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Issue
#9
ANABOLIC/ANDROGENIC STEROIDS - A BASIC DESCRIPTION.
By
Sanjac.
This article
will attempt to describe, in layman's terms, the fate of Anabolic/Androgenic
Steroids (AAS) in the human body. The intent is to look at steroids
from a general view, not to describe the different individual steroids.
Of course, the author does not condone the use of steroids by anyone
not under the care and supervision of a qualified medical professional.
TYPES
OF STEROIDS
Anabolic/Androgenic Steroids can be roughly classified into two
types, oral and injectable. When you eat food or consume anything
orally, the great majority of the ingested substances pass through
the liver prior to entering the bloodstream. For this reason, "injectable"
AAS cannot be taken orally because the liver will deactivate the
steroids in this "first pass". Deactivation in the liver usually
involves the addition of one or more hydroxyl (OH) groups to increase
the solubility of the molecule in water, making excretion in the
urine more easily accomplished.
Oral Steroids
Oral steroids involve modification of the parent steroid to make
it harder for the liver to degrade the steroid molecules. This modification
is almost always the addition of an alkyl (methyl) group at the
17 position of the steroid ring. The liver can still degrade the
steroid, but not as effectively as the un-modified steroid. Therefore,
oral steroids make several cycles through the bloodstream before
being excreted. Most oral steroids are, to various degrees, excreted
from the body unchanged.
Injectable
Steroids
The injectable AAS are very effectively degraded in just a single
pass through the liver. If this is so, then how can the injectables
be effective? The answer is called a "depot" (or reservoir), which
allows a regular release of steroid into the bloodstream. As steroid
is removed from the bloodstream by the liver, more steroid is being
released into the bloodstream from the depot. There are several
ways to provide such a reservoir of the steroid.
Suspension
The first way is to use pure testosterone (a crystalline solid)
suspended in water. Testosterone has a low solubility in water,
and the crystals slowly dissolve in the watery environment of the
tissue in which it is injected. The dissolved testosterone is carried
throughout the body by the bloodstream. For Testosterone suspension,
the "depot" is the actual physical site where the injection is made.
The crystals do not migrate to other parts of the body, and the
presence of the crystalline testosterone can cause some pain at
the injection site. The testosterone dissolves at a (relatively)
constant rate, and lasts for a few days in the body. Winstrol suspension
is similar.
Esters
The other way to provide a depot of steroid is to use a water-insoluble
form of the steroid that can be converted in the body to the parent
steroid, which has some solubility in water (bloodstream). Most
commonly, the parent molecule is esterified with an organic acid,
and the resulting ester is soluble in oil, but only very slightly
soluble in water. Commonly used organic acid groups are acetate
(C2), propionate (C3), enanthate (C7), decanoate (C10), and undecylenate
(C11). The longer the carbon chain of the acid, the more oil-soluble
the ester, and the longer it takes for the ester to turn into the
parent steroid (de-esterification). A type of enzyme that is found
throughout the body facilitates the de-esterification reaction to
form the parent steroid from the ester. The enzyme actually catalyzes
the reaction in both directions, so it can also attach an organic
acid back onto the parent steroid. So, for example, testosterone
enanthate can actually be turned into testosterone palmitate. There
is some good evidence that steroid esters are, to some extent, stored
in fat cells.
It is commonly
believed that esters form a depot of oil/ester that stays at the
injection site. This is not true. While the depot concept holds
true for esters (because they slowly release the parent steroid
over time), the esters actually disperse throughout the body after
injection, prior to (and during) the de-esterification reaction
to form the parent steroid. They do not stay at the injection site.
For example, the ester testosterone enanthate has been found in
tissues throughout the body, including hair samples of subjects
who have injected T200. If a bio-contaminant is introduced at the
time of injection (non-sterile conditions), the body will attempt
to encapsulate the contaminated material, and an abcess will form.
In this case it appears as if the ester has remained at the injection
site. But under normal sterile conditions, the oily solution will
disperse. Injecting too much at one site or injecting too frequently
at one site will not cause an abcess.
Transport
of Steroids in the Bloodstream
Once the steroid has been released from the depot (or the oral steroid
has been absorbed from the intestine), it is transported throughout
the body in the bloodstream. Carrier proteins (Albumin and Sex Hormone
binding Globulin) bind about 98% of testosterone under natural conditions.
Thus, only 2% of the hormone is free to carry out its actions. When
exogenous steroid is present, the level of free steroid is much
higher than 2%. Bear in mind that the hormone is not permanently
bound to the some of the proteins, but is constantly binding and
un-binding from the protein. At any given time, about 2% of the
hormone is un-bound in the natural state. So, if the 2% unbound
hormone were to magically disappear, then the proteins would release
more hormone such that 2% (of the remaining total) would come unbound.
The bloodstream is the mechanism by which the hormones reach their
target tissues (muscle).
Action of
Steroids
Androgen
Receptor Activation
Once a free molecule of steroid reaches the muscle cell, it diffuses
into the cell. The diffusion can be with or without transport-protein
assistance. Once in the cell, the AAS is makes its way to the cell
nucleus where it can bind with an androgen receptor (AR), and activate
the receptor. Two of these activated receptor complexes join together
to form the androgen response element (ARE). The ARE interacts with
DNA in the nucleus, and increases the transcription of certain genes
(such as muscle protein genes). As long as the ARE is intact, it
accelerates gene transcription. Remember, though, that the AAS and
the receptor are in a state of flux (binding and un-binding), just
like with the Carrier proteins. So the ARE can be deactivated just
by losing one of the two AAS that are bound to the AR's. This equilibrium
situation explains why 1 gram per week testosterone is more effective
than 1/2 gram per week, even though 1/2 gram appears to be more
than enough to saturate all the AR's in the body. The higher concentration
makes it more likely that the receptors will be occupied by an AAS,
and the ARE will be intact for a longer period of time, on average.
Other Actions
Activation of the androgen receptor is a key mechanism in the action
of AAS. However, this mechanism by itself does not explain the differences
between steroids (i.e., nandrolone activates the AR better than
testosterone, but is not as good of a mass-building product). Other
actions involve primarily the central nervous system, and involve
actions such as motor activation (muscle coordination) and mood
(i.e., aggressiveness). The mechanism by which AAS effect these
actions is not well understood at this time. Another effect occurs
in the liver, where some steroids cause the release of certain Growth
Factors. The different actions of the different AAS explains why
a stack of two different types of AAS is often better than one by
itself.
Elimination
of Steroids
The liver is a primary route to deactivation of steroids, the chemical
structure is changed here to make the steroid more soluble in water
for excretion through the kidneys. A good portion of many steroids
also are excreted as-is, without any alteration by the liver, or
by formation of the sulphate, which is more water soluble. Many
in the medical community have believed that AAS cause liver damage
because levels of certain enzymes (AST and ALT) are elevated when
steroids are used. Elevated levels of these enzymes are seen in
patients with liver damage from other causes, so the conclusion
is that AAS must cause liver damage because these enzymes are elevated.
Recent work, however, has shown that a true marker of liver damage,
GGT, remains unchanged when some AAS are used, and now it is questioned
whether AAS are really damaging to the liver (the 17 alpha-alkylated
AAS do cause damage in some rare cases, and this damage is reversible
upon cessation of steroid use). The same thought processes were
used to claim kidney damage, but that is unlikely as well.
SJ
Copyright
2000 Jason Meuller and Anabolic Extreme. This material may not be
copied, reproduced, or transmitted without the express written permission
of the copyright owners.
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