title: Characterization of an Na+/K+/Cl- co-transport in primary cultures of rat astrocytes.
abstract: The furosemide- and bumetanide-sensitive component of the 86Rb+ uptake into primary cultures of rat astrocytes was fully dependent on the simultaneous presence of Na+ and Cl- in the incubation mixture and is therefore most likely an Na+/K+/Cl- co-transporter. As expected for such a co-transporter, its activity is insensitive to 0.1 mM amiloride and to 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid, and of the tested anions, only Br- could partly replace Cl-. The K0.5 values for K+, Na+ and Cl- activation were 2.7, 35 and 40 mM, respectively. The activity of the co-transporter was stimulated 1.5-times in hyperosmolar (500 mosM) medium.
mesh_terms: D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002034:Bumetanide / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology; D007473:Ion Channels / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D011917:Rats, Inbred Lew; D012414:Rubidium Radioisotopes; D012964:Sodium / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D002712:Chlorides; D007473:Ion Channels; D012414:Rubidium Radioisotopes; D028021:Sodium-Potassium-Chloride Symporters; D002034:Bumetanide; D010042:Ouabain; D000584:Amiloride; D005665:Furosemide; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium