Exam 3: Alcohol Flashcards
form of alcohol used in beverages
ethanol (ethyl alcohol)
unscheduled
toxic forms of alcohol
isopropyl and methyl alcohol
methanol metabolites and posioning symptoms
metabolites: in liver: formic acid and formaldehyde
poisoning symptoms: blindness, coma, death, antifreeze!!
isopropyl alcohol (rubbing alcohol) metabolite and poisoning symptoms
metabolite: acetone
poisoning symptoms: flushing, headache, dizziness, nausea, vomiting, anesthesia, hypothermia, low BP, shock, respiratory depression
percentage alcohol
percent expressed as grams of alcohol / 100mL solution
proof of alcohol
double the percentage of alcohol
- a beverage 50% alcohol by volume is 100 proof
16th century England - alcohol tax and burn, no-burn test
standards for wine, beer, hard liquor, wine cooler that each raise your blood alcohol content (BAC) by same amount
wine: 5 oz glass
beer: 12 oz can
hard liquor: cocktail with 1.5 oz spirits
wine cooler: 12 oz
BAC (blood alcohol content/concentration)
reported in mg alcohol/ 100mL blood
ex: 80mg alcohol /100mL blood = 0.08% BAC
absorption of alcohol
ROA: oral (most common), rectal, inhalation
ethanol absorbed from GI tract, enters most tissues - even brain
many factors influence blood levels of ethanol: behavioral effects based on BAC not amount consumed
passive diffusion: high concentration to low
greater concentration of alcohol consumed more rapid the movement
food slows absorption
sex differences in absorption and distribution
-lower total body water content in women
-reduced 1st pass metabolism in women
(alcohol dehydrogenase in gastric fluids is 60% more active in men than women)
distribution- prenatal ethanol
alcohol readily passes through placental barrier and fetus will quickly reach same BAC as mother
- fetal alcohol syndrome (FAS) from alcohol exposure causes long term developmental consequences
FAS: fetal alcohol syndrome
- intellectual disability and developmental delays
- low birthweight; failure to thrive and grow
- neurological problems: some infants born with high alcohol levels experience withdrawal after birth
- physical abnormalities: craniofacial malformations, cardiac defects, kidney development issues, undescended testes, skeletal abnormalities in fingers and toes
metabolism and excretion of alcohol
95% metabolized by liver
other 5% excreted by lungs and measured with Breathalyzer - BAC can then be calculated
what converts alcohol to acetaldehyde?
what converts acetaldehyde into acetic acid and acetone?
alcohol dehydrogenase: converts alcohol to acetaldehyde
aldehyde dehydrogenase (ALDH): converts acetaldehyde to acetic acid and acetone
what population has genes that code for inactive form of ALDH
- drinking alcohol results in build up of toxic acetaldehyde
10% asian population
cytochrome p450
converts alcohol to acetaldehyde when in higher doses
if alcohol consumed with other drugs
they compete for same enzyme (cytochrome p450)
drug molecules can accumulate to dangerous levels
prescription an OTC have warning labels regarding this
induction
metabolic tolerance
- regular alcohol consumption increases CYP450 enzymes that metabolize alcohol
- inc rate of alcohol metabolism - reduction in behavioral effects
caveat to metabolic tolerance
prolonged heavy use of alcohol causes liver damage that impairs metabolism of alcohol and many other drugs
elimination of alcohol
zero order kinetics
0.015% every hour
BAC
grams alcohol/ 100mL blood
widmarks formula
BAC = (g/body weight x r) x 100
r= 0.55 females
r=0.68 males
what does alcohol do to the BBB
disturbs the BBB proteins and lipids
makes it more permeable to other things
glutamate and alcohol
- alcohols inhibits NMDA receptors (glutamate antagonist) - depressant
- reduces glutamate release in hippocampus
- produces amnesia for events that take place during intoxication (blacking out)
glutamate and alcohol effects on development
reduced NMDA receptors in adulthood
learning and memory impairment in children whose mothers consumd alcohol in pregnancy
chronic changes from alcohol
upregulation of NMDA receptors to compensate
withdrawal
cannot go cold turkey
glutamate release increases after 10 hours - CNS hyperexcitability and seizures
- excessive Ca influx - cell death from oxidative stress
GABA and alcohol
alcohol binds GABA A receptors and opens channels allowing Cl to enter cell and hyperpolarize membrane
reduces likelihood of action potential
effects of neurotransmission: GABA
- alcohol potentiates receptor function of GABA
- location of receptors dictates events: reduction in anxiety, inc motor impairment and inc sedation
- cerebral cortex, hippocampus, thalamus - depressant effects on cognition
- Nacc and VTA - inc dopamine associated with reward
opioids (endorphins)
contribute to reinforcing effects of alcohol
acute alcohol: inc endogenous endorphin levels
chronic: reduces natural endorphin levels - dysphoria with chronic use and withdrawal
dopamine
- alcohol indirectly inc dopamine in Nacc - reinforcement
- withdrawal after chronic use reduces firing rate of mesolimbic neurons and dec DA release in NAcc
