Movement from storage tissues

Functionally, ferritin, in conjunction with transferrin, regulates the movement of iron from the gastrointestinal tract to various tissues responsible for iron storage as well as to the bone marrow. 

The rate of iron oxidation in the plasma or iron entry in the absence of Cp is not adequate to meet the Fe(III)-transferrin demands of the erythroid bone marrow cells or other tissues for iron. The impetus for the movement of iron into the plasma may arise from the generation of significant concentration gradients by Cp between intracellular iron in the iron storage organs and the iron concentration of the capillary systems, thus promoting a rapid eflBux of iron from the reticuloendothelial system. 

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