Wednesday, November 10, 2010

Prolactin and Hair loss







High Prolactin level and Hair Loss:
It has been shown recently that some hair loss is related to higher Serum Prolactin level.
An abnormally high level of prolactin (hyperprolactinemia) is a condition characterized by elevated serum levels of the hormone prolactin in non-pregnant individuals. Hyperprolactinemia may cause progressive pattern hair loss due to an indirect effect on increasing free testosterone level. Prolactin also enhances LH (Luteinizing Hormone) receptors in Leydig Cells, resulting in testosterone secretion, which leads to spermatogenesis.
Prolactin delays hair regrowth in mice. It has been shown in research that Treatment of organ-cultured human scalp HFs with high-dose PRL (400 ng/ml) results in a significant inhibition of hair shaft elongation and premature catagen development, along with reduced proliferation and increased apoptosis of hair bulb keratinocytes. Human scalp hair follicles are both a target and a source of prolactin, which serves as an autocrine and/or paracrine promoter of apoptosis-driven hair follicle regression.

Conditions associated with elevated prolactin secretion

 
Hyperprolactinaemia is the term given to having too-high levels of prolactin in the blood, which can result from:
  • Prolactinoma
  • Excess thyrotropin-releasing hormone (TRH), usually in primary hypothyroidism stimulates prolactin secretion
  • Many antipsychotic  Anti depressant medications
  • Increased Emotional stress
  • Pregnancy and lactation- Oxytocin sectreion by nipple stimulation releases Prolactin. Estrogens provide a well-studied positive control over prolactin synthesis and secretion, and increasing blood concentrations of estrogen during late pregnancy appear responsible for the elevated levels of prolactin that are necessary to prepare the mammary gland for lactation at the end of gestation.
  • Some sexual disorders
  • PCOS ( POLY CYSTIC OVARIAN SYNDROME)
  • It has also been shown that prolactin levels after sex are 4x higher than prolactin levels after masturbation but these hormonal changes are very short term and does not affect hair loss
  • daylight exposure significantly alters prolactin levels. This temporary increase in the number of telogen hair follicles
  •  
Dopamine released by Hypothelamus in turn inhibits Prolactin.


Treatment:

In one of the studies at Argentina Prolactin Inhibitor like Bromocriptine (dopamine receptor agonists), Quinagolide, Pergolide, Cabergolide have been shown to help those with Hyperprolactinemia and have not been benefited otherwise.



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Tonsure or head shave does it help hair growth?

Well there is religious reasons why many people tonsure there head ( in Hindus at times it a sacrifice of symbol of aeasthetics esp. in females). But it is a common belief esp. in some parts of India that if you are losing hair and have thin baby hairs and if you repeatedly shave your head you may grow new hairs or better hairs.
Well shaving or tonsure is only external to skin and does not directly affect the roots which are responsible for the hair growth. The hairs outside the skin does not get the blood supply or nutrition and does not even have any repair capacity and may even be affected by environment.
By removing the outside hairs you are not actually stimulating hair follicle to grow hair. As in case after of shaving of the beard hair the initial stubble feels thorny strong and sharp the initial hair growth after shaving of the head feels thorny sharp and that has perhaps given this belief. But within few days again when the hairs grow little longer that feeling disappears.

Perhaps the benefit of shaving head is the ease of using or applying Minoxidil. Other thing is the illusion of less hair fall because the small hair are not visible when they fall but the long hairs are apparently visible. So person with shaved head or short hair may be psychologically benefited.



In some religion young babies are tonsured with the belief that it will grow new or better hairs. This is not true. In many religions they do not tonsure/shave off their child's hair. At 1 year, the babies usually get mature hair with baby hair falling off. On the other hand, it is know of kids who still have baby hair even after a few tonsures. Shaving does not help hair growth is controlled by genes and hormones.