K+ influx components in ascites cells: the effects of agents interacting with the (Na+ + K+)-pump.
Several agents known to interact with the (Na+ + K+)-pump were tested for their effects on the components of steady-state K+ flux in ascites cells. 86Rb+ was used as a tracer for K+, and influx was differentiated into a ouabain-inhibitable "pump" component, a Cl--dependent and furosemide-sensitive "exchange" component, and a residual "leak" flux. All agents tested (ouabain, quercetin, oligomycin, phosphate) affected both the "pump" flux and the Cl--linked flux. These findings suggest a linkage between the activity of the Na/K ATPase and the Cl--dependent K+ exchange flux. In the discussion we point out that the mechanism of this linkage could be direct; e.g., Cl--dependent exchange may represent a mode of operation of the Na/K ATPase. However, data from this and other systems tend to suggest an indirect linkage between the Na+ pump and a KCl symporter, perhaps via a change in the level of intracellular ATP.
D000818:Animals; D001201:Ascites / Q000378:metabolism*; D001693:Biological Transport, Active / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D051379:Mice; D009374:Neoplasms, Experimental / Q000378:metabolism; D009840:Oligomycins / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology*; D010710:Phosphates / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D011794:Quercetin / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D002712:Chlorides; D005419:Flavonoids; D009840:Oligomycins; D010710:Phosphates; D010042:Ouabain; D011794:Quercetin; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium