Alcohol - Chapter 9

Alcohol Metabolism:

(1) Alcohol is metabolized by the enzyme alcohol dehydrogenase into an acetaldehyde. (2) Acetaldehyde is metabolized by the enzyme aldehyde dehydrogenase into *acetic acid*. [Exercise, coffee, and other strategies do not speed up the rate of metabolism]

Types of beer: (1) (2) (3)

(1) Ale (2) Lager (3) Light beer

Alcohol Toxicity: Long-Term Risks and Effects

(1) Brain tissue loss and cognitive impairment ----> Wernicke-Korsakoff syndrome (2) Heart disease: ----> cardiomyopathy, heart attack, hypertension, stroke ----> Alcohol's beneficial effects on HDL may reduce heart attack risk among moderate drinkers and is therefore considered cardioprotective (3) Liver disease: ----> hepatitis, fatty liver, cirrhosis

Alcohol Mechanisms of Action:

(1) CNS depressant ----> Used as anesthetic until the late 19th century ----> Alcohol has many effects on the brain; multiple mechanisms at work (2) *Enhances the inhibitory effect of GABA at the GABA-A receptor* (3) Blocks the effects of the excitatory transmitter glutamate (4) Also affects dopamine, serotonin, and acetylcholine neurons (5) Also increases opioid activity in several brain regions

Varieties of Wine: (5)

(1) Generics vs. varietals ----> Determined by type of grapes and flavor (2) Red vs. white (3) Sweet vs. dry (4) Sparkling wines (5) Fortified wines ----> Alcohol content near 20 percent

Grain neutral spirits is used to make various beverages:

(1) Gin: distillate filtered through juniper berries and then diluted with water (2) Vodka: mixture of grain neutral spirits and water

Inhibition of vasopressin release leads to: (5)

(1) Increased urination (2) Impaired cognition (3) Disrupted circadian rhythm (4) Lowered blood pressure (5) Enhanced aggression

Factors in wine quality include: (1) (2) (3) (4)

(1) Selection and cultivation of grapevines (2) Good weather (3) Timing of harvest (4) Careful monitoring of fermentation and aging

Lager

(Most common type in U.S.) Uses a type of yeast that settles to the bottom of the mash to ferment Cool temperature and slower fermentation

Alcohol Metabolism:

(a) If rate of intake = rate of metabolism, BAC is stable (b) If rate of intake > rate of metabolism, BAC increases

The Liver metabolizes about ______ oz. of alcohol/hour

0.25 oz

Standard drink has about 0.5 ounce of pure alcohol =

12-oz beer 4-6 oz of wine 1 oz of 100-proof spirits or 1.5 oz

Yeast has a limited tolerance for alcohol - When alcohol concentration reaches ___ percent, the yeast dies and fermentation ceases.

15

Peak blood levels reached ____ to ____ min depending upon concentration and what else is in the digestive tract.

30-60 min

Fetal Alcohol Syndrome (FAS)

A collection of physical and behavioral abnormalities associated with mother's alcohol use during pregnancy Related to peak BAC and to duration of alcohol exposure Prevalence: 0.2-1.5 per 1,000 births

Blackouts

A danger sign of excessive alcohol use - Reversible, - alcohol induced dementia, - characterized by stupor (dulled senses and poor cognitive function) - anterograde amnesia (inability to form new memories)

Proof:

A measure of a beverage's alcohol content (US) Twice the percentage of alcohol by weight 90-proof whiskey is 45 percent alcohol ----> (90/200) = 45%

Disinhibition (during lower concentration):

A weakening of behavioral control that displays as poor risk assessment, engagement in dangerous behavior, and impulsivity (decision making without reflecting adequately on the consequences of those decisions).

