[The role of the thymus gland in the development of adaptation reactions of the immune system during fractionated low-level gamma irradiation].

: In experiments with normal and thymectomized rats it has been revealed that exposure of normal animals to 0.35 Gy of gamma-radiation induces changes in blood cells subsets, depression of NK functional activity, decrease in polymorphonuclear leukocyte basal chemiluminescence level, suppression of the delayed type of hypersensitivity reaction and stimulation of local IgE-synthesis in respiratory organs. At the same time irradiation of adult thymectomized animals did not resulted in significant fluctuations in cellular and humoral immunity indices as well as blood cells functional activity level. Some mechanisms of radiation-induced immune system disturbances mediated via thymus are discussed.