Growth
Hormone
and
IGF-1
By:
Eric
D.Marchewitz
I
am
not
a
huge
fan
of
synthetic
growth
hormone,
but
I
recognize
that
what
separates
the
TRULY
HUGE
from
the
average
guy
is
the
stacking
of
Growth
Hormone
(GH)
with
androgens.
Growth
hormone
on
its
own
doesn’t
seem
to
really
add
a
ton
of
size
on
you
though
and
it
does
carry
some
risks,
so
it’s
not
the
best
choice
in
my
opinion
for
a
stand
alone
product.
It
will
however
really
increase
satellite
cells
over
straight
androgen
boosting
alone
and
other
supplements.
The
major
problem
with
GH
on
a
cycle
is
that
it
won’t
put
tons
of
size
on
your
right
away.
We
make
a
GH
product
(IGH-1)
that
you
can
take
to
increase
your
own
GH
production
but
it
will
not
pack
size
on
you
instantly.
If
you
are
not
committed
to
the
long
haul,
then
honestly, GH
products
are
not
for
you.
If
you
want
to
put
on
muscle
that
lasts
and
is
with
you
for
life,
then
a
good
GH
product
will
help
you
get
to
that
goal.
Even
REAL
GH
cycles
are
gaged
in
terms
of
months
of
use, not
days.
GH
cycles
last
for
6
months
and
you
don’t
see
real
results
for
at
least
45
days.
This
is
why
that
a
GH
releaser
is
not
going
to
pack
on
pounds
of
muscle
in
15
days
like
a
cycle
of
prohormones,
even
4
iu
of
GH
injections
will
take
a
long
time
to see
the
effect
you
desire.
That
isn’t
to
say
that
GH
isn’t
EXTREMELY
useful,
it
is
more
like
an
important
part
of
a
good
long
term
plan
vs.
androgens
that
give
an
immediate
effect
that
feels
damn
good.
I
take
a
GH
releaser
every
night,
since
reading
the
studies
PROVING
that
GH
is
a
valuable
part of
changing
your
genetics.
When
1+1=3
When
you
combine
growth
hormone
with
a
powerful
androgen,
you
get
some
serious
muscle
building,
because
GH
increases
satellite
cell
proliferation,
gets
you
lean
and
increases
IGF-1
production.
IGF-1
builds
muscle
and
increases
satellite
cell
expression
while
burning
fat.
This
is
what
makes
growth hormone
worth
the
300-400
dollars
per
week
the
professionals
spend
on
a
cycle,
even
before
IGF-1
was
available.
Growth
hormone
burns
fat,
but
also
greatly
increases
IGF-1
levels,
which
if
you
are
in
the
circle
of
knowledge
is
VERY
important,
since
IGF-1
is
a natural
anabolic.
Most
of
the
IGF-1
on
the
market
today
is
either
fake
or
worthless,
because
IGF-1
must
be
cold
packed
and
shipped
immediately.
IGF-1
degrades
very
quickly,
but
if
you
are
lucky
enough
to
get
your
hands
on
some
REAL
IGF-1,
you
are
in
for a
treat.
Expect
to
pay
at
least
$300
per
week
though
for
the
real
stuff.
IGF-1
and
GH
can
be
stimulated
by
the
body,
meaning
that
your
natural
levels
can
be
increased,
which
gives
you
the
ability
to
get
most
of
the
same
results
as
a
pro
bodybuilder
without
the
expense
or
risk.
GH
secretagogues
(things
that
increase
your
natural production
or
secretion)
are
on
the
market
and
they
should
at
least
include
things
like
ArgininePryoglutamate,
Ornithine,
Astragulus,
and
L-Dopa.
These
are
the
most
potent
Growth
Hormone
secretagogues
on
the
market
and
can
sky
rocket
your
GH
levels,
allowing
you
to
build
slabs of
muscle.
GH
is
pretty
easy
to
increase
with
the
use
of
secretagogues,
but
IGF-1
is
very
tough
to
boost
naturally.
