Fig. 4.

Hepcidin functions via effects on ferroportin mediated iron efflux. Hepcidin binds to and results in the internalization and degradation of ferroportin, leading to a block in iron efflux from ferroportin expressing cells (duodenal enterocytes, hepatocytes, macrophages, and placenta). In low hepcidin states, iron taken up by these cells is exported via ferroportin. Conversely, in high hepcidin states, the loss of membrane ferroportin results in iron sequestration, typically within cytosolic ferritin. Fe, iron; Fpn, ferroportin.