akn
Musclechemistry Member
As we see from our discussion with estrogen, in
considering the physiological effects of any steroid, we
must look at all of its active metabolites, and not just the
initial compound. This includes not only estrogenic
products, but androgenic metabolites as well. With this in
mind, it is important to note that the potency of
testosterone is considerably increased in many androgen
responsive tissues when it converts to
dihydrotestosterone. More commonly referred to by the
three-letter abbreviation DHT, this hormone is, in fact,
measured to be approximately three to four times
stronger than testosterone. It is the most potent steroid
found naturally in the human body, and important to
discuss if we are to understand the full activity of
testosterone, as well as other anabolic/androgenic
steroids that undergo a similar conversion.
Testosterone is converted to dihydrotestosterone upon
interaction with the 5-alpha reductase enzyme. More
specifically, this enzyme removes the C4-5 double-bond of
testosterone by the addition of two hydrogen atoms to its
structure (hence the name di-hydro testosterone). The
removal of this bond is important, as in this case it creates
a steroid that binds to the androgen receptor much more
avidly than its parent steroid. 5-alpha reductase is present
in high amounts in tissues of the prostate, skin, scalp, liver,
and various regions of the central nervous system, and as
such represents a mechanism for the body to increase the
potency of testosterone specifically where strong
androgenic action is needed. In these areas of the body
little testosterone will actually make its way to the
receptor without being converted to dihydrotestosterone,
making DHT by far the active form of androgen here.
DHI and Androgenic Side Ellects
In some regards this local potentiation of testosterone's
activity may be unwelcome, as higher androgenic activity
in certain tissues may produce a number of undesirable
side effects. Acne, for example, is often triggered by
dihydrotestosterone activity in the sebaceous glands, and
the local formation of dihydrotestosterone in the scalp is
typically blamed for triggering male pattern hair loss. You
should know that it is a terrible misconception among
bodybuilders that dihydrotestosterone is an isolated
culprit when it comes to these side effects. All
anabolic/androgenic steroids exert their activities, both
anabolic and androgenic, through the same cellular
androgen receptor. Dihydrotestosterone is no different
than any other steroid except that it is a more potent
activator of th is receptor than most, and can be formed locally in certain androgen-sensitive tissues. All steroids
can cause androgenic side effects in direct relation to their
affinity for this receptor, and DHT has no known unique
ability in this regard.
Benelits 01 DHI
While a lot of attention is being paid to the negative side
effects of the androgen dihydrotestosterone, you should
know that there are some known benefits to the strong
androgenic activity brought about by this hormone as
well. For example, DHT plays an important role in the
organization and functioning of the central nervous
system. Many neural cells contain active androgen
receptors, and it is thought that there may even be a
specific importance of dihydrotestosterone in this area of
the body. Studies have shown DHT to have a profoundly
greater impact in these cells compared to testosterone.
More specifically, animal models demonstrated that both
testosterone and DHT would result in increased androgen
receptor proliferation in neural cells three and seven
hours after being administered, however only DHT was
able to sustain this increase at the twenty-one hour
mark.44 Although some might contend that this difference
is simply due to DHT forming a more stable and lasting
complex with the androgen receptor, others suggest that
DHT and testosterone might even be affecting neural cells
differently, such that the dihydrotestosterone-receptor
complex and testosterone-receptor complex might be
activating the transcription of different target genes.
The strong interaction between the central nervous
system and skeletal muscles, collectively referred to as the
neuromuscular system, is of key importance to the
athlete. There appears to be little doubt that the ability of
the body to adapt to training, and to activate nerve
endings in muscle tissue, is reliant on the interactions of
the neuromuscular system. Inhibiting the formation of
DHT during a testosterone cycle may therefore
inadvertently interfere with strength and muscle mass
gains. This would explain why bodybuilders commonly
report a drop in steroid potency when they add the 5alpha
reductase inhibitor finasteride to a testosterone
cycle. Many complain strength and even muscle mass
gains slow significantly when this medication is added,
which would not make sense if testosterone and
androgen receptor activation in muscle tissue were solely
responsible for growth. Clearly more is involved, and we
cannot look at dihydrotestosterone simply as a side-effect
hormone.
