产前应用地塞米松对先天性膈疝大鼠模型胎肺发育及Wnt7b表达的影响  

Effects of fetal lung development and the expression of Wnt7b after exposure to prenatal dexamethasone in rat model of congenital diaphragmatic hernia

作　　者：肖尚杰[1] 何秋明 杨文熠[1] 朱士博 夏慧敏 

机构地区：[1]广东省妇幼保健院新生儿外科,511400 [2]广州市妇女儿童医疗中心新生儿外科

出　　处：《中华小儿外科杂志》2014年第3期212-217,共6页Chinese Journal of Pediatric Surgery

基　　金：广东省自然科学基金（7002325）

摘　　要：目的研究产前应用地塞米松（Dex）对除草醚（Nitrofen）诱导的先天性膈疝（congenitaldiaphragmatichernia，CDH）大鼠模型中胎肺发育及胎肺中wnt7b表达的影响，探讨地塞米松改善CDH肺发育不良的可能机制。方法采用数字随机法将12只孕鼠分为3组，利用Nitrofen诱导制作CDH胎鼠模型。其中，地塞米松组（CDH＋Dex组）与CDH组在孕第9．5天给予Nitrofen，前者产前应用地塞米松治疗，后者则不予地塞米松治疗，未作任何治疗的正常胎鼠为对照组。于孕21．5d行剖腹产，解剖胎鼠，取出胎肺。采用组织学检查方法评估各组胎肺的发育情况。采用实时荧光定量PCR方法检测各组胎肺中Wnt7bmRNA的表达情况。采用免疫组织化学方法检测各组胎肺中wnt7b蛋白的表达情况。结果成功构建CDH胎鼠模型。对照组胎肺发育较为成熟，CDH组胎肺发育明显滞后，CDH＋Dex组胎肺发育有所改善。对照组、CDH组和CDH＋Dex组的平均肺泡面积分别为（1443．37±285．94）μm2、（332．83±72．19）μm2和（929．36±110．31）μm2；平均肺泡间隔厚度分别为（6．17±1．54）μm、（9．72±2．18）μm和（7．01±1．32）μm；肺血管数／HP分别为（7．20±0．91）个、（3．68±1．03）个和（6．84±0．78）个；管腔面积占血管总面积比分别为（38．74±4．94）％、（15．76±4．87）％和（37．12±7．03）oA。与对照组相比，CDH组胎肺平均肺泡面积减少，平均肺泡间隔增厚，每高倍视野肺血管数减少，血管管腔狭窄，组间差异均有统计学意义（均P〈0．01）；与CDH组相比，CDH＋Dex组胎肺平均肺泡面积增大，平均肺泡间隔厚度减小，每高倍视野肺血管数增加，血管管腔增大，组间差异亦有统计学意义（均P〈0．01）。以21．5d胎龄的对照组胎肺作为对照样本，CDH组和CDH＋Dex组胎肺Wnt7bmRNA的相对表达量分别为1．58±0．19和0．72±0．15。CDH组Objective To explore the effects of antenatal administration of dexamethasone （Dex） on fetal lung development and the expression of Wnt7b in rat model of nitrofen-induced congenital diaphragmatic hernia （CDH） and elucidate the possible mechanism of prenatal dexamethasone in improving pulmonary hypoplasia associated with CDH. Methods A total of 12 pregnant rats were randomly divided into CDH ± Dex, CDH and control groups. CDH was induced in pregnant rats after a dose of 100 mg nitrofen at Day 9. 5 of gestation （term, 22 days）. Dex （0. 4 mg/kg） was given by an intraperitoneal injection at Days 18. 5 and 19. 5 of gestation. Cesarean section was performed at Day 21 of gestation. The fetuses were divided into 3 group of A, control~ B, nitrofen- induced CDH; C, nitrofen-induced CDH with antenatal Dex treatment. The histological structures offetal rat lungs were observed microscopically. The parameters of area of alveolar space, thickness of alveolar septum, number of pulmonary artery and diameter of pulmonary artery were compared to examine the lung development. The expression of Wnt7b mRNA in fetal lungs was detected by real- time quantitative polymerase chain reaction （PCR）. And the expression of Wnt7b protein was detected by immunohistochemistry. Results Histological detection showed that prenatal Dex dosing improved lung development in CDH rats. The alveolar space of control, CDH and CDH ± Dex groups was （1 443. 37 ± 285.94）, （332. 83 ± 72. 19） and （929. 36 ± 110. 31）μm2 respectively, the thickness of alveolar septum （6. 17 ± 1.54）, （9. 72 ± 2. 18） and （7. 01 ± 1.32） gm, the number of pulmonary artery （7. 20 ± 0. 91）, （3. 68 ± 1.03） and （6. 84 ± 0. 78） and diameter of pulmonary artery （38. 74 ± 4. 94） %, （15.76 ± 4. 87）% and （37. 12 ± 7. 03）%. At Day 21, Wnt7b relative mRNA expression in CDH and CDH ± Dex groups was 1.58 ± 0. 19 and 0. 72 ± 0. 15 compared to control group. The Wnt7b expression in CDH group was significantly higher

关 键 词：疝 横膈 支气管肺发育不良 地塞米松 

分 类 号：R965[医药卫生—药理学]