Radiation-induced changes in lung tissue and the size of rat blood nanoparticles in the early long-term period after irradiation

Objective. To evaluate the effect of local chest X-ray irradiation on the histological picture of lung tissue and the size profile of blood nanoparticles in young rats in the early long-term period after irradiation.

Materials and methods. A single local irradiation of 6-month-old Wistar rats was performed using a biological X-ray machine X-RAD 320 Precision X-ray Inc at doses of 0.1, 1 and 15 Gy. After a 3-week post-radiation period, the sizes of nanoscale blood particles were measured by dynamic light scattering method; a histological examination of the rats’ lungs, non-irradiated and irradiated, was performed.

Results. With increase of the absorbed dose from 0.1 to 15.0 Gy, interstitial edema increases with infiltration by lymphocytes and neutrophils, and with the simultaneous formation of interstitial pneumonia and bronchopneumonia (15 Gy), the stroma/parenchyma ratio increases (rs= 0.365; p=0.001), the size of nanoparticles in the blood increased significantly after irradiation of young rats with a dose of 15 Gy. A conducted comparative analysis of the effects of ionizing radiation on young and mature rats revealed that if a young organism is prone to a more acute, destructive inflammatory reaction, then the body in adulthood triggers the mechanisms of chronic inflammation and fibrosis faster, which in the long term increases the likelihood of severe respiratory failure.

Conclusion. It was found that age is a critical factor determining the severity of radiation damage to the lungs. The experimental data obtained can serve as a theoretical basis for assessing radiation damage, taking into account the age of the body, helping to minimize the risks of radiation therapy and various radioecological disasters.

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