Effect of wortmannin and SB203580 on the stimulus-induced phosphorylation of p38 MAP kinase and AKT kinase. Neutrophils were preincubated for 15 minutes in the absence or presence of 12.5 nM wortmannin or 10 μM SB203580, and subsequent stimulations were performed with either PF-4 (4 μM) or TNF (9 ng/mL) alone or a combination of both stimuli for 10 minutes. Phosphorylation of p38 MAP kinase (A) was evaluated by Western blot analysis as described in the legend to Figure 2; phosphorylation of AKT kinase (B) was analyzed by Western blot analysis as described in the legend to Figure 4. The data from one representative experiment of 5 and 4 (panels A and B, respectively) are given.