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Growth hormone
preparations of reasonable purity had been made in the 1920s and
were shown to be effective in rats and dogs, but the need for
primate growth hormone in primates was not recognised until the late
1940s. In contrast, the first successful use of growth hormone
in a human pituitary dwarf did not come until 1958.
(Creutzfeldt-Jakob
disease) with the human brain extracts carrying CJD prions.
The
introduction of biosynthetic human growth hormone in the mid-1980s
opened the way for clinical trials to be instituted on a large
scale. These have largely been directed to determine whether growth
hormone could be used for a wider number of indications rather than
restricted usage to growth hormone deficiency.
Since the
mid 90's, much research and effort has been expressed in
applying hGH to ageing and age related problems and
complications.
Whilst
biosynthetic hGH production is still a very expensive and
complicated process, the relative costs have decreased as more
researchers apply endocrinology to diseases and conditions far
removed from apparent endocrine dysfunction with some startling
results.
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Human Growth Hormone was identified
[arguably] in the 1920's and until the 1980's, was extracted from
donor corpse's pituitary glands in a very expensive and moderately
risky process.
During this time, it is suspected that CJD,
a condition linked with Mad Cow Disease, may have been passed on to
hGH recipients.
In the '80's, a very expensive but far
more reliable synthetic version of hGH was discovered, opening the
door for a far wider experiment and research vista.
As a result of this research, especially
from the mid 1990's, many conditions and diseases which have not
been thought of as hGH related have shown remarkable response and
remission/cure including many age related conditions.
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[3] The pituitary gland is sometimes called
the "master" gland of the endocrine system, because it controls the
functions of the other endocrine glands.
The pituitary gland is no
larger than a pea, and is located at the base of the brain. The
gland is attached to the hypothalumus (a part of the brain that
significantly affects & regulates pituitary gland) by nerve fibers. The pituitary gland
itself consists of three sections:
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the anterior lobe
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the intermediate lobe
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the posterior lobe
hGH or somatotropin is produced by a group
of cells in the anterior pituitary gland called somatrophs. [4]
In many American based texts, the
structure and function of the intermediate lobe is relegated to be
included in the anterior lobe. It is probably worth mentioning
that the intermediate pituitary lobe is only present during very
early development in humans and is essentially integrated into the
anterior pituitary in early childhood at the latest.
Differentiation of three lobes has been
argued because of endocrine (hypothalamic ducts) and vascular
structure.
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[3] The University of Maryland
[4] http://web1.caryacademy.org |
About the size of a garden pea and
positioned right in the middle of the brain's base.
The Pituitary is divided into three parts,
front, middle and rear.
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Each lobe of the
pituitary gland produces certain hormones. [3]
anterior lobe:
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growth hormone (somatotropin)
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prolactin - to stimulate milk
production after giving birth
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ACTH (adrenocorticotropic
hormone) - to stimulate the adrenal glands
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TSH (thyroid-stimulating
hormone) - to stimulate the thyroid gland
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FSH (follicle-stimulating
hormone) - to stimulate the ovaries and testes
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LH (luteinizing hormone) - to
stimulate the ovaries or testes
intermediate lobe:
posterior lobe:
Somatotropin production is
regulated by somatostatin (inhibitory) and GHRH, both
produced in the hypothalamus and Ghrelin, secreted from the
stomach.
Bowen [5] summarises the hGH
influences thus:
Growth hormone-releasing hormone (GHRH) is a
hypothalamic peptide that stimulates both the synthesis and
secretion of growth hormone.
Somatostatin (SS) is a peptide produced by several
tissues in the body, including the hypothalamus.
Somatostatin inhibits growth hormone release in response to
GHRH and to other stimulatory factors such as low blood
glucose concentration.
Ghrelin is a peptide hormone secreted from the
stomach. Ghrelin binds to receptors on somatotrophs and
potently stimulates secretion of growth hormone. Other
effects of ghrelin include stimulating gastric emptying and
having a variety of positive effects on cardiovascular
function (e.g. increased cardiac output). It is not totally
clear whether the cardiovascular effects are a direct effect
of ghrelin or represent an indirect effect of ghrelin's
ability to stimulate growth hormone secretion. Blood
concentrations of ghrelin are lowest shortly after
consumption of a meal, then rise during the fast just prior
to the next meal.
Growth hormone secretion is also part of a negative
feedback loop involving IGF-I. High blood levels of IGF-I
lead to decreased secretion of growth hormone not only by
directly suppressing the somatotroph, but by stimulating
release of somatostatin from the hypothalamus.
Growth hormone also feeds back to inhibit GHRH secretion
and probably has a direct (autocrine) inhibitory effect on
secretion from the somatotroph.
Integration of all the factors that affect growth hormone
synthesis and secretion lead to a pulsatile pattern of
release. Basal concentrations of growth hormone in blood are
very low. In children and young adults, the most intense
period of growth hormone release is shortly after the onset
of deep sleep.
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[3] The University of Maryland
[5] R.Bowen - Colorado State University
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The pituitary gland plays a
controlling role in many key functions of the body, including
controlling many other glands within the body that produce hormones.
Growth hormones as well as
hormones controlling; sex, sex drive, reproduction, tanning, parts
of the nervous system, lactation (making milk), thyroid function,
fluid balancing and parts of the birth process.
There are three major chemicals in the body that
stimulate or suppress hGH production. Two are produced in the brain
and one in the stomach.
Peak conditions for hGH production is the time period
on and following the onset of deep sleep and an empty stomach.
A sound night's sleep and avoiding going to bed with
a full stomach, especially after indulging in carbohydrate rich
foods will assist in maximum hGH production in healthy individuals.
