Merad Z, Wild A E
Department of Biology, School of Biological Sciences, University of Southampton, UK.
Placenta. 1992 May-Jun;13(3):291-304. doi: 10.1016/0143-4004(92)90044-t.
The route of IgM transport to the rabbit fetus was investigated by comparing its localization with that of IgG in the yolk sac splanchnopleure and uterine tissues using direct immunofluorescence and immunodiffusion analysis. IgM was first detected in fetal serum at 20 days of gestation but was present in uterine fluid at 18 days, the earliest stage tissues and fluids were examined. IgM was co-localized with IgG in the yolk sac endoderm basement membrane and in the vascular mesenchyme of the yolk sac splanchnopleure providing evidence of its transport to fetal blood; it was also present in vesicles in the yolk sac endoderm. IgM could not be detected in uterine fluid of nonpregnant uterine horns of rabbits unilaterally pregnant. Human IgM injected into the maternal circulation was readily transported to the uterine fluid and across the yolk sac splanchnopleure to fetal blood indicating that IgM secreting plasma cells, found to be present in the uterine stroma, contributed little towards IgM in the uterine fluid. Degenerating paraplacental decidual tissue, a feature of rabbit pregnancy, is suggested to be a major route for maternal immunoglobulin transport to the uterine fluid.
通过直接免疫荧光和免疫扩散分析，比较兔胎儿中IgM与IgG在卵黄囊脏壁层和子宫组织中的定位，研究了IgM向兔胎儿的转运途径。在妊娠20天时首次在胎儿血清中检测到IgM，但在妊娠18天时子宫液中就已存在IgM，这是最早检查组织和液体的阶段。IgM与IgG在卵黄囊内胚层基底膜和卵黄囊脏壁层的血管间充质中共定位，这为其向胎儿血液转运提供了证据；它也存在于卵黄囊内胚层的小泡中。在单侧妊娠的兔非妊娠子宫角的子宫液中未检测到IgM。注入母体循环的人IgM很容易转运到子宫液中，并穿过卵黄囊脏壁层进入胎儿血液，这表明子宫基质中发现的分泌IgM的浆细胞对子宫液中IgM的贡献很小。兔妊娠的一个特征是胎盘旁蜕膜组织退化，这被认为是母体免疫球蛋白转运到子宫液的主要途径。
