title: Cl- transport in a glioma cell line: evidence for two transport mechanisms.
abstract: Cl- transport was studied in the glioma cell line LRM55 . Our results indicate that LRM55 cells contain two major Cl- transporters, an anion exchanger and a K+/Cl- cotransporter , and that these are similar to the Cl- porters found in primary cultures of astrocytes. The exchanger was studied by measuring fluxes of Cl- (as 36Cl-). 36Cl- flux was trans-stimulated by Cl- or HCO-3 and was inhibited by SITS or furosemide. The K+/Cl- cotransporter was studied by measuring fluxes of 36Cl- and K+ (as 86Rb+). External K+ stimulated 36Cl- influx, and external Cl- stimulated 86Rb+ influx. Furosemide, but not SITS, inhibited the K+/Cl- cotransporter . As in primary cultures of astrocytes, the steady-state concentration of Cl- in LRM55 cells was higher than that predicted from passive equilibration according to the membrane potential. LRM55 cells appear to be a good in vitro model for glial Cl- transport.
mesh_terms: D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D001639:Bicarbonates / Q000378:metabolism; D002460:Cell Line; D002712:Chlorides / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology; D005910:Glioma / Q000378:metabolism*; D007473:Ion Channels / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D011188:Potassium / Q000378:metabolism; D051381:Rats; D012964:Sodium / Q000378:metabolism; D013120:Spinal Cord Neoplasms / Q000378:metabolism*; D013696:Temperature
chemical_list: D001639:Bicarbonates; D002712:Chlorides; D007473:Ion Channels; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D005665:Furosemide; D012964:Sodium; D011188:Potassium