Mayhew T M, Wadrop E, Simpson R A
Department of Human Morphology, University of Nottingham, UK.
J Anat. 1994 Jun;184 ( Pt 3)(Pt 3):535-43.
A cross-sectional sample of human placentae was collected at 12-41 wk, and growth mechanisms within villous subcompartments (trophoblast epithelium, stroma and fetal capillary endothelium) were assessed using state-of-the-art design-based stereological methods. Physical disectors (adjacent pairs of sections) were used to count nuclei in syncytiotrophoblast and in cells of the cytotrophoblast, stroma and endothelium. The volumes of trophoblast and stroma and the surface areas and lengths of capillaries were employed to assess the overall growth of each compartment. Growth within compartments was monitored as total number of nuclei (a measure of nuclear proliferation) and compartment size per nucleus (a measure of hypertrophy). During gestation, all compartments grew dramatically. Numbers of nuclei increased exponentially and followed an uninhibited growth model. Volumetric growth of the placenta did not keep pace with the increase in total nuclear number (all types). Growth of trophoblast was exclusively hyperplastic and proceeded at an average net recruitment rate of 15 million nuclei per hour with a numerical predominance of syncytiotrophoblast nuclei of 9:1. There was no evidence of hypertrophy: trophoblast volume per nucleus averaged 1080 microns 3. Growth within stroma involved cell proliferation (17 million nuclei per hour) and the volume of stroma per nucleus declined at a rate of about 24 microns 3 per week. Capillary growth was hyperplastic (5 million endothelial squames per hour) and, possibly, hypertrophic (the mean area of a squame increased by about 18 microns 2 per week). Linear growth of vessels exceeded cellular recruitment and the density of squames along the capillaries decreased each week by about 5 per mm.(ABSTRACT TRUNCATED AT 250 WORDS)
收集了12至41周的人胎盘横断面样本，并使用基于设计的先进体视学方法评估绒毛亚区（滋养层上皮、基质和胎儿毛细血管内皮）内的生长机制。使用实体解剖器（相邻切片对）对合体滋养层以及细胞滋养层、基质和内皮细胞中的细胞核进行计数。利用滋养层和基质的体积以及毛细血管的表面积和长度来评估每个亚区的整体生长情况。各亚区内的生长情况通过细胞核总数（核增殖的一种度量）和每个细胞核的亚区大小（肥大的一种度量）进行监测。在妊娠期，所有亚区均显著生长。细胞核数量呈指数增长，遵循无抑制生长模型。胎盘的体积增长未能跟上总细胞核数量（所有类型）的增加。滋养层的生长完全是增生性的，平均净招募率为每小时1500万个细胞核，合体滋养层细胞核在数量上占主导，比例为9:1。没有肥大的证据：每个细胞核的滋养层体积平均为1080立方微米。基质内的生长涉及细胞增殖（每小时1700万个细胞核），每个细胞核的基质体积以每周约24立方微米的速度下降。毛细血管的生长是增生性的（每小时500万个内皮鳞片），并且可能是肥大性的（每个鳞片的平均面积每周增加约18平方微米）。血管的线性生长超过细胞招募，沿毛细血管的鳞片密度每周下降约5个/毫米。（摘要截断于250字）
