Effect of 11,12-EET on ERK phosphorylation in HUVECs: role of GPR40. Cells were pretreated with vehicle, MEK inhibitor U0126 (1 μm) (A), or GPR40 antagonist GW1100 (10 μm) (B). 11,12-EET (1 μm) was then added and incubation continued for 10 min. C, GPR40 protein level and knockdown in HUVEC treated with control and GPR40 siRNA for 48 h. D, effect of GPR40 knockdown on 11,12-EET-stimulated phospho-p42/44 (P-ERK). Both phospho-p42/44 (P-ERK) and total p42/44 (ERK) were measured by immunoblotting. Each value represent mean ± S.D. of three independent experiments. ** and * indicate p < 0.001 and p < 0.05, respectively, compared with the untreated control. ## indicates p < 0.005, compared with 11,12-EET alone. § indicates p < 0.05, compared with control siRNA with 11,12-EET.