ABSTRACT
<p><b>OBJECTIVE</b>To access the expression of transforming growth factor beta1 (TGF-beta1) in the lung of Nitrofen-induced congenital diaphragmatic hernia rat model.</p><p><b>METHODS</b>Twelve timed-pregnant Sprague-Dawley rats were randomly divided into two groups, namely control group and CDH group on day 9.5 of gestation. Each rat in the CDH group was given 125 mg of Nitrofen (dissolved in seed fat) by gavage. Each rat in the control group was given the same dose of single oil. On day 16 of gestation, the two groups mentioned above were divided into three subgroups, and fetuses were delivered by cesarean section respectively on day 16, 18 and 21 of gestation. After the fetuses were checked for diaphragmatic hernia, lung tissue weight (LW) and body weight (BW) of each fetus on gestational day 21 were recorded. Lung histologic evaluations were made with microscope and TGF-beta1 immunohistochemistry staining were performed with image analyzing.</p><p><b>RESULTS</b>At day 16 of gestation, no visible diaphragm closure was observed in all fetuses. Diaphragmatic hernia was observed in 32 of the 44 rat fetuses of the CDH groups on day 18 and day 21 of gestation (72.7%). Lw/Bw of the 21d subgroups of CDH group were lower than those of corresponding control group (P < 0.01). Observed under the microscope, the lungs of fetuses in CDH groups showed marked hypoplasia. The expression of TGF-beta1 was detected in cytoplasmic, without definite expression in nuclear. It was significantly stronger that the expression of TGF-beta1 was in the lungs of the CDH group than that of the control group (P < 0.01).</p><p><b>CONCLUSIONS</b>Nitrofen interferes with lung development in early stage of the fetal before the diaphragm developed. TGF-beta1 would be one of the important factors which lead to pulmonary hypoplasia.</p>