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:
“Industrial man—a sentient reciprocating engine having a fluctuating output, coupled to an iron wheel revolving with uniform velocity. And then we wonder why this should be the golden age of revolution and mental derangement.”
—Aldous Huxley (1894–1963)
“Hate-hardened heart, O heart of iron,
iron is iron till it is rust.
There never was a war that was
not inward; I must
fight till I have conquered in myself what
causes war, but I would not believe it.”
—Marianne Moore (1887–1972)
“Along the iron veins that traverse the frame of our country, beat and flow the fiery pulses of its exertion, hotter and faster every hour. All vitality is concentrated through those throbbing arteries into the central cities; the country is passed over like a green sea by narrow bridges, and we are thrown back in continually closer crowds on the city gates.”
—John Ruskin (1819–1900)