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Male pattern baldness: sebaceous gland hypothesis


#1

Male pattern baldness: sebaceous gland hypothesis.

Publication: Cosmetics and Toiletries

Publication Date: 01-JUL-90

Author: Inaba, Masumi ; Inaba, Yoshikata

(Old hypothesis- But does it hold good now?)

Clinical observation of patients treated with subeutaneous tissue shaving as a radical treatment for bromidrosis has led the authors to question what is commonly believed about the hair cycle.(1) Until quite recently, the hair cycle was believed to be divided into three stages, anagen, catagen and telogen. Hair regeneration was considered to start from remnant dermal papilla cells or secondary hair germ located at the lowest portion of telogen follicles (Hair Bulb Theory.(2)

The authors have found indications that the essential hair center is located at the upper isthmal portion of the hair follicle close to the secretory duct opening of the sebaceous gland (Sebaceous Gland Hypothesis).

The hair follicle and sebaceous gland form a unit called the pilosebaceous unit. The sebaceous gland has been believed to function only as an exocrine gland which secretes sebum, a surface lipid that moistens the skin and the hair shaft. The relationship between the hair follicle and the sebaceous gland has been studied extensively. However, most studies focused on the morphological difference between them. Few dealt with the relationship between the two, and much remains unclear.

The authors have suggested that the sebaceous gland functions not only as an exocrine gland, but also as an endocrine gland which constantly acts on and controls the hair bulb through the hormones and enzymes it excretes. Basic aspects of essential hair regeneration such as how the hair follicle is regenerated from the upper isthmal portion, how the new hair is formed, and whether or not the conventional hair cycle theory is sufficient have been questioned. Understanding these aspects is essential if the causative mechanism is to be discovered and an effective treatment developed for male pattern baldness.

According to the sebaceous gland hypothesis, MPB occurs because sebaceous glands enlarge. The enlarged sebaceous gland increases sebum production leading to clogging of pores and malnutrition of hair root and also produce excessive amounts of DHT which exert a suppressive action on the hair root.

On the basis of sebaceous gland hypothesis MPB is caused not only by hereditary factors but also by nutritional factors. The direction for new preventive measures and treatments may lie in reducing sebaceous gland size.


#2

my hypothesis is a bit better :slight_smile: sebaceous glands infected by some kind of mites leaking their contents into the follicle and mites overgrowing, building collonies deeper and deeper and immune system attacks it all and shuts it down because it finds forreign bodies.

if your sbaceous glands are small enough you’re safe.

I rly would like to find a study that studies difference between scalp hair follicle sebaceous glands and facial sebaceous glands. If the two would invovle different type of 5ar, the last bit would fit together and the theory would explain everything, from donor dominance, to topical penicilin being helpful


#3

» my hypothesis is a bit better :slight_smile: sebaceous glands infected by some kind of
» mites leaking their contents into the follicle and mites overgrowing,
» building collonies deeper and deeper and immune system attacks it all and
» shuts it down because it finds forreign bodies.
»
» if your sbaceous glands are small enough you’re safe.
»
» I rly would like to find a study that studies difference between scalp
» hair follicle sebaceous glands and facial sebaceous glands. If the two
» would invovle different type of 5ar, the last bit would fit together and
» the theory would explain everything, from donor dominance, to topical
» penicilin being helpful

or a study that shows that finasteride decreases sebum production on the scalp (I believe it did for me).


#4

I found this study on hamsters.

The effect of estradiol on the sebaceous gland of the hamster ear and its antagonism by tamoxifen.
To evaluate the antagonism between estradiol and tamoxifen in the sebaceous gland of the hamster ear, animals were topically treated, and the size of the sebaceous glands was measured by histoplanimetry. The systemic effects were described by determining the estradiol and testosterone plasma levels and within the testes, and the size of the seminal vesicles and the contralateral sebaceous gland. The administration of 0.1 micrograms estradiol resulted in a diminution in the size of the treated glands but left all other parameters unchanged, indicating a purely local effect. A higher dose of estradiol (1 microgram) further decreased the size of the treated glands, but this was combined with a systemic effect, i.e. low plasma testosterone, decrease in testis size and a diminution of the contralateral ear gland. Ten micrograms of estradiol maximally suppressed all of the androgen effects without side effects. The administration of tamoxifen alone also decreased the size of the sebaceous glands without side effects, but it did not affect the production or effects of androgens. When administered in combination with estradiol, it antagonized the effects of this hormone completely. We conclude that tamoxifen inhibits the negative effect of estradiol on sebaceous-gland size. It acts predominantly in a systemic manner, because a metabolisation to monohydroxytamoxifen is necessary.

I know, hamsters and sebaceous glands of the ear.

I also found the following discussion of topical Tamoxifen.
http://www.regrowth.com/hairloss-forums//viewthread.cfm?f=1&t=14597

Your not bald-you just have alot of dormant hair follicles that haven’t been awakened yet. University of Michigan(scUM) Medical Center researchers found that rubbing a cream containing the cancer-fighting drug tamoxifen on rats just one time activated dormant hair follicles and increased hair growth. Applying the drug repeatedly caused the rats to produce too much hair. The treatment worked only in mice that were genetically altered to create baldness. Bald men have dormant follicles-healthy but not producing hair. This research is exciting because it shows we may be able to wake up these dormant follicles(Genes Dev, 17: 1219-1224, 2003)

I know one of the side effects of oral Tamoxifen is hairloss. But has anybody every tried it topically? Could the effects be different topically? Could it be shrinking the sebaceous glands causing hair growth?


#5

» Your not bald-you just have alot of dormant hair follicles that haven’t
» been awakened yet. University of Michigan(scUM) Medical Center researchers
» found that rubbing a cream containing the cancer-fighting drug tamoxifen on
» rats just one time activated dormant hair follicles and increased hair
» growth. Applying the drug repeatedly caused the rats to produce too much
» hair. The treatment worked only in mice that were genetically altered to
» create baldness. Bald men have dormant follicles-healthy but not producing
» hair. This research is exciting because it shows we may be able to wake up
» these dormant follicles(Genes Dev, 17: 1219-1224, 2003)
»
» I know one of the side effects of oral Tamoxifen is hairloss. But has
» anybody every tried it topically? Could the effects be different
» topically? Could it be shrinking the sebaceous glands causing hair growth?

That’s weired, so basically they blocked estrogen receptors and got regrowth. That’s a comlete 180 to what bryan usually preaches i.e. that estrogen is good for hair.