Antimalarial choline analogs are transported by the P falciparum choline carrier. (A) Uptake of [³H]-T16 and [³H]-pentamidine (both at 50 nM) into isolated parasites over 10 minutes at 22°C in the presence (□) or absence () of 5 mM choline. Data are mean ± SE for duplicate observations from 4 individual experiments. (B) Concentration-dependent inhibition by choline of [³H]-pentamidine (50 nM) uptake into isolated P falciparum parasites over 10 minutes at 22°C. Data are mean ± SD for duplicate observations from 3 individual experiments. (C) Effect of transport inhibitors furosemide (200 μM), amiodarone (200 μM), bepridil (200 μM), and bafilomycin A1 (100 nM) on [³H]-choline (20 nM) and [³H]-pentamidine (50 nM) uptake into isolated P falciparum parasites over 10 minutes at 22°C. Data are mean ± SD for duplicate observations from 3 individual experiments. ^**P < .001, Mann-Whitney U test for significance of difference between means.