Physiological iron-binding proteins and reticuloendothelial system (RES) (RES)

The physiological iron-binding proteins and the reticuloendothelial system (RES) constitute the integrated network responsible for maintaining systemic iron homeostasis. The RES, now often referred to as the mononuclear phagocyte system, consists of specialized macrophages in the spleen, liver, and bone marrow that recycle iron from aged erythrocytes and process exogenous iron supplements [1][3]. Within this system, iron is managed by specific proteins: transferrin facilitates transport through the plasma, while ferritin and hemosiderin serve as primary storage forms [1]. Therapeutic interventions, particularly intravenous iron complexes like iron sucrose or ferric carboxymaltose, utilize the RES as a metabolic gateway where the iron is liberated from its carbohydrate shell before being incorporated into the body's natural iron-binding proteins [2]. This system is critical in the pathology of iron deficiency anemia and the anemia of chronic disease, where inflammatory cytokines can cause iron sequestration within the RES, limiting its availability for erythropoiesis [3]. Consequently, the RES and its associated proteins are the functional site of action for iron replacement therapies.

Other names

Mononuclear phagocyte systemMPSIron transport and storage systemRES

Intravenous iron complexes are sequestered by the reticuloendothelial system, where the iron is dissociated from its carbohydrate carrier and subsequently incorporated into physiological iron-binding proteins like ferritin and transferrin [2].