The investigation object: mechanisms of chronic inflammation in the conditions of action of low dose-rate ?-radiation. The investigation goal: cellular reactions of lymphoid organs at action of low dose-rate ?-radiation in different doses at chronic inflammation. Methods of research: pathophysiological, physicochemical, histological, immunohistochemical and statistical. The theoretical and practical importance of the received results: Obtained results extend present knowledge about effects and mechanisms of low dose rate gamma-irradiation particularly at chronic inflammation, and hence are important for pathophysiology and radiobiology. They can be used for the following research activity, in education process, at development of prophylaxis principles of radiation influence and pathogenic therapy in patients with chronic inflammatory and radiation diseases. Data of cellular reactions in lymphoid organs and radiation doses, which correspond to carcinogenesis risk in lymphoid tissue at chronic inflammation, can be important for revealing of risk groups of people, who live in radiation polluted territories or work at increased radiation level conditions. The scientific novelty of the investigation results: For the first time there were shown particulars of the series of cellular reactions of thymus and spleen tissues at low dose rate gamma-irradiation in various doses (0.1, 0.5, 1.0 Gy), including small dose (0.1 Gy) against the background of chronic inflammation, namely, increase of free radical oxidation processes in thymus and spleen, slowing down of accidental transformation of the thymus, typical for chronic inflammation, increase of thymocyte proliferation, hyperplasia of white pulp of the spleen, increase of macrophage and plasmocyte reactions in spleen at active migration of immune cells, decrease of T-cells depletion, decrease of B-cell proliferation and increase of T-cell proliferation in lymphoid tissue. At that, activity of oncosuppressor protein p53 in lymphocytes of thymus and spleen is insufficient, which testifies to increase of probability of cancer transformation in lymphoid tissue at low dose rate gamma-irradiation against the background of chronic inflammation, especially at low dose. There were revealed dose dependence of the effect of low dose rate gamma-radiation, its immediate and delayed effects on studied parameters, dependence of effects on inflammation time points, to which irradiation was performed. The degree of implementation: results of the research were implemented into the educational process at departments of pathophysiology of Kharkiv, Donets'k, Bukovyna, Ternopil State Medical Universities, Sumy State University. Branch of usage: medicine, pathophysiology, radiobiology, radiation medicine, oncology.
