Fig. 4

Acute hyperoxia resulted in an adequate oxidative stress response and caffeine reduced the response. Quantitation of lung homogenates by ELISA of a) total glutathione, b) H₂O₂, c) HO-1, and d) MDA/ lipid peroxidation with 3 days’ postnatal oxygen exposure (P3) and recovery (P3_P15) and 5 days’ postnatal oxygen exposure (P5) and recovery (P5_P15), respectively. Data are expressed relative to the normoxia-exposed control group (100%) and the 100% values are a) 19.2 μM/mg, 13.4 μM/mg, 17.8 μM/mg, and 13.7 μM/mg protein, b) 1.8 μM/mg, 3.1 μM/mg, 1.0 μM/mg, and 3.0 μM/mg protein, c) 17.2 ng/mg, 5.9 ng/mg, 20.0 ng/mg, and 5.2 ng/mg protein, and d) 3.3 μM/mg, 3.7 μM/mg, 1.3 μM/mg, and 3.3 μM/mg protein for P3 and P3_P15 or P5 and P5_P15 groups, respectively. Error bars represent SEM, n = 5/group. *p < 0.05 and **p < 0.01 versus control (NO); #p < 0.05 and ##p < 0.01 versus hyperoxia group (HY) with Mann Whitney test