Transcript Hormones - prakashamarasooriya

Hormones and Steroids
L. Scheffler
Lincoln High School
1
The Endocrine System
The endocrine
glands are
ductless. That is
they secrete
hormones
directly into the
blood stream.
Hormones elicit
responses in
cells that have
the appropriate
receptors. These
cells are known
as target cells
Male
Female
2
Hormones
Hormones are
produced in the
endocrine glands and
transported to various
active sites in the body.
Hormones are primarily
chemical messengers
which control a variety
of functions in the
body.
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Endocrine Glands
The endocrine glands
are controlled by the
pituitary gland which
is found at the base
of the brain.
The pituitary gland is
in turn controlled by
the hypothalamus.
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Thyroxine
Produced in the Thyroid.
Contains iodine.
Regulates metabolism.
Hypothyroidism results in
lethargy, sensitivity to cold
and dry skin.
Hyperthyroidism results in
anxiety, weight loss,
intolerance to heat and
protruding eyes.
Hyperthyroidism often results
in an enlarged thyroid
5
Adrenalin
Produced by the Adrenal
glands
Stimulant closely related
to amphetamine
Released at times of
excitement
Results in:
• Dilation of pupils and airways
• Increased heartbeat
• Release of sugar in blood stream
• Fight or flight response
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Adrenalin
Adrenalin is
synthesized in
the body from
tyrosine.
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Insulin
Protein– 51 amino acids
Formed in pancreas
Regulates blood sugar
levels
Diabetes-Hypoglycemia
results in thirst, weight
loss, lethargy, circulation
problems and coma in
severe cases.
Hyperglycemia results
from too little insulin.
leads to dizziness and
fainting
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Steroids
Steroids have a characteristic structure
with four rings:
They differ
in terms of
the side
chains on
the steroid
skeleton
Steroid structure
9
Cholesterol
Cholesterol is the basic building block for all
other steroids.
Cholesterol is formed in the liver and found in
all tissues, the blood, brain, and spinal cord.
10
Cholesterol
Cholesterol is a soft, fat-like,
waxy substance found in the
bloodstream and in all your
body's cells.
It's normal to have
cholesterol. Cholesterol is
an important part of a
healthy body because it's
used for producing cell
membranes and some
hormones.
Too much cholesterol in the blood is a major risk for
coronary heart disease (which leads to heart attack) and
for stroke. Hypercholesterolemia is the medical term for
high levels of blood cholesterol.
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Cholesterol (LDL vs. HDL)
HDL (High Density Lipoproteins or good
Cholesterol
About one-fourth to one-third of blood
cholesterol is carried by high-density
lipoprotein (HDL). HDL cholesterol is known
as “good” cholesterol, because high levels
of HDL seems to protect against heart
attack. Low levels of HDL (less than 40
mg/dL) also increases the risk of heart
disease
LDL (Low Density Lipoproteins or Bad Cholesterol)
When too much LDL (bad) cholesterol circulates in the
blood, it can slowly build up in the inner walls of the
arteries that feed the heart and brain forming plaque.
Plaque can narrow the arteries and make them less
flexible. If a clot forms and blocks a narrowed artery,
heart attack or stroke can result.
12
Cholesterol and Triglycerides
Elevated triglycerides can be due
to overweight/obesity, physical inactivity,
cigarette smoking, excess alcohol
consumption and a diet very high in
carbohydrates (60 percent of total calories
or more).
Triglycerides are a form of fat made in the
body.
People with high triglycerides often have a
high total cholesterol level, including a
high LDL (bad) level and a low HDL (good)
level
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Sex Hormones
Male
Female
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Sex Hormones
There are only slight differences between the
male and female sex hormones. Yet these
differences are enough to allow for
significant changes in the secondary sex
characteristics.
Both sexes have both sets of hormones
Deficiencies in the sex hormones result in
changes in external sex characteristics such
as facial hair and genital size.
