Iron
Iron is an essential element for human beings. The control of this necessary but potentially toxic substance is an important part of many aspects of human health and disease. Hematologists have been especially interested in the system of iron metabolism because iron is essential to red blood cells. In fact, most of the human body's iron is contained in red blood cells' hemoglobin, and iron deficiency is the most common cause of anemia.
When body levels of iron are too low, then hepcidin in the duodenal epithelium is decreased. This causes an increase in ferroportin activity, stimulating iron uptake in the digestive system. An iron surplus will stimulate the reverse of this process.
In individual cells, an iron deficiency causes responsive element binding protein (IRE-BP) to bind to iron responsive elements (IRE) on mRNAs for transferrin receptors, resulting in increased production of transferrin receptors. These receptors increase binding of transferrin to cells, and therefore stimulating iron uptake.
Read more about this topic: Human Homeostasis
Famous quotes containing the word iron:
“By the flow of the inland river,
Whence the fleets of iron have fled,
Where the blades of the grave-grass quiver,
Asleep are the ranks of the dead:—”
—Francis Miles Finch (1827–1907)
“The majority of the men of the North, and of the South and East and West, are not men of principle. If they vote, they do not send men to Congress on errands of humanity; but while their brothers and sisters are being scourged and hung for loving liberty,... it is the mismanagement of wood and iron and stone and gold which concerns them.”
—Henry David Thoreau (1817–1862)
“A shadow has fallen upon the scenes so lately lighted by the Allied victory.... From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent.”
—Winston Churchill (1874–1965)