title: Regulation of extracellular fluid volume and blood pressure by pendrin.
abstract: Na(+) is commonly designed as the culprit of salt-sensitive hypertension but several studies suggest that abnormal Cl(-) transport is in fact the triggering mechanism. This review focuses on the regulation of blood pressure (BP) by pendrin, an apical Cl(-)/HCO(3)(-) exchanger which mediates HCO(3)(-) secretion and transcellular Cl(-) transport in type B intercalated cells (B-ICs) of the distal nephron. Studies in mice showed that it is required not only for acid-base regulation but also for BP regulation as pendrin knock-out mice develop hypotension when submitted to NaCl restriction and are resistant to aldosterone-induced hypertension. Pendrin contributes to these processes by two mechanisms. First, pendrin-mediated Cl(-) transport is coupled with Na(+) reabsorption by the Na(+)-dependent Cl(-)/HCO(3)(-) exchanger NDCBE to mediate NaCl reabsorption in B-ICs. Second, pendrin activity regulates Na(+) reabsorption by the adjacent principal cells, possibly by interaction with the ATP-mediated paracrine signalling recently identified between ICs and principal cells. Interestingly, the water channel AQP5 was recently found to be expressed at the apical side of B-ICs, in the absence of a basolateral water channel, and pendrin and AQP5 membrane expressions are both inhibited by K(+) depletion, suggesting that pendrin and AQP5 could cooperate to regulate cell volume, a potent stimulus of ATP release.
authors: INSERM UMRS 970-Paris Cardiovascular Research Center (PARCC), Paris, France.
authors: Juliette
authors: J
authors: Hadchouel
authors: Cara
authors: C
authors: Büsst
authors: Giuseppe
authors: G
authors: Procino
authors: Giovanna
authors: G
authors: Valenti
authors: Régine
authors: R
authors: Chambrey
authors: Dominique
authors: D
authors: Eladari
mesh_terms: D000818:Animals; D027321:Anion Transport Proteins / Q000378:metabolism*; D000838:Anions / Q000378:metabolism; D051402:Aquaporin 5 / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology*; D045604:Extracellular Fluid / Q000378:metabolism*; D006801:Humans; D017136:Ion Transport; D009399:Nephrons / Q000378:metabolism; D019899:Paracrine Communication; D000076988:Sulfate Transporters
chemical_list: D027321:Anion Transport Proteins; D000838:Anions; D051402:Aquaporin 5; C494849:Slc26a4 protein, mouse; D000076988:Sulfate Transporters