The early effects of ouabain on potassium metabolism and rate of proliferation of mouse lymphoblasts.

Murine lymphoblasts grown in suspension culture in the presence of ouabain showed a dose dependent and sequential decrease in 86Rb+ (K+ analogue) influx, cellular potassium content, and growth rate. An increase in eosin staining and a decrease in cell number was observed after two hours in the presence of 1 mM ouabain; 1 muM ouabain was without effect on any of the parameters measured. Ouabain inhibition was rapidly and completely reversible at concentrations that were not cytotoxic.