Trinder D, Batey R G, Morgan E H, Baker E
Department of Medicine, Westmead Hospital, New South Wales, Australia.
Am J Physiol. 1990 Oct;259(4 Pt 1):G611-7. doi: 10.1152/ajpgi.1990.259.4.G611.
The effect of intracellular iron content on transferrin and iron uptake by cultured hepatocytes isolated from fetal rat liver was examined with ferric ammonium citrate and the iron chelator desferrioxamine (DFO). Incubation of the cells with ferric ammonium citrate for 24 h significantly increased the cellular nonheme iron level, whereas the number of transferrin binding sites and the uptake of transferrin and iron were reduced. In contrast, when iron-treated cells were incubated with DFO for 24 h, the cellular nonheme iron level was not altered, but the number of transferrin binding sites was increased. Treatment of the cells with exogenous iron and/or DFO did not affect the uptake of transferrin and iron by the nonsaturable processes. These results indicated that, in cultured hepatocytes, transferrin receptor expression and the subsequent uptake of transferrin and iron are regulated by the size of an intracellular, chelatable iron pool, whereas the uptake of iron by the nonsaturable processes is dependent on the extracellular transferrin concentration.
用柠檬酸铁铵和铁螯合剂去铁胺（DFO）研究了细胞内铁含量对从胎鼠肝脏分离的培养肝细胞转铁蛋白和铁摄取的影响。用柠檬酸铁铵孵育细胞24小时显著提高了细胞非血红素铁水平，而转铁蛋白结合位点数量以及转铁蛋白和铁的摄取减少。相反，当用铁处理的细胞与DFO孵育24小时时，细胞非血红素铁水平未改变，但转铁蛋白结合位点数量增加。用外源性铁和/或DFO处理细胞不影响非饱和过程对转铁蛋白和铁的摄取。这些结果表明，在培养的肝细胞中，转铁蛋白受体表达以及随后转铁蛋白和铁的摄取受细胞内可螯合铁池大小的调节，而非饱和过程对铁的摄取取决于细胞外转铁蛋白浓度。
