Vitamin A decreases the incidence and severity of nitrofen-induced congenital diaphragmatic hernia in rats

Abstract

Congenital diaphragmatic hernia (CDH) is a major cause of refractory respiratory failure in the newborn. Pulmonary hypoplasia often limits survival. Vitamin A (Vit A) is an important signal for lung growth. We hypothesized that antenatal treatment with Vit A would stimulate lung growth and decrease mortality in experimental CDH induced in rats by ingestion of the herbicide nitrofen (2,4-dichlorophenyl- p-nitrophenyl ether). Nitrofen was administered to pregnant rats on day 12 of gestation (term 22 days). Rats were assigned to five groups: three groups received one dose of oral antenatal Vit A (15,000 IU) before ( day 10), concomitant with ( day 12), or after ( day 14) nitrofen administration; one group received only nitrofen; and a control group received vehicle (olive oil). The incidence of CDH was markedly lower in all groups receiving Vit A ( day 10, 44%; day 12, 20%; and day 14, 40%) compared with the nitrofen-treated group (84%; P < 0.05). The 72-h survival was higher in all 3 Vit A-treated groups ( day 10, 40%; day 12, 58%; and day 14, 70%) compared with the nitrofen-treated group (16%; P< 0.05). Lung-to-body weight ratio and radial saccular count were significantly increased by Vit A. Antenatal treatment with Vit A lowers the incidence and severity of experimental CDH and increases lung growth and maturation.