Regulation of human skin pigmentation in situ by repetitive UV exposure - Molecular characterization of responses to UVA, UVB and SSR

To test the hypothesis that different mechanisms and/or factors might be involved in physiological pigmentary responses of the skin to different types of UV, we used whole human genome microarrays and immunohistochemical analyses to characterize human skin in situ to examine how melanocyte-specific proteins and paracrine melanogenic factors are regulated by repetitive exposure to suberythemal doses of different types of UV (UVA, UVB or SSR). Six volunteers with skin type II-III were irradiated with SSR, UVA or UVB radiation for 2 weeks (5 times per week, 10 times total) after preliminary determination of their MEDs. Biopsies were taken 3 days after the last irradiation.