| Abstrakt: |
UV irradiation of the human skin leads to induction of oxidative stress and inflammation mediated by reactive oxygen radicals, lipid peroxidation, liberation of arachidonic acid from membrane phospholipids and formation of prostaglandins and leucotrienes. We investigated lipid mediators, such as F2-isoprostanes (8-iso-PGF2α, 9α,11α-PGF2α) and monohydroxyeicosatetraenoic acids (HETEs)in the dermal interstitial fluid obtained by a cutaneous microdialysis technique. Defined areas on the volar forearm of 10 healthy volunteers were exposed to UVB irradiation (2060 mJ/cm2). Microdialysis membranes were cutaneously inserted beneath the irradiated area. The probes were perfused with isotonic saline solution, and microdialysate samples were collected at 20-min intervals up to 45 h. Oxidized arachidonic acid derivatives (2-, 3-, 5-, 812- and 15-HETEs, 8-iso-PGF2α and 9α,11α-PGF2α) could be detected and quantified in microdialysates of normal skin in the picomole (HETEs) and femtomole (isoprostanes) range and after UVB irradiation using sensitive gas chromatography-mass spectrometry/negative ion chemical ionization. UVB irradiation enhanced the levels of 8-iso-PGF2α after 24 h significantly, whereas the HETE levels were slightly increased within shorter time intervals (3 h after UVB irradiation). Further investigations have to show whether these new findings are relevant to validate therapeutic strategies for topical and systemic UV prevention agents or for monitoring of specific therapeutic strategies in inflammatory skin disorders.Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR] |
