The effect of SB203580 and PD98059 on neutrophil superoxide production.

(A, D) Neutrophils were preincubated with inhibitors at the range of concentrations indicated, for optimal times as described in “Materials and methods,” before stimulation for 10 minutes with 1 μM FMLP and measurement of superoxide production. (B, E) Parallel samples were primed by incubation with either FCS diluent, GM-CSF, or TNF-α for 30 minutes before stimulation with FMLP as in panels A and D. (C, F) Cells were stimulated with 100 ng/mL TPA for 5 minutes.