妊娠肝内胆汁淤积症患者脐带血管病变及血管活性物质的表达与胎儿窘迫发生的关系

目的 探讨妊娠肝内胆汁淤积症(ICP)患者脐带血管病理改变、脐带血管活性物质表达的变化与胎儿窘迫发生的关系.方法 应用HE染色法制片,光镜下观察25例ICP伴有胎儿窘迫(ICP窘迫组)、25例ICP不伴胎儿窘迫(ICP对照组)以及27例正常妊娠妇女(正常妊娠组)新生儿脐带血管病理改变;应用免疫组化辣根过氧化物酶-生物素标记(SABC)法测定内皮型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)及内皮素1(ET-1)蛋白在各组脐静脉内皮细胞中的表达量,以平均吸光度(A)值表示;应用循环酶法测定脐静脉血总胆酸水平并进行相关性分析.结果 (1)脐静脉血总胆酸水平:ICP窘迫组为(19.0±2.3)μmol/L,ICP对照组为(9.0±1.7)μmol/L,正常妊娠组为(4.4±1.5)μmol/L,各组分别比较,差异均有统计学意义(P＜0.05).(2)脐静脉病理改变:ICP患者脐静脉内皮细胞单层扁平结构丧失,细胞向管腔耸立,梭形排列,细胞排列不均甚至脱落.ICP窘迫组患者脐静脉内皮细胞出现此病理改变的发生率(92%,23/25)明显高于ICP对照组(68%,17/25),差异有统计学意义(P＜0.05).(3)脐静脉内皮细胞中eNOS蛋白表达量:ICP窘迫组为0.09±0.06,ICP对照组为0.21±0.08,正常妊娠组为0.47±0.07,各组分别比较,差异均有统计学意义(P＜0.05).脐静脉内皮细胞中iNOS蛋白表达量:ICP窘迫组为0.20±0.04,ICP对照组为0.21±0.05,正常妊娠组为0.26±0.04,两ICP组分别与正常妊娠组比较,差异均有统计学意义(P＜0.01,P＜0.05);而ICP窘迫组与ICP对照组间比较,差异无统计学意义(P＞0.05).(4)脐静脉内皮细胞中ET-1蛋白表达量:ICP窘迫组为0.49±0.08,ICP对照组为0.32±0.07,正常妊娠组为0.14±0.06,两ICP组分别与正常妊娠组比较,差异均有统计学意义(P＜0.01,P＜0.05).(5)脐静脉血总胆酸水平与其病理改变的关系:脐静脉血总胆酸水平升高是脐静脉病理改变的危险因素;且与脐血管内皮细胞eNOS、iNOS的蛋白表达量呈负相关关系(r1=-0.88、r2=-0.45,P＜0.01);与脐血管内皮细胞ET-1蛋白的表达量呈正相关关系(r3=0.79,P＜0.01).结论 ICP患者脐静脉血高胆酸状态可能损伤脐静脉内皮细胞,且与其eNOS、iNOS蛋白表达下调、ET-1蛋白表达上调有关,脐静脉的这些改变可能与ICP患者胎儿窘迫的发生有关.

Relationship of the occurrence of fetal distress and change of umbilical cord and expression of vasoactive substance in umbilical vein in intrahepatic cholestasis of pregnancy

OBJECTIVE: To investigate the changes of umbilical cord and the vasoactive substance in umbilical vein in intrahepatic cholestasis of pregnancy. METHODS: By HE staining method we analyzed the pathologic change of umbilical cord of 25 women with intrahepatic cholestasis of pregnancy (ICP) and fetal distress (ICP fetal distress group), 25 ICP women without fetal distress group (ICP control group) and 27 normal pregnancies (control group). The nitric oxide synthase (NOS) and endothelin-1 (ET-1) were detected in human umbilical vein endothelial cells (HUVEC) by immunohistochemistry method. Umbilical vein total bile acid (TBA) and NOS and ET-1 were measured. RESULTS: (1) A remarkable high TBA level was found in umbilical vein in ICP, and it was higher in ICP fetal distress group (19.0 +/- 2.3) micromol/L than in ICP control group (9.0 +/- 1.7) micromol/L (P < 0.05); it was higher in ICP control group than the control group (4.4 +/- 1.5) micromol/L (P < 0.05). (2) A significant difference was found in the endotheliocytes of umbilical vein in ICP fetal distress group compared with ICP control group. The ratio of cells with pathological changes in ICP fetal distress group (92%, 23/25) was higher than ICP control group (68%, 17/25; P < 0.05). The occurrence of the pathological changes was associated with TBA. (3) The expression of eNOS in ICP fetal distress group 0.09 +/- 0.06 was lower than in ICP control group 0.21 +/- 0.08 (P < 0.05), and it was lower in ICP control group than in control group 0.47 +/- 0.07 (P < 0.05). In contrast, the expression of ET-1 in ICP fetal distress group 0.49 +/- 0.08 was higher than in ICP control group 0.32 +/- 0.07 (P < 0.05), and it was higher in ICP control group than control group 0.14 +/- 0.06 (P < 0.05). The expression of inducible nitric oxide synthase (iNOS) in ICP fetal distress group 0.20 +/- 0.04 and ICP control group 0.21 +/- 0.05 was lower than in control group 0.26 +/- 0.04 (P < 0.05), but no significant difference was found in ICP fetal distress group and ICP control group (P > 0.05). (4) The expression of eNOS, iNOS and ET-1 was correlated with umbilical vein TBA in ICP (r1 = -0.88, r2 = -0.45, r3 = 0.9; P < 0.01), respectively. CONCLUSIONS: High level of TBA in ICP is harmful to the umbilical vein endothelium, which is correlated with the raised expression of ET-1, and the decreased expression of eNOS,and iNOS in human umbilical cord endothelium cells. All these changes of umbilical vein may be associated with the occurrence of fetal distress in ICP.