Intracellular calcium increase induced by ATP treatment.

DCs previously loaded with 6 μmol/L FURA2-AM and treated with 2.5 mmol/L probenecid were tested in perfusion with either standard saline (including 1 mmol/L CaCl₂) (A,C) or calcium-free saline (including 1 mmol/L EGTA) (B). The arrows indicate the application of control saline alone (Ct) or 5 mmol/L ATP (ATP). Intracellular calcium changes were detected by monitoring the variation of the ratio obtained from emission at 510 nm elicited under 340-nm and 380-nm excitation wavelengths. These measurements are representative of 3 separate experiments and were obtained from the same cellular microscopic field.