FIGURE 5.

Ins1,4,5P₃-induced Ca²⁺ increases are abolished after melatonin stimulation. Infected RBCs co-loaded with Fluo4-AM and caged-IP₃ were challenged with melatonin (10 μm) prior to flash photolysis of caged-IP₃. A, representative trace of cells from the same coverslip responding to melatonin (solid line) or IP₃ uncaging (dotted line). Similar results were obtained in 5 separate experiments, with 54 total cells analyzed. B, representative trace of cells (2 out of 54) which released Ca²⁺ to both stimuli. C, percentage of cells responding to melatonin (10 μm), photolysis of caged-IP₃ or both (data are the mean ± S.E. from five experiments). D, representative traces of cells in which flash photolysis of caged-IP₃ was performed during the melatonin-induced Ca²⁺ transient, showing no further Ca²⁺ release with the uncaging of IP₃ (representative of 4 cells from three independent experiments).