Effects of estrogen on lung development in a rat model of diaphragmatic hernia

PurposeThe study aimed to observe the influence of estradiol on rat models with congenital diaphragmatic hernia (CDH) and understand the potential mechanism.MethodsEleven pregnant female Sprague-Dawley rats were randomly divided into 3 groups on day 9.5 of gestation: group C (n = 2) was administered 2 mL of olive oil, whereas group N (n = 3) and group E (n = 6) were administered 200 mg of nitrofen. Antenatal estradiol was given subcutaneously to group E on days 18.5, 19.5, and 20.5 of gestation. Histologic evaluations, incidence of CDH, and the immunoreactivity of transforming growth factor (TGF)-β1 in lung were observed. In addition, the mRNA levels of TGF-β1, type I TGF-β receptor (TβRI), and type II TGF-β receptor (TβRII) were determined.ResultsHistologically, the lungs of group N fetuses were hypoplastic compared with those of group C and had thick-walled septa with poorly developed saccules. Group E showed improved mesenchymal differentiation with well-developed saccules. There was no significant difference between the incidence of CDH in group N and that in group E. The expression of TGF-β1 in lung tissue and arterioles in group N were significantly higher than those in group C and E. Moreover, relative mRNA expression levels of TGF-β1 and TβRI in group N were markedly higher than those in group C, whereas those in group E were significantly decreased compared with group N.ConclusionsEstradiol can promote lung development in rats with CDH. The down-regulation of TGF-β1 and its signaling pathway may play a role in this effect.