Fig. 4.

Effect of TNF on the activation of p38 MAPK and ERK. Eosinophils (1 × 10⁶) were stimulated for various times with TNF (20 ng/ml) followed by detection of (a) phosphorylated-p38 MAPK and (b) phosphorylated-ERK in the cell lysate by Western blot. In (c), eosinophils (1 × 10⁶) were treated without or with SB 203580 (SB) (1, 5, 10, 20 μm) for 1 h followed by stimulation with TNF (20 ng/ml) for 5 min. p38 MAPK activity was assessed by the expression of phosphorylated ATF-2 by Western blot. This result is representative of essentially identical results of triplicate experiments.