Final: Iron (Fe) Flashcards
(27 cards)
What are the primary functions of iron?
Component of heme (hemoglobin and myoglobin); electron transport chain
What happens with iron deficiency?
hypochromic microcytic anemia
What are diet sources of iron?
Carnivores = RBCs of prey Herbivores = inorganic sources
What is the major clinical symptom of iron deficiency in growing animals?
listless and poor feed intake
How does ferritin protect an animal from excessive dietary iron?
Binds free iron when it is in surplus; iron is sequestered for the life of the cell
What are symptoms of iron toxicity?
Diarrhea, reduced feed intake, wgt gain
What substances does iron interfere with (absorption)?
copper and zinc
Why is free iron in tissues so harmful?
It is a strong oxidizing agent, very reactive, may lead to oxidative stress.
It is also required by bacteria for their growth so excess could contribute to infection
Why are plants a poor source of iron?
Plant tissue itself is not very high in iron and iron is usually bound to phytate when present
Why do animals that stay on milk diets tend to become anemic?
Milk is notoriously poor in iron; animal is growing fast and needs to make new RBC and iron enzymes
How efficiently is iron absorbed?
Very efficiently across the intestine (has specific heme absorption mechanisms)
What are inorganic sources of iron?
Ferric oxide (poor availability) Ferrous sulfate (highly soluble, more available)
What does ascorbic acid do in relation to iron?
Enhances absorption in man and monogastrics
Where is iron stored when it is not immediately needed?
liver
What is hepcidin?
Hormone made in liver when liver iron levels are adequate
More than ___% of heme iron is absorbed across the apical membrane.
90%
Only ___% of non-heme iron is absorbed across apical membrane of epithelial cells.
10-15%
What is iron deficiency like in adult animals?
Rare; nearly all diets supply adequate Fe for adult animals!
What is the usual exception to adult animals that causes iron deficiency?
hemorrhaging
What type of iron do carnivores ingest?
heme iron
What type of iron do herbivores ingest?
non-heme iron
What do young animals rely on for iron until weaning?
liver stores of iron developed in utero
What is unique about piglets and iron?
They are born with almost no iron stores, so are anemic, esp those raised in confinement (pasture = mud ingestion generally meets needs)
What are signs of anemia in piglets?
Slow growth, rough hair coats, pale MM
