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Presence of immunoreactive β‐endorphin in human skin

2001; Wiley; Volume: 10; Issue: 5 Linguagem: Inglês

10.1034/j.1600-0625.2001.100502.x

1600-0625

Marjolein Wintzen, Sara Winter, Jacoba J. Out‐Luiting, Sjoerd G. van Duinen, B.J. Vermeer,

Skin Protection and Aging

The production and its induction by ultraviolet radiation (UVR) of proopiomelanocortin (POMC)-derived peptides by keratinocytes has been reported, albeit not consistently. Recently we demonstrated that only under specific culturing conditions human keratinocytes are capable of producing a beta-endorphin (betaE)-like peptide with the characteristics of beta-lipotropin (betaLPH). Here the presence and UV-induction of betaE-immunoreactivity (betaE-IR) in keratinocytes in human skin in vivo was investigated. betaE-IR was detectable by immunohistochemistry in keratinocytes of the follicular matrix and to some extent in cells of sweat ducts, but was absent from epidermal keratinocytes. Absence of betaE-IR was confirmed by radioimmunoassay of HPLC-fractionated extracts of normal epidermis. Repeated exposure to solar-simulated UVR had no effect. This investigation is the first to demonstrate the presence of betaE-immunoreactive material in the follicular matrix of corporal hairs and in duct cells of sweat glands. The possible meaning of these results is discussed.