Occurrence of singlet oxygen oxygenation of oleic acid and linoleic acid in the skin of live mice

Department of Food Science, Graduate School of Nutrition and Bioscience, The University of Tokushima, Tokushima, Japan.
Free Radical Research (Impact Factor: 2.98). 04/2008; 42(3):197-204. DOI: 10.1080/10715760801948088
Source: PubMed


To assess the contribution of singlet molecular oxygen [O(2) ((1)Delta(g))] to lipid peroxidation in vivo, this study combined gas chromatography-mass spectrometry with thin layer chromatography to analyse peroxidized lipids in the skin of hairless mice. Hydroxyoctadecenoate isomers and unconjugated hydroxyoctadecadienoate isomers derived from peroxidized oleic acid and linoleic acid, respectively, which are specific to O(2) ((1)Delta(g))-dependent oxygenation, were detected in the skin of live mice under ordinary feeding conditions. Short-term ultraviolet A (UVA)-irradiation of the skin in vivo elevated levels of the unconjugated hydroxyoctadecadienoate isomers significantly, whereas the irradiation of skin homogenate in vitro increased levels of all isomers derived from both O(2) ((1)Delta(g)) and free radical-dependent oxygenation to a much greater extent. This is the first report to demonstrate the occurrence of O(2) ((1)Delta(g))-specific oxygenation of unsaturated fatty acids in living animals.

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    • "O2 (1Δg) oxygenation-specific lipid hydroperoxide isomers appeared in the peroxidized phospholipids of mouse skin homogenate after irradiation with UVA light.(31) We recently developed a new method for the gas chromatography-mass spectrometry (GC-MS) analysis of esterified fatty acid hydroperoxides, and demonstrated that O2 (1Δg) oxygenation–specific hydroperoxides isomers accumulated in the skin lipids of hairless mice at higher levels due to the exposure of UVA.(32) These animal studies clearly indicated that O2 (1Δg) originating from type-II photosensitized oxidation participates in the oxidative stress and injury to the skin seen after chronic exposure to UVA. "
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