There
is
only
one
ingredient
I
know
that
increases
IGF-1
naturally.
This
is
in
products
like
Formadrol
Extremepictured
above,
and
the
ingredient
is
Daidzein,
which
is
the
only
known
naturally
occurring
IGF-1
secretagogue.
So
how
does
GH
increase
satellite
expression?
Again,
let’s
look
at
the
literature.
GH
and
IGF-1
on
Satellite
Cell
Expression
Effects
of
growth
hormone
on
skeletal
muscle.
I.
Studies
on
normal
adult
rats.
Ullman
M,
Oldfors
A.
Department
of
Pathology,
Gothenburg
University,
Sweden.
A
study
was
made
on
the
effects
of
recombinant
human
growth
hormone
(rhGH)
on
fast
and
slow
skeletal
muscle
in
normal
adult
female
rats.
Daily
injections
of
4
IE
of
rhGH
over
36
days
resulted
in
increased
levels
of
insulin-like
growth
factor
I
in
serum and
increased
body
weight.
Morphometric
analysis
of
the
muscle
fibres
of
the
extensor
digitorum
longus
(EDL)
and
soleus
muscles
revealed
a
significant
increase
in
diameter
of
both
type
1
and
type
2
fibres
in
both
muscles.
The
DNA:
protein
ratio
and
the
number
of satellite
cells:muscle
fibre
in
cross-sections
was
increased
in
the
GH-treated
rats
in
relation
to
controls.
The
results
show
that
rhGH
has
pronounced
effects
on
both
cell
proliferation
and
muscle
fibre
growth
in
skeletal
muscle
of
normal
adults
rats.
IGF-1
induces
human
myotube
hypertrophy
by
increasing
cell
recruitment.
Jacquemin
V,
Furling
D,
Bigot
A,
Butler-Browne
GS,
Mouly
V.
CNRS
UMR
7000
Cytosquelette
et
Developpement,
Paris,
France.
Insulin-like
growth
factor-1
(IGF-1)
has
been
shown
in
rodents
(i)
in
vivo
to
induce
muscle
fiber
hypertrophy
and
to
prevent
muscle
mass
decline
with
age
and
(ii)
in
vitro
to
enhance
the
proliferative
life
span
of
myoblasts
and
to
induce
myotube
hypertrophy.
In
this study,
performed
on
human
primary
cultures,
we
have
shown
that
IGF-1
has
very
little
effect
on
the
proliferative
life
span
of
human
myoblasts
but
does
delay
replicative
senescence.
IGF-1
also
induces
hypertrophy
of
human
myotubes
in
vitro,
as
characterized
by
an
increase
in
the mean
number
of
nuclei
per
myotube,
an
increase
in
the
fusion
index,
and
an
increase
in
myosin
heavy
chain
(MyHC)
content.
In
addition,
muscle
hypertrophy
can
be
triggered
in
the
absence
of
proliferation
by
recruiting
more
mononucleated
cells.
We
propose
that
IGF-1-induced
hypertrophy
can involve
the
recruitment
of
reserve
cells
in
human
skeletal
muscle.
Insulin-like
growth
factor
1
and
muscle
growth:
implication
for
satellite
cell
proliferation.
Machida
S,
Booth
FW.
Department
of
Biomedical
Sciences,
University
of
Missouri-Columbia,
E102
Veterinary
Medical
Building,
1600
East
Rollins
Road,
Columbia,
MO
65211,
USA.
Insulin-like
growth
factor
1
(IGF-1)
has
been
shown
to
rescue
the
aging-related
or
inactivity-induced
loss
of
muscle
mass
through
the
activation
of
satellite
cells.
However,
the
signalling
pathways
and
the
mechanism
by
which
IGF-1
affects
satellite
cells
have
not
been
not
completely
identified.
The purpose
of
the
present
review
is
to
provide
current
understanding
of
the
cellular
and
molecular
events
underlying
IGF-1
induced
proliferation
of
satellite
cells.
