细菌性宫内感染致早产大鼠模型的建立

The establishment of a rat model of intrauterine bacterial infection and preterm birth

目的复制大鼠细菌性宫内感染模型,并探讨其与早产发生的关系。方法将20只孕15d的大鼠随机分成感染组和对照组各10只,分别于子宫腔内接种1浊度大肠杆菌悬浮液和无菌生理盐水,于分娩后观察子宫和胎盘组织的病理变化及仔鼠的死产率、平均活胎数和早产发生率。结果感染组大鼠子宫和胎盘存在炎症反应,而对照组大鼠未见炎症反应。感染组大鼠共分娩108只幼仔,死产率为8.3%;对照组大鼠共分娩118只,死产率为3.4%,两组比较差别无显著性意义(χ2=2.542,P>0.05)。感染组每只大鼠平均活胎数为(9.90±2.42)只,对照组为(11.30±2.06)只,两组差别无显著性意义(t=1.392,P>0.05)。感染组大鼠早产发生率为70.0%,对照组大鼠为10.0%,两组比较差别有显著性意义(P<0.05)。宫内感染致早产的危险度分析:OR=21.000,95%CI=1.777～248.013。结论采用大肠杆菌宫内接种方法建立的宫内感染大鼠模型与亚临床型宫内感染相似,可增加早产发生率,利用该模型可进行宫内感染与早产儿疾病的发病机制研究。

Objective To develop a rat model of intrauterine bacterial infection and to investigate the relationship of intrauterine bacterial infection and preterm birth in the model.Methods Twenty female SD rats with15d of gestation were randomly divided into two groups:the infection group received intrauterine in-oculation of suspension of Escherichia coli,and control group received intrauterine injection of a sterile normal saline.The uterine and the placenta were examined histopathologically;and the number of stillborn rates,the live fetus and the incidence of preterm birth were observed.Results Intrauterine E.coli inoculation produced inflammation of uterine and placenta in all animals of infection group,but all cases of control group had no histological evidence of intrauterine infection.There were108fetuses from infection group and the stillborn rates were8.3%,118fetuses from control group and the stillborn rates were3.4%(χ 2 =2.542,P>0.05).The aver-age live fetus per rat were(9.90±2.42)and(11.30±2.06)in infection group and in control group respectively(t=1.392,P>0.05).Preterm birth occurred in70%of rats in treatment group and in10%in control group(P<0.05).By risk analysis,intrauterine infection had a high risk for preterm birth(OR=21.0,95%CI=1.777～248.013).Conclusions The established model in this study may be useful to investigation for mechanism of intrauterine infection leading to preterm conditions.[