【作者】 王静波；

【导师】 史常旭；

【作者基本信息】 第三军医大学 ， 妇产科学， 2003， 硕士

【摘要】 妊娠肝内胆汁淤积症（intrahepatic cholestasis of pregnancy，ICP）是一种妊娠特发性肝脏疾病，主要发生于妊娠中晚期，以皮肤瘙痒、黄疸、血清胆汁酸升高、肝功轻至中度异常为主要特点，发病具有明显的地域性和季节性差异。ICP对孕妇的影响较轻，皮肤瘙痒和生化异常多于产后2-4周自行恢复，未见孕妇死亡的报道。其主要危害在胎儿，可造成羊水粪染、早产、胎儿窘迫和围生儿死亡等多种不良结局，由于发病机制不清，难以采取有效的监护手段预测胎儿的宫内状况。 胎盘作为母胎连接的桥梁和胎儿营养供应的唯一中介，其功能状态与胎儿发育密切相关，胎盘血流量的调节更是其中的中心环节，在胎儿的成长过程中具有不可替代的重要作用。由于胎盘是一个无神经支配的器官，局部分泌的血管舒缩激素水平可通过内分泌和旁分泌途径直接影响胎盘血管的舒缩和血流量的调节，与胎儿的营养供应和生长发育密切相关。在胎盘分泌的血管舒缩激素中，一氧化氮（nitric oxide，NO）/内皮素（endothlin，ET）、以及前列环素（prostacyclin，PGI2）/血栓烷A2（thromboxane A2，TXA2）是具有代表性的成员，其功能紊乱可导致胎盘血流量异常，是妊高症、早产、IUGR等多种母婴并发症的发病原因之一。为研究母体血清、脐血清、胎盘NO/ET、PGI2/ TXA2含量变化和ICP围生儿不良结局之间的关系，本实验通过建立ICP大鼠动物模型，采用放射免疫、免疫组化、半定量反转录PCR等方法，测定ICP大鼠和部分ICP患者血清、脐血清以及胎盘NO/ET、PGI2/ TXA2的表达变化，结果如下：1. 皮下注射EE可成功建立大鼠ICP模型，动物出现血清生化改变和胆酸水平升高，电镜下病变肝脏可见胆小管扩张、线粒体变性等形态学改变，同时孕鼠的胆汁淤积可累及胎鼠肝脏，即ICP大鼠的子代也存在肝内胆汁淤积。2. ICP孕妇血清舒缩因子与对照组相比无明显变化，但脐血清NO水平下降、ET水平显著升高，与对照组相比，有极显著性差异，表明ICP患者存在胎盘、脐带局部的血管舒缩激素失衡，并可能为ICP胎儿并发症的原因之一。ICP孕妇血清ALP和TBiL与胎儿体重呈显著负相关，可部分反映胎儿的宫内状况。3. ICP患者胎盘存在eNOS、iNOS和ET表达异常，其中eNOS、iNOS表达显著下降，而ET表达水平则明显上升，与脐血NO、ET水平的变化一致，可能是脐血清<WP=8>血管舒缩激素异常的重要原因之一。本实验结果表明：EE可建立稳定的大鼠ICP动物模型；ICP患者胎盘存在一定程度的内分泌功能紊乱，并导致了胎儿-胎盘局部血管阻力的异常升高，为探讨ICP母儿并发症的发生机制增添了一个新的研究途径。ICP导致血管舒缩因子分泌失调的具体机制尚不明确，是否与母体内胆汁酸浓度异常升高有关、以及NO、ET的分泌异常与母儿结局的关系仍需进一步研究。更多还原

【Abstract】 Intrahepatic cholestasis of pregnancy(ICP) ,or obstetric cholestasis,is a liver disease characterized by generalized skin pruritus with an increase in serum bile acids that appears during the second half of pregnancy ,lasts until the end of gestation,and disappears a few days after delivery.A mild abnormality in alanine aminotransferase may occur. There is considerable geographical and seasonal variation in the incidence of ICP. In the viewpoint of maternity, it is benign except that pruritus is severe. In the fetus, however, the course is not the case. The disease is closely related to a high incidence of perinatal complications, including an increased fetal distress and preterm delivery, a higher incidence of meconium passage and an increased perinatal mortality rate. Unfortunately,conventional fetal surveillance ,such as weekly nonstress tests and amniotic fluid volume assessment lack the ability to predict impending fetal demise in this condition.Some reports showed perinatal mortality ranges from 11%-20% in ICP women when untreated. In a review of published cases before 1988,the reported still birth rate in women of cholestasis was 10 of 1000 births, meconium staining in 27%, fetal distress occurred in 18% cases.The pathogenesis of fetal complicatioons has not been fully determined.As the singulare source of fetal oxygen and nutrition ,the role of placenta is very important in fetal growth and development. Many studies of the mechanism of fetal asphyxia in ICP have been performed in the aspects of placenta. Bile acid and meconium could result in umbilical vessels and placental chorionic veins constriction which may aggrevate fetal hypoxia. It has been reported that different kinds of vasoactive substances can be secreted by human placenta trophoblast, which took part in controlling blood flow by autocrine, paracrine and endocrine pathway.In order to explore the pathogenesis of fetal distress in , we measured the levels of nitric oxide /endothelin, prostacylin /thromboxane A2 in serum which drawn from ICP rat and ICP patients as well as umbilical vein. The expression of endothlin nitric oxide synthase, inducible nitric oxide synthase and endothelin in human placenta were investigated used immunohistochemical method. The semi-quantative reverse polymerase chain reaction were<WP=6>used to investigated the expression of induced nitric oxide synthase in human placenta.The following conclusion may be achieved in this study:1.ICP rats model may be successfully established by treated with 17-а-ethinylestradiol(EE), inject subcutaneously for five days, 2.5mg/kg/day. Compared with control group,the serum levels of ALP and ALT in EE group increased significantly. There was no marked change in hepatocytes of EE group under hematoxylin-eosin staining and the same as bile canaliculi under silver nitrate staining. In hepatocyte of EE group, mitochondria swelling and bile canaliculi dilated under electron microscope. The same ultrastructure changes have been seen in hepatocyte of their fetal rats.Correspondingly, body weight and live birth of the fetal rats in EE group were lighter and shorter than those of control group significantly. 2.Compared to control group,the values of vasoactive substances in serum of ICP rats and ICP patients were not significantly different, except that the levels of NO in ICP rats was significantly higher than those of control rats,which is probably resulted from the application of estrogens.But in serum of umbilical blood of ICP patients, the values of NO decreased and ET increased significantly than those of normal pregnancy, which may effect the regulation of placental blood and may be one of the causes for human placenta dysfunction and high impedance of fetoplacental circulation. In addition, the relationship between levels of ALP and TBiL in serum of ICP patients and fetal weight were significantly negative, which indicated ALP and TBiL may be useful in the prediction of fetal conditions.3. The expression of inducible and endothlin nitric oxide synthase as well as t更多还原