Rosiglitazone, a Peroxisome Proliferator-Activated Receptor-γ Agonist, Restores Alveolar and Pulmonary Vascular Development in a Rat Model of Bronchopulmonary Dysplasia

PURPOSE We tested whether rosiglitazone (RGZ), a peroxisome proliferator-activated receptor-γ agonist, can restore alveolar development and vascular growth in a rat model of bronchopulmonary dysplasia (BPD). MATERIALS AND METHODS A rat model of BPD was induced through intra-amniotic delivery of lipopolysaccharide (LPS) and postnatal hyperoxia (80% for 7 days). RGZ (3 mg/kg/d, i.p.) or vehicle was given daily to rat pups for 14 days. This model included four experimental groups: No BPD+vehicle (V), No BPD+RGZ, BPD+V, and BPD+RGZ. On D14, alveolarization, lung vascular density, and right ventricular hypertrophy (RVH) were evaluated. RESULTS Morphometric analysis revealed that the BPD+RGZ group had significantly smaller and more complex airspaces and larger alveolar surface area than the BPD+V group. The BPD+RGZ group had significantly greater pulmonary vascular density than the BPD+V group. Western blot analysis revealed that significantly decreased levels of vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 by the combined exposure to intra-amniotic LPS and postnatal hyperoxia were restored by the RGZ treatment. RVH was significantly lesser in the BPD+RGZ group than in the BPD+V group. CONCLUSION These results suggest that RGZ can restore alveolar and pulmonary vascular development and lessen pulmonary hypertension in a rat model of BPD.