Differentiation between serum stimulation of ouabain-resistant and sensitive Rb influx in quiescent NIH 3T3 cells.
The addition of serum to quiescent NIH 3T3 mouse cell cultures resulted in a 10- to 20-fold increase of Rb influx which was resistant to ouabain, and only a three- to fourfold activation of ouabain-sensitive Rb influx. Stimulation of the ouabain-resistant Rb influx following serum addition reached its maximum within 2 min. The stimulation of ouabain-resistant Rb influx was a result of Vm increase while the Km for Rb was unchanged. Ouabain-resistant Rb influx, after serum addition, was resistant to amiloride and sensitive to ethacrynic acid. Replacing chloride in the medium by NO3-, CO3- and CH3COO- resulted in a drastic decrease in the ouabain-resistant Rb influx. It appeared, therefore, that the ouabain-resistant Rb influx in NIH 3T3 cells was Cl--dependent.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002453:Cell Cycle; D002478:Cells, Cultured; D002712:Chlorides / Q000494:pharmacology; D003470:Culture Media; D004351:Drug Resistance; D051379:Mice; D010042:Ouabain / Q000494:pharmacology*; D012413:Rubidium / Q000378:metabolism*
D002712:Chlorides; D003470:Culture Media; D010042:Ouabain; D012413:Rubidium