(a) Respiratory mechanics in 8 week old HO-1 transgenic mice exposed to hyperoxia as neonates. Inspiratory capacity, resistance, compliance, elastance, tissue elastance, and tissue damping, were measured. Values are the mean ± SEM of 3 separate determinations in each group. *, p<0.05; ** vs normoxia; p<0.01 vs normoxia; †, p<0.01 vs WT. (b, c) Lung MRI in 4 day old HO-1 transgenic mice exposed to hyperoxia as neonates. (b) Percent ratio of lung density to total lung volume calculated using the Vitrea software after outlining the lung with a computer-assisted free-outline technique. Each value is shown as an empty (normoxia) or filled (hyperoxia) triangle. There are no statistical differences among groups. (c) Representative transverse, coronal, and three-dimensional reconstruction images of HO-1-FL(H) lungs exposed to 3-day hyperoxia as neonates. Dotted line outline the lung density.