Alcohol Metabolism Flashcards
Name 5 types of alcohol.
- Methanol
- Ethanol
- Propanol
- Butanol
- Pentanol
What is the simplest alcohol?
Methanol (CH3-OH)
Because it is small and because of the hydroxyl group, ethanol is soluble in what environments?
Aqueous & lipid environments
What is the most common type of alcohol consumed in alcoholic beverages?
Ethanol
Which type of alcohol can pass freely into body cells (no transporter)
Ethanol
Primary catabolic route of ethanol in non-alcoholics, utilizes what enzymes in liver?
Alcohol & aldehyde dehydrogenases
- known as ADH & ALDH enzymes
What is the end product of the primary catabolic route in non-alcoholics?
Acetyl CoA -> TCA Cycle
- or forms Fatty acids
What is the secondary catabolic route all so known as?
MEOS CYP2E1 - microsomal ethanol oxidizing system
Secondary catabolic route is upregulated in
Alcoholics
Secondary catabolic route utilizes what?
Oxygen & NADPH + H+
In the secondary catabolic route what undergoes oxidation?
Fatty acids
Secondary catabolic route produces damaging by products such as: (3)
- Lipid hydroperoxides
- Superoxides
- Hydroxyl radicals
When the process of ethanol catabolism doesn’t continue to Acetyl CoA, reactive acetylaldehyde can bind to …
Proteins (usually lysine portion) & forms an adduct
Adducts can cause major damage to cells and may induce what?
Harmful immune response
A highly reactive oxygen radical that participates in adduct formation
HER: Hydroxyethyl radical
A reactive molecule that is generated during lipid peroxidation and participates in adduct formation
HNE: 4-hydroxy-2-nonenal
MDA: Malondialdehyde
Compounds that contain MDA plus acetaldehyde plus protein components
MAA: Mixed MDA-acetaldehyde-protein adducts
Proteins that appear to be preferentially modified by aldehydes include: (6)
- Hemoglobin
- Albumin
- Tubulin
- Lipoproteins
- Collagen
- Ketosteroid reductase
A component of cell structures called microtubules that are essential for cell division as well as for the secretion and transport of proteins within the cells.
Tubulin
Key to digestion, it influences the production of bile acid biosynthesis
Ketosteroid reductase
Folate + B12 + B6 =>
SAM
What are the micronutrients required for alcohol metabolism? (4)
- Folate + B12 + B6 -> SAM
- Niacin = NAD
- Zinc
- Antioxidants (ACES: Vit. A, Vit. C, Vit. E, Selenium)
List 5 enzyme systems that combat adducts and oxidative stress.
- SAM
- Phosphatidylcholine
- Glutathione (GSH)
- SOD
- Catalase
What 2 enzyme systems can decrease adduct formation?
Phosphatidylcholine & Glutathione (GSH)
What enzyme removes hydrogen peroxide, with the by product being water?
Catalase
With excess ETOH intake what can occur?
Fatty liver
If ETOH intake continues with fatty liver, it can further lead to …?
Fibrosis & cirrhosis of the liver
Fatty liver, fibrosis & cirrhosis of the liver could be attenuated by what?
Phosphatidylcholine (aka lecithin)
What are 4 symptoms of ETOH toxicity “Hangover”
- Dehydration
- GI Upset
- Circadian Rhythm Alteration and Sleep Disorders
- Headache
Dehydration is from the decreased release of what hormone, that regulates salt and water balance.
Aldosterone
Decrease release of aldosterone from dehydration results in?
Hypoglycemia & Acidosis
Drop in NAD+ /NADH ration is due to
Dehydration
Dehydration leads to accumulation of
Lactic acid
Dehydration lowers production of _____, which causes mood changes, & general body weakness.
Glucose
Low alcohol content beverages stimulate what?
Stomach acid production
How do hard drinks (>20 vol%) cause GI upset?
Irritate stomach lining and cause inflammation
What leads to stomach and abdominal pains, nausea, & vomiting?
Increased pancreatic secretions combined with increased intestinal activity.
Headache symptom of Hangover results from alcohol causing … & influencing …
- Vasodilation of small blood vessels, thins the blood
- Influences neurotransmittes such as histamine, serotonin, prostoglandins.
The rise in what following drinking may be the true culprit of hangover symptoms?
Acetylaldehyde concentration
1 drink per day of red wine is associated with what?
Increased HDL cholesterol
Red wine may prevent what?
Oxidation of lipoproteins
Red wine, white wine, and grape juice were all equally able to …., where as alcohol by itself was ineffective.
Preserve antioxidant potential
