[Studie] Hormonen en haar/talg

[ugh]

Hier een review met uitgebreide technische info over het effect van hormonen op de pilosebaceous unit (haarzakje + talgklier).

Er wordt verder ook ingegaan op Hirsutism, Acne Vulgaris, en Pattern Alopecia.

Abstract:

Am J Med. 1995 Jan 16;98(1A):80S-88S. Related Articles, Links

Role of androgens in the developmental biology of the pilosebaceous unit.

Rosenfield RL, Deplewski D.

University of Chicago, Pritzker School of Medicine, Department of Pediatrics, Illinois.

The growth and development of pilosebaceous units in their characteristic pattern depends on the interaction of androgens and diverse biologic factors. Stromal-epithelial interactions are essential features. Considerable evidence suggests that androgens stimulate the growth of sensitive pilosebaceous units primarily by acting on specific stromal cells and that androgens and retinoic acid interact to regulate specific stages of sebocyte differentiation.

Publication Types:

• Review
• Review, Tutorial

PMID: 7825644 [PubMed - indexed for MEDLINE]

Full Text:
http://edrv.endojournals.org/cgi/content/full/21/4/363

[ugh]

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

Br J Dermatol. 2006 Jan;154(1):85-9.Related Articles, Links

Female pattern hair loss, sebum excretion and the end-organ response to androgens.

Birch MP, Lashen H, Agarwal S, Messenger AG.

Department of Dermatology , Royal Hallamshire Hospital, Sheffield S10 2JF, UK.

BACKGROUND: Although female pattern hair loss can be a feature of hyperandrogenism, many women with hair loss show no clinical or biochemical features of androgen excess. It is possible that hair loss in nonhyperandrogenic women is due to a high level of response to androgens by scalp hair follicles. In this study we explored this idea using sebum excretion as a marker of the cutaneous end-organ response to androgens. OBJECTIVES: To test the hypothesis that hair loss in nonhyperandrogenic women is due to an increased cutaneous end-organ response to androgens. METHODS: We studied 100 women, 41 with female pattern hair loss (without hirsutism), 29 with hirsutism (with and without scalp hair loss) and 30 subjects without hair problems. We measured hair density on the frontal scalp, forehead sebum excretion, serum free androgen index (FAI), and body mass index (BMI). RESULTS: The mean FAI was significantly raised in hirsute women compared with nonhirsute women (P < 0.001), but there was no difference in FAI levels between nonhirsute women with and without hair loss. The mean BMI was also significantly elevated in hirsute women (P < 0.01) but there was no difference in BMI between nonhirsute women with and without hair loss. The mean sebum excretion was higher in hirsute women than nonhirsute women but the difference was not statistically significant. There was no difference in sebum excretion between nonhirsute women with and without hair loss. There was no correlation between hair density and sebum excretion. CONCLUSIONS: Our results show that sebum excretion is not elevated in women with female pattern hair loss. This may indicate that different androgen-response pathways operate in controlling hair growth and sebum excretion. The alternative explanation is that nonandrogenic mechanisms are involved in mediating hair loss in some women.

[ugh]

http://www.diagnose-me.com/cond/C489728.html

[...]Recently, a group of Japanese researchers reported a correlation between excessive sebum in the scalp and hair loss. Excessive sebum often accompanying thinning hair is attributed to an enlargement of the sebaceous gland. They believed excessive sebum causes a high level of 5-alpha reductase, the enzyme which converts testosterone into dihydrotestosterone (DHT), and pore clogging, thus malnutrition of the hair root and a shift into the resting phase.[...]

Niet echt heel recent, namelijk uit de jaren 80 of 90 ofzo.

http://www.folica.com/Hair_Loss_Treat_d1283.html

Medical researchers in Asia believe that hair loss is caused mainly by insufficient blood supply to the scalp. The other possibility is excessive sebum, or oil, in the scalp, which causes clogged pores and malnutrition of the hair root ("Sebaceous Gland Hypothesis" proposed by Dr. Yoshikata Inaba of The Inaba Aesthetic Surgery in Tokyo).

Het boek met de studie:
http://www.med-estetica.com/Cientifi...6-AndroAlo.htm

[ugh]

http://www.hairlosstalk.com/discussi...ic.php?t=13962

New Hypothesis about Common Baldness
AJ Soler
Elda - Alicante, Spain

"Common baldness or Alopecia affects a high number of people. The etiology and pattern of hair loss has not been completely xplained, probably because hair is one of the most dynamic mammalian structures. The hair follicle can both renew itself through an intrisic stem cell population and has the ability to cycle asynchronously (It can grow and rest independent of other follicles).

Sebum is vital for hair growth, and it is created and eliminated continuously due to its high instability. In this hypothesis, the existence of a sebum flow outward and another one inward towards the hair follicle, is proposed. If there are problems of elimination in its way outward, this causes problems in the inward flow. Therefore the detention of sebum flow towards the inside of the hair follicle is proposed as the initial and triggering factor of common baldness.
This hypothesis provides a simple explanation of the characteristic pattern of hair loss and why Alopecia affected areas do not appear at the sides and back of the head. These are the areas we rest daily on absorbent surfaces such as the pillow, where sebum can be drained driectly, avoiding in this way its possible detention. The hair located in the "sensitive" areas has to eliminate sebum by carrying it longitudinally along the hair shaft, or in a transversal way by contact with neighbouring hair.

On the other hand, it seems that the follicular papilla is a result of migration of transient amplifying cells from the bulge region to the hair germ during anagen induction.

It is then logical to think that the route of such cells is the same that sebum must cover. If sebum stops, then its physical, chemical and biological properties change and may cause an alteration or decrease of the cells that reach their aim, which can explain the miniaturization process that is observed in common baldness.

From that point the rest of alterations in other involved systems, such as the hormonal, immune, circulatory, fibrosis processes, etc. can be explained.

Baldness is a degenerative process that affects each hair individually, easily reversible at the initial stages, and more difficult to reverse as time goes by."

[Kretos]

Is deze tekst ook in het Nederlands beschikbaar? Mijn Engels is niet zo goed. Ik ben benieuwd wat er nu precies gezegd wordt over het verband tussen de gebieden die niet aangetast worden door AGA en het feit dat we op die gebieden rusten.

[kevin]

Hahaha wat een onzin. Er wordt gezegd dat ik niet kaal wordt aan de zij- en achterkant, omdat ik daarop rust en slaap