先天性膈疝大鼠模型肺内转化生长因子-β1表达的动态观察

摘要

Objective To assess the expression of transforming growth factor betal (TGF-β1) in the lung of Nitrofen-induced congenital diaphragmatic hernia (CDH) rat model.Methods Twelve timod-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 garage.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-β1 immunohistochemistry staining were performed with image analyzing.Results 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-β1 was detected in cytoplasmic,without definite expression in nuclear.It was significantly stronger that the expression of TGF-β1 was in the lungs of the CDH group than that of the control group (P<0.01).Conclusions Nitrofen interferes with lung development in early stage of the fetal before the diaphragm developed.TGF-β1 would be one of the important factors which lead to pulmonary hypoplasia.%目的 观察转化生长因子-β1(TGF-β1)在先天性膈疝(CDH)模型大鼠胎鼠肺内的表达情况.方法 12只成年雌性SD大鼠孕后9.5 d随机分为对照组和膈疝组,膈疝组给予Nitrofen125 mg/只灌胃,对照组给予等最食用油灌胃.至孕16 d,各组再随机分为3亚组,分别于孕16、18和21 d对孕鼠行剖宫产,观察胎鼠膈疝形成情况,记录孕21 d胎鼠体重和肺重;光镜下进行组织学观察和测量,免疫组织化学染色和图像分析对胎鼠肺内TGF-β1表达进行定位、定量分析.结果 膈疝组共有32只胎鼠形成膈疝,致畸率为72.7%.膈疝组孕21 d亚组肺重与体重之比小于相应时段对照组之亚组(P<0.01).膈疝组各亚组均存在肺发育不良,其发育明显滞后于对照组的相应亚组.两组TGF-β1免疫组织化学染色呈细胞质阳性.膈疝组各时期胎肺中TGF-β1的表达均强于对照组(P<0.01).结论 Nitrofen诱导的大鼠CDH模型在膈肌闭合之前,肺组织形态已有发育不良的表现.TGF-β1可能是导致肺发育不良的重要因子之一.