Stoffel M H, Friess A E, Hartmann S H
Department of Veterinary Anatomy, University of Bern Veterinary School, CH-3012 Bern, Switzerland.
J Reprod Fertil. 2000 Mar;118(2):315-26.
In dogs, passive immunity is conferred to fetuses and neonates by the transfer of maternal immunoglobulin G through the placenta during the last trimester of pregnancy and via the mammary gland after parturition, respectively. However, morphological evidence of transplacental transport is still lacking. The aim of the present study was to localize maternal immunoglobulin G in the labyrinthine zone and in the haemophagous zone of the canine placenta by means of immunohistochemistry and immunocytochemistry. In the labyrinthine zone, immunoglobulin G was detected in all the layers of the materno-fetal barrier including the fetal capillaries. Immunoreactivity was particularly prominent in maternal basement membrane material as well as in the syncytiotrophoblast. However, this evidence of transplacental transport of immunoglobulin G originated from a limited number of unevenly distributed maternal vessels only. In the cytotrophoblast of the haemophagous zone, immunoglobulin G was localized to phagolysosomes at various stages but was never detected within fetal vessels. The results indicate that maternal immunoglobulin G is degraded in cytotrophoblast cells of the hemophagous zone and, therefore, that transplacental transport is restricted to a subpopulation of maternal vessels in the labyrinthine zone.
在犬类中，被动免疫分别通过妊娠最后三个月期间母体免疫球蛋白G经胎盘的转运以及产后经乳腺的转运赋予胎儿和新生儿。然而，经胎盘转运的形态学证据仍然缺乏。本研究的目的是通过免疫组织化学和免疫细胞化学方法，在犬胎盘的迷路区和噬血区定位母体免疫球蛋白G。在迷路区，在包括胎儿毛细血管在内的母胎屏障的所有层中均检测到免疫球蛋白G。免疫反应性在母体基底膜物质以及合体滋养层中尤为突出。然而，这种免疫球蛋白G经胎盘转运的证据仅源于数量有限且分布不均的母体血管。在噬血区的细胞滋养层中，免疫球蛋白G定位于不同阶段的吞噬溶酶体，但从未在胎儿血管中检测到。结果表明，母体免疫球蛋白G在噬血区的细胞滋养层细胞中被降解，因此，经胎盘转运仅限于迷路区的一部分母体血管。
