Radiation-Induced Changes in Nucleic Acids of Brain Neurons

Abstract

Purpose: Study of radiation-induced changes in the content of nucleic acids in neurons of the brain after exposure to ionizing radiation in doses of 0.1 – 1.0 Gy. Material and methods. The study was carried out in compliance with the rules of bioethics on 240 white outbred male rats at the age of 4 months. by the beginning of the experiment, exposed to a single exposure to γ-radiation of 60Co in doses of 0.1–1.0 Gy. Neuromorphological methods were used to assess morphometric and tinctorial parameters of nerve cells, as well as the dynamics of changes in the content of nucleic acids in neurons during the entire life span of animals. Statistical processing of the results was carried out using the Statistica 6.1 software packages, using parametric criteria. Results: In control and irradiated animals throughout their life, there are undulating changes in the content of nucleic acids in the neurons of the brain with a gradual decrease in indicators by the end of the experiment. At the same time, changes in the level of DNA in the nuclei and RNA in the nucleoli are usually associated with changes in the size of the structures of their localization, and the RNA content in the cytoplasm is apparently associated with changes in the physiological state of neurons (rest, excitation, inhibition) and the corresponding structural and functional rearrangement of nerve cells. Nucleic acid changes do not have a linear dose and time dependence on the factors investigated. At the end of the experiment, when death of both irradiated and control animals is observed, the content of nucleic acids in neurons is statistically significantly reduced in all groups, and to a greater extent in irradiated animals. Conclusion: No functionally significant radiation-induced changes in the content and topochemistry of the products of histochemical reactions were revealed in the detection of nucleic acids in the structures of brain neurons. However, in some periods of observation, the content of nucleic acids in neurons in irradiated animal’s changes to a greater extent than in animals of age control.