静脉注射免疫球蛋白对宫内感染胎鼠脑组织Toll样受体4表达影响的实验研究

The effect of intravenous immune globulin on Toll-like receptor 4 expression of brain tissues in fetal rats with intrau-terine infection

目的观察静脉注射免疫球蛋白(IVIG)对围产期炎症暴露的胎鼠及子鼠脑组织Toll样受体4(TLR4)的影响。方法将40只SD大鼠孕鼠随机分成干预组、实验组、对照组3组。干预组16只于受孕第17天给予脂多糖(LPS)腹腔注射,剂量为350μg/kg,制备宫内感染模型,取雌鼠后尾静脉,于造模成功后3h按2g/kg注射IVIG1次。实验组16只以相同的方法制备孕鼠宫内感染模型。对照组8只,在大鼠孕第17天给予等量生理盐水腹腔注射。取腹腔注射后的第24小时(孕第18天)、孕第19天、孕第21天以及生后1d。用苏木精-伊红染色法观察各组胎盘及各时间点脑组织的病理改变,比较各组胎鼠的体质量,用PCR法测得各组子鼠脑中TLR4-mRNA的含量,用免疫组织化学法观察各组各时间点脑组织TLR4的表达情况。结果实验组孕鼠胎盘及子宫壁充血水肿,白细胞浸润,子鼠脑白质水肿,并出现形态幼稚的细胞,甚至可见局灶性出血。实验组及干预组子鼠体质量出现不同程度减轻,与对照组比较,差异有统计学意义(P<0.01)。实验组与干预组子鼠脑内TLR4-mRNA及TLR4的表达量在不同时间点出现不同程度的增高。结论宫内LPS感染可导致胎儿脑组织炎性反应,及时使用IVIG可以减少小胶质细胞的持续活化从而抑制胎儿脑组织的炎症反应,降低脑损伤的程度,达到脑保护的作用。

Objective To observe the effect of IVIG on Toll-like receptor 4 expression of brain tissues exposed on perina- tal inflammation. Methods Forty pregnant SD rats were randomly divided into three groups：intervention group （LPS ＋ IVIG group） （16 rats）,in the 17th day of the conception, give them LPS intraperitoneal injection, with the dose of 350 μg/kg. Give 2 g/kg immune globulin injection from the female rats＂ tail vein three hours after the models were made; experimental group （LPS group）（16 rats）, use the same way to make intrauterine infection model of pregnant rats; Control group （NS group）（8 rats）,give intraperitoneal injection of normal saline at the 17th day of gestation. Take intraperitoneal injection of 24 hours （pregnant day 18）, pregnant day 19, pregnant day 21, and the day after birth. Observe the placenta and the point of time of the pathological changes of the brain tissue with hematoxylin-eosin staining;compare the weight of the fetal rat; PCR was used to measure the TLR4-mRNA content; immune staining was used to observe each group＇s TLR4 expression at each time point. Re- suits In the experimental group, pregnant rats placenta and uterine wall had congestion and edema,and there was leukocyte in- filtration,white matter edema and morphology of naive cells,or even visible focal hemorrhage. In experimental group and inter- vention group offspring weight had varying degrees of loss,there being significant differences compared to control group（P〈0.01）. In experimental group and the intervention group＇s offspring brain, the TLR4-mRNA and TLR4 expression volume are both increased at different time point. Conclusion Intrauterine LPS infection can lead to fetal brain tissue inflammatory re- sponse and giving IVIG timely can reduce the sustained activation of microglia, which inhibits fetal brain tissue inflammation, thereby reducing the extent of brain damage,and achieve the effect of brain protection.