0.40 BAC (%)

About LD50

Distilled Spirits: Liqueurs or cordials

Alcohol content 20 to 25 percent Originally made from brandy mixed with flavorings from herbs, berries, or nuts *Now typically made from flavored, diluted grain neutral spirits*

Physiological Effects: Fluid balance

Alcohol has a diuretic effect that: ----> Increases urine output ----> lowers blood pressure in some people

Sexual behavior

Alcohol use enhances interest in sex but impairs physiological arousal Linked to unsafe sex

Behavioral Effects

Alcohol use serves as a social signal for a time-out from responsibilities, work, and seriousness Intoxicated individuals focus on the here and now, with little care for future consequences

Fetal alcohol effects *

All alcohol-related *developmental* abnormalities associated with prenatal alcohol exposure Prevalence: 80-200 per 1,000 births

Alcohol readily passes through the blood-brain barrier, allowing neural tissues to reach _____ quickly.

BALs (Blood Alcohol Level)

Alcohol is a chemical term that covers a class of substances. Which one do we drink? A) Isopropyl alcohol B) Methyl alcohol C) Ethyl alcohol D) Isobutyl alcohol

C) Ethyl alcohol (Ethanol)

Physiological Effects: Hormonal effects

Chronic abusers of alcohol can develop a variety of hormone-related disorders ----> Disrupted reproductive functioning

Grain neutral spirits:

Clear, tasteless, nearly pure alcohol (190 proof) produced by distillation Sold as Everclear to consumers and used in research Used in commercial products as a gasoline additive, cleaner, solvent Contains relatively few *congeners* (by-products, impurities)

Alcohol's effects via GABA pathway:

Depressant: cortex, hippocampus, thalamus Reinforcing: nucleus accumbens, VTA

Physiological Effects: Peripheral circulation

Dilation of peripheral blood vessels ----> drinkers lose body heat but feel warm

Distilled Spirits: Whiskey

Distillate of fermented *malted barley* Distilled at a *lower proof (160)* and so contains more congeners and some flavor from the grain used Rye whiskey, *corn whiskey (bourbon)*, blended whiskey Usually aged for at least two years Early U.S. distiller from Bourbon County, KY, gave beverage its name

Alcohol and Pregnancy Facts:

Drinking during pregnancy increases risk of spontaneous abortion Data do not prove that low levels of alcohol use during pregnancy are safe or that they are unsafe

Distillation:

Evaporation and condensing of alcohol vapors to produce beverages with alcohol content higher than 15 percent Process discovered in Arabia around AD 800 Introduced into Europe in about the 10th century In U.S., began on a large scale at the end of the 18th century

Fruits + yeast =

Fermentation will begin (Fruits naturally contain sugar)

Light beer

Fermented longer at a cooler temperature More sugar is converted to alcohol Then water added

Actions of alcohol involve multiple neurotransmitter systems:

GABA Glutamate Endogenous opioid Dopamine Serotonin Endocannabinoid systems

Fetal Alcohol Syndrome (FAS): Diagnostic criteria

Growth retardation before and/or after birth Pattern of abnormal features of the face and head Evidence of central nervous system abnormality

Reading assignments for next class 1. College Drinking_NIAAA 2. Why Colleges Haven't Stopped Binge Drinking - NYT_Dec2014

How Alcohol Affects Your Brain And Body: https://www.youtube.com/watch?v=VAlE-UESTOA

0.15 BAC (%)

Large, consistent increases in reaction time

0.05 BAC (%)

Lowered alertness, release of inhibitions, impaired judgment

How is beer made?

Made by adding *barley malt* to other cereal grains *Hops* are added with yeast to give beer its distinctive flavor

Wine Production:

Made from fermented grapes Produced by both small and large wineries Most wines contain about 12% alcohol

0.20 BAC (%)

Marked depression in sensory and motor capability, intoxication

Heavy drinking

Men: at least 4 drinks per day Women: at least 3 drinks per day

Binge drinking

Men: drinking occurs in short time period consisting of at least 5 drinks per day for men and 4 for women

Moderate drinking

Men: two drinks per day Women: one drink per day

If someone drinks enough to pass out:

Place the person on their side and monitor breathing or take to ER Do not leave the person alone

Chronic alcohol administration:

Reduces GABAA receptor levels/sensitivity; lowers increases in β-endorphin levels

0.25 BAC (%)

Severe motor disturbance, staggering, great impairment

0.10 BAC (%)

Slower reaction times, impaired motor function, less caution

Society's love-hate relationship with alcohol:

Social lubricant? Adjunct to a fine meal? "Demon rum"?

