Effects of continuous gamma irradiation on nucleic acids in rat blood

Effects of continuous gamma irradiation on quantitative changes of nucleic acids in rat blood as well as on 3H-thymidine incorporation into leucocytes (in vitro) have been investigated. Irradiation was administered for periods ranging from 3 to 11 days with dose rates of 10 or 100 R/d. At both dose rates the character of changes in the blood was identical, though it was more distinct with the higher dose rate. The concentration of nucleic acids in blood leucocytes decreased only after the seventh day of irradiation with 100 R/d. At the same time, the quantity of DNA per leucocyte of the irradiated animals gradually increased with growing radiation dose. Proceeding from the increased incorporation of 3H-thymidine it is supposed that continuous irradiation causes an increase of the relative number of incomplete blood cells, which have a greater capacity for 3H-thymidine incorporation. (author)