Iron - health and disease Flashcards
what is the Fenton reaction?
Fe2++ H2O2→ Fe3++ HO• + OH− (Fenton reaction)
iron requires to be?
regulated
the body has no means of ——— of iron?
excretion
where is majority of body iron found?
in haem
what is harm?
porphyrin ring and iron
where does iron aborpstion mainly occur?
mainly duodenum
what is duodenal cytochrome B?
it is found in l uminal surface and this reduces ferric iron to ferrous form
what is DMT-1?
transports ferrous iron into the duodenal enterocyte
what is ferroportin?
it facilitates iron export from the enterocyte
passed on to transferrin for transport elsewhere
what is hepcidin?
the major negative regulator of iron uptake
where is hepcidin production?
it is produced in liver in response to increased iron load and inflammation
hepcidin binds to?
ferroportin and causes its degradation
iron is therefore trapped in
duodena, cells and macrophages
hepcidin levels ——— when iron deficient
decrease
why do we asses functional iron in hemoglobin?
because that is where the bulk of the iron that is going to be used is
how do we asses transport iron/iron supply to tissues?
%saturation of transferrin with
what is the main protein that transfers iron around the body?
transferrin
how do asses storage iron?
serum ferritin
tissue biopsy
what is empty transferrin called?
alpo-transferrin
transferrin transports —- from donor tissues such as macrophages, intestinal cells and hepatocytes to tissues expressing —————
iron
transferrin receptors
which area is especially rich in transferrin receptors?
erythroid marrow
what does transferrin saturation measure?
serum iron/total iron binding capacity(to transferrin) x 100 %
what does transferrin saturation reflect?
proportion of diferric transferring (high affinity for cellular transferrin receptors)
ferretin is a
spherical intracellular protein
what does ferritin store?
up to 4000 ferric ions
ferritin is a ——- measure of storage iron
indirect
serum ferritin also acts as an?
acute phase protein so goes up with infection, malignancy etc.
what are the consequences of negative iron balance?
- exhaustion of iron stores
- iron deficient erythropoiesis - falling red cell MCV
- microcytic anaemia
- epithelial changes
what are epithelial changes that could occur as a consequences of negative iron balance?
skin
koilonychia
angular stomatitis
hypo chromic microcytic anaemias is?
deficient hemoglobin synthesis
haem deficiency examples?
low body iron
anaemia of chronic disease (normal body iron)
congenital sideroblastic anaemia
examples of globin deficiency?
thalassemia
iron deficiency can be confirmed by a combination of?
anaemia (decreased hemoglobin iron) and reduced storage of iron (low serum ferritin)
