Define Intra enterocyte transport - non-haem iron absorption?
Intra enterocyte transport: In the enterocyte, the absorbed iron can have one of the following metabolic fates:
- transported through the enterocyte into the blood, and
- stored in the enterocyte for future use or elimination.
Iron is transported through the enterocyte to the baso-lateral membrane by iron binding protein- mobilferrin. Mobilferrin can also bind to Ca, Cu and Zn. The multiple metal ion-binding properties of mobilferrin may be partially responsible for interactions between these minerals at absorptive surface. The iron which is not transported across the cell for release is stored as ferritin in mucosal cells. If required for the body, it is released for transport. If not needed, the iron remains as ferritin and is excreted when mucosal cells are sloughed off in the lumen, thus, ferritin in the enterocyte acts as an 'iron sink', trapping excess iron and removing it via intestinal excretion.