LOCALIZATION OF ANDROGEN RECEPTORS IN HUMAN SKIN BY IMMUNOHISTOCHEMISTRY - IMPLICATIONS FOR THE HORMONAL-REGULATION OF HAIR-GROWTH, SEBACEOUS GLANDS AND SWEAT GLANDS

A mouse monoclonal antibody against the N-terminal region of human androgen receptor (AR) was used to identify receptors by immunoperoxidase staining in frozen serial sections of skin from scalp, face, limb and genitalia of men and women aged 30-80 years. AR staining was restricted to cell nuclei. In sebaceous glands, AR were identified in basal and differentiating sebocytes. The percentage of receptor-positive basal sebocyte nuclei in the temple/forehead region was greater in males (65%) than in females (29%). AR staining was restricted to the cells of dermal papillae in anagen and telogen hair follicles. The percentage of dermal papillae containing AR was greater in males (58%) than in females (20%). The number of positively stained dermal papillae was lowest in female scalp skin. In 163 hair follicles sectioned, AR were absent from germinative matrix, outer root sheath (including the bulge region), inner root sheath, hair shaft and hair bulb, and from the capillaries present in some large dermal papillae. AR were present in pilosebaceous duct keratinocytes, suggesting that androgens may influence pilosebaceous duct keratinization. AR were also identified in interfollicular epidermal keratinocytes and dermal fibroblasts although, in both cell types, intensity and frequency of staining were greatest in genital skin. AR were identified in luminal epithelial cells of apocrine glands in genital skin and in certain cells of the secretory coils of eccrine sweat glands in all body sites. This study indicates that androgens regulate sebaceous gland and hair growth by acting upon two different types of target cells, the epithelial sebocytes of sebaceous glands and the mesenchymal cells of the hair follicle dermal papilla. AR staining in either cell type was not influenced by age in adults. The distribution of AR in human skin is consistent with the diverse effects of androgens on the structure and function of skin and its appendages.