Starreveld J S, van Dijk H P, Kroos M J, van Eijk H G
Department of Chemical Pathology, Erasmus University Rotterdam, The Netherlands.
Clin Chim Acta. 1993 Oct 29;220(1):47-60. doi: 10.1016/0009-8981(93)90005-o.
During gestation the transplacental iron transport is very important to the fetus. Iron uptake by the placenta can be studied in cultured cytotrophoblasts. The influence of culture time and human differic transferrin on the number and distribution of transferrin receptors (TfRs) was investigated in human cytotrophoblasts. Cytotrophoblasts cultured for 2.5 h had few TfRs (0.28 pmol/mg protein). With time, total TfR amounts increase (4.14 pmol/mg protein at 70 h). They increase to a higher level in cells cultured in iron-poor medium, indicating that iron has an effect on the TfR synthesis/breakdown ratio. TfRs were distributed between two 'active' (located at the cell surface and intracellularly) and one 'inactive' (located intracellularly) receptor pools. TfR distribution among these pools was modulated by culture time and iron. Trophoblasts regulated iron uptake by variation of number of surface TfRs via changes in total TfRs and redistribution of TfRs among the receptor pools.
在妊娠期，经胎盘的铁转运对胎儿非常重要。胎盘对铁的摄取可在培养的细胞滋养层细胞中进行研究。在人细胞滋养层细胞中，研究了培养时间和人差异转铁蛋白对转铁蛋白受体（TfRs）数量和分布的影响。培养2.5小时的细胞滋养层细胞几乎没有TfRs（0.28 pmol/mg蛋白）。随着时间的推移，TfR总量增加（70小时时为4.14 pmol/mg蛋白）。在缺铁培养基中培养的细胞中，TfR总量增加到更高水平，表明铁对TfR的合成/分解比率有影响。TfRs分布在两个“活性”（位于细胞表面和细胞内）和一个“非活性”（位于细胞内）受体池中。这些池中TfR的分布受培养时间和铁的调节。滋养层细胞通过改变总TfRs数量以及TfRs在受体池之间的重新分布，来调节表面TfRs数量，从而调控铁的摄取。
