Calcium flux studies of Fura-2–loaded THP-1 cells.

C3a (1 μg/mL) or SDF-1β (300 ng/mL) was added at indicated time points, and calcium flux was evaluated by spectrophotofluorimetry. (A) Response to C3a followed by SDF-1β. (B) Cells were preincubated for 30 minutes with the C3aR antagonist (C3aRA) SB290157 (5 μM). (C) Cells were stimulated first by desArg-C3a (1 μg/mL), followed by C3a (1 μg/mL). Data presented are from a representative experiment, which was repeated 3 times with similar results.