PSYC62H3 Lecture Notes - Lecture 5: Dipping Tobacco, Nucleus Accumbens, Cotinine
Document Summary
Nicotine: central psychoactive ingredient in tobacco, tobacco comes from plant leaves of nicotiana, forms: cigarettes, cigars, hookah, vaping, chew, snuff, dipping tobacco, dissolvable tobacco, pharmacokinetics. Nicotine tar adheres to tissues in the mouth, nose, throat, lungs, and skin. Freebase form of nicotine best absorbs thru mucous membranes in the mouth. Peak absorption is 7min (cigarettes) to 25min (smokeless tobacco products) In liver, cyp-2a6 enzymes metabolize 80-90% of nicotine, producing the active metabolite cotinine (this is what contains the addictive properties) Half-life for nicotine is approximately 2 hours. Chronic smokers have a 30% faster elimination rate of nicotine than non-smokers: effect on the ns. Nicotine is an agonist for cholinergic nicotine receptors. Channels close and cannot be opened even when agonist is bound. Receptors remain in an inactivated state longer than an activated state. Also influences acetylcholine, glutamate, gaba, norepinephrine, serotonin, and vasopressin: other effects. Nicotine also reduces appetite in both non-tobacco users and long-term smokers: cognitive and motor functioning.
