Effect of the superoxide scavenger MnTMPyP and inhibitor of NADPH oxidase apocynin on the uric acid–induced increase in the mRNA expression and protein release for MCP-1 in 3T3-L1 adipocytes. 3T3-L1 adipocytes were incubated in the presence of 15 mg/dL uric acid with or without MnTMPyP (25 μmol/L, 30-min preincubation), apocynin (200 μmol/L), or rosiglitazone (10 μmol/L) for 7 days. Medium was changed once during this period with the fresh aliquot containing the same additives and stored at −80°C to pool with the medium collected at the end of the treatment. Total mRNA was isolated from the monolayer while media were used for measuring concentration of adipokines. The effect of uric acid in the presence or absence of antioxidants is shown in A for the relative expression of the mRNA for MCP-1 and in B for the concentration of MCP-1 in the pooled conditioned medium. The effect of rosiglitazone on the urate-stimulated MCP-1 production is shown in C (relative mRNA expression) and in D for the released protein. The values are mean ± SEM for three independent experiments performed in triplicate. *P < 0.05 and **P < 0.01 (nonparametric Mann-Whitney U test) in comparison with untreated adipocytes. &P < 0.05 (nonparametric Mann-Whitney U test) for the effect of an antioxidant/rosiglitazone. CTRL, control; Rosi, rosiglitazone; UA, uric acid.