Figure 3

Ozone induced oxidative stress and changes of phosphorylation of p38 MAPK and expression of MKP-1 in lung tissues. A: Malondialdehyde (MDA) concentration in lung tissues supernatants measured spectrophotometrically. B: Activity of Glutathione peroxidase (GSH-Px) in lung tissue supernatants measured by spectrophotometry. C: Western blot analysis of phosphorylated and non-phosphorylated p38 MAPK. The activation of p38 MAPK was determined by the ratio between phospho- and non-phospho- p38 MAPK. The bands were cut from the film where the samples were blindly subjected to polyacrylamide gel electrophoresis and rearranged accordingly. D: Western blot analysis of phosphorylated MKP-1 (p-MKP-1) in lung tissues. This was determined as a ratio against β-actin. Band densities were determined and results plotted graphically for the 7 animals in each group. E: Fold change of MKP-1 mRNA in lung tissues tested by quantitative RT-PCR (n = 7). *:p < 0.05; **:p < 0.01; ***: p < 0.001.