explain about iron metabolism - source, absorption, transport, storage and excretion
Answers
Answer:
Iron is one of the most essential trace element • Total body iron content is 3 to 5 g. • 75% present in blood, the rest is in liver, bone marrow & muscles. •Many proteins have been identified playing roles in iron metabolism. Some proteins such as ferritin or Tf are the main cargos of blood iron, whereas peptides such as iron regulatory proteins (IRPs), hepcidin, and matriptase (Mt2) are key determinants of iron regulation at different physiological levels. A set of different proteins, notably divalent metal transporter-1 (DMT1), ferroportin (FPN1), and transferrin receptors (Tfrs) in association with ferroxidases such as duodenal cytochrome B, ceruloplamin (Cp) and heme carrier protein (HCP1), are involved in the cellular membrane transportation of iron [23]. Others proteins such as myoglobin (Mb), Hb, and many different enzymes are the ‘end’ products of iron metabolism, because they require iron for their functions.
source
Red meat, pork and poultry.
Seafood.
Beans.
Dark green leafy vegetables, such as spinach.
Dried fruit, such as raisins and apricots.
Iron-fortified cereals, breads and pastas.
Peas.
absorption
The absorption of most dietary iron occurs in the duodenum and proximal jejunum and depends heavily on the physical state of the iron atom. At physiological pH, iron exists in the oxidized, ferric (Fe3+) state.
transport.
Iron in intestinal mucosal cells or stored in the liver (see below) may be transferred into the blood for transport to other tissues. The iron (III) storage form must be reduced to iron (II) in order to cross the plasma membrane. In the blood, iron (II) is reoxidized to iron (III) by ferroxidase II.
storage
The human body stores iron in the form of ferritin and hemosiderin in liver, spleen, marrow, duodenum, skeletal muscle and other anatomic areas.
excretion
iron is ultimately excreted in urine, which has been reported to include 62.4±4.1 µg/g creatinine (Cr) in healthy subjects