Spin-trapping of free radicals during phthalocyanine photosensitization of lymphoma cells in vitro.
Spin-trapping and electron spin resonance (ESR) spectroscopy were used to detect free radicals generated during light exposure of lymphoma cells sensitized in vitro by metallotetrasulfophthalocyanines (Al-PcS4 and Zn-PcS4). 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) and alpha-phenyl-beta-tert-butylnitrone (PBN) were used as spin-trapping agents. Hydroxyl radical spin-adducts were detected under conditions of both extracellular and intracellular photosensitization. In addition, organic radicals of different origin and/or variable yields were trapped, depending on the photosensitization conditions and the spin-trap used. For comparison, analogous experiments were carried out with another tumor-localizing photosensitizer, Photofrin II.
Gantchev
T G
TG
Department for Cell and Molecular Biology of Cancer, National Centre of Oncology, Sofia, Bulgaria.
D002051:Burkitt Lymphoma / Q000188:drug therapy* / Q000378:metabolism; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005110:Extracellular Space / Q000378:metabolism; D005609:Free Radicals; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007424:Intracellular Fluid / Q000378:metabolism; D009589:Nitrogen Oxides; D009942:Organometallic Compounds / Q000494:pharmacology; D010778:Photochemotherapy; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D013113:Spin Labels; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D003497:Cyclic N-Oxides; D005609:Free Radicals; D007211:Indoles; D009589:Nitrogen Oxides; D009942:Organometallic Compounds; D011838:Radiation-Sensitizing Agents; D013113:Spin Labels; C048577:aluminum tetrasulfophthalocyanine; C029217:phenyl-N-tert-butylnitrone; C052735:zinc tetrasulfophthalocyanine; C017245:5,5-dimethyl-1-pyrroline-1-oxide