Tobacco and Nicotine
Adapted from a presentation by George Sanchez, 4th year Biomedical Science major, Texas A&M University
Method of Delivery
• Tobacco products include
cigarettes, cigars, and pipe
tobacco, which are
smoked; snuff, which is
inhaled into the nose; and
chewing tobacco, which is
chewed but not swallowed.
• Inhalation of tobacco
smoke is the fastest and
most efficient way yet
discovered to deliver
nicotine to the brain.
History of Tobacco
• Tobacco was first used by
the peoples of the pre-
• Native Americans
apparently cultivated the
plant and smoked it in
pipes for medicinal and
Tobacco Spreads to Europe
Adventurers like Jean Tobacco Tobacco
Nicot of France (where
introduced to introduced to
nicotine derives its name)
mid 1500’s 1558 1565
introduced to introduced to
Tobacco in the Colonies
• The first successful
commercial crop was
cultivated in Virginia in
1612 by Englishman John
• Within seven years, it was
the colony's largest export.
• Over the next two
centuries, the growth of
tobacco as a cash crop
fueled the demand in North
America for slave labor.
Early Discoveries of the Effects of
The 20th Century
• In 1930, researchers in Cologne, Germany, noticed
that many cancer patients were smokers.
• Eight years later, Dr. Raymond Pearl of Johns
Hopkins University reported that smokers do not
live as long as non-smokers.
• By 1944, the American Cancer Society began to
warn about possible ill effects of smoking, although
it admitted that "no definite evidence exists" linking
smoking and lung cancer.
The Tobacco Industry
• By 1954 the major U.S.
tobacco companies had
formed the tobacco industry
research council to counter the
growing health concerns.
• Mass-marketing began for
filtered and low-tar cigarettes
that promised a "healthier"
smoke (now we know
smokers compensate by
smoking more and inhaling
The Next Big Blow to Tobacco
• 1964, Surgeon General's
Advisory Committee on
Smoking and Health put
SURGEON GENERAL’S WARNING: out a 387-page report
Smoking Causes Lung Cancer, Heart
Disease, Emphysema, And May stating that cigarette
Complicate Pregnancy. smoking is causally related
to lung cancer.
• In 1965, Congress passed
the Federal Cigarette
Labeling and Advertising
Act requiring the Surgeon
General's warnings on all
Tobacco Industry on the Run
Smoking is banned announces Food and Drug
on all interstate buses Administration’s plan to
and all domestic regulate tobacco, especially
airline flights lasting sales and advertising aimed
6 hours or less at minors
advertising was Mississippi files the first of 22
banned state lawsuits seeking to
recoup millions of dollars from
tobacco companies for
smokers’ Medicaid bills
Addiction to Smoking:
A Global Problem
One-third of the •It is one of few
global adult causes of mortality
population smokes. that is increasing.
Of those who smoke during
•Smoking causes adolescence and throughout
one-third of deaths life, one-half die from
in men aged 35-69. smoke-related diseases.
Smoking is Addictive
• 80% of attempts to quit
smoking fail within a
• In the U.S., 70% of
smokers say they would
like to quit.
• 3% are successful each
Normal Lung Smoker’s Lung
The complex mixture called tobacco ‘tar’, and carbon
monoxide, are mainly responsible for most of the diseases
that are associated with the long-term use of tobacco.
Nicotine Addictive Component
• Nicotine produces effects that are
commonly seen with other addictive drugs
such as amphetamines and cocaine.
• Craving and self-administration
• Increase in movements
• Reinforces place reference (learned
associations – bars, restaurants, etc.)
Structure of Nicotine
Click here to learn more about how molecules interact
with protein “receptors” on cell membranes.
The Idea of Molecular Receptors
• Drugs bind to cell membranes
• Regions on membrane where this
binding occurs are called molecular
receptors or binding sites
• Binding sites are proteins that are
specific matches to the drug molecule
(fit together like a key in a lock)
• Effect of the drug is achieved by this
binding (like the key and lock, think of
it as opening a function in the cell)
Long-Term Use Leads to
• Long-term use increases
the number of molecular
receptors in brains of
• Increased number of
receptors increases the
“demand” for nicotine
• When receptors are
unoccupied by nicotine,
they “complain” – “Where
is our nicotine?”
Why Do Smokers Crave
• Nicotine acts in nervous system circuits that
release a “reward” chemical – dopamine
• Brain learns to “like” the release of
• When nicotine is withdrawn, the brain’s
reward system signals the craving to restore
Craving for Nicotine
• Craving is high when nicotine is at low
• Craving is satisfied when nicotine levels are
restored to levels to which nerve cells have
• Nerve cells learn that nicotine is normal, lack
of nicotine is abnormal
• After a night of abstinence, dopamine concentration
in brain is at its lowest level.
• First cigarette strongly activates dopamine release.
• Tolerance occurs quickly, because receptors adapt
• Throughout a day, episodes of cigarette smoking
are separated by short periods of abstinence;
nicotine levels drop and receptors “cry out for their
Addiction Process is Still a
• If an individual quits smoking for a few weeks, the
number of nicotine receptors returns toward normal
(like that of non smokers).
• Craving can still exist even years after quitting.
• Long-term changes have occurred in neural circuits.
• Smokers remember the behaviors that were linked to
sensory cues and reinforced.
Think Before You Act
Smoking is the leading cause of