TABLE 2.

pHi dependence of tafenoquine accumulation in Leishmania promastigotes^a

Promastigote	pHi		TFQ uptake (AU/mg protein)
	Control	NH4Cl	Control	NH4Cl
WT	6.75 ± 0.01	7.69 ± 0.02*	10,775 ± 149	7,009 ± 95*
R4	7.21 ± 0.02	7.45 ± 0.01*	8,809 ± 84	8,462 ± 67*
revR4	7.11 ± 0.01	7.41 ± 0.02*	9,657 ± 127	8,524 ± 59*

^aWT, R4, and revR4 L. major promastigotes were pretreated at 28°C with 20 mM NH₄Cl for 1 min and incubated with 5 μM tafenoquine (TFQ) in the presence of NH₄Cl for 15 min. pHi values were determined as described in the legend of Fig. 2. Data are the means ± SD from three independent experiments. Significant differences were determined by Student's t test (*, P value was <0.05 versus the corresponding control without NH₄Cl). AU, arbitrary units.