[Changes in chromatin conformation induced by ionizing radiations with different LETs in resting and proliferating...

The method of flow cytometry was used to study conformation changes in rat hepatocyte chromatin exposed to various doses of X-rays and fission neutrons (mean energy of 0.85 MeV). Chromatin decondensation induces by both X-rays and neutrons was shown to be a function of dose. The saturation effect was observed for X-rays doses ranging from 4 to 6 Gy; for fission neutrons no saturation effect was noted within the dose range from 0.5 to 4 Gy. The initial chromatin level, that changed during the cell cycle and upon ageing, influence induction of conformation changes in the chromatin. The authors discuss the dependence of the processes of repair and fixation of damages to hereditary cell structure on the chromatin conformation at the time of exposure.