Figure 3.

Effect of SP600125 (Panel a), U0126 (Panel b) or SB239063 (Panel c) on JNK, p42/p44 (or ERK) and p38 MAPK activation. Growth-arrested rat airway smooth muscle cells were pretreated with either vehicle or increasing concentrations of SP600125 (0.5–50 μM), U0126 (0.25–20 μM) or SB239063 (0.1–20 μM) followed by stimulation with 10 ng ml⁻¹ of IL-1β. Lysates were subjected to immunoblotting with the use of antisera directed against phosphorylated p42/p44, p38 or c-jun, as described in Methods. Autoradiographs generated were quantitated by densitometry. For each panel is shown a representative Western blot, together with the mean±s.e.m. densitometric measurements from four experiments. ^*P<0.05, ^**P<0.01, ^***P<0.001 versus IL-1β alone stimulated cells.