title: A confocal microscopy study of the very early cellular response to oxidative stress induced by zinc phthalocyanine sensitization.
abstract: Oxidative stress has been involved in several biological and pathological processes. Reactive oxygen species have been shown to play both beneficial and deleterious roles. The present work contributes to the understanding of the very early events of cellular response to oxidative stress. Oxidative stress was produced intracellularly by light activation of zinc phthalocyanine (ZnPc) at a light dose that did not lead to apoptosis or necrosis. Phthalocyanine was photoactivated using the 647-nm laser line of a confocal microscope through the objective lens causing oxidative stress and allowing observation of the evoked phenomena at the single cell level and in real time. Mitochondria membrane potential (DeltaPsi(m)), intracellular pH, calcium concentration, and generation of reactive oxygen species (ROS) were recorded using specific vital fluorescent probes and quantified by image processing and analysis. Subcellular localization of ZnPc was also studied in order to determine the primary and intermediate ROS target.
authors.affiliation: Applied Biophysics and Biomedical Optics Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, 157 73 Zografou Campus, Athens, Greece. ealexan@central.ntua.gr
authors.forename: Eleni
authors.initials: E
authors.lastname: Alexandratou
authors.forename: Dido
authors.initials: D
authors.lastname: Yova
authors.forename: Spyros
authors.initials: S
authors.lastname: Loukas
mesh_terms: D002118:Calcium / Q000032:analysis; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000032:analysis / Q000494:pharmacology; D054833:Isoindoles; D008564:Membrane Potentials / Q000187:drug effects; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000737:chemistry / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000737:chemistry / Q000187:drug effects / Q000502:physiology; D009942:Organometallic Compounds / Q000032:analysis / Q000494:pharmacology; D018384:Oxidative Stress; D017319:Photosensitizing Agents / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism*; D017967:Zinc Compounds
chemical_list: D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine; D002118:Calcium