Figure 4.

Differential effects of formoterol on basal, thrombin- and PDGF-induced ERK1/2 phosphorylation in human PAVSM cells. A: (R,R) and racemic, but not (S,S) formoterol inhibit ERK1/2 phosphorylation in human PAVSM cells. Cells serum-deprived for 48 h were treated with 10 μM (R,R), (S,S), racemic formoterol or diluent for 30 min followed by immunoblot analysis with anti-phospho ERK1/2 and anti-total ERK1/2 antibodies. Top panel: Images are representative of three independent experiments. Bottom panel: Statistical analysis of three separate experiments, n = 3 for each experimental condition. Data represent mean values ± SE by ANOVA (Bonferroni-Dunn). Phospho-ERK/total ERK ratio for diluent-treated cells was taken as one fold. B: Cells serum-deprived for 48 h were treated with 1 U/ml thrombin, 10 ng/ml PDGF, or diluent for 30 min followed by immunoblot analysis with anti-phospho ERK1/2 and anti-total ERK1/2 antibodies. Top panel: Representative images from three independent experiments. Bottom panel: Statistical analysis of three independent experiments; n = 3 for each experimental condition. Data are mean values ± SE by ANOVA (Bonferroni-Dunn). Phospho-ERK/total ERK ratio for diluent-treated cells was taken as one fold. C, D: (R,R) formoterol inhibits thrombin-, but not PDGF-induced ERK1/2 phosphorylation in human PAVSM cells. Cells were serum-deprived for 48 h, incubated for 30 min with 10 μM (R,R), (S,S), or racemic formoterol in the presence or absence of 10 ng/ml PDGF, and then immunoblot analysis with anti-phospho-ERK1/2 and anti-total ERK1/2 antibodies was performed. C: Representative images. D: Statistical analysis of three separate experiments. Data are mean ± SE by ANOVA (Bonferroni-Dunn). Phospho/total ERK ratio for diluent-treated cells was taken as one fold. *p < 0.05 for diluent vs. (R,R) formoterol; **p < 0.01 for diluent vs. thrombin; ***p < 0.01 for thrombin vs. thrombin + (R,R) formoterol.