Interaction between dermal papilla cells and follicular epithelial cells in vitro: effect of androgen.

In a study from 1995, researchers investigated the role of testosterone in human hair follicles by examining the presence of androgen receptors and the effects of testosterone on cell proliferation. They found that androgen receptors were present in the dermal papilla cells of beard and axillary hair, but not in occipital scalp hair follicles. Testosterone did not stimulate the proliferation of either outer root sheath cells or dermal papilla cells when cultured alone. However, when outer root sheath cells were co-cultured with beard or axillary dermal papilla cells, without direct contact, testosterone significantly stimulated their proliferation. This effect was concentration-dependent and could be blocked by cyproterone acetate. The results suggest that dermal papilla cells from beard and axillary hair follicles produce diffusible growth factors in response to androgens, which then promote the growth of follicular epithelial cells.