Kaufmann P, Schröder H, Leichtweiss H P
Placenta. 1982 Oct-Dec;3(4):339-48. doi: 10.1016/s0143-4004(82)80027-1.
The fetal side of the isolated guinea-pig chorio-allantoic placenta has been perfused with a fluid containing horseradish peroxidase. Electron micrographs show that protein is transferred across the fetal capillary endothelium via micropinocytosis as well as by transport through intercellular clefts. Under normal hydrostatic pressure no pinocytosis or other signs of fetomaternal protein transfer across the trophoblast have been observed. Instead, macrophages ingest the proteins that have reached the interstitial space between fetal endothelium and trophoblast. When the fetal venous pressure is raised up to 20 mmHg about 30 to 50 per cent of the arterial perfusion fluid, including proteins, is shifted into the maternal lacunae. In the beginning of this process slender tubules, and later on bag-like channels, appear that cross the trophoblast and probably connect lacunae and interstitium. The inner surface of the channels and the maternal lacunar surface are labelled by peroxidase. This indicates a fetomaternal transfer of proteins conveyed by the fluid shift. Protein transfer and fluid shift return to their previous levels when the fetal venous pressure is reduced. The size and number of channels are reduced but their structure and the reversibility of the events refute the possibility that they are of traumatic origin. It cannot be decided whether the channels are pre-existent but unrecognizable, or de-novo formations.
已用含有辣根过氧化物酶的液体对分离出的豚鼠绒膜尿囊胎盘的胎儿侧进行灌注。电子显微镜照片显示，蛋白质通过微胞饮作用以及通过细胞间裂隙的转运穿过胎儿毛细血管内皮。在正常静水压力下，未观察到跨滋养层的微胞饮作用或其他母胎蛋白质转运的迹象。相反，巨噬细胞摄取到达胎儿内皮和滋养层之间间隙的蛋白质。当胎儿静脉压升高至20 mmHg时，约30%至50%的动脉灌注液（包括蛋白质）会转移到母体腔隙中。在这个过程开始时，会出现细长的小管，随后是袋状通道，它们穿过滋养层，可能连接腔隙和间质。通道的内表面和母体腔隙表面被过氧化物酶标记。这表明通过液体转移实现了母胎蛋白质的转运。当胎儿静脉压降低时，蛋白质转运和液体转移恢复到先前水平。通道的大小和数量减少，但它们的结构以及这些事件的可逆性排除了它们是创伤性起源的可能性。无法确定这些通道是预先存在但未被识别，还是新生形成的。
