title: Differential modulation of inflammatory markers in plasma and skin after single exposures to UVA or UVB radiation in vivo.
abstract: BACKGROUND
  Solar light generates inflammatory responses in exposed skin. These effects are generally attributed to UVB light. However, skin is expose d to a huge quantum of UVA photons as UVA is a predominant part of sunlight and the radiation used in tanning beds. We examined the effects of a single exposure to UVA and UVB wavebands on cytokine levels in skin and plasma, myeloperoxidase (MPO) activity, expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) in skin.
  
  
  METHODS
  Hairless mice were irradiated with either UVA (10 or 20 J/cm²) or UVB (200 or 800 mJ/cm²). The effects were assessed after 4/24 h. Plasma cytokine levels were evaluated using a Bio-Plex cytokine assay. Cytokine, iNOS and COX-2 levels in skin were determined by Western blot. Skin MPO activity was monitored spectrophotometrically.
  
  
  RESULTS
  UVB induced up-regulation of interleukin-1β (IL-1β) and interleukin-6 (IL-6) and decrease in interleukin-10 (IL-10) mainly after 4 h. In contrast, UVA caused increase in levels of tumor necrosis factor-alpha (TNF-α) and IL-6 after 4 h and up-regulated IL-10 and interleukin-12 (IL-12) after 24 h. The increase in MPO activity from infiltrated leucocytes was observed only in UVB irradiated animals. iNOS was up-regulated 4 h after UVA and UVB treatment. No significant effect on COX-2 expression was detected.
  
  
  CONCLUSIONS
  UVA and UVB light affected several inflammatory markers. For individual waveband, changes in plasma parameters did not correlate with those in skin. Thus evaluation of plasma samples cannot simply be replaced by determination in skin specimens and vice versa.
authors.affiliation: Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Vostalova
authors.forename: Alena
authors.initials: A
authors.lastname: Rajnochova Svobodova
authors.forename: Adela
authors.initials: A
authors.lastname: Galandakova
authors.forename: Jarmila
authors.initials: J
authors.lastname: Sianska
authors.forename: Dalibor
authors.initials: D
authors.lastname: Dolezal
authors.forename: Jitka
authors.initials: J
authors.lastname: Ulrichova
mesh_terms: D000818:Animals; D015153:Blotting, Western; D051546:Cyclooxygenase 2 / Q000378:metabolism / Q000528:radiation effects; D016207:Cytokines / Q000097:blood / Q000528:radiation effects; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism / Q000528:radiation effects; D009195:Peroxidase / Q000378:metabolism / Q000528:radiation effects; D012867:Skin / Q000378:metabolism / Q000528:radiation effects; D013053:Spectrophotometry; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D016207:Cytokines; D009195:Peroxidase; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2