Integrated interrelations of connective tissue parameters during the rats’ body response to local irradiation

Objective. To establish histological changes in lung tissue and the interrelationship of these changes with the properties of nanoscale blood particles in laboratory animals caused by local irradiation of their upper torso with X-rays.

Materials and methods. Local irradiation of Wistar rats was carried out using a X-RAD 320 Biological Irradiator (Precision X-Ray, USA) in doses of 0.1, 1, and 15 Gy. After a 3-week post-irradiation period, the activity of catalase and superoxide dismutase, sizes and zeta-potential of nanoparticles were measured in blood; a histological analysis of the lungs was carried out for rats non-irradiated and irradiated by various X-rays doses.

Results. A semi-quantitative assessment of the pulmonary fibrosis progression showed an increase in the fibrosis grade depending on the irradiation dose (rs = 0.5531, p˂0.0001). In the blood of irradiated animals, the size and zeta potential of nanoscale particles increased significantly after irradiation of rats with a dose of 0.1 Gy (p < 0.05). The activities of superoxide dismutase and catalase in the irradiated rat’s blood changed non-monotonically depending on the dose.

Conclusion. In the experimental animal model, significant changes in the body state were found after irradiation with a low dose (0.1 Gy) at different hierarchical levels. The changes are more pronounced in the blood antioxidant system and the system of nanoparticles of blood, less — at the level of composition and structure of the organ (lung). Further study of radiation and induced changes of blood nanoparticles is advisable not only to deepen the understanding of mechanisms of development of post-radiation pathological conditions but also to evaluate the efficacy of new radioprotective drugs in an experiment with a view to their subsequent introduction into clinical practice.

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