Flashcards in Liver Deck (17):
What are the 7 (main) functions of the liver?
Toxin/Drug metabolism and excretion
Bilirubin metabolism and excretion
Why is ferritin clinically important?
As concentration of ferritin is directly proportional to the total iron stores in the body.
Name two common water soluble vitamins
Vitamins B and C
Name four common lipid soluble vitamins
Vitamins A, D, E and K
What impact does being water or lipid soluble have on required intake of vitamins?
Water soluble vitamins pass more readily through the body, therefore, require more regular intake than fat soluble vitamins (as they can be stored).
Where is B12 stored?
What clotting factors are produced by the liver?
What is lipogenesis controlled by?
Insulin levels (and sensitivity)
What is the importance/function of drug biotransformation reactions?
To make the drugs water-soluble so they can be excreted in the urine
What happens in phase 1 of biotransformation reactions?
Functionalization = Add or expose functional groups
This causes a small increase in hydrophilicity.
What happens in phase 2 of biotransformation reactions?
Conjugation = Conjugation with endogenous molecules causing covalent bonds to form.
Causes a large increase in hydrophilicity
Give an example of drug that does NOT undergo a phase 1 reaction and instead instantly undergoes conjugation.
Where in cells do biotransformation reactions mainly occur?
In the smooth endoplasmic reticulum (SER)
What is the purpose of Cytochrome P450 enzymes?
They oxidise the substrate and reduce oxygen and generate a reactive free radical compound.
What builds up if there is in an excess of ethanol and what does this cause?
Acetaldehyde (which accumulates in the liver)
It contributes to alcohol-induced hepatitis by forming adducts with amino acids.
It also binds to glutathione and therefore predisposes cells to damage by peroxide and other free radicals.
What occurs in Active drug to active metabolites reactions?
An active drug may be converted to another active form