Antenatal vitamin A decreases ventilation-induced lung injury in the lamb model of congenital diaphragmatic hernia

OBJECTIVE: Infants with congenital diaphragmatic hernia (CDH) are susceptible to ventilation-induced lung injury. Vitamin A may protect the lung from injury during ventilation. The authors investigated the effects of antenatal vitamin A on ventilation-induced lung injury in CDH lambs using lung myeloperoxidase (MPO) activity as an indicator of lung injury. METHODS: Left-sided diaphragmatic defects were created in 10 lambs at 79-81 days' gestation. Six CDH lambs had right jugular venous catheters inserted at 120 days' gestation and were given vitamin A until 135 days' gestation. Four CDH lambs were not treated. Twin littermates (n = 3) served as controls. All lambs were delivered at 136-139 days of gestation and ventilated for 2 hours. Lambs were sacrificed following ventilation and samples of left lung were snap frozen. MPO was extracted from lung tissue and MPO activity was assayed. RESULTS: CDH lambs treated with antenatal vitamin A demonstrated significantly lower MPO activity than untreated CDH lambs (0.0477±0.0150 vs. 0.1106±0.0230 units/mg protein, p<0.05). CONCLUSION: This is the first study to look at the effect of vitamin A on lung injury in CDH. In the lamb model of CDH, antenatal vitamin A decreases ventilation-induced lung injury.