Fig. 5. SB203580 interferes with the effects of anisomycin p38 MAP kinase activity on GJIC. Each treatment group was exposed to 0.02% dimethyl sulfoxide as vehicle alone for 90 minutes (control), anisomycin at 10 µg ml^-1 for 60 minutes, SB203580 plus anisomycin (pretreatment of SB203580 for 30 minutes, then co-treatment with anisomycin for an additional 60 minutes) or SB203580 alone for 90 minutes. Cells with or without pretreatment with SB203580 at 10 µM were exposed to 10 µg ml^-1 of anisomycin for 60 minutes. After treatment, samples were prepared as described in Fig. 2B. (A) Typical immunoblot analyses using specific antibodies against phosphorylated forms of p38 MAP kinase, JNK and ß-actin as protein-loading control. (B) This result is representative of three experiments, each performed with a different preparation of cells and plotted as the fold activity (mean±s.e.m.) of band density relative to that of control by densitometric analysis. (C) Results are expressed as the percentage (mean±s.e.m.) of RR relative to that of control cells (100%) of at least three separate experiments. ^*P<0.05 versus cells incubated with control; ^**P<0.01 versus cells incubated with control. (D) To examine the effect of anisomycin as protein synthesis inhibitor, we used [³⁵S]-methionine metabolic labelling. The [³⁵S]-methionine-incorporated protein levels were shown as radioactivity by liquid scintillation spectrometry. For comparison, the radioactivity of control was arbitrarily set at 1. Results were expressed as means±s.e.m. of three separate experiments.