Nicotine

Question 1

Nicotine

Answer 1

The main psychoactive ingredient in the tobbaco plant (Nicotiana tabacum). Nicotine is a natural insecticide developed by tobacco plants as a defence mechanism.

Question 2

Many indigenous peoples used tobacco for ___

Answer 2

spiritual and religious purposes.

Question 3

Tobacco was first introduced to Europe in the [answer] century.

Answer 3

15th

Question 4

By which century was use of tobacco across Europe widespread?

Answer 4

16th century (1500s)

Question 5

As early as the [answer] century, there were questions about the safety of tobacco.

Answer 5

17th

Question 6

The [early or late] [answer] century saw researchers focus on the adverse effects of tobacco.

Answer 6

early 20th century

Question 7

Cigarettes

Definition, nicotine content, nicotine bioavailability

Answer 7

Most commonly used tobacco product. A tobacco blend rolled in a sheet of paper, often has a filter at the end to reduce the amount of tobacco tar being inhaled.

Contains 6-11mgs of nicotine, 1-2mgs of which are bioavailable.

Question 8

Cigars

Definition, nicotine content

Answer 8

Rolled bundles of dried tobacco leaves.

Hard to define nicotine content, but can contain up to 335 mgs of nicotine.

Question 9

Pipes/Hookahs (water pipes)

Usage

Answer 9

Pipes are utilized for inhaling tobacco blends (often have water pipes/pass through containers of water). Used in the Middle East for centuries.

Question 10

Smokeless tobacco

Answer 10

Eg. Chewing tobacco. Can be absorbed through the mouth/mucus membranes.

Question 11

Vaporizers/E-cigarrettes

Answer 11

‘Replacement therapy’ where nicotine is isolated and heated, to reduce the amount of tar consumed when smoking.

Question 12

Juuls/Vapes/Vaping

Answer 12

A type of e-cigarette that uses nicotine salts (nicotine converted to salt form). Reduces the “burn” that comes with smoking. However, these salts have a quicker nicotine peak and are much more potent.

Very popular amongst teenagers and young adults. Billion dollar tobacco business.

Question 13

Four risks tobacco use/exposure can increase

Answer 13

• Rates of cancer
• Rates of cardiovascular disease (CVD)
• Rates of pulmonary disease
• Rates of pregnancy complications

Effects oral health as well.

Question 14

Emphysema

Answer 14

Causes significant shortness of breath. Transfer of O2 and CO2 in the lungs is more difficult/decreased.

Question 15

Nitrosamines

Answer 15

A main class of carcinogenic compounds found in tobacco smoke. Eg. tar

Question 16

Teratogens

Answer 16

Something that can cause physiological abnormalities in an embryo.

Question 17

First-hand, second-hand and third-hand smoke

Answer 17

First-hand smoke: Someone themselves smoking.
Second-hand smoke: Breathing in the smoke of someone smoking.
Third-hand smoke: Breathing in remnants of tobacco smoke that gather on the material of the smoker’s environment.

Fewer risks with non-tobacco products, but still risky, and not studied as much, especially in the long-term.

Question 18

Nicotine can be absorbed through:

Answer 18

The mouth, nose, throat, lungs

Question 19

What method is most effective for nicotine delivery?

The exception being most e-cigarettes

Answer 19

Inhalation

Question 20

Peak concentration after smoking a cigarette (lungs)

Answer 20

5-7 mins

Question 21

Peak concentration after consuming tobacco through most products besides cigarettes

Answer 21

20-30 mins

Question 22

Nicotine is metabolized by which organ?

Answer 22

The liver

Question 23

What is nicotine’s active metabolite?

Answer 23

Cotinine

Question 24

Mentholation

Answer 24

Slows the metabolism of nicotine

Question 25

With nicotine, genomic [answer] affect the rate of metabolism

Answer 25

polymorphisms

Slower metabolism of nicotine = less likely to get addicted

Question 26

Nicotine is a [answer] partial [agonist/antagonist], at [answer] receptors.

Answer 26

Nicotine is a cholinergic (as in affects acetylcholine) partial agonist at nicotinic receptors
(nAChRs),

Nicotinic receptors have five different subunits.

Question 27

Are nicotinic receptors ionotropic or metabotropic?

Answer 27

Ionotropic

Question 28

Distribution of Nicotinic Receptors (nAChRs)

Answer 28

Found in peripheral nervous system:
* Neuromuscular junction
* Ganglia of autonomic nervous system (first time users may start sweating due to activation of sweat glands, feel sick, etc.)

Found in central nervous system:
* Hippocampus and cerebral cortex
* Basal ganglia
* Ventral tegmental area and nucleus accumbens

Question 29

The three ways nicotine effects dopamine release

Answer 29

Nicotine receptors activated in the ventral tegmental area (VTA) send signals to the nucleus accumbens (NAcc) to release dopamine. As well, when nicotine binds to heteroreceptors (pre-synaptic release modulators) on the terminal region of a VTA neuron, it enhances the dopamine release. It also inhibits MAOI (monoamine oxidase) which also enhances the effects of dopamine as it slows the metabolism of dopamine.

TL;DR/Key Points:
1. Receptors tell VTA to tell NA to release dopamine
2. On terminal of axons in VTA dopamine release is inhanced by dopamine
3. Nicotine inhibits MAOI

Question 30

Acute tolerance with nicotine/how it works

Answer 30

Nicotine can cause acute tolerance. There is often upregulation with nicotinic receptors (increased receptor numbers). As well, due to desensitization, ion channels may start staying closed even if nicotine is attached, thus nicotine in a way starts acting as a “functional antagonist.” These both are mechanisms to counteract usage of nicotine after it’s used at least once during the day. Thus, people get less of a “hit” each time they smoke throughout the day due to the build-up of tolerance.

Question 31

Half-life of nicotine

Answer 31

2 hours (shorter in chronic smokers)

Question 32

Half-life of continine

Answer 32

17 hours

Question 33

Physiological effects of nicotine

Answer 33

• Sympathomimetic effects (activates the sympathetic nervous system, speeds up heart rate, raises blood pressure, etc.)
• Cognition and movement (stabilizes movement, cognitive enhancer/attention)… but don’t forget, the enhancement only works until tolerance is built
• Reduces appetite/appetite suppressant (also a sympathomimetic effect)

Question 34

Naïve (first time) users of cigarrettes report what effects vs. habitual smokers?

Answer 34

Naïve users report negative subjective effects. Habitual users report positive subjective effects, and have built tolerance to negative subjective effects.

Question 35

Chippers

Answer 35

• Similar to social smokers
• Resistant to addictive effects of nicotine like withdrawal
• Surprisingly common
• There are genetic and environmental mechanisms affecting them

The one exception to habitual smokers becoming addicted to smoking!

Question 36

Nicotine

The “magic timeframe” after which withdrawal symptoms have diminished

Answer 36

2 weeks

Question 37

Nicotine replacement therapy

Answer 37

Eg. Gum, patches, nasal spray, vapes

Question 38

Which antidepressant is used to treat nicotine addiction?

Answer 38

Buproprion, an NDRI and nAChR antagonist

Buproprion is considered an atypical antidepressant.

Question 39

Better rates of abstinence in:
Women or men?
Which ethnicity?
Which socioeconomic status?

Answer 39

Men, European Americans, higher socioeconomic status

Question 40

Groups don’t usually achieve higher than a [X]% quitting rate in studies about smoking/tobacco/nicotine.

Answer 40

50%

Smoking is very hard to quit.