Okay jeg er lidt forvirret pt. Jf et link tidligere postet. (
http://www.bio.net/bionet/mm/mol-evol/1 ... 05012.html)
Rhodes L et al., "The Effects of Finasteride (Proscar) on Hair Growth, Hair
Cycle Stage, and Serum Testosterone and Dihydrotestosterone in Adult Male and
Female Stumptail Macaques
(Macaca arctoides)" J Clin Endocrinol Metab 1994; 79: 991
"Finasteride, a 5 alpha-reductase inhibitor, was administered orally (1
mg/kg.day) for 6 months to six male and five female stumptail macaques. Vehicle
was given to five male and five female animals over the same period of time.
Hair weights in a defined 1-in.2 area of frontal scalp were measured
periodically every 1-2 months, and serum was collected for measurement of
testosterone and dihydrotestosterone. In addition, scalp biopsies were taken
before and 6 months after treatment to evaluate the micromorphometry of hair
follicles. Results showed that both male and female serum dihydrotestosterone
levels were significantly reduced (60-70%) by finasteride treatment. Both males
and females showed statistically significant increases in mean hair weight over
the treatment period compared to controls (P = 0.034). In addition, there was a
statistically significant increase in mean follicle length (measured
histologically in scalp biopsies)
compared to baseline in the finasteride-treated animals (P = 0.028)."
In the stumptail macaque, reducing the effects of testosterone increases hair.
So, increases in testosterone in Homo sapiens may be the reason for reduced
hair. Different areas of hair growth respond to testosterone in differing
amounts. "Androgens [testosterone] stimulate hair growth in some areas, e.g.,
beard, but may cause regression and baldness in the scalp." Clin. Endocrinol
(Oxf) 1993; 39: 633. My basic principle, of my work, is that the hormone, DHEA,
is used in transcription and replication of genes. (DHEA is used to "read"
genes for gene activity and copy genes for equal distribution in cell division.)
I have suggested that tissues differ in their use of DHEA; this is how I
explain evolution of eukaryotes and multicellularity. Therefore, tissues will
require different levels of DHEA for specific gene expression. Scalp hair and
beard hair are examples of this. I suggest the differentiating factor is the
availability of DHEA. It has been found that the receptor for DHEA can bind
dihydrotestosterone (the 5 alpha-reductase product) secondarily. That is,
"Bound [3H]DHEA was displaced sensitively by DHEA and secondarily by
dihydrotestosterone, but not effectively by other steroids, including DHEA
sulfate." J. Clin. Endocrinol. Metab. 1995; 80: 2993. This means, to me, that
DHEA is absorbed for growth of hair primarily, but the by-product of
testosterone, dihydrotestosterone, can compete for its receptor. (This should
happen at the cell surface and within the cell.) Therefore, expression of genes
dependent on less DHEA will be adversely affected by the presence of
dihydrotestosterone. This is why increased testosterone reduces hair over the
body, but not the hair producing tissues of the face.
Betyder dette at man som følge af øget test får øget skægvækst og hårvækst "andre" (hvad så andre betyder

) steder på kroppen; Men at mindsket hår på resten af kroppen er et resultat as well.