Total body exposure to ultraviolet radiation does not influence plasma levels of immunoreactive beta-endorphin in man.
OBJECTIVE
A growing number of reports support evidence of proopiomelanocortin (POMC)-derived peptides in human skin cells, although not consistently. Also the effect of ultraviolet radiation (UVR) on cutaneous and plasma levels of these POMC peptides has not been established unequivocally. We hypothesized that production of beta-endorphin (betaE) may explain the sense of well-being many people experience when sun-bathing. The aim of the present study was to investigate whether exposure of the skin to UVR elevates plasma betaE.


METHODS
Healthy volunteers (n=26) received a single, weighted dose of 15 J/cm2 of UVA. Several times during the hour following irradiation, plasma betaE- immunoreactivity (betaE-IR) was determined by radioimmunoassay. The effect of repeated exposure was assessed in 35 patients treated with UVB, UVA, or UVA-1. Plasma ACTH-IR was monitored in parallel.


RESULTS
Overall, plasma levels of betaE-IR and ACTH-IR showed no significant changes during the experiment, indicating that these peptides are not influenced by single or repeated exposures to UVR of different wavelengths.


CONCLUSIONS
On the basis of these results, the skin does not appear to contribute significantly to the levels of circulating betaE or ACTH. These data offer no support for the hypothesis that exposure to UVR leads to an increased concentration of circulating betaE, which could contribute to the feeling of well-being that often accompanies sun-bathing.
Wintzen
M
M
Department of Dermatology, Leiden University Medical Center, Leiden, the Netherlands. mwintzen@knmg.nl
Ostijn
D M
DM
Polderman
M C
MC
le Cessie
S
S
Burbach
J P
JP
Vermeer
B J
BJ
D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000276:immunology; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D011863:Radioimmunoassay; D012867:Skin / Q000528:radiation effects*; D014466:Ultraviolet Rays; D001615:beta-Endorphin / Q000097:blood* / Q000276:immunology / Q000528:radiation effects
D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone