Fig. 1.

SQ reduces intracellular ATP levels. Changes in intracellular ATP levels were determined on the basis of changes in the luminescence of L. donovani 3-Luc promastigotes treated with the following SQ concentrations: 5 (■), 10 (○), 30 (□), 50 (▴), 100 (●), and 200 (♢) μM. Promastigotes were preloaded with 25 μM DMNPE-luciferin, SQ was added (time zero) once luminescence had reached a plateau, and the luminescence was monitored as described in Materials and Methods. Luminescence changes were normalized with respect to the control untreated parasites. Similar results were obtained in three independent experiments.