Ion transport by ouabain resistant and sensitive ehrlich ascites carcinoma cells

Cell division, net Na+‐K+ and amino‐acid transport of cultured Ehrlich ascites is reversibly inhibited by Ouabain at a final concentration of 1 × 10–3M. A line of Ehrlich ascites cells resistant to the growth inhibiting effects of Ouabain has been developed. These cells behave similarly to Ouabain‐sensitive cells in the following respects doubling time, S phase time, chromosome number, cell surface charge density, rate of incorporation of C14 Uridine and 3H‐Thymidine, sensitivity to Digoxin and Digitoxin, steady state Na+, K+ levels and rate of loss of K+ and gain of Na+ in cold. Ouabain resistant cells differ from sensitive cells only with respect to the effect of ouabain on active Na+, K+ transport. Although Ouabain inhibits active Na+, K+ transport in sensitive cells it has no significant effect in resistant cells.