Lipids extracted from the skin of C57BL/6J mice injected subcutaneously with α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) and exposed to topical protoporphyrin IX (PPIX) and visible light had significantly higher levels of POBN spin adducts compared with dark PPIX exposed or vehicle-treated controls. Computer analysis of the POBN adduct electron paramagnetic (spin) resonance (EPR) spectra indicated that two radical species were present in each extract, one of which was a lipid-derived carbon-centered adduct (1, aN = 14.8 G and aH = 2.6 G), whereas the other (2, aN = 13.8 G and aH = 1.8 G) was probably oxygen centered. Adduct 2 was present in greater proportion in lipids extracted from PPIX/light-exposed mice compared with dark or vehicle-treated controls. These findings suggest that PPIX/light generates free radicals in mouse skin, thus providing a radical mechanism for PPIX-induced photosensitivity. Our approach may be useful for the detection of free radicals generated by other skin photosensitizers and may also provide a means for testing putative skin-protecting agents.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 82 • No. 3