Differences in female hormone levels control
the female menstrual cycle.
15
Female Hormones and Birth
Control
Oral contraceptives (the pill) combine
synthetic progesterone and estrogen.
These two hormones act to stop the release
of LHRH by the hypothalamus and FSH and
LH by the pituitary.
This results in the ovaries not being
stimulated and ovulation stops
In effect, the female reproductive system is
fooled because the drug mimics the action of
progesterone in a pregnant woman
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Oral Contraception and
Synthetic Hormones
Progesterone is quite expensive and breaks down
rapidly in the liver.
Progesterone-like synthetic chemicals such as
norethynodrel and norethindrone are now commonly
used in birth control pills.
They are combined with an estradiol-like compound to
prevent irregular menstrual flow.
The molecular framework of the synthetic chemicals in
synthetic pills is similar to progesterone.
The –COCH3 group on the D ring is replaced by the –
OH and –C=CH on C17.
These changes cause the synthetic steroids to tightly
bind with the receptor sites, preventing rapid
breakdown by the liver.
This allows the pill to be administered orally.
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Oral Contraceptives
The molecular framework of
the synthetic chemicals in
synthetic pills is similar to
progesterone.
– The –COCH3 group on
the D ring is replaced by
the –OH and –C=CH on
C17.
These changes cause the
synthetic steroids to tightly
bind with the receptor sites,
preventing rapid
breakdown by the liver.
This allows the pill to be
administered orally.
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Anabolic Steroids
Anabolic Steroids are similar to testosterone.
Like testosterone they promote increased
muscle mass and growth.
Anabolic steroids may be helpful for
patients suffering from long, debilitating
illnesses.
Testosterone-like steroids cause minimal
side effects and can be used to stimulate
muscle growth, increase muscle mass, and
help such patients recover their body weight.
Prolonged use can have serious side effects.
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Anabolic Steroids
Several steroids that
resemble
testosterone have
been synthesized
including:
– Norethandrolone
– Oxymetholone
– Methyltestosterone
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Abuse of Anabolic Steroids
Many athletes have found that they can
enhance their performance by using anabolic
steroids.
Testosterone is more prevalent in men and is
principally responsible for muscle build-up.
Women who use anabolic steroids have
much to gain because, initially, there is only
a low concentration of testosterone present
in their bodies.
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Abuse of Anabolic Steroids
Taking large doses of anabolic steroids causes
harmful side effects.
In men: impotence, baldness, problems in urinating,
smaller testes,
In women: changes in secondary sex characteristics,
build up of muscles and increased facial hair,
Both men and women also experience
• violent temper,
• increased aggressive behavior as well as
• diseases such as liver tumors, high blood
pressure and heart attacks.
Anabolic steroids are strictly forbidden at
international athletic competitions.
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Human Growth Hormone (hGH)
Stimulates growth, cell
reproduction and
regeneration
Causes increased height
(growth spurt) in children
Causes increased muscle
mass, protein synthesis,
organ growth, breaking
down of fat for energy
(lipolysis), stimulates
immune system
http://hypericum.files.wordpress.com/2008/02/hgh2.jpg
Human Growth Hormone (hGH)
An anabolic agent similar to anabolic steroids
and testosterone
Doping with hGH forbidden in professional
athletics
Recent studies have shown excessive hGH in
male athletes decreases stamina and hinders
athletic performance
hGH may only increase water weight stored in
muscles without truly increasing muscle protein
synthesis
Human Growth Hormone (hGH)
hGH has been used to treat conditions that
stunt growth, decrease body fat or regenerate
wasted muscle (Turner syndrome, PraderWilli syndrome, muscle wasting from AIDS)
Also used to treat hGH deficiency
Beneficial effects of hGH in individuals with
the above conditions are greater than its
effects in healthy humans.
Side effects of treatment include
hypertension, joint and muscle pain, immune
rejection of foreign hGH