hemeandironquestions

Question 1

what does a small erythrocytes mean

Answer 1

problem with not enough cytoplasm most likely due to an iron deficiency anemia.

Question 2

tell me about the hydroxyl radical

Answer 2

highly reactive and does loads of damage can be made from H2O2 from iron or copper

Question 3

how is iron lost

Answer 3

no regulated way because its always bound to protein so lost when the cells containing it are lost like the intesitne and kidney cells that die off and are excreted. Or with blood loss. Or with intravascular hemolysis but this is pathological.

Question 4

what is the distibution of iron in the body

Answer 4

80% is in the active forms hemoglobin myoglobin transferrin and cytochormes, and 20% in inactive forms ferritin and hemosiderin as a long term storage.

Question 5

what are the gatekeepers for iron entry from the gut

Answer 5

enterocytes

Question 6

what transporter in the enterocytes lets iron Fe2+ up

Answer 6

DMTI

Question 7

how does iron Fe3+ get in

Answer 7

reduced by cytochome B to iron 2+ and then DMT1

Question 8

how does Heme get into the body

Answer 8

the heme transporter takes it up and then it is transferred by ferritin for storage,

Question 9

how does iron get from the enterocytes to the circulation

Answer 9

Ferroportin 1 will export the iron from ferritin to transferrin by making first into Fe3+ by hephaestin

Question 10

what does hepcidin do

Answer 10

it regulates the activity of ferroportin 1 and thus regulates how much iron will enter the circulation.

Question 11

how does iron get into the cells

Answer 11

trasferrin carrying Fe3+ wil bind to a receptor and this whole complex will be taken it and then the iron will be reduced to Fe2+ by importing H+ into the vesicle and will unbind transferrin and then DMT1 will export it from the vesicle to the cells cytoplasm.

Question 12

what happends to ferritin over time

Answer 12

it will denature and become water insoluble, hard to mobilize and is a sign of iron overdose.

Question 13

what is the main iron regulator and how does it work

Answer 13

hepcidin is the main regulator, so low hepcidin= high uptake of iron, and it also regulate the release of iron from macrophages.

Question 14

what is HFE

Answer 14

an upstream regulator that will cause low hepcidin expression.

Question 15

tell me about the regulation of intracelluar storage for a quick response

Answer 15

the RNA is already made but is bound to proteins in the cytoplasm, this protein will prevent translation. If iron is high in the cytoplasm it will bind to the Iron regulatory protein ACONITASE and this will free the RNA to be translated.

Question 16

tell me about iron response elements

Answer 16

found on RNA of, ferritin free iron increases translation 5’, ALA synthase free iron will incraese translation 5’ edn, Trasferrin receptors here the IRE is found in the 3’ end and will repress the translation to lower the uptake.

Question 17

tell me about serum iron concentration

Answer 17

it just tells you about total amount so if you have too much and its toxic but not about any specific stores of iron

Question 18

tell me about total iron binding capacity or transferrin saturation

Answer 18

TIBC measure unoccupied transferrrin the higher the TIBC the lower the stores. So transferrin saturation measure occupied transferrin the higher the sat the higher the iron stores.

Question 19

tell me about serum ferritin test

Answer 19

a fraction of ferritn is present in serum and best measure for body iron stores.

Question 20

tell me about the red cell protoporphyrin

Answer 20

iron free precursor to heme the lower the iron stores the higher the protoporphyrin.

Question 21

what are some causes of iron deficiency

Answer 21

chronic blood loss, chronic disease, poor dietary intake, intestinal parasites, malabsorptive disease like celiac

Question 22

what does an iron deficiency lead to

Answer 22

anemia, mycrocytosis

Question 23

what causes iron overload

Answer 23

blood transfusions, slow erythropoiesis renal failure, hereditary hemochromatosis type 1 up to 10 % of the population are carriers.

Question 24

what do you look for in iron overload

Answer 24

high transferrin saturation and hemosiderin deposits

Question 25

how does lead effect heme sythesis

Answer 25

PBG sythas or ALAL dehyratease, and ferrochelatse

Question 26

what regulates the ALA sythase

Answer 26

regulated by HEME

Question 27

what is acute intermittent porphyria AIP

Answer 27

caused by deficiency in porpoobilnogen daminase PBGD. ALA and PBG accumulate in the circulation giving urine dark red color can be life threatening and causes confusion and pain in the abdomin.

Question 28

tell me about Porphyria cutanea tarda PCT

Answer 28

results for a deficiency of uroporphyrinogen decarbocylase, leads to a buildup of porphins can be detected in urin with a UV light

Question 29

tell me about lead poisoning

Answer 29

lead inhibits ALA dehyrase and ferrochelatase, accumulation of ALA and heme precursors and causes sympotoms similar to the porphyrias.