I sent the following email to the author of the study reported a couple days ago in the news, "Elevated Testosterone Induces Apoptosis in Neuronal Cells". I did my own meta-analysis of the research and came up with the following message. With luck, this guy will respond and either concede or tell me what I missed.
Basically, I found out what the bros here have said all along : the doses in this study are about 500 times what a steroid cycler would actually use.
The study with your name as the first author, Elevated Testosterone
Induces Apoptosis in Neuronal Cells, contains the statement "Despite
the complexity of the blood-brain barrier, the lipid permeable nature
of testosterone and the duration of these treatments (more than weeks)
suggest that significant amounts of this hormone would be accessible
to neuronal tissues".
I found evidence after a 30 minute visit to my college library that
strongly suggests this statement is incorrect.
In Psychoneuroendocrinology, volume 26, p 273-285
"Cerebrospinal fluid and plasma testosterone levels in post-traumatic
stress disorder and tobacco dependence"
In this study, actual human subjects had their serum total
testosterone concentrations and CSF total testosterone concentrations
measured at regular intervals over a 6 hours period. The average
concentration in these subjects, some of whom had elevated
testosterone concentrations as a result of tobacco smoking, was 24.7
pg/ml. That is 2.47 ng/dl, or 0.085 nanomolar. These subjects had
serum testosterone levels within the normal range : approximately 500
ng/dl.
By contrast, your study considered 100 nanomolar in the fluid you had
the blastoma neurons bathing in, analogous to CSF in vitro, to be a
"low" concentration of testosterone. Yet, I have just established
that normal concentrations of testosterone in CSF to be 1166 times
lower than what you consider "low" in your study.
Well, in subjects taking doses of hormones, their CSF testosterone
levels will likely be elevated along with their serum testosterone
levels.
How much elevation? The same study contains the statement "The total
amount of testosterone detected in CSF approximates that found free in
plasma" It supports this statement by referencing the following
studies :
"Steroid hormones and steroid hormone binding globulins in
cerebrospinal fluid studied in individuals with intact and with
disturbed blood-cerebrospinal fluid barrier."
(on PubMed, the abstract mentions that 2 nanomolar was the highest
level of CSF testosterone found)
Serum Hormone Binding Globulins and Alubumin concentrations in Human
Cerebrospinal Fluid - Journal of Steroid Biochemistry, volume 26
p557-560, 1987
Ok, so assume these 3 research studies, all agreeing with each other,
are correct : total testosterone in CSF approximates concentration
found free in plasma. Back to this study :
http://www.arthurdevany.com/webstuff...osterone%20%22
The HIGHEST level of free testosterone reported by any of the study
particpants, some of whom were injected with 600mg of testosterone
enanthate per week, was 62.5 ng/dl or 2.17 NANOmolar. Again, the
"low" dose in your study bathed cells in vitro with 46 times this
amount...and you did not observe a difference in cell viability.
Conclusion : the deleterious effects of anabolic steroids are not
caused by neuronal apoptosis demonstrated by your study. While in
this section of the library, I found stacks of books explaining dozens
of known mechanisms where testosterone acts as a neurohormone,
modulating numerous receptors and affecting behavoir on a systemic
level. Given that brain concentrations of this hormone vary normally
around a couple of nanomolar, the organ must be incredibly sensitive
to this hormone to affect behavoir on the level actually observed.
Increasing the free testosterone in the brain by a factor of 6 might
have profound changes on behavoir in function, causing every
deleterious effect observed : but not permanent neuron destruction, or
at least not by the mechanism you have researched.
It's not surprising that giving 500 times the amount found even in
individuals at supraphysiologic serum testosterone levels causes
Neuronal Apoptosis.
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