Expression
and
splicing
of
the
insulin-like
growth
factor
gene
in
rodent
muscle
is
associated
with
muscle
satellite
(stem)
cell
activation
following
local
tissue
damage.
Hill
M,
Goldspink
G.
Basic
Medical
Sciences
and
Department
of
Surgery,
Royal
Free
and
University
College
Medical
School,
Royal
Free
Campus,
Rowland
Hill
Street,
London
NW3
2PF,
UK.
Muscle
satellite
cells
are
mononuclear
cells
that
remain
in
a
quiescent
state
until
activated
when
they
proliferate
and
fuse
with
muscle
fibres
to
donate
nuclei,
a
process
necessary
for
post-embryonic
growth,
hypertrophy
and
tissue
repair
in
this
post-mitotic
tissue.
These
processes
have
been
associated with
expression
of
the
insulin-like
growth
factor
(IGF-I)
gene
that
can
undergo
alternative
splicing
to
generate
different
gene
products
with
varying
functions.
To
gain
insight
into
the
cellular
mechanisms
involved
in
local
tissue
repair,
the
time
courses
of
expression
of
two
IGF-I
splice
variants produced
in
muscle
were
determined
together
with
marker
genes
for
satellite
cell
activation
following
local
muscle
damage.
Using
real-time
RT-PCR
with
specific
primers,
the
mRNA
transcripts
in
rat
tibialis
anterior
muscles
were
measured
at
different
time
intervals
following
either
mechanical
damage
imposed
by electrical
stimulation
of
the
stretched
muscle
or
damage
caused
by
injection
with
bupivacaine.
It
was
found
that
the
autocrine
splice
variant
mechano
growth
factor
(MGF)
was
rapidly
expressed
and
then
declined
within
a
few
days
following
both
types
of
damage.
Systemic
IGF-IEa
was
more slowly
upregulated
and
its
increase
was
commensurate
with
the
rate
of
decline
in
MGF
expression.
Satellite
cell
activation
as
measured
by
M-cadherin
and
one
of
the
muscle
regulatory
factors
MyoD
and
the
sequence
of
expression
suggests
that
the
initial
pulse
of
MGF
is
responsible for
satellite
cell
activation,
as
the
systemic
IGF-IEa
mRNA
expression
peaks
after
the
expression
of
these
markers,
including
M-cadherin
protein.
Later
splicing
of
the
IGF-I
gene
away
from
MGF
but
towards
IGF-IEa
seems
physiologically
appropriate
as
IGF-IEa
is
the
main
source
of
mature
IGF-I
for
upregulation
of
protein
synthesis
required
to
complete
the
repair.
GH
on
Muscle:
Growth
hormone
/
insulin-like
growth
factor-1
axis
during
puberty.
Christoforidis
A,
Maniadaki
I,
Stanhope
R.
Department
of
Endocrinology,
Great
Ormond
Street
Hospital
and
the
Middlesex
Hospital
(UCLH),
London,
UK.
Puberty
is
a
dynamic,
transitional
period
of
life
which
is
characterized
by
the
acquisition
of
secondary
sexual
characteristics
leading
to
the
development
of
fertility.
Puberty
is
accompanied
by
sexually
dimorphic
changes
in
linear
growth,
body
proportions
and
body
composition.
The
pubertal
growth
spurt
is influenced
by
a
number
of
factors
such
as
hormones,
nutrition,
physical
activity
and
general
health,
acting
mostly
in
concert
in
order
to
modify
a
genetic
potential
for
growth.
Growth
hormone
(GH)
is
traditionally
considered
to
be
the
main
regulator
of
growth.
During
puberty,
elevated sex
steroid
concentrations
(especially
oestrogens)
stimulate
GH
production,
leading
to
an
activation
of
the
whole
GH/Insulinlike
growth
factor-1
(IGF-1)
axis.
