Radiation-Induced Changes in Protein Content in the Brain Neurons

The aim of research was to study radiation-induced changes in the protein content in the brain neurons after exposure to small doses of ionizing radiation.

Material and methods. The study was performed in compliance with the rules of bioethics. The study included 300 male rats, aged 4 months at the beginning of the experiment, that were exposed to radiation in total doses of 0.1; 0.2; 0.5 and 1 Gy given as a single dose or fractionated (equal portions for 5 days with a dose rate of 0.5 and 6.6 Gy/h). Morphometric and tinctorial parameters of neurons and the dynamics of protein content in the brain neurons over the entire life span of animals were assessed using neuromorphological methods. The results obtained were statistically processed using software packages Statistica 6.1, which included parametric criteria and mathematical modeling.

Results. In animals of the control group and in animals exposed to radiation wave-like changes in the protein content in the brain neurons occurred during the whole life; in animals exposed to irradiation parameters of these changes gradually decreased by the end of the irradiation period. Regression analysis showed that irradiation in the studied doses had a nonlinear stochastic effect on the protein content in neurons, had no dose-time dependence and did not result in significant organic changes in the brain neurons. At the end of the experiment, with the death of both irradiated and control animals, the protein content in neurons was statistically significantly reduced in all groups, but to a greater extent in irradiated animals. Moreover, the greatest decrease in protein content was observed in the pear-shaped neurons of the cerebellar cortex, and the parietal cortex neurons were more resistant to the radiation factor in terms of protein content.

Conclusion. No significant radiation-induced changes in the content and topochemistry of histochemical reaction products were revealed when detecting protein in the structures of brain neurons. At the end of the experiment, the protein content in the neurons of the parietal cortex of the irradiated  animals practically correlated to that in animals of age control, and was statistically significantly reduced in other parts of the brain.

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