C30T L&S Drugs in the Brain Lecture 12: Alcohol
Ethyl Alcohol = ethanol Psychoactive substance ingested by humans
OH group is polar, hydrophilic "Alcohol is a liaison, mediating between water and oil" It is the 2nd simplest alcohol (1st is methanol) Equally soluble in oily things and watery things Can cross blood-brain barrier has psychoactive effects Beer & wine has a little bit of alcohol, mainly made of water Know Latin name of yeast spelled correctly: saccharomyces cerevisiae Alcoholic Beverages Wine--made from microbial fermentation of fruit, honey, rice Beer, ale, malt liquor--fermented grain, barley, wheat, corn Malt liquor is an American invention States differ by what you can call "beer" In some states, you cannot call an alcohol content above 6% "beer" call it "malt liquor" Other countries do not have malt liquor Europe calls it "strong beer" Alcohol Content Straight fermentation Not more than ~15-20% alcohol content Beer has 5-7% Yeast starts dying in its own waste Yeast is poisoned by alcohol Most potent wines and sake no more than 15-17% alcohol If you want more alcohol, need to use another method Distillation Distillari--Latin root, meaning "drip down" Invented between 1000-1200 years ago near Baghdad and Avalon Result of Middle Eastern alchemy Looking for the alcohol extract for perfumes, plant essential oils Art of Distillation Book written in London, England by John French in 1651
Has a long subtitle Still--source of heat, container Fermentation, boils off More elaborate structures allow for cooling off Double distillation makes it more pure Can have multiple distillations to further purify alcohol, leaving behind heavier molecules with flavor Alcoholic Beverages Distilled alcoholic beverages = spirits Brandy, cognac, etc (grapes) Whiskey (roasted grain) Vodka, gin (grain, potato) Mescal, tequila (agave) Rum (sugar cane) Alcohol content is ~ 25-50+% Cognac--brandy made in cognac region of France Scotch whiskey--a special way of making whiskey in Scotland Bourbon-- whiskey made in Kentucky Vodka has several distillations Very refined Gin= multiple distilled alcohol + juniper and 20 other herbs Mescal--made from Mexican succulent plant Schnapps--fruit brandy Sherry & port--fortified wine, 20% alcohol Add brandy to wine, aged in barrels It is acceptable in the US for private individuals to make beer & wine As long as it is not sold Use of stills to make alcoholic beverages is banned Only companies in the industry can use stills But stills can be used to make medicinal tinctures or perfumes Cannot sell beer and wine without license Alcohol content is determined by heat and how long you leave it in there Grain alcohol, neutral spirits, aqua vitae Aqua vitae= water of life Term is given to highly distilled alcohol Usually comes from grain Highest possible concentration of alcohol is 95% Cannot go higher 5% is water Because it is an azoetrope--no change on boiling Mixture, keep boiling, no changes
Interaction between ethanol and water molecule in vapor state Stuck in ratio 19:1 Slightly lower boiling point makes it more stable Proof = percent x 2 45% alcohol = 90 proof Historical tradition developed a couple of centuries ago To test potency, pour whiskey on gunpowder If water and you light will it, fizzle If alcohol and you light it, will pop 50% ethanol or more would facilitate the combustion of gunpowder 50% alcohol is 100 proof 190 proof is the highest you can obtain by distillation (95%) Metabolism of Alcohol Takes place primarily in the liver Subject to 1st pass metabolism Broken down by enzymes in the liver (metabolize) Ethanol acetaldehyde acetic acid Enzymes: alcohol dehydrogenase and acetaldehyde dehydrogenase Enzyme--large protein with amino acids Has a pocket where molecule of interest (ethanol) can fit, bend, and chemical reaction occurs Used to facilitate chemical reaction that otherwise would not happen Transform ethanol to acetaldehyde Acetaldehyde attaches to acetaldehyde dehydrogenase H H C H H H C H
ACETALDEHYDE DEHYDROGENASE
H C H
ALCOHOL DEHYDROGENASE
OH
ethanol
H C O acetaldehyde
H H C H
OH C O acetic acid
Acetic acid = vinegar Not toxic
Can be used by body as a source of energy It goes to further biological pathways and are used in all parts of the body as ATP It is the reason why alcohol has calories Sex differences: females are slower Believed females have lower levels of these enzymes in stomach Ethnic differences: some Asians have lower activity of acetaldehyde dehydrogenase Hot sensation = flushing, headache 50% Chinese have this Step to acetic acid slower so acetaldehyde builds up, bad for you Tylenol (acetylmetaphine) toxicity to liver Dangerous with alcohol, liver problems as a result Acetylemetaphine is a widely used medicine Regular consumption of alcohol as a depressant Drug Interactions Some drugs inhibit one or both enzymes Example: cimetidine (Tagamet ) and ranitidine (Zantac ) Over-the-counter, used to treat stomach acid, heart burn Widely used medications Both inhibit alcohol hydrogenase Make it less effective Blood level alcohol after drinking a certain amount Graph: Time (minutes after ethanol ingestion of 0.3 g/kg ob body weight) Peak 30 minutes Effect an alcohol shows on blood Much higher blood level for same amount of alcohol consumed Block histamine receptors in body, stop stomach acid release Inhibit alcohol dehydrogenase "one drink" every 1-2 hours (metabolized) "one standard drinks" equals (on average)... 1 ounce spirits 1 (12 ounce) beer 1 glass (4 ounce) wine Approximately, because alcohol content varies Blood Alcohol Level (BAL) or Blood Alcohol Concentration (BAC) BAC = # of grams of ethanol in 100 ml of blood (definition in US) Approximately equal to % of ethanol in the blood Blood approximately same density as water Look at breathalyzer--more alcohol in blood, more alcohol vapor in lungs Standard formula The more you drink, the higher your BAC is
Shape of curves depend primarily on body size Dose-dependent California Department of Motor Vehicles BAC chart 2 drinks in approximately one hour period 0.09 BAC in 100 lb person 0.05 BAC in 160 lb person BAC 0.01 threshold intoxication 0.04 relaxation, behavioral inhibition, impaired judgment 0.08 legally intoxicated (for driving), reaction time and coordination impaired 0.15 gross intoxication, balance and movement impaired 0.30 loss of consciousness 0.40 approximately human LD50 People die, most prominently on college campuses because binge drinking, fraternity hazing Influenced by tolerance If not used to it, may be passed out by 0.08 BAC