Chloride transport by isolated gill cells of the fresh water adapted rainbow trout ( Salmo gairdneri)

1. 1. Epithelial cells isolated from the gills of fresh water adapted rainbow trout remained viable in saline media for at least 8 hr, and with the use of chloride-36, chloride uptake was demonstrated. 2. 2. Chloride uptake was inhibited by the following compounds: amiloride (10 −4M) reduced influx of chloride by 21.2%, SITS (4-acetamido-4'-iso-thiocyanato-2-2' disulphonic acid; 10 —M) 37.6%, H;DIDS (4,4-diisothiocyano-dihydrostilbene 2,2-disulphonic acid; 10 — M) 26%, ouabain (10 —M) 20%, furosemide (10 —M) 24.4%, acetazolamide (10 —M) 30.8% and ethacrynic acid (10 —M) 23.7%. 3. 3. The occurrence and possible mechanisms of Na +/H + and Cl −/HCO 3 − exchange, Na/K/Cl cotransport, and the roles of carbonic anhydrase and Na +K +ATPase in ion uptake in the gills of freshwater fish are discussed.