TY - JOUR T1 - The ClC-3 chloride channel and osmoregulation in the European Sea Bass, Dicentrarchus labrax A1 - Bossus,Maryline A1 - Charmantier,Guy A1 - Blondeau-Bidet,Eva A1 - Valletta,Bianca A1 - Boulo,Viviane A1 - Lorin-Nebel,Catherine AD - IFREMER, Equipe Adaptat Ecophysiol & Ontogenese, UMR5119, EcoSyM,CNRS,IRD,UM2,UM1, F-34095 Montpellier 05, France. AD - AD - UR - https://doi.org/10.1007/s00360-012-0737-9 DO - 10.1007/s00360-012-0737-9 KW - ClC-3 chloride channel KW - Na+/K+-ATPase KW - Dicentrarchus labrax KW - Osmoregulation KW - Osmosensing N2 - Dicentrarchus labrax migrates between sea (SW), brackish and fresh water (FW) where chloride concentrations and requirements for chloride handling change: in FW, fish absorb chloride and restrict renal losses; in SW, they excrete chloride. In this study, the expression and localization of ClC-3 and Na+/K+-ATPase (NKA) were studied in fish adapted to SW, or exposed to FW from 10 min to 30 days. In gills, NKA-alpha 1 subunit expression transiently increased from 10 min and reached a stabilized intermediate expression level after 24 h in FW. ClC-3 co-localized with NKA in the basolateral membrane of mitochondria-rich cells (MRCs) at all conditions. The intensity of MRC ClC-3 immunostaining was significantly higher (by 50 %) 1 h after the transfer to FW, whereas the branchial ClC-3 protein expression was 30 % higher 7 days after the transfer as compared to SW. This is consistent with the increased number of immunopositive MRCs (immunostained for NKA and ClC-3). However, the ClC-3 mRNA expression was significantly lower in FW gills. In the kidney, after FW transfer, a transient decrease in NKA-alpha 1 subunit expression was followed by significantly higher stable levels from 24 h. The low ClC-3 protein expression detected at both salinities was not observed by immunocytochemistry in the SW kidney; ClC-3 was localized in the basal membrane of the collecting ducts and tubules 7 and 30 days after transfer to FW. Renal ClC-3 mRNA expression, however, seemed higher in SW than in FW. The potential role of this chloride channel ClC-3 in osmoregulatory and osmosensing mechanisms is discussed. Y1 - 2013/07 PB - Springer Heidelberg JF - Journal Of Comparative Physiology B-biochemical Systemic And Environmental Physiology SN - 0174-1578 VL - 183 IS - 5 SP - 641 EP - 662 ID - 26044 ER -