DYNAMICS OF STRUCTURAL CHANGES AND CD68 AND KI-67 MARKER EXPRESSION IN RAT THYMUS AFTER A SINGLE EXPOSURE TO IONIZING RADIATION

Abstract

Objective - to examine the dynamics of structural changes and CD68 and Ki-67 marker expression in the thymus of rats at different time intervals after a single total irradiation in sublethal dose. Material and methods. In 30 rats after 3, 7, 14 and 30 days after experimental irradiation at a dose of 5 Gy, thymus was studied using histological, morphometric and immunohistochemical methods (Ki-67 and CD68 markers). Results. On the 3rd day after irradiation, the «inversion» of the thymus layers was detected with a decrease in the relative cortical area (by 15.1% as compared with data in controls) and a depletion of cell populations. Simultaneously, a significant increase in the expression of Ki-67 and CD68 markers in the subcapsular area was noted (by 71.3% 242.1% in comparison with the control, respectively). In subsequent time points of the experiment, a gradual recovery of thymus histoarchitectonics and cell populations was found that was due to the proliferative activity of thymocytes in the subcapsular zone at a constant level of expression of CD68 marker. Conclusions. The greatest expression of the morphologic changes in the thymus took place at 3 and 7 days after irradiation, with the restoration of histoarchitectonics and cell populations on the 30th day of the experiment.

Keywords

thymus / gamma-irradiation / rats

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