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The Hydraulic Influence in Androgen Related Hair Growth. Implications in
Autoimmune Disease
The following is a post from Mr. Foote in HairSite Topical Forum on October 24, 2002.
Androgen related changes in hair growth represent something of a mystery. Through the action of Dihydrotestosterone (DHT), hair growth is increased in specific areas of the body. Elevated levels of DHT produce a general increase over the larger part of the body, often accompanied by hair loss in specific areas of the scalp. Because of this 'opposite' effect, a genetic difference in the hair follicles is proposed. This view is supported through the success of the 'plug graft' transplantation technique. However this is unsatisfactory, because transplantation procedures that should work well according to this theory, ultimately fail. There is an alternative 'mechanism', that demonstrates its origins in the prime function of hair as an insulator. This simple mechanism makes sense of all the recognised effects of DHT in the dermal system, and throughout the body. In DHT related hair growth it can be directly observed. The implication is that DHT achieves its effects through a primary physiological action that can be easily tested given the necessary expertise. Given existing knowledge, such a proven action of DHT would have serious implications for further understanding of female susceptibility to autoimmune disease. In a previous issue of Medical Hypotheses (1), this author suggested a simple 'hydraulic' explanation for the apparently contrary effects of the hormone DHT upon hair growth. It has been thought that DHT has a direct effect upon the cells in which it is produced through the conversion of Testosterone. However this has not been proven, and expert opinion now accepts that the causal action of DHT has not been defined (2). DHT is often referred to as a 'skin' hormone as much of the total quantity is produced in the periphery. The recognised effect of DHT upon hair follicles involves changes in their size and depth within the Dermis (3), (4). Larger follicles produce more hair cells during the Anagen growth phase of the hair cycle. In general, DHT acts to produce larger hair follicles cycle by cycle so increasing hair growth. It has also been shown that sebaceous and sweat gland efficiency is related to the action of DHT (5), (6). Where DHT increases hair growth there is a corresponding increase in sebum production, and reduced sweating efficiency. Where DHT reduces hair growth, there is a reduction in sebum production and increased sweating efficiency. There is therefore a known link between the action of DHT, and the activity of the main dermal structures. The usually permanent hair growth of plug graft transplantation is often quoted as proof of genetically different hair follicles. The problem here is the ultimate failure of the scalp reduction techniques of hair transplantation. In male pattern baldness, the fully productive follicles at the sides and back of the head are described as being genetically permanent. It is claimed that these follicles are resistant to the withering effect of DHT upon other scalp follicles. Technically, then, the most efficient method of relocating some of these resistant follicles to the bald area is through scalp reduction. In these procedures bald tissue is removed and hair producing tissue is drawn together from the sides and back of the head. Over two or three procedures the productive tissue meets in the middle, covering the previously bald area. However, this effect is only temporary, and over time the allegedly resistant hair growth recedes back to its approximate starting point. This fact is demonstrated through the procedure being no longer offered in the reputable clinics. The relative success of plug grafting can logically be explained by means other than the genetic difference theory. The recognised effects of DHT upon the dermal structures suggests a common mechanism that explains the production of DHT in the peripheral tissues. In the telogen resting phase, the hair follicles are shortened. The subsequent Anagen phase involves the growth and lengthening of the follicle within the dermis. (Accepted hair cycle). All 'normal' processes of cellular growth are governed by the restraints of contact inhibition. Therefore through contact inhibition, the size of the 'new' follicle is ultimately dictated by the space allowed in the dermal tissue. The analogy I would make is that the dermal tissue represents the mould into which the follicle structure is poured. It follows that any expansion or shrinkage of tissue around hair follicles would have a pronounced effect upon follicle size, and therefore hair production. The effect of such tissue movement around hair follicles is best visualised through the example of a mature follicle. With reference to Fig.1 a, b, c, Expansion of surrounding tissue compresses and distorts the follicle structure. An actively growing hair would be shed as a club hair because of the peripheral reduction of the follicle's production area. There are associated factors that would influence the exact response of follicles to any change in the tissue fluid pressures around them. The natural resilience of the tissue would govern the amount of distortion for any given change in fluid pressure. Another important factor is the length of the original follicle. Because tissue expands or shrinks exponentially, longer follicles would experience greater changes through this tissue movement. This adds up to as a specific response in both developing and mature follicles to movement in surrounding tissue. These movements are created through changes in tissue fluid pressures. It is therefore important to ask why should hair follicles be responsive to change in tissue fluid pressures?