considering the physiological effects of any steroid, we
must look at all of its active metabolites, and not just the
initial compound. This includes not only estrogenic
products, but androgenic metabolites as well. With this in
mind, it is important to note that the potency of
testosterone is considerably increased in many androgen
responsive tissues when it converts to
dihydrotestosterone. More commonly referred to by the
three-letter abbreviation DHT, this hormone is, in fact,
measured to be approximately three to four times
stronger than testosterone. It is the most potent steroid
found naturally in the human body, and important to
discuss if we are to understand the full activity of
testosterone, as well as other anabolic/androgenic
steroids that undergo a similar conversion.
Testosterone is converted to dihydrotestosterone upon
interaction with the 5-alpha reductase enzyme. More
specifically, this enzyme removes the C4-5 double-bond of
testosterone by the addition of two hydrogen atoms to its
structure (hence the name di-hydro testosterone). The
removal of this bond is important, as in this case it creates
a steroid that binds to the androgen receptor much more
avidly than its parent steroid. 5-alpha reductase is present
in high amounts in tissues of the prostate, skin, scalp, liver,
and various regions of the central nervous system, and as
such represents a mechanism for the body to increase the
potency of testosterone specifically where strong
androgenic action is needed. In these areas of the body
little testosterone will actually make its way to the
receptor without being converted to dihydrotestosterone,
making DHT by far the active form of androgen here.
DHI and Androgenic Side Ellects
In some regards this local potentiation of testosterone's
activity may be unwelcome, as higher androgenic activity
in certain tissues may produce a number of undesirable
side effects. Acne, for example, is often triggered by
dihydrotestosterone activity in the sebaceous glands, and
the local formation of dihydrotestosterone in the scalp is
typically blamed for triggering male pattern hair loss. You
should know that it is a terrible misconception among
bodybuilders that dihydrotestosterone is an isolated
culprit when it comes to these side effects. All
anabolic/androgenic steroids exert their activities, both
anabolic and androgenic, through the same cellular
androgen receptor. Dihydrotestosterone is no different
than any other steroid except that it is a more potent
activator of th is receptor than most, and can be formed locally in certain androgen-sensitive tissues. All steroids
can cause androgenic side effects in direct relation to their
affinity for this receptor, and DHT has no known unique
ability in this regard.
Benelits 01 DHI
While a lot of attention is being paid to the negative side
effects of the androgen dihydrotestosterone, you should
know that there are some known benefits to the strong
androgenic activity brought about by this hormone as
well. For example, DHT plays an important role in the
organization and functioning of the central nervous
system. Many neural cells contain active androgen
receptors, and it is thought that there may even be a
specific importance of dihydrotestosterone in this area of
the body. Studies have shown DHT to have a profoundly
greater impact in these cells compared to testosterone.
More specifically, animal models demonstrated that both
testosterone and DHT would result in increased androgen
receptor proliferation in neural cells three and seven
hours after being administered, however only DHT was
able to sustain this increase at the twenty-one hour
mark.44 Although some might contend that this difference
is simply due to DHT forming a more stable and lasting
complex with the androgen receptor, others suggest that
DHT and testosterone might even be affecting neural cells
differently, such that the dihydrotestosterone-receptor
complex and testosterone-receptor complex might be
activating the transcription of different target genes.
The strong interaction between the central nervous
system and skeletal muscles, collectively referred to as the
neuromuscular system, is of key importance to the
athlete. There appears to be little doubt that the ability of
the body to adapt to training, and to activate nerve
endings in muscle tissue, is reliant on the interactions of
the neuromuscular system. Inhibiting the formation of
DHT during a testosterone cycle may therefore
inadvertently interfere with strength and muscle mass
gains. This would explain why bodybuilders commonly
report a drop in steroid potency when they add the 5alpha
reductase inhibitor finasteride to a testosterone
cycle. Many complain strength and even muscle mass
gains slow significantly when this medication is added,
which would not make sense if testosterone and
androgen receptor activation in muscle tissue were solely
responsible for growth. Clearly more is involved, and we
cannot look at dihydrotestosterone simply as a side-effect
hormone.
