['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.', '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.', '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.'] Does total body exposure to ultraviolet radiation influence plasma levels of immunoreactive beta-endorphin in man?