Pulmonary hypoplasia is a common cause of neonatal morbidity and is due to many factors, including congenital diaphragmatic hernia (CDH) and oligohydramnios (O). We hypothesized that epidermal growth factor (EGF), believed to have a role in growth of the fetal lung, may differ in its effect on pulmonary hypoplasia due to these conditions. We induced pulmonary hypoplasia in fetal rats either by maternal ingestion of 2,4-dichlorophenyl-p-nitrophenyl ether (Nitrofen) (115 mg/kg) on day 11 of a 21 day gestation (n=10 litters), or by puncture of the amniotic sac on day 16 to induce O (n=20 litters). Organs were harvested at 21 days and EGF was determined in lung and liver by RIA. The EGF values were compared to those in control (C) fetuses (n = 7 litters). Data are mean ± s.e.m.Table

Table 1
Full size table

We conclude that although the lungs subsequent to CDH and O are of similar size, relative lung growth, but not liver growth, is greatly reduced in the CDH fetuses compared to O fetuses. In addition, EGF is significantly reduced per lung and per gram of lung, but not liver, in the CDH fetuses compared to O fetuses. We speculate that CDH leads to a greater inhibition of EGF production, and that EGF has a greater effect on lung than liver growth.