Fludarabine uptake into JVM-2 cells.

(A) Time course of fludarabine uptake. Cells were incubated with 1 μM fludarabine either in an NaCl (▪) or a choline chloride (▴) medium. Na⁺-dependent transport (○) was calculated by subtracting those rates measured in choline medium from those measured in Na⁺ medium. (B) Discrimination among the different nucleoside transporter systems was performed as described in Figure 2. Transport rates were measured at 5 seconds. Results are the mean ± SE of 3 different determinations measured in triplicate.