title: Photodynamic effect of Radachlorin on nerve and glial cells.
abstract: BACKGROUND
  Radachlorin, a chlorine-derived photosensitizer, is used currently in photodynamic therapy (PDT) of skin cancer. In this work we studied Radachlorin-PDT effect on peripheral nerve and glial cells that are damaged along with tumor tissue.
  
  
  METHODS
  We used simple model objects - a crayfish stretch receptor that consists of a single sensory neuron surrounded by glial cells and crayfish nerve cord consisting of nerve fibers and ganglia. Radachlorin absorption and emission spectra were registered using spectrophotometer and spectrofluorimeter. Radachlorin accumulation and intracellular localization were studied using the fluorescence microscope. Necrotic and apoptotic cells were visualized using propidium iodide and Hoechst 33342. Neuronal activity was registered using standard electrophysiological methods.
  
  
  RESULTS
  Radachlorin absorption spectrum in the physiological van Harreveld saline (pH 7.3) contained maximums at 420 and 654nm. Its fluorescence band 620-700nm had a maximum at 664nm. In the crayfish stretch receptor Radachlorin localized predominantly to the glial envelope and penetrated slightly into the neuron body and axon. Radachlorin rapidly accumulated in the crayfish nerve cord tissue within 30min. Its elimination in the dye-free solution occurred slower: 11% loss for 2h. Radachlorin-PDT inactivated the neuron and induced necrosis of neurons and glial cells and glial apoptosis at concentrations as low as 10(-10)-10(-9)M.
  
  
  CONCLUSIONS
  Radachlorin rapidly accumulates in the nervous tissue, mainly in glial cells, and demonstrates very high photodynamic efficacy that characterize it as a promising photosensitizer.
authors: A.B. Kogan Research Institute for Neurocybernetics, Southern Federal University, Rostov-on-Don 344090, Russia.
authors: M A
authors: MA
authors: Neginskaya
authors: A.B. Kogan Research Institute for Neurocybernetics, Southern Federal University, Rostov-on-Don 344090, Russia.
authors: E V
authors: EV
authors: Berezhnaya
authors: Department of Biophysics and Biocybernetics, Southern Federal University, Rostov-on-Don 3440290, Russia.
authors: M V
authors: MV
authors: Rudkovskii
authors: Department of Biophysics and Biocybernetics, Southern Federal University, Rostov-on-Don 3440290, Russia.
authors: S V
authors: SV
authors: Demyanenko
authors: Department of Biophysics and Biocybernetics, Southern Federal University, Rostov-on-Don 3440290, Russia. Electronic address: auzd@yandex.ru.
authors: A B
authors: AB
authors: Uzdensky
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D003400:Astacoidea; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D011166:Porphyrins / Q000008:administration & dosage* / Q000493:pharmacokinetics*
chemical_list: D004338:Drug Combinations; D017319:Photosensitizing Agents; D011166:Porphyrins; C000593241:bremachlorin
keywords: Apoptosis; Glia; Necrosis; Neuron; Photodynamic therapy; Radachlorin