ALCOHOL

Question 1

Where is alcohol absorbed from

Answer 1

GI tract and then it diffuses throughout the body including brain

Question 2

BAC is what

Answer 2

mg alcohol/100ml of blood

Question 3

What is alcohol metabolized by

Answer 3

alcohol dehydrogenase in liver and gastric fluid

remainder 5% alcohol is excreted by the lungs

Question 4

Alcohol metabolism

2 steps, 2 enzymes

Answer 4

alcohol —> acetaldehyde by alcohol dehydrogenase

acetaldehyde —> acetic acid by ALDH

Question 5

ALDH POLYMORPHISM ASIANS

Answer 5

ALDH inactive in asians, causes buildup of acetaldehyde and thats why some people get really sick

Question 6

CYP2E1

Answer 6

metabolizes ethanol and other drugs. Thats why when alcohol Is consumed with other drugs, drugs can accumulate to dangerous levels as they are competing for hte same enzyme

Question 7

Name the four alcohol tolerance mechanisms

Answer 7

1. acute (single exposure)
2. metabolic (increases cp450 liver enzymes)
3. pharmacodynamic - neurons adapt via compensatory changes to cell function
4. behavioural - actions can be done better under alcohol

Question 8

Acute toxicity alcohol

Answer 8

high doses result in unconsciousness/death

most people dont reach lethal levels because they vomit or pass out before that

Question 9

Chronic toxicity

Answer 9

brain damage (Korsakoff's syndrome = confusion, disoriented, tremors, poor coordination, ataxia)
anterograde amnesia due to b1 deficiency

Question 10

Two types of effects on neurons alcohol

Answer 10

nonspecific actions - alters composition of polar heads, disrupts relationships of proteins in membrane (unstable)
2. specific actions - interacts with specific sites on particular proteins.

Question 11

Alcohols effects on GABA transmission

Answer 11

Binds to GABA-A receptors and causes receptor to stay open longer and open broader, enhancing effect of GABA-A.

Question 12

What does repeated exposure of alcohol on GABA-A do

Answer 12

reduces GABA a mediated inhibition by reducing cl- influx, contributing to pharmacodynamic tolerance and withdrawal symptoms.

Question 13

Alcohol effects on glutamate transmission

Answer 13

reduces effects of NMDA glutamate receptors - thought to cause impairments in learning/memory
decreases glutamate release
repeated exposure - unregulates NMDA receptors

Question 14

alcohol withdrawal symptoms

Answer 14

hyper excitability/seizures, more glutamate

depressed responding for rewarding stimuli

Question 15

Alcohol on DA transmission

Answer 15

Acute: increases VTA DA neuron firing and enhances DA release in NAc
repeated: sensitize effects of alcohol on DA

Question 16

Opioids do what for alcohol

Answer 16

contribute to reinforcing and potentially pleasurable effects of alcohol, increases endorphin and enkephalin production/release
- alcohol induced opioid release may contribute to its ability to increase DA release

Question 17

chronic administration of alcohol does what to opioid

Answer 17

reduces opioid production which may contribute to the dysphoria that accompanies chronic alcohol use and withdrawal