High-affinity pentamidine transport in bloodstream (A) and procyclic (B) forms of T. brucei brucei in the presence of various concentrations of unlabeled inhibitors:▴, pentamidine; ○, DB820; ■, CPD0801. [3H]Pentamidine concentration was 25 nM, and incubation time was 60 s. The experiments shown are representative of at least three independent experiments, each performed in triplicate. Error bars are standard errors.