Lung function and pulmonary artery blood flow following prenatal maternal retinoic acid and imatinib in the nitrofen model of congenital diaphragmatic hernia

Background: Lung and pulmonary vascular maldevelopment in congenital diaphragmatic hernia (CDH) results in significant morbidity and mortality. Retinoic acid (RA) and imatinib have been shown to improve pulmonary morphology following prenatal administration in the rat nitrofen-induced CDH model. It remains unclear if these changes translate into improved function. We evaluated the effect of prenatal RA and imatinib on postnatal lung function, structure, and pulmonary artery (PA) blood flow in the rat CDH model. Methods: Olive oil or nitrofen was administered alone or in combination with RA or imatinib to pregnant rats. Pups were assessed for PA blood flow by ultrasound and pulmonary function/morphology following delivery, intubation, and short-term ventilation. Results: Neither RA nor imatinib had a negative effect on lung and body growth. RA accelerated lung maturation indicated by increased alveoli number and thinner interalveolar septa and was associated with decreased PA resistance and improved oxygenation. With the exception of a decreased PA pulsatility index, no significant changes in morphology and pulmonary function were noted following imatinib. Conclusion: Prenatal treatment with RA but not imatinib was associated with improved pulmonary morphology and function, and decreased pulmonary vascular resistance. This study highlights the potential of prenatal pharmacologic therapies, such as RA, for management of CDH.