As a part of the lay discussion, external suppression
of the hGH inhibiting mechanisms is quite dangerous as the body
regulates all hormones carefully and with purpose. Encouraging
the lifting of overall activity and vitality is a much more
clinically sensible approach to hGH level increases.
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[6] The major isoform of the human growth
hormone is a covalent bound peptide [protein] of 191 amino acids and a molecular weight of
about 22,000 daltons. Somatotropin is made up of
four helices containing 21-30 amino acids each. The structure of
somatotropin is "characterized by an anti-parallel up-up-down-down
arrangement of the helices.
GH is structurally
and apparently evolutionarily homologous to prolactin and chorionic
somatomammotropin.
Despite marked structural similarities
between growth hormone from different species, only human and
primate growth hormones have significant effects in humans.
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[6] Text from Wikipedia with thanks. |
A significantly large structure, hGH
(human growth hormone) is a fragile structure, easily compromised by
enzyme or Ph fluctuations.
Only growth hormone from primates or
humans causes any effect in the human system.
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Growth hormone has two types of effects, both of which are highly
beneficial to the vital, active human body as you'll see below.
One main type of action of the HGH is its direct effects on other
kinds of cells. The growth hormone binds to its receptor on target
cells, then creates some particular action. Fat cells, for example,
are the target cells of HGH, so they have growth hormone receptors.
Once bonded there, the growth hormone causes them to break down
triglyceride and suppresses their ability to take up and accumulate
circulating lipids -- in other words, fat storage is prevented!
HGH also acts to create other indirect effects in the body by
causing secretion of IGF-1, an insulin-like growth factor hormone.
IGF-1 is secreted from the liver and other tissues in response to
growth hormone. This is the action that governs mostly
growth-related effects of HGH.
What is meant by "growth"?
The obvious answer is, growth means something getting bigger. But
don't be hemmed in by that definition. Growth requires many, many
coordinated processes in the body, and that in turn means a complex
dance of lots of different hormones, which typically are the
messengers that tell different parts of the body what to do and
when. Growth hormone indirectly stimulates the synthesis of
cartilage cells, resulting in bone growth.
This same effect is also the power behind muscle growth. It
stimulates both the differentiation and proliferation of muscle
cells, stimulates amino acid uptake and synthesizes protein in
muscle and other tissues. This is where HGH's ability to influence
overall muscle and skin tone comes from.
How about metabolism?
Growth hormone has important effects on:
Protein metabolism: HGH causes
increased amino acid uptake, increased protein synthesis and
decreased oxidation of proteins.
Fat metabolism: HGH enhances the
utilization of fat -- gives your body the ability to break down fat
cells more efficiently.
Carbohydrate metabolism: HGH is one of several hormones that
maintain blood sugar within a normal range.
Without HGH …
Because of the abilities of HGH mentioned above, you can soon see
that without it, muscle tone declines, fat stubbornly sits in the
body and resists metabolism, and hair, skin and nails (all composed
of proteins) deteriorate. In fact, scientists now believe that HGH
has a role in most healthy functions of the body, including sexual
function, proper operation of stomach and bowels, liver, and all
glandular systems.
Whether HGH is directly interacting with certain cells, or
playing its key part in the correct function of other bodily
systems, it's essential throughout the body for youthful vigour and
health!
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hGH acts in two ways in the body, directly
and indirectly.
Its direct action is on cells which have
receptor sites for hGH. It stimulates and regulates many of
those cell's basic and advanced functions, especially those
typically associated with the "no longer twenty years old" syndrome!
Its indirect actions are seen when
different glands have hGH receptor sites, triggering and regulating
the function of many, more distant, actions and reactions.
Decrease in these 'downstream' processes typically represent the
markers of middle and later age.
Whilst hGH is certainly used in growth,
this does not truly define what it does. Maybe if we called it
human tissue vitality hormone we might see a true picture.
The everyday replacing of cells,
maintenance of cartilage, bone, muscle,.. pretty much everything we
are made of,.. it is all under hGH's influence.
Every part of those things typically seen
as advancing years, from thinning skin to bulging waist line are all
coincident to - and consistent with - falling hGH levels.
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Your body must always produce HGH or you would not be able to
function at all. As you pass about 20 years old, your body produces
less and less hGH each year.
By age 60 you will probably have lost 75% of the HGH that your
body produced.
If you are a numbers person, here are some average HGH secretion
levels:
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At 20 years old we average 500 micrograms/day
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At 40 years old we average 200 micrograms/day
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At 80 years old we average 25 micrograms/day
The half life of hGH in serum appears to
range over all research sources at between 9 to 50 minutes.
Almost all sources show the fragility of the hGH peptide in an acid
environment (stomach) and the non-gastric permeation due to the
molecule's size.
Subcutaneous introduction of hGH or
stimulation of the anterior pituitary gland are the only two
generally recognised methods to significantly raise serum hGH
levels.
See
METHODS for more |
Your body must always produce HGH or you would not be able to
function at all. As you pass about 20 years old, your body produces
less and less hGH each year.
By age 60 you will probably have lost 75% of the HGH that your
body produced.
If you are a numbers person, here are some average HGH secretion
levels:
-
At 20 years old we average 500 micrograms/day
-
At 40 years old we average 200 micrograms/day
-
At 80 years old we average 25 micrograms/day
The hGH molecule is very fragile, lasting
between 9 and 50 minutes in the body. It is also too big to go
through the stomach membranes and to fragile to survive the enzymes
in saliva and acids of the stomach.
Most research agrees that only injecting
hGH directly or stimulating the pituitary to produce hGH seems to
have any logical likelihood of working.
See
METHODS for more |
