Baker E, Page M, Morgan E H
Am J Physiol. 1985 Jan;248(1 Pt 1):G93-7. doi: 10.1152/ajpgi.1985.248.1.G93.
The regulation of transferrin and iron release from the liver was studied using adult rat hepatocytes in primary monolayer culture. The cells were prelabeled by incubation with rat transferrin doubly labeled with iodine-125 and iron-59. Approximately 50% of the 125I-transferrin but only 10% of the iron-59 taken up by the cells was released during reincubation for 24 h. Less than 10% of the refluxed transferrin was catabolized as indicated by the protein-free iodine-125 values. These results suggest that at least part of iron uptake by hepatocytes is mediated by the reversible binding of transferrin in a manner comparable with erythroid cells and placenta. However, several iron chelators mobilized hepatic iron, in contrast to erythroid cells. Apotransferrin and desferrioxamine released a maximum of about 20% iron-59 with little effect on transferrin binding. A greater proportion of the iron-59 was available for chelation after shorter uptake times (1-2 h) than longer times. Hence, there are at least three iron compartments in hepatocytes in culture: rapidly refluxing iron that may be transferrin bound, a fixed pool, and a chelatable pool that may represent iron in transit between plasma transferrin and ferritin.
利用原代单层培养的成年大鼠肝细胞研究了转铁蛋白和肝脏铁释放的调节。细胞通过与用碘 - 125和铁 - 59双重标记的大鼠转铁蛋白孵育进行预标记。在再孵育24小时期间，细胞摄取的125I - 转铁蛋白中约50%被释放，但摄取的铁 - 59仅10%被释放。如无蛋白碘 - 125值所示，回流转铁蛋白中不到10%被分解代谢。这些结果表明，肝细胞对铁的摄取至少部分是由转铁蛋白的可逆结合介导的，其方式与红细胞和胎盘类似。然而，与红细胞不同，几种铁螯合剂可动员肝脏铁。脱铁转铁蛋白和去铁胺最多释放约20%的铁 - 59，对转铁蛋白结合影响很小。与较长摄取时间相比，较短摄取时间（1 - 2小时）后更多比例的铁 - 59可用于螯合。因此，培养的肝细胞中至少有三个铁池：可能与转铁蛋白结合的快速回流血池、固定池以及可能代表血浆转铁蛋白和铁蛋白之间转运铁的可螯合池。