When this mechanism is considered in terms of the dermal system as a whole, it tells a story of an integrated, temperature responsive mammalian dermal system. Sebaceous glands are also "hollow" structures. Sebum production is known to be related to the size of these glands (7). The coiled structure of sweat glands provides a large surface area for the absorption of fluid (8). Sweat gland efficiency is therefore related to the fluid pressure in surrounding tissue. With reference to Fig.2, a & b, in the mammalian hydraulic dermal model, a reduction in environmental temperature reduces blood flow to surface tissue to conserve heat. Blood diverted from surface tissue maintains a good supply to the hair root itself. The reduced blood flow in tissue around hair follicles reduces tissue fluid levels and this tissue shrinks. This tissue shrinkage creates an enlargement of both developing and established hair follicles. The hollow structure of sebaceous glands is also enlarged, and oil production increases in line with hair production to create a 'winter coat'. Sweat gland efficiency is reduced because of reduced fluid levels, but this is not relevant in cold conditions. As environmental temperatures increase the reverse effect occurs. Blood flow is increased in surface tissue to dissipate heat. The increased fluid level distorts and reduces the size of hair follicles and sebaceous glands to produce a 'moult', and reduced hair and oil production. Importantly the increased fluid levels ensure an adequate supply of raw material for the sweat glands in warm conditions. This 'hydraulic' mechanism has other important benefits for hairy mammals. Any tissue injury will create an inflammatory response. The increased fluid level creates a localised moult around the injury. This allows easier cleaning and significantly reduces the risk of serious infection.
Before puberty, the primary area of significant human hair growth is the scalp, for whatever reason the follicles of the scalp are enlarged. There is certainly no evidence for a tendency for humans to produce increased hair growth in response to reduced temperatures. Perhaps the increased fat content of our dermal tissue increases resilience, and takes us out of the range of temperature induced changes in hair growth. Other factors may however create changes in tissue fluid pressure sufficient to 'move' our resilient tissue. If this hydraulic hair growth adjustment mechanism is valid in human hair patterns, the areas involved will be privileged in some way towards changes in tissue fluid pressures. At puberty changes in hair pattern in both sexes are known to be related to the action of the DHT component of Androgen. The specific areas of the body involved are the groin and armpits. In men increased levels of DHT produces beard growth and a general increase in body hair growth. There is an obvious direct relationship between the primary areas of increased growth, and concentrations of superficial lymphatic drainage vessels, (9). The lymphatic drainage system plays a major role in the control of tissue fluid levels. According to this hydraulic hair growth mechanism, this directly observable relationship implies that DHT significantly increases lymphatic drainage efficiency. TThe recognised effects of DHT are as follows: 1. Increased body hair growth. (5). 2. Increased Sebum production. (5). 3. Change in the efficiency of normal, non specialised sweat glands. (6). 4. Reduced scalp hair growth. (5). 5. Hyperplastic enlargement of the prostate gland. (5). All these recognised effects could logically be linked to as a primary action of DHT upon lymphatic drainage efficiency. Such an action is fully consistent with the 'performance' characteristics of Androgen, and the common view of DHT as a testosterone amplifier. A general increase in tissue fluid turnover ensures that nutrient supply, and waste removal in tissues is maximised. This allows the full androgenic effects to be achieved. Consisting of a network of blind ending vessels with one way valving, a number of factors influence lymphatic drainage (9). DHT may act upon target cells in lymphatic vessels to increase sensitivity and the periodic rate of contraction. This would increase the pumping efficiency. Given the complexity and high pressures of the human cardiovascular system, it is easy to understand how such an action of DHT could cause opposite effects of fluid retention in vulnerable areas. The prostate gland is known for its poor fluid drainage characteristics (5). In the case of the prostate, a high fluid level gives a significant evolutionary advantage. The effect is to increase the prostatic secretions that are important in successful breeding (5). It is the direct
observations of an 'opposite' effect of DHT upon the head that
demonstrates the principle. The proposed influence of DHT as a lymphatic drainage 'improver', makes sense of its increased production in peripheral tissues. To introduce such a substance solely in the core of the body would risk a back pressure effect because of the lymphatic valving system, encouraging fluid retention in the periphery. I suggest such an effect is observable in male pattern baldness. The human head has a very complex vascular system and a high pressure blood supply. This complex system is associated with the requirements of the human brain (6). The beard growth induced by DHT can be seen to be related to the lymphatic vessels that are concentrated in the face and neck (9). Given the high pressure fluid 'feed', it is easy to see how a back pressure effect can be produced at the top of the head because of increased drainage lower down. In male baldness you can usually see a point on the forehead where the 'swelling' starts. This can be quite low down in some individuals. This forehead 'bump' is important, as the pitting oedema test shows increased fluid levels above this point compared to below it. I think the popular phrase 'a shiny bald head' demonstrates the observable smoothing effect on skin of swollen tissue. According to the hydraulic hair growth mechanism, tissue shrinkage will increase hair growth. The drug Minoxidil, (Upjohn), was originally developed as an antihypertensive. It is known to have a significant effect upon the body's fluid transport system. (10). Whatever the mechanism involved, the net effect is a reduction in tissue fluid levels. This is observable when Minoxidil is used on the bald scalp. The use of Minoxidil generates wrinkling of the skin that demonstrates shrinkage of underlying tissue. The successful hair transplantation techniques involve plug grafts. Cylinders of tissue up to four or five millimetres in diameter containing active follicles are grafted into bald tissue. Theoretically, once these grafts have healed they would become subject to the same oedematous conditions as the surrounding tissue. There is however a significant difference between the successful plug grafts and unsuccessful scalp reduction. This is the 'wall' of scar tissue that forms around each plug graft. According to the hydraulic hair growth mechanism, this scar tissue should reinforce the graft against expansion. There could also be a secondary factor of reduced blood flow into the graft because of the scar tissue. If tissue reinforcement is the dominant factor in the survival of follicles in plug grafts, there will be certain observations in mature grafts. With reference to Fig. 3, hair growth would be concentrated around the edges of the graft near the scar. There may be some expansion and distortion of follicles, and this would produce asymmetrical follicles and wavy hair growth. In the larger grafts there would be a dome effect in the centre of the graft and reduced hair growth. Such a reinforcing effect would also be demonstrated by continued expansion of surrounding tissue leaving the grafts as pits in the scalp. This scenario would explain the modern trend towards the smaller plug grafts as these would be relatively more successful, and cosmetically acceptable.