This
activation
is
mostly
characterized
by
an
increase
in
the
amplitude
of
GH
pulses
rather
than
an
increase
in
frequency
or
in
duration. Interactions
between
GH
and
sex
steroids
(especially
androgens)
express
an
anabolic
effect
on
muscle
mass,
bone
mineralization
and
body
proportion
which
constitutes
the
male
and
the
female
adult
body
composition.
Intact
insulin
and
insulin-like
growth
factor-I
receptor
signaling
is
required
for
growth
hormone
effects
on
skeletal
muscle
growth
and
function
in
vivo.
Kim
H,
Barton
E,
Muja
N,
Yakar
S,
Pennisi
P,
Leroith
D.
Diabetes
Branch,
National
Institute
of
Diabetes
and
Digestive
and
Kidney
Diseases,
National
Institutes
of
Health,
9000
Rockville
Pike,
Building
10,
Room
8D12,
Bethesda,
Maryland
20892-1758,
USA.
GH
and
IGF-I
are
potent
regulators
of
muscle
growth
and
function.
Although
IGF-I
is
known
to
mediate
many
of
the
effects
of
GH,
it
is
not
yet
clear
whether
all
effects
of
GH
are
completely
dependent
on
the
IGF-I
system.
To
evaluate
the
biological
effects of
the
GH/IGF-I
axis
on
muscle
growth,
we
administrated
recombinant
human
GH
to
mice,
which
lack
IGF-I
function
specifically
in
skeletal
muscle,
due
to
the
overexpression
of
a
dominant-negative
IGF-I
receptor
in
this
tissue
(MKR
mice).
GH
treatment
significantly
increased
the
levels
of hepatic
IGF-I
mRNA
and
serum
IGF-I
levels
in
both
wild-type
(WT)
and
MKR
mice.
These
GH-induced
effects
were
paralleled
by
increases
in
body
weight
and
in
the
weights
of
most
GH-responsive
organs
in
both
groups
of
mice.
Interestingly,
unlike
WT
mice,
GH
treatment
had no
effect
on
skeletal
muscle
weight
in
MKR
mice.
GH
treatment
failed
to
reverse
the
impaired
muscle
function
in
MKR
mice.
Furthermore,
MKR
mice
exhibited
no
effects
of
GH
on
the
cross-sectional
area
of
myofibers
and
the
proliferation
of
satellite
cells.
Taken
together,
these data
suggest
that
the
in
vivo
effects
of
GH
on
muscle
mass
and
strength
are
primarily
mediated
by
activation
of
the
IGF-I
receptor.
Insulin-like
growth
factor
1
and
muscle
growth:
implication
for
satellite
cell
proliferation.
Machida
S,
Booth
FW.
Department
of
Biomedical
Sciences,
University
of
Missouri-Columbia,
E102
Veterinary
Medical
Building,
1600
East
Rollins
Road,
Columbia,
MO
65211,
USA.
Insulin-like
growth
factor
1
(IGF-1)
has
been
shown
to
rescue
the
aging-related
or
inactivity-induced
loss
of
muscle
mass
through
the
activation
of
satellite
cells.
However,
the
signalling
pathways
and
the
mechanism
by
which
IGF-1
affects
satellite
cells
have
not
been
not
completely
identified.
The purpose
of
the
present
review
is
to
provide
current
understanding
of
the
cellular
and
molecular
events
underlying
IGF-1
induced
proliferation
of
satellite
cells.
The
effects
of
growth
hormone
and/or
testosterone
in
healthy
elderly
men:
a
randomized
controlled
trial.
Giannoulis
MG,
Sonksen
PH,
Umpleby
M,
Breen
L,
Pentecost
C,
Whyte
M,
McMillan
CV,
Bradley
C,
Martin
FC.
Department
of
Diabetes
and
Endocrinology,
GKT
School
of
Medicine,
King's
College
London,
St.
Thomas'
Hospital,
London
SE1
7EH,
UK.
