Fig. 2

Regulation of iron homeostasis. Dietary iron absorbed through the enterocytes (shown in the circle), mainly in the duodenum. The absorbed dietary iron is then exported into the circulation passing through the basolateral membrane via FPN. Iron is then transported throughout the body tissues by binding to the circulating transferrin in the blood circulation. Most of the iron is utilised in the bone marrow to produce haemoglobin and RBCs. When senescent, the RBC will be phagocytised by macrophages and the iron will be released into the plasma following the body need. The liver-derived peptide hepcidin regulates body iron intake and distribution by binding to plasma membrane FPN on enterocytes, macrophages, and other body cells and stimulating its internalisation and destruction. In an iron-deficient body, hepcidin concentrations are low, stimulating iron absorption and delivery to the plasma, and into other tissue organs; in an iron-sufficient body, hepcidin concentrations are higher, inhibiting iron release from reserves, restricting iron absorption into the plasma and iron uptake into the tissue organs. This figure was created using BioRender.com