Tobi, Simon E. and Paul, Nigel and McMillan, Trevor J. (2001) Glutathione modulates the level of free radicals produced in UVA irradiated cells. Journal of Photochemistry and Photobiology B: Biology, 57 (2-3). pp. 102-112. ISSN 1011-1344
Full text not available from this repository.Abstract
We have developed an assay to detect reactive oxygen species (ROS) generated by UVA radiation utilising chemical probes which become fluorescent upon oxidation. Using a human bladder carcinoma cell line (MGH-U1) and spontaneously immortalised keratinocytes (HaCaT), we have shown a UVA (narrow band 365±5 nm) dose-dependent increase in fluorescence by flow cytometry following loading of the cells with either dihydrorhodamine 123 (DHR) or 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA). The UVA response of both DHR and DCFH was enhanced by elevation of intracellular levels of the photosensitiser protoporphyrin IX by incubation for 2.5 h with 5-aminolaevulinic acid. Depletion of the antioxidant glutathione (GSH) using the inhibitor -buthionine-sulphoximine (BSO), resulted in an increase in the UVA-induced fluorescence of DCF but not of rhodamine 123. Conversely, raising intracellular GSH levels with N-acetyl cysteine (NAC) had relatively little protective effect in terms of degree of induced fluorescence.