0.30 BAC (%)

Stuporous but conscious—no comprehension of what's going on

0.35 BAC (%)

Surgical anesthesia; about LD1, minimal level causing death

Fermentation

The production of alcohol from sugars through the action of yeasts Forms the basis of all alcoholic beverages

Alcohoot Smartphone Breathalyzer

The world's first law enforcement grade smartphone breathalyzer. The small device, along with the Alcohoot mobile app, enables you to test your blood alcohol level quickly, accurately, and easily.

If someone drinks enough to vomit:

They should stop drinking Vomiting reflex is suppressed at BACs above 0.20 percent and can quickly reach lethal levels

Extreme drinking

Two or three times the number of drinks considered as binge drinking

Ale

Uses a top-fermentation yeast Warm temperature and shorter fermentation

Alcohol and Gender Differences

Women tend to be more susceptible than men to the effects of alcohol after consuming the same amount Women tend to weigh less and have a higher proportion of body fat ----> "Tank" into which alcohol is added is smaller

Alcohol facts

World's most important psychoactive drug Second most widely consumed beverage Alcoholic beverages have been consumed for thousands of years, perhaps as far back as 8000 BC According to surveys, more than half of all U.S. individuals 12 and older have consumed alcohol within the last 30 days

Gastric alcohol dehydrogenase

a stomach enzyme that metabolizes a small amount of alcohol is less active in women Women absorb a greater proportion of the alcohol they drink

90-95% of ingested alcohol is metabolized by the enzyme ________________; the remainder is excreted or metabolized by _______.

alcohol dehydrogenase P450

Crime and violence

alcohol use is statistically related to violence - Homicide - Assault, including family violence, sexual assault, date rape - Suicide

Alcohol priming

an urge to consume more alcohol after consuming 1 to 2 drinks

Alcohol inhibits ______ channels. ----> ________ neurotransmitter release from axon terminals.

calcium Reduces

Absorption is faster in the presence of __________ beverages.

carbonated

Higher alcohol concentrations:

depressant effects

Alcohol dehydrogenase:

enzyme that metabolizes alcohol into acetaldehyde (Metabolite)

Effects are influenced by _______. For example, placebo effects explain many of the effects on social behavior

expectations

Effects are influenced by the individual's alcohol ________. For example, a higher BAC is needed to impair a chronic heavy drinker

experience

Alcohol is distributed throughout body fluids and therefore can be measured from any tissue. The most common method of measuring BAC is:

from expired air

Chronic alcohol administration ________ number of NMDA receptors

increases (Contributes to greater risk of seizure)

Liver responds to chronic intake of alcohol by ______ enzyme activity. (Contributes to tolerance among heavy users)

increasing

Alcohol produces depressant effects by:

inhibiting excitatory glutamate NMDA receptors

Light drinking

less than 2 drinks per day for men; less than 1 drink per day for women

About 90% is metabolized in the _____. About 2% of alcohol is _______ unchanged

liver excreted

Alcohol is less distributed in fatty tissues, so a lean person will have a ______ BAC than a fatter person

lower

Cereal grains contain starch, which must be converted to sugar by _____ before fermentation can begin.

malt

Acetaldehyde:

metabolite produced from enzymatic conversion of alcohol with alcohol dehydrogenase

Blood alcohol concentration (BAC):

number of grams of alcohol in a 100-ml volume of blood a measure of the concentration of alcohol in blood, expressed as a % in terms of grams per 100 ml

Alcohol is a GABAA receptor ______ modulator.

positive Enhances GABA-A receptor inhibitory effects

Lower concentrations:

pseudo-excitatory effects

Because alcohol is so readily absorbed by all tissues, a pregnant women exposes her fetus to the _______ blood level she has

same

Absorption is _______ if there is food or water in the stomach

slower

Absorption - Most absorbed in the _____________, some absorbed in the __________.

small intestine stomach

Effects depend on the _____ _____. For example, effects are greater when BAC rises rapidly

time course

Alcohol is _____ and _____ soluble. Readily diffuses across all cell membranes

water and fat