Figure 5.

[³H]pentamidine uptake by various s427-derived trypanosome lines. (a) [³H]pentamidine concentration was 50 nM, reflecting predominantly HAPT1-mediated uptake. (b) [³H]pentamidine concentration was 1 μM, reflecting predominantly LAPT1 uptake. Rates were determined from the slopes of time courses over 10 min with timepoints at 0, 1, 3, 5, 7.5 and 10 min. Lines were linear, with none of the lines showing significant deviation from linearity in a runs test (GraphPad Prism 5.0). Slopes of control time courses in the presence of 1 mM unlabelled pentamidine were all non-significantly different from zero (F-test, GraphPad Prism 5.0), whereas uptake with unlabelled inhibitor was highly significantly different from zero (typically P < 0.0001). Results are the mean of three to four independent experiments, each performed in triplicate. (c, d) Uptake of [³H]pentamidine in bloodstream forms of B48/AQP2 was determined as described in the legend to Figure 4. The experiments shown are representative of three independently performed replicates. (c) Uptake of 30 nM [³H]pentamidine. (d) Uptake of 1 μM [³H]pentamidine. Solid squares, coincubation with various concentrations of unlabelled pentamidine; open circles, coincubation with propamidine. **P < 0.01; ***P < 0.001.