Studies on the intrauterine substance and mechanism that accelerates fetal lung maturation

绒毛膜炎（CAM）被认为是早产的主要原因之一。有报道称，与未使用CAM分娩的早产儿相比，使用CAM分娩的早产儿的胎儿肺成熟加快，部分使用CAM分娩的早产儿被诊断为慢性肺部疾病，包括Wilson-Mikity综合征。这种早产儿的慢性肺部疾病对这些疾病产生影响。本研究旨在探讨羊水中中性粒细胞产生的活性氧是否参与了CAM胎肺成熟的促进作用，并通过在CAM胎肺中注入1 mM黄嘌呤+黄嘌呤氧化酶，（100 mU/ml、10 mU/ml、1 mU/ml、0.1mU/ml）系统（X/XO），于孕16天取羊水，于孕19天取胎肺。检测胎肺表面活性物质相关蛋白A、B、C（sp-A、B、C）mRNA的表达。RT-PCR检测孕19天X/XO组Sp-A、sp-B、sp-C mRNA表达较对照组明显升高。此外，我们还观察了别嘌呤醇和过氧化氢酶对sp-A、B、C mRNA表达的影响，认为X/XO引起羊水中活性氧自由基的增加是促进胎肺成熟的重要因素之一。

Chorioamnionitis (CAM) is considered as one of main causes of preterm delivery. It is reported that the fetal lung maturation of the premature infants delivered with CAM is accelerated compared with that of premature infants delivered without CAM.The parts of premature infants delivered with CAM are reported to diagnosed as having chronic lung disease including Wilson-Mikity syndrome. This chronic lung disease of premature infants exerts an influence on those prognoses. It is not clarified yet about the mechanism and substances that accelerate fetal lung maturation in CAM.Purposes of this study is to examine whether or not reactive oxygen species produced from the neutrophils that increase in amniotic fluid, involve as one of promotive substances of fetal lung maturation in CAM.We infused xanthine 1mM+xanthine oxidase (100mU/ml, 10mU/ml, 1mU/ml, 0.1mU/ml) system (X/XO) and produced reactive oxygen species in amniotic fluid in 16th day of pregnant wister rats and gather fetal lungs in the 19th day of gestation. We measured surfactant associated protein A,B,C (sp-A,B,C) mRNA in fetal lung. Sp-A,sp-B,sp-C mRNA of the group that administered X/XO obviously increased in comparison with that of control group of the 19th day of gestation by RT-PCR method. Also, we observed effects of allopurinol and catalase which attenuated the expression of sp-A,B,C mRNA.In conclusions, reactive oxygen species in amniotic fluid by X/XO administration were considered as one of the important factors which accelerate fetal lung maturation.