Nicotine Flashcards
What are the 2 major species of tobacco plant
1) large leaf form
2) small leaf form
Which is commonly used today and where does it come from
Large leaf form is used in modern day tobacco and it originated in South America where Native peoples domesticated it 5000 years ago
Where is the small leaf form from
native to eastern North America and the islands of the West Indies. Same plant encoutnered by Columbus in 1492
What is the botanical name of tobacco and where did it originate
Nicotiana Tabacum; Nicot’s surname (introduced tobacco in Portugal) and tabaco which means tobacco in spanish and portugese
How was most tobacco use smoked at first
through pipe smoking, cigar smoking and chewing and later developed into snuff
When were cigarettes first used
in Europe in the mid nineteenth century and their popularity exploded over the next 30 years
What 2 developments occurred once cigarettes gained popularity
1) new methods of curing tobacco leaves that improved their flavor
2) the invention of cigarette machines
how many cigarettes are able to be produced per minute on modern day machines
4000 to 8000 per minute
In 1828 how much nicotine was in dry tobacco leaves
5%
How much nicotine is in the typical cigarette and how much reaches the blood stream
between 6 and 11 mg although only 1 to 3 mg reach the bloodstream
How does nicotine enter the smoker’s lungs?
tiny particles called tar which is a mixture of hydrocarbons
Why is tar important in cigarettes
it contributes to the taste and smell of cigarette smoke
What is the quickest way to get nicotine straight to the brain
smoking
what principal metabolite transforms 70-80% of nicotine in the body
cotinine
What is the outcome of individuals with low CYP2A6
have less nicotine metabolism and are les likely to become smokers. If they are smokers they will smoke less. Therefore, slow breakdown may produce a protective effect against smoking
What are the mechanisms of action of nicotine
works by activating nicotinic cholinergic receptors (ionotropic receptors- fast acting)
feelings of calmness and relaxation may actually be caused by what? and why?
relief from withdrawal symptoms because nicotine given to nonsmokers = feelings of heightened tension, lightheadedness, dizziness and nausea
What is the outcome of abstinent smokers being given nicotine regarding cognition
they show enhanced performance on many cogitive and motor tasks, particularly those showing attentional demands
What has been found of cognitive outcomes of nicotine use for both smokers and non smokers
has a positive influence on cognitive and motor functioning
What are the two types of cholinergic receptors
nicotinic receptors and muscarinic receptors
What do nicotinic receptors do
ionotropic
– fast acting receptors that regulate the ability of the neuron the fire
When ACh binds, the channel opens and Na+ and
Ca2+ enter the neuron or muscle cell
(depolarization -> excitatory).
What are muscarinic receptors
Muscarinic receptors are metabotropic
• Five types: M1 – M5
• Operate via second messengers (G protein) – slow acting
What is the function of acetylcholinesterase
breaks acetylcholine down to choline and acetic acid.
What is the function of CYP2A6
metabolizes nicotine, caffeine, estrogen and antidepressants
