The answer to neutron radiation of different exposure time was demonstrated in nuclei of isolated human buccal epithelial cells by the method of assessment of the degree of chromatin condensation. As a neutron radiation source two sources Pu-Be IBN-17 (Russia) have been used. The range of emitted neutrons energies was 100 keV - 10 MeV, the neutron flux 5 * 107 n/s, the irradiation was isotropic. Cell samples were exposed to radiation during 1 - 64 minutes. Exposed cells were stained with 2% orcein in 45% acetic acid. The content of the heterochromatin granules quantity (HGQ) was counted in nuclei of 100 cells, and the mean number of HGQ per nucleus was determined as a measure of chromatin condensation. The nonlinear dependence of chromatin condensation in the nuclei (cell stress reaction) from irradiation time was observed. The maximum value of HGQ reached after 16-minute exposure, further increase of the exposure time lead to decrease of HGQ. The data has been analyzed for compliance with the single- and double-hit models of the Poisson distribution, as well as the Gaussian and Wigner distributions. It is found that the Poisson distribution as a model of radiation impact reflects changes in cell reaction of chromatin condensation most accurately.
cell stress, heterochromatin, neutron radiation, Gauss distribution
1. Kudryashov Yu.B. Radiacionnaya biofizika (ioniziruyuschie izlucheniya). M.: FIZMATLIT, 2004, 448 s. [Kudryashov Y.B. Radiation Biophysics (ionizing radiation). M.: FIZMATLIT, 2004, 448 p. (In Russ.)]
2. Petrashova D.A., Belisheva N.K., Pelevina I.I., Mel'nik N.A., Zol'zer F. Genotoksicheskie effekty v bukkal'nom epitelii gornyakov, rabotayuschih v usloviyah oblucheniya prirodnymi istochnikami ioniziruyuschego izlucheniya. Izv. Samar. NC RAN, 2011, t.13, s.1792-1796. [Petrashova D.A., Belisheva N.K., Pelevin I.I., Miller N.A., Zolzer F. Genotoxical effects in buccal epithelia at miners, working in the conditions of irradiation by natural sources of ionizing radiation. Bul. Samara SC., 2011, v.13, pp.1792-1796.]
3. Gong-Min Chang, Ya-Bing Gao, Shui-Ming Wang [et al.] Protecting Intestinal Epithelial Cell Number 6 against Fission Neutron Irradiation through NF-kB Signaling Pathway. BioMed Research International, 2015, vol. 2015, article ID 124721, 8 pages.
4. Heber E.M., Hawthorne M.F., Kueffer P.J., Garabalino M.A. [et al.] Therapeutic efficacy of boron neutron capture therapy mediated by boron-rich liposomes for oral cancer in the hamster cheek pouch model. PNAS, 2014, vol. 111, pp. 16077-16081.
5. Shckorbatov Y. The state of chromatin as an integrative indicator of cell stress. In: New Developments in Chromatin Research, Editors: Neil M. Simpson and Valerie J. Stewart. Chapter 6. Nova Science Publishers, Inc. New York, 2012, pp. 123-144.
6. Kuznetsov K.A., Kyzym P.S., Onishchenko G.M., Berezhnoy A.Y., Shckorbatov Y.G. [et al.] Chromatin changes under exposure to neutron radiation. Proceedings of the International Conference "Advances in cell biology and biotechnology", Lviv, 11-13 October 2015, p. 83.
7. Shckorbatov Y.G., Shakhbazov V.G., Bogoslavsky A.M., Rudenko A.O. On age-related changes of cell membrane permeability in human buccal epithelium cells. Mech. Ageing Develop, 1995, vol. 83, pp. 87-90.
