Fig. 2.
NO synthase (NOS) inhibition enhances COX-2 induction in rat aortic SMCs. A: SMCs were pretreated with vehicle (n = 3) or NG-monomethyl-l-arginine (l-NMMA, 1 mmol/l; n = 3), an inhibitor of NOS, for 30 min before stimulation with LPS + IFN-γ, and COX-2 mRNA was detected by real-time PCR (expressed as fold increase over baseline). *P ≤ 0.05 vs. time zero; †P ≤ 0.05 vs. vehicle. B: SMCs were pretreated with l-NMMA (n = 4) or vehicle (n = 4) before stimulation with LPS + IFN-γ, and COX-2 expression was measured by Western blot analysis. C: SMCs were pretreated with various concentrations of l-NMMA (0.1–5.0 mmol/l; n = 5) before stimulation, and nitrite accumulation was determined by the Griess assay. D: SMCs were again treated with l-NMMA (0.1–5.0 mmol/l; n = 5) before stimulation and COX-2 expression was assessed. E: SMCs were pretreated with 1H-[1,2,4] oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 μmol/l; n = 4) or vehicle (n = 4) before stimulation, and COX-2 expression was measured by Western blot analysis. The ratio of protein of interest to actin control was expressed following densitometric analysis. Data are means ± SE. *P ≤ 0.05 vs. vehicle.