The Radioprotective Effects of Low-Intensity Laser Radiation on Rat Peripheral Blood Cells

Abstract—The radioprotective effect of low-intensity laser radiation on blood cells was studied on Wistar rats. The following procedures was carried out: single total body γ-radiation (dose of 3 Gy) of rats; over-vein irradiation with continuous laser radiation (λ = 670 nm); and combined γ- and laser irradiation, which varied among different series of experiments according to the number of procedures and the energy density of the laser radiation (2.5 J/cm², 1.25 J/cm²). The influence of γ- and laser radiation on the number of peripheral blood cells in rats, the activity of antioxidant defense enzymes (superoxide dismutase and catalase), and on the blood absorption spectra in regions sensitive to its oxygenation were studied. On the 4th day after γ-irradiation, the radioprotective effect of low-intensity laser radiation was manifested as an increase in the average number of leukocytes (up to 1.4 times) and lymphocytes (up to 1.8 times) in comparison with reduced γ-irradiation, in an increase in the relative lymphocyte proportion in the leukocyte population (up to 1.5 times), and in an increase in the activities of catalase and superoxide dismutase, which were decreased by the γ-irradiation. It was found that the changes in the number of erythrocytes, leukocytes, lymphocytes, and superoxide dismutase activity initiated by γ-radiation alone and by combined laser and γ-radiation differed in individual rats and depended on individual initial values. The molecular mechanisms of the observed photo-radiobiological effects are discussed.