Figure 3.

Thg releases Ca²⁺ from more than one compartment in P. falciparum parasites. [Ca²⁺]_c was monitored in isolated PfGCaMP3 parasites at the trophozoite stage suspended in the cuvette of a spectrofluorometer, as described in the legend of Fig. 2. The PfGCaMP3 parasites were sequentially exposed to 10 μm Thg then 30 μm CPA (A and B), CPA then Thg (C and D), or DMSO control (E and F) in the presence (A, C, and E) or absence (B, D, and F) of extracellular Ca²⁺ (no CaCl₂ added plus addition of 100 μm EGTA). The CPA Ca²⁺ response was blocked after Thg addition (A and B); however, the Thg Ca²⁺ response was not abolished by CPA (C and D). A–F are representative traces. The mean peak Ca²⁺ response to each drug addition is plotted in the presence (G) or absence (H) of extracellular Ca²⁺. The data are the means ± S.D. from three or more independent experiments with individual data points shown. Statistical significance was calculated by one-way ANOVA with Bonferroni's multiple comparison test. In G, *, p = 0.017; **, p = 0.0013; ****, p < 0.0001. In H, *, p = 0.0256; **, p = 0.0035; ****, p < 0.0001; φ, p = 0.0257; Σ, p = 0.0124.