Figure 5

Effect of protein kinase inhibitors on p44 and p42 MAPK phosphorylation induced by UTP. (A) Western blot detection of phosphorylated p44 (white columns) and p42 (black columns) MAPK in the presence of 100 nM wortmanin or 250 nM staurosporine in theca cells stimulated or not with 10 μM UTP (5 min). In (B), down regulation of PKC was induced by an overnight (18 h) cell incubation with 1 μM PMA, and then phosphorylation of p44 and p42 MAPK was assayed for cells treated or not with 10 μM UTP (5 min). Data points represent the average optical density (± S.E.M.) of three independent experiments expressed as a percent of the basal level (*p < 0.05 vs. UTP, one-way ANOVA and Bonferroni's test).