Alcohol & the Liver Flashcards
How does alcohol cause neurological effects?
it interacts with the lipid bilayer of neurons and makes it leak sodium and potassium depressing the activity of neurons
What are the alcoholic signs?
neurological disturbances, jaundice, altered breath, oesophageal varices, feminisation, extensively scarred liver, portal hypertension, enlarged collateral vessels, ascites, hand tremor, hypogonadism, easy bruisability, muscle wasting, oedema, infertility in women, impotence in men
What are the different types of alcohol induced liver damage?
fatty liver, alcoholic hepatitis and cirrhosis
Is fatty liver reversible?
yes
What percentage of liver functioning hepatocytes are required for normal liver function?
40%
What percentage of alcohol enters blood from the stomach?
30%
Is alcohol metabolised in the stomach?
a little bit - there is some alcohol to dehydrogenase in gastric mucosa - more in males than females
What slows alcohol absorption in the stomach?
fat in food
What enzyme converts ethanol to acetaldehyde?
alcohol dehydrogenase
What is a biproduct of this reaction?
NADH
What is the result of the increase in NADH?
represses gluconeogenesis and leads to hypoglycaemia
How else can ethanol be converted to acetaldehyde?
CYP2E1 metabolism
How do you develop tolerance to alcohol?
upregulating CYP2E1
Why are women more affected by alcohol?
because alcohol does not distribute in fat
How long does it take for the body to clear one standard drink?
an hour
Why can this rate not be increased?
Because alcohol dehydrogenase works at vmax after 2 drinks
Why should patients on warfarin not drink alcohol?
because the CYP2E1 is up regulated so drugs will have less effect
What causes alcohol induced liver damage?
neglecting dietary intake of antioxidants, alcohol interferes with transport of glutathione, increased use of CYP2E1, alcohol promotes absorption of iron - all of these cause increased free radicals, also acetaldehyde reacts with proteins and compromises their function
What is Wernicke Korsakoff syndrome?
thiamin deficiency due to poor nutrition and alcohol metabolism
What are the symptoms of Wernicke Korsakoff syndrome?
nystagmus, wide step, confusion, hypothermia, amnesia, confabulation
What converts acetylaldehyde to acetate?
two forms of aldehyde dehydrogenase - ALDH2 is the mitochondrial form that is more important
What causes Asian flush?
an inactive variant of ALDH2
What is disulfiram?
A drug which inhibits ALDH used to treat alcoholics - causes tachycardia, nausea and vomiting when drinking
What is a gene that contributes to alcohol addiction?
dopamine D2 receptor
What are the signs of alcoholism on physical examination?
spider naevi, palmar erythema, gynaecomastia, feminisation of hair patterns, testicular atrophy, muscle wasting, enlarged liver, enlarged spleen, metabolic flap
What liver enzymes would be elevated in alcoholic liver disease?
GGT, ALT and CDT
How does alcohol cause dehydration?
by depressing the pituitary gland leading to decreased production of anti diuretics
What is foetal alcohol syndrome?
irreversible birth disorders brought on by drinking alcohol during pregnancy
