The Effect Of Tetrandrine And Its Significance On EGF And EGFR In The Lung Of Nitrofen-induced Congenital Diaphragmatic Hernia Rat Model

Background\purpose: The hypoplastic lung and persistent pulmonary hypertension are the principle causes of high mortality and morbidity in infants with congenital diaphragmatic hernia (CDH). The pathogensis of pulmonary hypoplasia in CDH is not understood fully. So the surgical repair of the hernia is relatively uneventful. Several other methods have been used to treat patients with CDH in utero, but the outcomes were also disappointing. Perhaps the most effective prevention and cure for CDH is to exploit new drugs to facilitate heart-lung development. The traditional Chinese medicine "Tetrandrine"(TET) is considered as a new calcium-channel blocker and has extensively been applied in the clinical treatment to pneumosilicosis, portal hypertension and pulmonary hypertension in China. To approach the effect of TET and its significance on epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) in the lung of nitrofen-induced CDH rat model, we designed this study.Methods: Sprague-Dawley rat with CDH was induced by maternaladministration of a single oral dose 115mg/kg of nitrofen to every rat on day 9.5 of pregnancy. Five groups of pregnant rats were designed on day 18.5: normal control (n = 4), CDH (n = 5), CDH plus Dex (n = 5), CDH plus Tet (n = 5), CDH plus Dex and Tet (n= 5). All fetuses were delivered by cesarean section on day 21. Accordingly, there were 5 groups of fetuses: normal controls (n = 36), nitrofen-induced CDH (n = 34), CDH plus Dex treatment (n = 34), CDH plus Tet treatment (n = 37), CDH plus Dex and Tet (n = 32). Lung tissue weight (LW) and body weight (BW) of each fetus were recorded, lung histologic evaluations and EGF, EGFR immunohistochemistry staining were performed with image analyzed.Results: CDH was observed in 64 of the 137 rat fetuses (46.7%). Lw/Bw of CDH group was lower than those of Dex , Tet, Dex+Tet and the normal contrast (P <0.05). The lungs of CDH fetuses showed marked hypoplasia, in contrast to improved mesenchymal differentiation in that of Dex, Tet, Dex+Tet fetuses. The expression of EGF and EGFR was detected as cytoplasmic and membranous staining, there was no definite nuclear staining noted. The intensity of EGF staining markedly varied with general tendency for weaker staining while EGFR expressed stronger and stronger in the lungs from CDH-NS, TET and DEX, T+D to the control (all of the P<0.05). It was found to be very similar compared the intensity of EGF and EGR expression in the lungs of TET with that of DEX (P<0.01), presence of CDH with that of absence of CDH (P<0.05), the herniated side with that of without herniaConclusion: Prenatal Tet administration had shown marked improvement in pulmonary hypoplasia that maybe through pre-regulating crest-time of EGF express and up-regulating EGFR express in the lungs of nitrofen-induced CDH rat model. Application with Tet and Dex associated would generate evident synergistic effect. The closure of diaphragm maybe require a normally developed lung and that pulmonary hypoplasia should be the cause of rather than the result of CDH.