Jauniaux E, Gulbis B
Academic Department of Obstetrics and Gynaecology, Royal Free and University College London Medical School, UK.
Hum Reprod Update. 2000 May-Jun;6(3):268-78. doi: 10.1093/humupd/6.3.268.
The exocoelomic cavity was probably the last remaining physiological body fluid cavity to be explored in the human embryo. Its unique anatomical position has enabled us to study the protein metabolism of the early placenta and secondary yolk sac and to explore materno-embryonic transfer pathways. The exocoelomic cavity forms inside the extraembryonic mesoderm alongside the placental chorionic plate and is now believed to be an important transfer interface and a reservoir of nutrients for the embryo. Maternal or placental proteins filtered in the extraembryonic coelomic cavity are probably absorbed by the secondary yolk sac which is directly connected with the primitive digestive system throughout embryonic development. Protein electrophoresis has shown that the coelomic fluid results from an ultrafiltrate of maternal serum with the addition of specific placental and secondary yolk sac bioproducts demonstrating that the exocoelomic cavity is a physiological liquid extension of the early placenta. The selective sampling of fluid from the exocoelomic cavity has also offered a novel approach to the study of drug and toxin transfer across the early human placenta and as a unique tool to explore embryonic physiology in vivo. Further investigation should include a comparison between the coelomic fluid values of a molecule and its quantifiable presence in decidual, placental and fetal tissues.
胚外体腔可能是人类胚胎中最后一个有待探索的生理性体液腔。其独特的解剖位置使我们能够研究早期胎盘和次级卵黄囊的蛋白质代谢，并探索母胎转移途径。胚外体腔在胚外中胚层内沿着胎盘绒毛膜板形成，现在被认为是一个重要的转移界面和胚胎的营养储存库。在胚外体腔内滤过的母体或胎盘蛋白可能被次级卵黄囊吸收，次级卵黄囊在整个胚胎发育过程中与原始消化系统直接相连。蛋白质电泳表明，体腔液是由母体血清的超滤液加上特定的胎盘和次级卵黄囊生物产物形成的，这表明胚外体腔是早期胎盘的生理性液体延伸。从胚外体腔选择性采集液体也为研究药物和毒素跨早期人类胎盘的转移提供了一种新方法，并作为探索体内胚胎生理学的独特工具。进一步的研究应包括比较分子在体腔液中的值与其在蜕膜、胎盘和胎儿组织中的可量化存在情况。
