modulation of renal Na(+)-Cl(-) cotransporter activity.

Vasopressin is a modulator of salt and water reabsorption, with known effects in the thick ascending limb and the collecting duct. Pedersen et al. present evidence that vasopressin administration increases the phosphorylation of the apical thiazide-sensitive Na(+)-Cl(-) cotransporter in the distal convoluted tubule. These effects appear to be independent of the renin-angiotensin system and to be mediated by the intracellular kinase SPAK. These observations expand the vasopressin-sensitive region of the nephron.