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:
“I was even more surprised at the power of the waves, exhibited on this shattered fragment, than I had been at the sight of the smaller fragments before. The largest timbers and iron braces were broken superfluously, and I saw that no material could withstand the power of the waves; that iron must go to pieces in such a case, and an iron vessel would be cracked up like an egg- shell on the rocks.”
—Henry David Thoreau (1817–1862)
“Let us roll all our strength, and all
Our sweetness, up into one ball:
And tear our pleasures with rough strife,
Thorough the iron gates of life.
Thus, though we cannot make our sun
Stand still, yet we will make him run.”
—Andrew Marvell (1621–1678)
“Should the German people lay down their arms, the Soviets ... would occupy all eastern and south-eastern Europe together with the greater part of the Reich. Over all this territory, which with the Soviet Union included, would be of enormous extent, an iron curtain would at once descend.”
—Joseph Goebbels (1897–1945)