Lack of hair due to alopecia or skin grafting procedures causes significant distress due to hair's
role in social and sexual communication. Only limited pharmacological agents are currently
available to stimulate hair growth; their development is hampered by inappropriate model
systems. Most research involves large terminal scalp follicles rather than the clinical targets of
tiny vellus or intermediate follicles.
The overall aim of this thesis was to develop a novel model system based on intermediate hair
follicles. Initially, intermediate follicles from female pre-auricular skin were characterised and
compared to matched terminal follicles. Intermediate follicles were smaller, less pigmented,
shorter and possessed a more 'tubular' bulb morphology than their more 'bulbous' terminal
counterparts. Significant correlations were demonstrated between various hair follicle
measurements and corresponding dermal papilla diameters.
Isolated terminal follicles grew significantly more than intermediate hair follicles in organ
culture for 9 days. Testosterone (10nM), the major regulator of human hair growth, increased
only intermediate follicle growth; the anti-androgen, cyproterone acetate (1¿M), prevented
this stimulation, unlike the 5¿-reductase type 2 inhibitor finasteride (40ng/ml).
Immunohistochemistry demonstrated androgen receptor and 5¿-reductase type 2 proteins in
both follicle types, while quantitative real-time PCR and gene microarray analysis detected
their increased gene expression in intermediate follicles.
Thus, smaller intermediate follicles showed major morphological and gene expression
differences to terminal follicles in vivo and retained significant, biologically-relevant
differences in vitro in organ culture including androgen-responsiveness. Therefore, intermediate hair follicles offer a novel, exciting, more clinically relevant, albeit technically difficult, model for future investigations into hair growth.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/5731 |
| Date | January 2011 |
| Creators | Miranda, Benjamin H. |
| Contributors | Randall, Valerie A., Tobin, Desmond J. |
| Publisher | University of Bradford, Plastic Surgery and Burns Research Unit, Department of Biomedical Sciences |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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