Wooding F B, Morgan G, Adam C L
The Babraham Institute, Cambridge, England.
Microsc Res Tech. 1997;38(1-2):88-99. doi: 10.1002/(SICI)1097-0029(19970701/15)38:1/2<88::AID-JEMT10>3.0.CO;2-A.
The ruminant placenta has a very uniform gross structure based on localised areas of fetomaternal membrane apposition and proliferation to form placentomes. There is no consistency, however, in the number or size of these placentomes (6-150), nor in the villus architecture of the individual placentome. The one consistent feature is the binucleate cell (BNC) population in the trophoblast. These BNC form 15-20% of the epithelium in all ruminants examined so far. They synthesise the placental lactogen hormone and other glycoproteins and migrate through tight junctions to fuse with a uterine epithelial cell to form initially fetomaternal hybrid trinucleate cells (TNC) and subsequently syncytial plaques (SP). Such SP may be transient or persist throughout pregnancy depending on the species. The wide range of deer species examined confirms the uniformity of the BNC hormone production, migration, and fusion pattern described for other ruminants. BNC migration produces predominantly transient TNC, but there are areas of SP largely restricted to the apex of the maternal crypts. Maternal large granule lymphocytes (LGL) are uniquely found in deer placentomal uterine epithelium; they are usually closely associated with TNC and SP sites, but the significance of the interactions remains to be established.
反刍动物胎盘具有非常统一的大体结构，其基于胎儿与母体胎膜贴附及增殖的局部区域形成胎盘小叶。然而，这些胎盘小叶的数量或大小（6 - 150个）以及单个胎盘小叶的绒毛结构并无一致性。一个始终存在的特征是滋养层中的双核细胞（BNC）群体。在目前所检查的所有反刍动物中，这些双核细胞占上皮细胞的15% - 20%。它们合成胎盘催乳素激素和其他糖蛋白，并通过紧密连接迁移，与子宫上皮细胞融合，最初形成胎儿 - 母体杂交三核细胞（TNC），随后形成合体斑块（SP）。根据物种不同，这种合体斑块可能是短暂的，也可能在整个孕期持续存在。对多种鹿类物种的广泛研究证实了所描述的双核细胞激素产生、迁移和融合模式在其他反刍动物中的一致性。双核细胞迁移主要产生短暂的三核细胞，但也有合体斑块区域，主要局限于母体隐窝的顶端。母体大颗粒淋巴细胞（LGL）独特地存在于鹿胎盘小叶的子宫上皮中；它们通常与三核细胞和合体斑块部位紧密相关，但其相互作用的意义尚待确定。