CONTEXT:
Declines
in
GH
and
testosterone
(Te)
secretion
may
contribute
to
the
detrimental
aging
changes
of
elderly
men.
OBJECTIVE:
To
assess
the
effects
of
near-physiological
GH
with/without
Te
administration
on
lean
body
mass,
total
body
fat,
midthigh
muscle
cross-section
area,
muscle
strength,
aerobic
capacity, condition-specific
quality
of
life
(Age-Related
Hormone
Deficiency-Dependent
Quality
of
Life
questionnaire),
and
generic
health
status
(36-Item
Short-Form
Health
Survey)
of
older
men.
DESIGN,
SETTINGS,
AND
PARTICIPANTS:
A
6-month,
randomized,
double-blind,
placebo-controlled
trial
was
performed
on
80
healthy,
community-dwelling,
older
men
(age,
65-80
yr). INTERVENTIONS:
Participants
were
randomized
to
receive
1)
placebo
GH
or
placebo
Te,
2)
recombinant
human
GH
(rhGH)
and
placebo
Te
(GH),
3)
Te
and
placebo
rhGH
(Te),
or
4)
rhGH
and
Te
(GHTe).
GH
doses
were
titrated
over
8
wk
to
produce
IGF-I
levels in
the
upper
half
of
the
age-specific
reference
range.
A
fixed
dose
of
Te
(5
mg)
was
given
by
transdermal
patches.
RESULTS:
Lean
body
mass
increased
with
GHTe
(P
=
0.008)
and
GH
(P
=
0.004),
compared
with
placebo.
Total
body
fat
decreased
with GHTe
only
(P
=
0.02).
Midthigh
muscle
(P
=
0.006)
and
aerobic
capacity
(P
<
0.001)
increased
only
after
GHTe.
Muscle
strength
changes
were
variable;
one
of
six
measures
significantly
increased
with
GHTe.
Significant
treatment
group
by
time
interactions
indicated
an
improved
Age-Related
Hormone
Deficiency-Dependent
Quality
of
Life
questionnaire
score
(P
=
0.007)
in
the
GH
and
GHTe groups.
Bodily
pain
increased
with
GH
alone,
as
determined
by
the
Short-Form
Health
Survey
(P
=
0.003).
There
were
no
major
adverse
effects.
CONCLUSION:
Coadministration
of
low
dose
GH
with
Te
resulted
in
beneficial
changes
being
observed
more
often
than
with
either
GH
or Te
alone.
Supraphysiological
growth
hormone:
less
fat,
more
extracellular
fluid
but
uncertain
effects
on
muscles
in
healthy,
active
young
adults.
Ehrnborg
C,
Ellegard
L,
Bosaeus
I,
Bengtsson
BA,
Rosen
T.
Research
Centre
for
Endocrinology
and
Metabolism,
Department
of
Internal
Medicine,
Sahlgrenska
University
Hospital,
S-413
45
Goteborg,
Sweden.
christer.ehrnborg@medic.gu.se
OBJECTIVES:
To
study
the
effects
on
body
composition
after
1
month's
administration
of
supraphysiological
doses
of
growth
hormone
(GH)
in
healthy,
active
young
adults
with
normal GH-IGF-I
axis.
SUBJECTS
AND
METHODS:
Thirty
healthy,
physically
active
volunteers
(15
men
and
15
women),
mean
age
25.9
years
(range
18-35),
participated
in
this
study,
designed
as
a
randomized,
double-blind,
placebo-controlled,
parallel
study
with
three
groups
(n
=
10:
five
men
and
five women
in
each
group).
The
groups
comprised
the
following:
placebo
(P),
GH
0.1
IU/kg/day
[0.033
mg/kg/day]
(GH
0.1)
and
GH
0.2
IU/kg/day
[0.067
mg/kg/day]
(GH
0.2).
