[Seasonal radiosensitivity of rats and dogs]

The data are submitted obtained on 10.5 thousands Wistar rats and 350 mongrel dogs exposed to gamma-radiation (LD40-LD100) in different seasons. The radiosensitivity of both animal species was the highest in autumn (August and September) and the lowest in winter (February and January). The seasonal DMF for rats and dogs with LD16, LD50 and LD84 was 1.24 and 1.31, 1.13 and 1.17 and 1.04 and 1.07, respectively. The curves for seasonal radiosensitivity of dogs with LD84, LD50 and LD16, exhibited a single--phase character throughout a year. For rats, the seasonal radiosensitivity curves with LD84 were single-phase, and the curve with LD50, and particularly LD16, exhibited the second peak of radioresistance in June. The increase in radioresistance of rats and dogs correlated with the increase in number of leukocytes in the peripheral blood of animals.