妊娠早期人胎盘绒毛血管紧张素的研究

STUDIES ON ANGIOTENSIN IN HUMAN PLACENTAL VILLI DURING THE FIRST TRIMESTER OF GESTATION

用生化提取、放射免疫测定及离体培养技术研究了妊娠早期人胎盘绒毛血管紧张素的含量与 变化，观察了血管紧张素Ⅱ对早孕胎盘人绒毛膜促性腺激素（ｈＣＧ）分泌的影响，并用ＡＢＣ法探 讨了血管紧张素Ⅱ的免疫组织化学定位。结果表明：妊娠６～１０周的人胎盘绒毛组织均检测到血管 紧张素，其含量随妊娠周龄增加而升高；离体培养的６～９周人胎盘绒毛亦能分泌血管紧张素，培 液中血管紧张素的水平与妊娠周龄呈平行关系；然而妊娠６～１０周母血中血管紧张素的含量无明 显变化。免疫组织化学结果指出早孕胎盘绒毛有ＡⅡ免疫阳性反应物质．免疫阳性物主要分布在合 体滋养层细胞内；在离体培养条件下，血管紧张素Ⅱ能刺激离体培养的人胎盘绒毛ｈＣＧ的分泌，其 受体阻断剂 ［Ｓａｒ１Ｉｉｅ８］ ＡｎｇⅡ（１０－８～１１－７ｍｏｌ／Ｌ）对 ｈＣＧ分泌无影响，当 ［Ｓａｒ１ Ｉｉｅ８］ ＡｎｇⅡ浓度 达１０－６ｍｏｌ／Ｌ时，绒毛ｈＣＧ分泌量显著降低。

The contents, localization of AugⅡ and the effect of Aug Ⅱ on hCG release were investigated in human placental villous tissue during the first trimester of gestation. Aug Ⅱ were detected by RIA in placental villi of 6-10 weeks of gestation, and its contents gradually increased with weeks of gestation. In vitro, AugⅡ was released into medium from explants of villous tissue at 6-9 weeks of gestation, and Aug Ⅱ concentrations in media were elevated in parallel With weeks of gestation. The levels of AugⅡ were much lower in maternal plasma than that of placental villi, and no significant change was found at the same time. The immunohistochemistry showed that Ang Ⅱ positive reaction existed in sync ytiotrophoblast cells. Funthermore,exogenous Aug Ⅱ stimulated hCG release in a dose dependent fashion. [Sar1 Ile8]Ang Ⅱ (AugⅡ antagonist)at 10-6mol/L inhibited hCG secretion. Therefore, we reasoned that human placental villi is one of the source for Aug Ⅱ generation during early pregnancy. The presence of component of the renin-angiotensin system (RAS) points to the possibility for local RAS in human placental villi at the first trimester.