Iron metabolism

From bacteria to humans, many molecular structures and metabolic pathways involve iron as an oxygen and/or electron carrier. However, despite its essential role for all living beings, iron is toxic by inducing the formation of free radicals. As a consequence, the human body has a fine regulation regarding the iron cycle and any unbalance can lead to diseases such as hemochromatosis and thalassemia.

The iron cycle

The human body barely absorbs iron from the outside. In fact, its loss is very low due to a constant recycling after the degradation of blood cells. The ion needs every day is approximately 20 mg, which contrasts greatly compared to a total pool of 3000 to 5000 mg.

Two cycles have be described for the iron metabolism: the intern cycle and the extern cycle. The intern cycle occurs in the human body itself between the tissue pool and the plasma and transferrine is responsible for the transport between these two compartments. Additionally, the extern cycle is only represented by the movement of iron between the intestins and the plasmatic compartment. Thus, the plasmatic compartment appears as a crossroad between both cycles