Figure 3
ET-1 induces COX-2 expression via a G i and G q proteins-coupled ET B receptor. (A, B) Cells were pretreated with Gi antagonist (GPA2) or Gq antagonist (GPA2A) for 1 h and then exposed to ET-1 for (A) 6 h and (B) 1 h. (C, D) Cells were transfected with siRNA for (C) Giα or (D) Gqα protein for 24 h and then exposed to ET-1 for 6 h. The (A, C, D) COX-2 protein and (B) mRNA were analyzed by Western blot and RT-PCR, respectively as described in Figure 1. Data are expressed as mean ± SEM of three individual experiments (n=3 in each group, #P<0.01 as compared with ET-1 alone).