Figure 6: Activation of primary rat alveolar macrophages with IFN- γ and IL-4 replicates the effects seen in NR8383 cells. (A) Fortyeight hours after treatment with IFN-γ and IL-4, gene expression of Arg1 and iNOS was assessed in primary rat alveolar macrophages. Relative to the IFN-γ-treated cells, IL-4-treated cells were significantly skewed toward the M2 state, as reflected by an elevated Arg1/iNOS ratio. Data presented as relative fold change on log scale, mean ± SEM, n=4. *p<0.05. (B) Primary rat alveolar macrophages treated with IFN-γ or IL-4 were challenged with 5 mU/ml GOX. After four hours, remaining H2O2 concentration was assessed by Amplex Red Assay. Cells treated with IFN-γ were significantly better at scavenging hydrogen peroxide. Data presented as relative scavenging activities compared to IL-4-treated cells, mean ± SEM, n=4, *p<0.05. (C) After forty-eight hours of treatment with IFN-γ or IL-4, gene expression of GCLC was assessed in the two groups as a surrogate for Nrf2 nuclear binding. Expression was significantly higher in cells treated with IFN-γ. Data presented as relative gene expressions, mean ± SEM, n=5, *p<0.05.