Lecture 22- Alcohol Flashcards
Exam 3
What is the main substance consumed when you drink alcohol?
- Ethenyl
- Our bodies produce it naturally and are equipped to get rid of it
metabolism when bac is <0.1 g/dl
What is the process of metabolism in the liver when bac is <0.1 g/dl?
- Alcohol dehydrogenase converts ethanol into acetaldehyde (also gives out water in process)
- Acetaldehyde (our body is equipped to get rid of it) is broken down into acetate by aldehyde dehydrogenase
What breaks down acetaldehyde and what does it get turned into?
- aldehyde dehydrogenase breaks down acetaldehyde
- final product is acetate
What is acetate metabolized to?
- CO2 and water or acetyl-CoA
What does acetaldehyde do?
is toxic and may be involved in the “hangover” effect
How does metabolism work when alcohol is in excess (>).1g/dl(22mM)?
- The microsomal ethanol oxidizing system
- produces acetaldehyde to acetate again via aldehyde dehydrogenase
What is cytochrome P450? What utilizes it?
- Utilized by microsomal ethanol oxidizing system
- prodces a bunch of byproducts including toxins, free radicals, and H2O2
- overtime this can lead to damage at cellular and organ level
What does Disulfiram “Antabuse” do?
- blocks the enzyme aldehyde dehyrogenase, leading to more acetaldehyde (makes it take longer to break down into acetate)
- this makes the hangover effect way worse
- issues: ppl can just not take the pill
What metabolizes the majority of ethanol and what can this cause?
- the liver
- fatty acid builds up in the liver, leading to cell death
Stages that lead to liver failure
- Alcoholic fatty liver
- alcoholic hepatitis
- cirrhosis
- liver failure
How do men and women differ when it comes to metabolizing alcohol?
- males have more involvement of the stomach in the break-down of alcohol (they begin breaking down alcohol much faster than females)
- this may have to do w enzymes
Excretion of alcohol
- 2-8% unchanged through lungs: why breathalyzers are useful for determining BAL
- 90-95% oxidized slowly via kidney
- Alc increases urination
How does alcohol increase urination?
- via ingestion of liquid
- and suppression of antidiuretic hormone (ADH)
Why is alcohol called a dirty drug?
- has multiple mechanisms of action
- no such thing as a nonspecific effect, all effects (although there are many) are quite specific
Alcohol and the reward system
- effects opioid peptide neurons, GABA-ergic terminals, glutamate terminals on the NAc
What does alc do interms of GABA and Glutamate?
- both enhances inhibition via GABA and decreases excitation via glutamate
Alc mechanism of action
- disturbes fine balance between excitatory and inhibitory influences, results in: anxiolysis, amnesia, ataxia, and sedation
- number of puntative sites of action have been identified; likely produces its effects by simultaneously altering function of numerous proteins that affect neuronal excitability
Additional sites of action
ligand-gated ion channels
- nicotinic acetylcholine receptors
- serotonin (5-HT3) receptors
Additional sites of action
multiple metabotropic receptors
- dopamine receptors
- opiod receptors
Additional sites of action
voltage-gated channels
- calcium channels
- sodium channels
Alcohol peripheral effects
- dilates blood vessels
- decreases body temperature
- increases effect of other depressant drugs
Chronic use effect on tolerance
- for a non-tolerant individual .4-.5 bac is enough to cause death
- however, in a tolerant individual… people seen driving with bac up to .77%!! .4g/dl will not be lethal
BAC g/dl 0.05-0.1 (non-tolerant individual/acute intoxication) effect
11-22 mM
- subjective high (buzz)
- anxiolysis
- sedation
BAC g/dl 0.1-0.2 (non-tolerant individual/acute intoxication) effects
22-44 mM
- motor impairment
- slurred speech
- blackouts
BAC g/dl 0.2-0.3 (non-tolerant individual/acute intoxication) effects
44-66 mM
- emesis (vomiting)
- stupor (near-unconsciousness)
BAC g/dl 0.3-.4 (non-tolerant individual/acute intoxication)
44-88mM
coma
BAC g/dl >.5 (non-tolerant individual/acute intoxication) effect
- respiraory depression
- death
Tolerances seen w alcohol
- acute tolerance: tolerance occurs within a few hours
- chronic tolerance: needing more alcohol to produce the same effects
- metabolic tolerance: increase in the enzymes that break down and get rid of alcohol int he body
Alcohol dependence/withdrawal symptoms
- sleep disruption
- ANS (sympathetic) activation
- tremors
- seizures
- psychological dependence- may occur w regular use of moderate daily amounts
Alcohol positive reinforcing effects
- slow due to PK
- gain pleasure
- altered consciousness
- conform to behavior of peers
Alcohol negative reinforcing effects
- relief of stress and negative emotions
- relief of withdrawal symptoms
