Galbraith G M, Galbraith R M, Faulk W P
Placenta. 1980 Jan-Mar;1(1):33-46. doi: 10.1016/s0143-4004(80)80014-2.
In primate pregnancy, fetal iron is derived from maternal transferrin; however, the mechanisms by which iron is taken up by the human placenta have not yet been established. In the present study, transferrin was demonstrated on the microvillous surface of human trophoblast in immunohistological studies of 130 mature and immature placentae from both normal and abnormal pregnancies. Similar results were found for baboon placentae. Upon short-term culture of placental tissue, the amount of trophoblast transferrin decreased and no incorporation of 14C lysine into transferrin could be detected by radioimmunoelectrophoresis. Thus this transferrin apparently was not synthesized by the placenta. When transferrin was removed from cryostat sections of placenta by treatment with chaotropic agents, subsequently added transferrin bound in an identical distribution. The specificity of this reaction was confirmed by the lack of binding of other serum proteins and by displacement procedures in which trophoblast transferrin was shown to be dislodged by transferrin added in vitro. These findings suggest that placental iron transport is predicated by binding of transferrin to specific receptors on trophoblast.
在灵长类动物妊娠过程中，胎儿的铁来源于母体转铁蛋白；然而，人类胎盘摄取铁的机制尚未明确。在本研究中，通过对130例来自正常和异常妊娠的成熟及未成熟胎盘进行免疫组织学研究，在人滋养层细胞的微绒毛表面证实了转铁蛋白的存在。狒狒胎盘也得到了类似结果。胎盘组织短期培养后，滋养层转铁蛋白的量减少，通过放射免疫电泳检测不到14C赖氨酸掺入转铁蛋白。因此，这种转铁蛋白显然不是由胎盘合成的。用离液剂处理胎盘冰冻切片以去除转铁蛋白后，随后添加的转铁蛋白以相同的分布结合。其他血清蛋白缺乏结合以及体外添加转铁蛋白可使滋养层转铁蛋白移位的置换实验证实了该反应的特异性。这些发现表明，胎盘铁转运是通过转铁蛋白与滋养层细胞上特定受体的结合来实现的。
