Lecture 13: Alcohol Flashcards
What is the functional group that defines alcohols?
Oxygen plus a proton (hydroxyl groups)
What are the characteristics of ethanol?
- Small
- Water soluble
- Freely crosses membranes
What is beer made from?
Grains
What is wine made from?
Grapes
Where does Vodka and Gin come from?
Potatoes
Which spirit is made from molasses?
Rum
What is Agave used to make?
Tequila
How does low pH effect ethanol?
It does not alter ethanol so as it passes through the stomach nothing happens to it
Where does most of the absorption of ethanol occur?
In the small intestine
In which population is BAC higher?
In females
What contributes to BAC after one drink being higher in females?
Females are generally smaller and less lean
How does a full stomach affect the peak BAC?
It slows absorption and lowers peak BAC
Which people have lower BAC?
Larger people and leaner people
What allows ethanol to get into the brain?
Ethanol’s small size
What is the difference between the BAC of men and women?
In general, men can have more drinks and have lower BACs
What are the effects of alcohol consumption on the behavior?
- Inhibited decision making and judgements
- Unstable mood and heightened emotions
- Decreased anxiety
- Increased aggression
- Increased addiction
What are the Physiological effects of alcohol consumption?
- Dilation of blood vessels in the skin
- Reduced blood clotting
- Increased HDL levels
What kind of kinetics does alcohol follow?
Zero order kinetics
What is zero order kinetics?
No matter what does is administered, there is a linear decrease in blood alcohol concentration
What are the main enzymes for alcohol elimination?
Alcohol dehydrogenase and aldehyde dehydrogenase
What limits the enzymes needed to metabolize alcohol?
They saturate quickly, and require NAD+ to operate
By what intervals do the alcohol enzymes work?
8g/hr or 0.015 BAC elimination per hour
What amount of alcohol is exhaled?
1/2200 of BAC
What kind of curve is seen in BAC curves?
A biphasic curve
What are the two phases of BAC?
- BAC rises stimulant ➡️
* BAC declines ➡️ depressant
What is personality like in the first phase?
Increased sociability, decreased anxiety
What neurotransmitters does ethanol modulate?
Glutamate and GABA
What does glutamate do?
Depolarizes cells and activates neurons
What does GABA do?
Inhibits activation of neurons
How does ethanol affect Glutamate and GABA neurons?
Ethanol inhibits Glutamate neurons and stimulates GABA neurons
What is the shift toward due to ethanol?
Hyperpolarization/Inhibition
How does EtOH affect GABA receptors?
Causes potentiation of GABAa receptors causing hyperpolarization of downstream neurons
How does EtOH affect Glu-NMDA receptors and voltage gated calcium channels?
Inhibits them preventing activation of downstream neurons
Why does Asphyxiation occur in lethal doses of alcohol?
Because it causes depressed activity in autonomic centres
What type of receptors are GABAa receptors?
Cys-loop ligand-gated channel superfamily receptors
What is meant by GABAa receptors are heteropentameric receptors?
They contain two alpha subunits, two beta subunits, and one other
What do GABAa receptors conduct?
Negative chloride into neurons
Which receptors are inhibited by EtOH?
NMDA receptors
What kind of receptors are NMDA receptors?
Ionotropic Glu receptor superfamily
What subunits do NMDA receptors usually contain?
2 NR1 subunits either 2 NR2 or 2 NR3 subunits
What do NMDA receptors conduct?
Positive currents in neurons depolarizing them
Why is Alcohol addicitve?
GABA neurons release inhibitory neurotransmitters onto DA receptors. If glutamate neurons are inhibited by EtOH they cannot tell GABA to release inhibitory GABA onto DA receptors causing an increased release of DA. It disinhibits dopamine receptors
Why does increased vasodilation in the skin occur with alcohol?
The outputs to vessels go down causing vasodilation
How does alcohol affect the stomach?
It cause loss of the stomach mucosal lining
Why does the spins occur?
EtOH permeates the endolymph and cupula. Then BAC starts to decline and EtOH diffuses out of the cupula before the endolymph. This makes the cupula more dense than the endolymph and so it does not stabilize when lying down and detects this as motion causing the spins
At what BAC does the spins occur?
0.04
How does the body express alcohol tolerance?
It up regulates the enzymes that metabolize alcohol
What is ethanol converted to?
A calorie dense acetate molecule
What happens to the acetate produced from alcohol?
It can enter the citric acid cycle and generate energy
What trimester is most susceptible to fetal alcohol spectrum disease?
3rd trimester
How does alcohol affect the brain?
It causes shrinkage of brain mass and overall function of the brain decreases due to acetaldehyde which is an ethanol metabolite
Where does alcohol increase cancer risk?
In the upper GI tract and stomach
Why does alcohol increase cancer?
It is metabolized by microflora increasing acetaldehyde concentration in the GI tract which is a carcinogen and interferes with DNA synthesis
