[Modification of radiation damage to biological objects by lasers]

A series of experiments had the purpose to study effects of gamma-rays 60Co (5 Gy) and the combined effects of laser 650 nm (1 mJ/cm2) and gamma-rays 60Co (5 Gy) on survivability, body mass, integument and mitotic index of marrow cells (MC) of young mice C57BL/6. Laser was applied to the mouse hairy back only. Ten months of gamma-irradiation brought death to 50% of mice; the combined irradiation killed only 30%. Starting on month six after gamma-irradiation, body mass was less in comparison with mice exposed to the combined irradiation. In addition, all mice lost body mass sharply before death. All gamma-irradiated mice were touched with grey over the period of 30 days; in 40 days, 10 of 20 mice had incipient local radiation alopecia on the back that passed fully within next month. However, all mice developed radiation ulcers on the fourth month since irradiation. Two mice formed also neck tumors. In 5 months tails fell off in 2 mice. Some grey streaks appeared on mice exposed to the combined irradiation 3 months later only; three mice remained black throughout the follow-up. Alopecia was found in three survivors in 5 months after irradiation. Mitotic activity of marrow cells obtained from mice on day 15 since exposure to lasing and combined irradiation was higher in comparison with cells from intact mice. In a year, the MC mitotic index was higher in mice exposed to the combined irradiation as compared with the gamma-irradiated mice.