Ethanol Metabolism Flashcards
Two different systems for metabolism
- Alcohol dehydrogenase
2. Microsomal ethanol oxidizing system using chytochrome P450
What is the product of ethanol metabolism?
acetaldehyde
What does alcohol dehydrogenase do?
Converts ethanol to acetaldehyde with generation of NADH
What does aldehyde dehydrogenase do?
Converts acetaldehyde into acetate with the generation of NADH
What causes toxicity or flushing and nausea when drinking?
Acetaldehyde,
- very slow variant of aldehyde dehydrogenase
- very fast acting alcohol dehydrogenase variant. (processes the ethanol faster than aldehyde dehydrogenase can perform the next step, there is accumulation of acetaldehyde.)
What enzyme does Disulfiram (Antabuse) inhibit?
Aldehyde dehydrogenase
What happens if the person keeps drinking while on Disulfiram (Antabuse)?
Accelerates damaged caused by acetaldehyde
Where does the acetate go after its produced in the liver?
Muscle tissue
- converted to acetyl CoA and into the TCA cycle
What two compounds effect the biochemistry of the body related to ethanol metabolism?
- Acetaldehyde: Damage the liver
2. NADH: Large amounts are produced.
What happens when you build up large amounts of NADH due to ethanol consumption?
Will cause pyruvate to be converted into lactate= lactic acidosis.
What is the secondary effect of lactic acidosis?
Underexcretion of uric acid= hyperuricemia
What happens in the fasting state, when alcohol is consumed?
Liver will try to perform gluconeogenesis, but the precursor will be diverted to the production of lactate.
Ethanol, fasting state, and low liver glycogen causes what?
Hypoglycemia
What does high levels of NADH inhibit?
Oxidation of fatty acids= liver accumulates fatty acids
Fat released to blood as VLDLs= hyperlipidemia
Fatty liver develops
How does high NADH affect acetyl CoA produced in the liver?
- It can’t be used by TCA cycle
- Causes oxaloacetate conversion back into malate to make NAD+
- Acetyl CoA is forced to ketone synthesis= ketoacidosis
