3.6 Alcohol Metabolism Flashcards
What are the two major routes (enzymes) of ethanol oxidation
Alcohol Dehydrogenase Cytochrome P450 (MEOS)
T or F, Alcohol is absorbed from all parts of the GI tract by diffusion especially by small intestine which is the most effective
True
Ethanol Oxidation produces what?
Acetaldehyde
What are the four main routes or enzymes used to oxidize ethanol?
Alcohol Dehydrogenase
Cytochrome P450
Catalase dependent system
Gastric oxidation
Where does MEOS occur?
Smooth Endoplasmic Reticulum
Where does Alcohol Dehydrogenase function?
Cytosol
What are the three results of oxidative ethanol oxidation?
- Acetaldehyde adducts form
- Increased ROS formation
- Increased NADH/NAD+ ratio
What is the common route of ethanol oxidation in occasional drinkers and low concentrations of alcohol
Alcohol Dehydrogenase – > Acetaldehyde –> Aldehyde Dehydrogenase –> Acetate
What occurs to the acetate that is produced by the Alcohol Dehydrogenase pathway?
It is typically converted to Acetyl CoA with the help of GTP
What is the major Isoenzyme for ADH and where is it found?
Class I
Found in Liver, Stomach and lungs
What allele of ALDH2 is least effective?
ALDH2*2/2
What are the top four consequences of Increased NADH/NAD+ ration?
- Hypoglycemia
- Lactic Acidemia
- Ketonemia
- Hyperuricemia
How does alcohol seem to produce more urine?
It inhibits the release of anti-diuretic hormone which in turn increases urine
What causes Hypoglycemia?
With increased NADH/NAD ratio, the GNG is suppressed and shifts towards Lactate which decreases glucose availability
What causes Ketonemia?
Increase in NADH prevents CAC from running. This leaves behind a build up of Acetyl CoA to be converted into Ketone Bodies