Ultimately there is a simple test that would prove or disprove any significant effect of DHT upon lymphatic drainage efficiency, and the role of this in autoimmune disease. Any changes in lymphatic drainage efficiency would create changes in tissue fluid levels and therefore changes in tissue counts of substances transported in this fluid. This generates the suggestion that DHT creates a significant difference in gender immunology that is consistent with female susceptibility to autoimmune disease. The transportation characteristics of immune components through the tissues and lymphatic system, is a fundamental part of immune responses. (11) Reduced lymphatic drainage would increase the infiltration and stagnation of immune components in tissues, in the absence of infection. This must significantly increase risk of an immune response to 'self', i.e. autoimmune disease. This would suggest that DHT has a significant protective effect through increasing lymphatic drainage. Such an action of DHT would also reduce the clinical effects of autoimmune responses through increasing clearance of tissue damaging substances. It is known that women who suffer from systematic lupus erythematosus (SLE), usually have a disproportionately low level of male hormones (12). Such an action of DHT would certainly oppose the conditions that exist in autoimmune diseases like SLE. In these diseases there is a tissue infiltration and stagnation of immune components that triggers other processes and tissue damage (13). If DHT is a central hormonal influence in female susceptibility to autoimmune disease, a measurable effect of a licensed drug would confirm this. The drug Finasteride (Merck & Co.) (14), significantly reduces levels of DHT in men. If this proposal is valid, Finasteride will significantly increase the infiltration and stagnation of immune components in tissues in the absence of infection. Confirmation of this
effect of Finasteride would make a case for boosting levels of DHT in
women with autoimmune diseases to an average female level. This could
provide a significant protective and treatment effect in some debilitating
and often fatal diseases. The common factor in any biological system is the fluid that the biological 'hardware' exists in. Biochemistry evolved within a hydraulic environment. It is logical that nature should use the hydraulic characteristics of pressure, levels, and turnover rates in the development and function of biological systems. I think this hydraulic hair growth adjustment mechanism demonstrates how 'biohydraulics' can create a beautifully simple and versatile response to environmental changes. A number of disease
processes could logically be linked to the hydraulic conditions within
tissues. Known gender differences in disease incidence support this
concept. The ability to 'adjust' the hydraulic conditions within tissues
could offer a significant therapeutic strategy against disease. It is,
therefore, important that the testing of the effects of Finasteride as
described, be performed by those with the necessary expertise. 1. Foote, S.I. Hair Growth and the Fluid Factor : Medical Hypotheses 44. 475-478, 1995. 2. PDR Entry/Propecia Tablets, (Merck & Co. Inc.) 1999. 3. Ebling F.J. Rook A. In : Rook A, Wilkinson D.S. and Ebling F.J., (EDS) Textbook of Dermatology, Blackwell, Oxford. 1979. 4. Hamilton, J.B., Male Hormone Stimulation is a Prerequisite and an Incitant in Common Baldness, Am. J. Anat. 1942, 71: 451-480. 5. Hamand, J. Prostate Problems. London: Thorsons, 1991. 6. Cabanac, M. Brinnell, H. Beards, Baldness, and Sweat Secretion. Eur. J. Appl. Physiol. 1988 58: 39-46. 7. Hinchliff, S., Montague, S., Physiology for Nursing Practice. London: Bailliere Tindall, 1991, 51. 8. Winwood, R.S., Smith, J.L., Anatomy and Physiology for Nurses. Edwards Arnold: London, 1985, 208. 9. Hinchliff, S. Montague, S. Physiology for Nursing Practice. London: Bailliere Tindall, 1991: 596. 10. Monthly Index of Medical Specialities, Haymarket Publishing Services; 1995, September. 272. 11. Janeway-Travers, Immuno Biology, Second Edition, 9:3, 1996. 12. Dechene, L. Chronic Fatique Syndrome: Influence of Histamine, Hormones and Electrolytes. Medical Hypotheses, 40: 55-66, 1993. 13. Janeway-Travers, Immuno Biology, Second Edition, 11:17, 1996. 14. Monthly Index of Medical Specialities. Haymarket Publishing Services; 1995 September. 198
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