Presence of immunoreactive beta-endorphin in human skin.
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.
Wintzen
M
M
Department of Dermatology, Leiden University Medical Center, The Netherlands. mwintzen@knmg.nl
de Winter
S
S
Out-Luiting
J J
JJ
van Duinen
S G
SG
Vermeer
B J
BJ
D000328:Adult; D004817:Epidermis / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011863:Radioimmunoassay; D012867:Skin / Q000378:metabolism* / Q000528:radiation effects; D014466:Ultraviolet Rays; D001615:beta-Endorphin / Q000378:metabolism*
D001615:beta-Endorphin