Riley S C, Leask R, Balfour C, Brennand J E, Groome N P
Department of Obstetrics and Gynaecology, University of Edinburgh, 37 Chalmers Street, Edinburgh, UK.
Hum Reprod. 2000 Mar;15(3):578-83. doi: 10.1093/humrep/15.3.578.
Inhibins are regulators of paracrine and endocrine function during pregnancy, but their intrauterine sites of secretion are not well established. In amniotic fluid, inhibin A-, inhibin B- and inhibin pro-alphaC-containing isoforms were present in high concentrations, whereas in maternal serum, inhibin A and pro-alphaC forms were present in high amounts, with low concentrations of inhibin B. In fetal cord serum, inhibin pro-alphaC was present in all samples, inhibin B was detectable in male but not female fetuses, with no detectable inhibin A in either sex. From cultured explants, both inhibin A and B were secreted by chorion laeve, whereas only inhibin A was secreted by placenta, with both tissues secreting inhibin pro-alphaC. Only low concentrations of both dimeric inhibins and pro-alphaC forms were secreted by decidua parietalis and amnion. The dual perfused placental cotyledon secreted both inhibin A and pro-alphaC into maternal perfusate, but only inhibin pro-alphaC into the fetal circulation and less than to the maternal side. We conclude that trophoblast is the predominant source of dimeric inhibins, but with markedly different secretion depending on its intrauterine location. There was a significant decrease in inhibin A and pro-alphaC in amniotic fluid collected at term active labour compared to elective Caesarean section (P < 0.001). This may reflect a local change in inhibin/activin processing at labour, likely in chorion laeve trophoblast cells, which may be important in the paracrine control of the feto-maternal communication required to maintain pregnancy and initiate labour.
抑制素是孕期旁分泌和内分泌功能的调节因子，但其在子宫内的分泌部位尚未完全明确。羊水中，含抑制素A、抑制素B和抑制素前体αC的异构体浓度较高，而母血中，抑制素A和前体αC形式含量较高，抑制素B浓度较低。胎儿脐血中，所有样本均存在抑制素前体αC，男性胎儿可检测到抑制素B，女性胎儿则未检测到，两种性别均未检测到抑制素A。在培养的外植体中，绒毛膜分泌抑制素A和B，而胎盘仅分泌抑制素A，两种组织均分泌抑制素前体αC。子宫壁蜕膜和羊膜仅分泌低浓度的二聚体抑制素和前体αC形式。双灌注胎盘小叶向母体灌注液中分泌抑制素A和前体αC，但仅向胎儿循环中分泌抑制素前体αC，且分泌量少于母体侧。我们得出结论，滋养层是二聚体抑制素的主要来源，但根据其在子宫内的位置，分泌情况明显不同。与择期剖宫产相比，足月活跃分娩时收集的羊水中抑制素A和前体αC显著减少（P < 0.001）。这可能反映了分娩时抑制素/激活素加工的局部变化，可能发生在绒毛膜滋养层细胞中，这可能对维持妊娠和启动分娩所需的胎儿-母体通讯的旁分泌控制很重要。
