Differential response of non-transferrin bound iron uptake in rat liver cells on long-term and short-term treatment with iron
Section snippets
Animals and feeding protocol
Female Wistar rats (120–140 g) were obtained from Wiga (Hannover, Germany). One group of rats was fed with Altromin C1000 standard rat diet with an iron content of 160 μg/g of food (normal rats). Four experimental groups of animals receiving different diets on the basis of iron-deficient Altromin C1038 (Altromin, Lage, Germany) were established. One group received this iron-poor diet (6 μg Fe/g diet) for 6 weeks (iron-deficient rats). Two groups of rats were fed a diet of C1038 enriched with
Results
The iron content of hepatocytes from rats fed a normal diet, from iron-depleted rats and from animals overloaded with iron by feeding with TMH-ferrocene or carbonyl-iron was determined and was correlated with properties of NTBI uptake into the hepatocytes isolated from these livers with respect to absolute rates, affinity, specificity and inhibition by apo- and holotransferrin at different concentrations.
Discussion
Iron metabolism in the mammalian organism is tightly regulated under normal conditions. The blood plasma contains an excess of the binding protein transferrin to avoid the occurrence of free, non-protein bound iron with high redox potential, which is highly toxic. Cells acquire iron by receptor-mediated endocytosis of transferrin, which is limited by the concentration of receptors at the cell surface. This, in turn, is regulated at the post-transcriptional level by one or two iron regulatory
Acknowledgements
This work was supported by the Austrian Research Fund, Proj.Nr, P-11594-Med.
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