RESULTS:
In
the
pooled
group
with
active
GH
treatment
(n
=
20)
the
results
showed
significant
increases:
IGF-I increased
by
134%
(baseline
vs.
after
1
month),
body
weight
by
2.7%,
fat
free
mass
by
5.3%,
total
body
water
by
6.5%
and
extracellular
water
(ECW)
by
9.6%.
Body
fat
decreased
significantly
by
6.6%.
No
significant
change
in
intracellular
water
was
detected.
The
observed increase
in
fat
free
mass
by
5.3%
was
explained
by
the
ECW
increase,
indicating
limited
anabolic
effects
of
the
supraphysiological
GH
doses.
Changes
were
noticeable
in
both
genders,
although
more
prominent
in
the
male
subjects.
Fluid
retention
symptoms
occurred
in
the
majority
of
individuals. CONCLUSIONS:
This
is,
to
our
knowledge,
the
first
placebo-controlled
trial
to
show
the
effects
of
supraphysiological
GH
doses
on
body
composition
and
IGF-I
levels
in
physically
active
and
healthy
individuals
of
both
genders;
the
results
indicate
limited
anabolic
effects
of
GH
with
these
supraphysiological
doses.
The
role
of
GH
as
an
effective
anabolic-doping
agent
is
questioned.
GH
alone
is
not
enough,
which
is
why
we
stack…
Here
is
an
example
of
an
effective
stacking
of
compatible
supplements
to
achieve
a
specific
objective.
Regulating
of
growth
hormone
sensitivity
by
sex
steroids:
implications
for
therapy.
KK,
Gibney
J,
Johannsson
G,
Wolthers
T.
Pituitary
Research
Unit,
Garvan
Institute
of
Medical
Research
and
Department
of
Endocrinology,
St.
Vincent's
Hospital,
Sydney,
Australia.
Growth
hormone
(GH)
is
an
important
regulator
of
body
composition,
reducing
body
fat
by
stimulating
fat
oxidation
and
enhancing
lean
body
mass
by
stimulating
protein
accretion.
The
emergence
of
differences
in
body
composition
between
the
sexes
during
puberty
suggests
sex
steroids
modulate
the
action of
GH.
Work
from
our
laboratory
have
investigated
the
influence
of
estrogens
and
androgens
on
the
metabolic
actions
of
GH
in
human
adults.
The
liver
is
an
important
site
of
physiological
interaction
as
it
is
a
sex
steroid
responsive
organ
and
a
major
target of
GH
action.
Estrogen,
when
administered
orally
impairs
the
GHregulated
endocrine
and
metabolic
function
of
the
liver
via
a
first-pass
effect.
It
reduces
circulating
IGF-I,
fat
oxidation
and
protein
synthesis,
contributing
to
a
loss
of
lean
and
a
gain
of
fat
mass.
These
effects occur
in
normal
and
in
GH-deficient
women
and
are
avoided
by
transdermal
administration
of
physiological
doses
of
estrogen.
In
contrast,
studies
in
hypopituitary
men
indicate
that
testosterone
enhances
the
metabolic
effects
of
GH.
Testosterone
alone
stimulates
fat
oxidation
and
protein
synthesis,
both
of
which are
enhanced
by
GH.
Studies
in
GH
deficiency
adults
have
consistently
reported
women
to
be
less
sensitive
to
GH
than
men.
In
summary,
estrogens
and
androgens
exert
divergent
effects
on
the
action
of
GH.
The
results
provide
an
explanation
for
sexual
dimorphism
in
body
composition
in
adults
and
the
genderrelated
response
to
GH
replacement
in
hypopituitary
subjects.
In
the
management
of
hypopituitarism,
estrogens
should
be
administered
by
the
parenteral
route
in
women
and
testosterone
be
replaced
in
men
to
optimize
the
benefits
of
GH
replacement.
Eric
D.
Marchewitz,
is
one
of
the
leading
supplement
experts
in
the
country,
his
articles
online
are
taken
from
his
best
selling
book
"
Supplements
For
Genetic
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"which
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This
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and
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The
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