| Background\purpose: Pulmonary hypoplasia is one of the most important reasons for the high morbidity and mortality of congenital diaphragmatic hernia(CDH). Despite surgical advances and advances in neonatal intensive care, mortality has still remained high. Then the research on how to improve antepartum fetal lung growth has become a focus. The teratogen Nitrofen produces a congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia in rodent fetuses that closely parallel observations made in humans. Tetrandrine(TET) is a alkaloid which is extracted from the root of Stephania tetrandra S.Moore which is a Menispermaceae plant of traditional Chinese medicine. It is mainly used clinically to treat hepatic fibrosis, hypoxia pulmonary artery hypertension and pneumosilicosis, etc. At this study, a CDH rat model was built to treat it with TET before parturition, and then to approach the effect of TET and its significance on transforming growth factor betal(TGF—β1) in the lung of Nitrofen-induced CDH rat model.Methods: Timed-pregnant Sprague-Dawley rats were divided into three groups, namely Control, Nitrofen and TET group on day 9.5 of gestation. Each rat in TET group and Nitrofen group was given 125 mg of Nitrofen (dissolved in seed fat) by garage. Each rat in the Control group, the same dose of single oil was given. Each rat in the TET group, TET 30mg/kg was given by gavage (once a day, for three days) on day 11.5 of gestation, each rat in the CDH group and the Control group, the same dose of NS were given. On day 16 of gestation, the three 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 a diaphragmatic hernia ,lung tissue weight (LW) and body weight (BW) of each fetus on gestational day 21 were recorded, lung histologic evaluations with microscope and electron microscope and TGF—β1 immunohistochemistry staining were performed, with image analyzed.Results: Diaphragmatic hernia was observed in 36 of the 47 rat fetuses of Nitrofen and TET groups on day 18 and day 21 of gestation (76.6%), the rate between Nitrofen and TET groups had no difference statistically (P=0.642) . Lw/Bw of subgroups of Nitrofen group and TET group were lower than those of corresponding Control group (P＜0.01), and Nitrofen group were lower than TET group(P＜0.01). Observed under the microscope and electron microscope, the lungs of fetuses in Nitrofen groups showed marked hypoplasia, in contrast to improvement in that of TET fetuses. The numbers of typeⅡpneumocytes in each group had no significant difference statistically (P=0.779) .The expression of TGF-β1 was detected as cytoplasmic and membranous staining, with no definite nuclear staining noted. The intensity of TGF-β1 staining markedly varied with general tendency for weaker staining in the lungs from CDH group and TET group to the Control group (all of the P＜0.01). Conclusion: On gestational day 16, proper pulmonary development in CDH is already impaired before the failed closure of the diaphragm. These data indicate that Nitrofen interferes with lung development in early of the fetal before and separate from diaphragm development. In this study, pulmonary hypoplasia followed with the rise of TGF-β1, indicates that TGF-β1 would be one of the most important factors which lead to pulmonary hypoplasia. In the lung of the fetuses with CDH ,the expression of TGF-β1 declined after the treatment with TET and the growth of the lung of the fetuses with CDH improved, which indicates TET can improve the growth of the lung of the Nitrofen-induced CDH fetuses by regulating the expression ofTGF-β1.
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