Aşan E, Kaymaz F F, Cakar A N, Dağdeviren A, Beksaç M S
Department of Histology and Embryology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
Ann Anat. 1999 Dec;181(6):549-54. doi: 10.1016/S0940-9602(99)80060-0.
In this study we examined the chorionic villi of 5 normal human placentas at 12-14 weeks of gestation ultrastructurally with regard to differentiation of the vascular components. The aim of the present report is to discuss the factors influencing vasculogenesis (in situ formation of blood vessels) at the ultrastructural level. Our observations have led us to think that the cytotrophoblast influences vasculogenesis in human chorionic villi. Mesenchymal-preendothelial cell groups were always found in very close association with the cytotrophoblast at the periphery of the villi, forming blood vessels. The cytotrophoblast probably attracts mesenchymal cells towards the margin of the villi by secreting vascular endothelial growth factor (VEGF). Once cells attach to the trophoblastic basement membrane they begin to differentiate into endothelial cells. This close structural relation between two cell types (cytotrophoblast and mesenchymal cells) may not be the only mechanism controlling vasculogenesis, but it seems to be one of the factors influencing the differentiation of mesenchymal cells into the endothelial cells of blood vessels in early human chorionic villi.
在本研究中，我们对5例妊娠12 - 14周的正常人类胎盘绒毛进行了超微结构检查，以观察血管成分的分化情况。本报告的目的是在超微结构水平上探讨影响血管生成（血管原位形成）的因素。我们的观察结果使我们认为，细胞滋养层影响人类绒毛膜绒毛中的血管生成。在绒毛周边，间充质前内皮细胞群总是与细胞滋养层紧密相连，形成血管。细胞滋养层可能通过分泌血管内皮生长因子（VEGF）将间充质细胞吸引到绒毛边缘。一旦细胞附着于滋养层基底膜，它们就开始分化为内皮细胞。这两种细胞类型（细胞滋养层和间充质细胞）之间紧密的结构关系可能不是控制血管生成的唯一机制，但它似乎是影响早期人类绒毛膜绒毛中间充质细胞分化为血管内皮细胞的因素之一。
