[Morphological characteristics of central and peripheral organs of rat immune system in time course of adaptation to external low-dose gamma irradiation]. / Morfologicheskaia kharakteristika tsentral'nykh i perifericheskikh organov sistemy immuniteta krys v dinamike adaptatsii k vneshnemu gamma-oblucheniiu v malykh dozakh.

The morphohistochemical changes in immune system lymphoid organs and skin of rats, exposed to single and fractionated gamma-radiation (0.35 Gy) were studied during 1 month. It has been revealed that single irradiation didn't significantly influence, while the fractionated irradiation in equal dose resulted in lymphoid cells elimination from thymus and spleen and changes in skin and bone marrow cells subsets, inducing the increase of lymphoid cells number and activation of tissue basophils and macrophages reaction.

[The role of the thymus gland in the development of adaptation reactions of the immune system during fractionated low-level gamma irradiation]. / Uchastie vilochkovoi zhelezy v razvitii adaptatsionnykh reaktsii immunnoi sistemy pri fraktsionirovannom gamma-obluchenii v malykh dozakh.

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.

[The functional dynamics of the system of immunity in rats during adaptation to single and fractionated exposures to low doses of external gamma irradiation]. / Dinamika sostoianiia sistemy immuniteta krys v protsesse adaptatsii k odnokratnomu i fraktsionirovannomu vozdeistviiu malykh doz vneshnego gamma-oblucheniia.

The content of serum corticosterone so as immunological and nonspecific reactivity in rats exposed to single or fractionated gamma-radiation (0.35 Gy) were studied during 1 month. It has been revealed that corticosterone level, dynamics of absolute amount of leucocytes, lymphocytes, Rc-receptor-bearing cells in blood, relative content of FcR(+)-cells in bone marrow, spleen and peripheral lymph nodes of irradiated animals depend on the scheme of irradiation. Single irradiation didn't significantly influence natural and antibody-dependent killer cells activity and basal chemiluminescence level of polymorphonuclear cells, while the fractionated irradiation in equal dose induced considerable fluctuations of these parameters. The direction and intensity of the disturbances depend on the time after irradiation.

[Immune reaction in monkeys to single and fractionated low-dose gamma-irradiation]. / Reaktsiia immunnoi sistemy obezían na odnokratnoe i fraktsionirovannoe gamma-obluchenie v malykh dozakh.

A study was made of total and local immunity of two groups of Papio hamadryads subjected to single and ten-fold external gamma-irradiation at a cumulative dose of 5 cGy. It has been shown that with equal dosages changes in the relative and absolute number of lymphocytes in the peripheral blood, the number of circulating T-cells and their functional activity are more pronounced in animals subjected to fractionated irradiation. Both groups exhibited similar disturbances in the functional activity of antibody-dependent killers and in local immunity of stomatopharynx. Analysis of the immunological data and the results of hydrocortisone content determinations in blood serum of exposed animals has demonstrated the presence of both direct effect of low-level radiation on the immune system and indirect effect that is particularly pronounced in case of multifraction long-term irradiation.

[The biological effects in animals in relation to the accident at the Chernobyl Atomic Electric Power Station. 8. The status of cellular immunity in different generations of rats]. / Biologicheskie éffekty u zhivotnykh v sviazi s avariei na Chernobyl'skoi AES. Soobshchenie 8. Sostoianie keltochnogo immuniteta u raznykh pokolenii krys.

In studying immunity in laboratory rats of different generations (P, F1 and F2) brought up in Chernobyl in 1989-1990 the authors have revealed the development of leuko- and lymphopenia; decrease in the absolute content of immunocompetent cells bearing Fc receptors to IgG; stable and long-lasting suppression of blood NK cell activity; reduction of antibody-dependent cytotoxicity; and changed ability of blood lymphocytes to interact contactly with allogenic mast cells. The most considerable disorders have been found in 6- and 9-month-old F1 rats and in 3- and 6-month-old F2 rats.

[Thymus participation in realizing the immunomodulating action of hydrocortisone]. / Uchastie vilochkovoi zhelezy v realizatsii immunomoduliruiushchego deistviia gidrokortizona.

It has been shown in experiments on CBA mice that in certain conditions injection of hydrocortisone (10 mg/kg) results in suppression of the delayed type hypersensitivity reaction and prolongation of the skin allograft survival. Preliminary thymectomy abolishes the immunomodulating effect of the drug, being, in the authors' opinion, the evidence for thymus involvement in mediation of the immuno-suppressive effect of hydrocortisone.

[Effect of calcitonin on lymphoid tissue cells in vitro]. / Vliianie kal'tsitonina na kletki limfoidnogo riada in vitro.

Calcitonin effect on lymphoid cells of the marrow, thymus, spleen and lymphoid nodes was studied on guinea-pigs and CBA mice. Calcitonin increased ThyI+ cell number in the marrow and thymus, restored rosette-forming ability of the thymus lymphocytes, heated at 45 degrees C within 1 hour, inducing an appearance of heteroerythrocyte receptors on their surface. The data obtained allow a conclusion that calcitonin is a substance, influencing the lymphoid tissue cell differentiation.

[Effect of levamisole on lymphoid cells in vitro]. / Vliianie levamizola na kletki limfoidnogo riada in vitro.

The paper is concerned with a study in the levamisole effect on lymphoid cells of bone marrow, thymus, spleen and lymph nodes of guinea pigs and CBA/mice. It is shown that levamisole stimulates the differentiation of immature bone marrow and thymus lymphocytes and restores the rosette-forming ability of thymocytes previously heated at 45 degrees C for an hour.