Figure 4: CCSP, SCGB3A2, and SCGB3A1 mRNA levels. mRNA was isolated from tissues obtained from (a) 7 d, (b) 14 d, and (c) 28 d animals exposed to room air or 85% O2 as indicated. CCSP, SCGB3A2, and SCGB3A1 mRNA levels were determined by qRT-PCR. Data (mean ± SEM, –6) was normalized to β-actin and represent fold change from d1 room air. Data were analyzed by two-way ANOVA followed by Tukey’s multiple comparison test post hoc. ( ).