Nicotine I Flashcards
(35 cards)
What is the general route to the brain of smoke containing nicotine?
- inhaled
- carried into lungs
- absorbed into pulmonary venous circulation
- moves into brain
- nicotine binds to and activates nicotinic acetylcholine receptors
What is the % of men who smoke globally and what is the % of women?
47% of men smoke and 12% of women smoke
What is the general trend of smoking looking globally?
industrialized nations are smoking less, while developing nations are increasing
by 2020, 85% of smokers will be in developing countries
what is the % of smokers in Canada?
19%
What plant is tobacco derived from?
Nicotiana Tabacum species
What is curing?
curing is removal of excess moisture from tobacco plant so it can be smoked.
By curing, it also produces up to 599 compounds
What are the two naturally occurring chemicals in tobacco plant?
nicotine and carotenoids
what are some of the dangerous of intentional additives added to tobacco by cigaret companies?
- mostly for flavour, modifying burn rate, ability to release nicotine
- additives can form carcinogenic chemicals when burned
what is the relationship between ethanol and nicotine?
Simple sugars that are added in the curing process can be converted to acetylaldehyde when burned
rats triple nicotine self-admin if acetylaldehyde is also given at much lower levels than seen with drinkers (only in young rats)
this is thought to be because of inhibition of MAO’s and boost neurotransmitter levels
What is apatite? why is it so dangerous?
the tobacco plant (nicotiana tabacum) is often fertilized with a mineral called apatite to starve the plants of nitrogen in order to impart a particular flavour
but apatite contains radium, and radioactive isotopes of lead and polonium
What is smokeless/chewing tobacco? what are some concerns with it?
the amount of nicotine absorbed is 3-4 times greater than cigarettes, but process of absorption is much slower
there are at least 28 carcinogens identified in chewing tobacco
it does lead to addiction even though absorption process is slow
and it does increase risk of oral cancers
How do electronic cigarettes work?
they don’t contain tobacco or require combustion but provide nicotine dosage via inhalation
- they contain a battery-powered atomizer that heats up and vaporizes a nicotine-containing liquid
- people say its safer than cigs because they provide behavioural cues that satisfy some cravings but could act as a gateway drug into tobacco
What are 4 concerns with e-cigs?
- inhalation of the liquid can be dangerous as it includes propylene glycol. Its not really tested
- also reported findings of nitrosamines … formed from non-pure nicotine (carcinogenic compounds)
- Fear that children will break them and swallow nicotine
- increasing evidence that nicotine itself may enhance cancer growth
What is diacetyl?
It is a compound found in flavoured e-cigs and was detected in 39 out 51 brands tested
it is also used to flavour buttered popcorn
what is popcorn lung?
the obliteration of respiratory tissue (bronchiolitis obliterates) in workers in buttered popcorn factories (collapsed lungs)
What is the effect on e-cigs on the immune system of the lungs?
- Using a modified Jaeger-Baumgartner Cigarette Smoke Machine: E-cig is puffed for 2sec. once every 10 seconds
- E-cig vapour is mixed with filtered air via peristaltic pump at 1.05L/min (this is to mimic a human smoking)
- Mice are exposed to this puff in a small chamber for 1.5 hours, twice per day for 2 weeks. There are three mice in the chamber.
- Electron paramagnetic resonance shows increase number of free radicals from the filtered air mixed with smoke
- At 1 hour after the final exposure, mice are infected intranasally with S. pneumoniae or influenza A. (viral or bacterial infection) and a control
What were the results of the effects of e-cigs on the immune system?
- detection of free radicals were found (1/100 of what is in cig smoke)
- exposure to e-cig smoke increases membrane lipid damage (peroxidation)
- e-cig smoke exposure resulted in macrophage infiltration into lungs similar to what is seem with tobacco
smoke - after 2 weeks of exposure to e-cig smoke, mice were exposed to different levels of influenza virus; and it was found that those exposed to smoke were more likely to die
When increasing the bacteria population 10 times, almost all of the infected mice died
there is increased inflammation and inflammatory agent in the lungs but they are unresponsive to bacteria (don’t work well)
What is hooka?
Shisha is a tobacco base with added ingredients
- shisha is used via hookas (water pipes)
- shisha is heated not burned, so it is better in the sense that it has less combustion materials
- smoke is cooled as it passes though the water
what are 5 negative aspects about shisha?
- one gram of tobacco shisha produces 11 times more carbon monoxide than 1 gram of cig tobacco
- smoke contains carcinogens that can be at the same or higher levels as cigs
- increases heart rate and BP
- Leads to lung disease
- Increased risk of oral and lung cancer
what is the smoking time, number of puffs and inhaled smoke per puff in hooka vs. cigs?
hooka:
smoking time –> 28-80 minutes
number of puffs –> 50-200 puffs
inhaled smoke per puff –> 0.15L
Cigs
smoking time –> 5-7 minutes
number of puffs –> 8-12 puffs
inhaled smoke per puff –> 0.5-0.6L
What is the function of nicotine?
nicotine:
- facilitates addiction
- mimics aCH at aCH receptors (agonist)
- binds to same side on the aCH receptor as aCH
- has a charge at low pH
- some studies suggest nicotine can promote spread of cancer
What is the relationship between nicotine and pH?
the charge on nicotine depends on pH (weak base)
What are the three forms of nicotine? and its properties?
- diproontated state –> has lots of [H+] and low pH … it has two hydrogens (ph 2)
- Monoprotonated state –> in between state; has only one proton (ph 5)
- Nonprotonated (free base) –> not a lot of [H+] and high ph; no hydrogens (ph 10)
what is the relationship between the 3 forms of nicotine and smoking adaption?
diprotonated form does not occur when smoking
- free-base is volatile –> more easily released from tobacco and increases ease of absorption; this is linked with higher dependance/adaption rate
non charged substances pass lipid bilayers quicker thats why
drug companies like to make non-protonated nicotine so it can cause addiction and more people to buy it
