055 The Distribution of Estrogen Receptor beta (ERbeta) is Distinct to that of ERalpha and the Androgen Receptor in Human Skin and the Pilosebaceous Unit.

M J Thornton, A H Taylor1, K Mulligan1, F Al-Azzawi1, C C Lyon2, J O’Driscoll2 & AG Messenger3. Dept Biomedical Sciences, University of Bradford, UK, 1Dept Obstetrics & Gynaecology, Leicester Royal Infirmary, UK, 2Dept Dermatology, Hope Hospital, Salford, UK, 3Dept Dermatology, Royal Hallamshire Hospital, Sheffield, UK

Androgens and estrogens have significant and distinct roles in hair and skin physiology. However, the exact roles and sites of action of these molecules are currently unknown and the presence of an estrogen receptor (ER) in human skin by immunohistochemistry has been difficult to prove. The recent identification of a second estrogen receptor (ERß) with a distinctly different immunolocalisation profile to the classical ER (ERa), suggests separate specific roles for ERa and ERß. Therefore, we have examined the distribution of ERa and ERß and correlated their expression with the androgen receptor (AR) in human scalp skin from men and women by immunohistochemistry. 4mm paraffin-embedded sections were incubated with either mouse anti-human ERa (1:50), rabbit anti-human ERß (1:50) or mouse anti-human AR (1: 25) antibodies at 4°C overnight. After amplification with specific secondary antibodies and avidin-biotin complexes, immunoreactive sites were visualised with diaminobenzadine (DAB) staining and unstained nuclei identified with light haematoxylin counterstaining. Endometrium, ovary, prostate and testis were used as positive control tissues. No staining was observed in the absence of the primary antibody or an equivalent concentration of isotype mouse or rabbit IgG. AR was present only in dermal papilla cells and basal sebocytes, whereas ERa was only detected in sebocytes. By contrast, ERß was widely distributed and strongly expressed in the epidermis, sebaceous glands, eccrine glands, dermal papilla and outer root sheath. There appeared to be no differences in the expression pattern of ERß between men and women, suggesting that the expression of ERß is not gender specific. The widespread distribution of ERß in human skin and the pilosebaceous unit suggests it may play an important role in the maintenance of human skin and the regulation of the pilosebaceous unit.