Figure 5

Effect of delayed RA treatment on alveolarization: Animals were treated with either Dex or saline from d1-14 followed by either CSO or RA from d24-36. A simplified distal architecture was seen in Dex-treated animals at both d37 (top) and d52 (bottom). RA-treated pups had smaller more numerous alveoli at d37 with changes no longer seen at d52. Early Dex + Later RA treatment resulted in restored secondary septation that was similar to that of saline controls at d37, and this was sustained to d52. (all images 100× magnification)