Effect of inhibitors on choline uptake. (A) Effect of ouabain (100 μM), substitution of sodium for N-methyl-D-glucamine, bafilomycin A1 (100 nM), FCCP (20 μM), and cesium chloride (10 mM) on the uptake of [³H]-choline (20 nM) into isolated P falciparum parasites over 10 minutes at 22°C. Data are mean ± SE for duplicate observations from 4 individual experiments. ^**P < .001 and ^*P > .001 < .05, Mann-Whitney U test for significance of difference between means. (B) Effect of known choline transport inhibitors furosemide (200 μM), amiodarone (200 μM), bepridil (200 μM), and HC-3 (50 μM) and antimalarial choline analogs T16 (1 μM) and pentamidine (1 μM) on the uptake of [³H]-choline (20 nM) into isolated P falciparum parasites over 10 minutes at 22°C. Data are mean ± SE for duplicate observations from 4 individual experiments. ^**P < .001 and ^*P > .001 < .05, Mann-Whitney U test for significance of difference between means.