Duz E.V., Kolosov M.S., Uzdenky A.B.
Southern federal university
At present, photodynamic therapy of brain tumors is developed. However, normal neurons and glial cells are damaged along with destruction of tumor cells. Therefore, mechanisms of photodamage and protection of normal cells have to be studied. For this purpose, we investigated photodynamic damage of glial cells in the model object - the crayfish nerve cord. The isolated nerve cord preparation was photosensitized with alumophthalocyanin Photosens (1 mM, 1 hour incubation), and irradiated 30 min with a diode laser (670 nm). To visualize cell nuclei, the preparation was fluorochromed by propidium iodide and Hoechst 33342, which reveal nuclei of necrotic and living cells. The nerve fibers in the ventral nerve cord are surrounded by numerous glial cells whose nuclei are distributed rather uniformly. After incubation for 1 and 9 hours in the darkness, the level of glial necrosis in control preparations was 3 and 15%, respectively. At 1 hour after photodynamic treatment it increased to 55%, and at 9 hour – to 90%. In control preparations the density of distribution of glial cells within ganglia and connectives was 7000 mm . It increased to 10000 mm at 1 hour after photodynamic treatment, and to 14000-15000 mm after 5 hours. Later, at 9 hour after the treatment it dropped to 11000 mm in ganglia but not in connectives. The mean distance between glial nuclei was 100 μm. It remained unchanged during post-treatment incubation. One can suggest that the observed increase in the density of glial cells after photodynamic treatment resulted from proliferation of some glial precursors directed to compensation of the cell damage and loss.
The work was supported by the President grant for young scientists МК-6042.2010.4.
Mr. Evgeny Duz
Department of Biophysics and Biocybernetics, Southen federal university, laboratory assistant
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