Cellular basis of differences in radiosensitivity of different strains of mice

A comparison of data pertaining to quantity and radiosensitivity of cells of the stem type in hemopoietic tissues of BALB/c and CBA mice, which differ in overall radiosensitivity (LD/sub 50///sub 30/ constitutes 579 and 761 rad, respectively), failed to demonstrate any appreciable differences. Investigation of the rate of recovery of CFU (colony forming unit) population, dynamics of cellularity of hemopoietic organs and amount of peripheral blood leukocytes in these strains of mice led to the conclusion that the greater radioresistance of CBA mice is based on faster proliferation of stem cells following irradiation of the animals.