Figure 4

p44 and p42 MAPK phosphorylation induced by UTP is blocked by suramin but not by PPADS. Cultures of mouse theca cells were incubated for 30 min with suramin (A) or PPADS (B) at the indicated concentrations; subsequently, 10 μM UTP was applied for 5 min, and p44 (black dots) and p42 (white dots) MAPK phosphorylation was detected by Western blot. Data points are the mean ± S.E.M. of three independent experiments.