PATHOHISTOLOGICAL CHANGES IN INBRED WHITE RATS’ THYMUS AND SPLEEN DURING ACUTE STRESS

Aim. To characterize in experiment pathological changes in the thymus and spleen of white rats in acute stress. Materials and methods. The experiment included 40 animals. Two experimental groups, 20 animals each, was formed: group I - intact animals living in standard vivarium conditions; group II - acute cold stress modeled in the following way: temperature +4 °C, exposition - 1,5 hours. On the day 10 th of the experiment the animals were withdrawn from the experiment and autopsy material was taken for subsequent histological study (spleen, thymus, Peyer’s plaques). Results. In the group with cold stress, vascular disorders (connective tissue edema and vascular plethora) and inversion of layers were observed in thymic tissue by the day 10 th of the experiment. In the cerebral and cortical layers, the areas of lymphocyte death, stroma collagenization were visualized and a large number of thymic bodies were formed. In thymic tissue, a great number of mast cells in the interlobular connective tissue, connective tissue of septa inside the lobules near the blood vessels as well as in the thymic parenchyma - in the lobular cortical substance and in the areas of lymphoid cell death - were detected. In the experimental group, marked signs of accidental thymic involution against the background of hemodynamic disorders as well as reaction of reticuloepithelial elements and mast cells were revealed. In the spleen of animals of this group there was decrease in white pulp volume - 22,98±2,45%; p <0,05 as compared to the control group. Conclusion. While comparing the data of histological study of animal organs the following patterns were found in both experimental and control groups: in animals exposed to acute stress changes typical for acute stress including reduction of thymic and splenic lymphoid tissue were revealed.

Lymphocytes, thymus, spleen, stress, pathohistolocal changes