Features of the Effects of Exposure to 90–170 MeV Proton Radiation on the Blood-Forming Organs in Mice under Total Irradiation with Proton Pencil Scanning Beam Depending on the Linear Energy Transfer of Particles

Abstract

The effect of proton radiation on the induction of cytogenetic damage in the bone marrow, the production of reactive oxygen species in whole blood, and the state of the thymus and spleen depending on linear energy transfer were studied during total irradiation of mice before the Bragg peak and at the peak in the dose range 0.1–1.5 Gy. It was found that the yield of polychromatophilic erythrocytes with micronuclei at all doses of proton radiation at the Bragg peak with a linear energy transfer of 2.5 keV/μm was close to the level of linear energy transfer with micronuclei for the corresponding doses of X-ray radiation with a linear energy transfer of 2.0 keV/μm; while when irradiated before the Bragg peak with a linear energy transfer of 0.7 keV/μm, the level of cytogenetic damage was significantly lower. The coefficient of relative biological effectiveness of proton irradiation calculated from the linear energy transfer by estimating micronuclei frequency at the Bragg peak was 1.15, and before the peak it was 0.63. Organ-specific differences in the patterns of pathophysiological effects were revealed, depending on the dose and linear energy transfer of protons on the thymus and spleen of mice, as well on the state of the antioxidant system of blood cells.