Write about Iron Haemostasis here.
- Transferrin = glycoprotein to which absorbed iron in the bloodstream is bound to. Each molecule binds two atoms of ferric iron. Normally about 20-45% of binding sites are filled. About 0.1% of total body iron is circulating in bound form to transferrin.
- Each day 0.5 - 1.0 mg of iron is lost in the faeces, urine and sweat. Loss of about 1- 2 mg of iron every day via desquamation of epithelium. Menstruation, growth (0.6 mg) and pregnancy (1-2 mg per day)
- Usually daily diet = 15-20 mg, roughly 10% absorbed
- Ferritin is a water-soluble complex of iron and protein (iron + apoferritin) used for storage (2/3 about 1000 mg, in reticuloendothelial cells, hepatocytes and skeletal muscle cells. Haemosiderin is an insoluble iron-protein complex found in macrophages in the BM, liver and spleen. 1/3 of stored iron (about 500 mg) stored as haemosiderin.
- 2.5-3g of iron in circulation as Hb
- TIBC = amount of iron that would appear in plasma if all the transferrin were saturated with iron