СТРУКТУРНАЯ ХАРАКТЕРИСТИКА БРЫЖЕЕЧНЫХ ЛИМФАТИЧЕСКИХ УЗЛОВ КРЫС ПРИ ОСТРОМ ЭМОЦИОНАЛЬНОМ СТРЕССЕ

Abstract

The aim was to study the structural features of mesenteric lymph nodes in rats with different resistance to stress factors. Material and methods. Mesenteric lymph nodes of 40 Wistar rats with different emotional resistance, determined by the index of motor activity in the “open field” test were studied. On the basis of test’s results rats they were divided into emotionally stable and predisposed individuals. Immobilization of a rat with electrocutaneous irritation was used as an experimental model of acute emotional stress. Mesenteric lymph nodes were fixed in 10% neutral formalin solution; the sections were stained with hematoxylin-eosin and by Van Gieson’s method. The linear dimensions of the structures were determined with an ocular ruler, planimetric ones - using a grid. Morphometric evaluation included the calculation of arithmetic mean and their errors. The reliability of the differences was determined by the method of confidence intervals. Results. The following parameters compared with the control were reduced in rats predisposed to stress: the total number of lymphoid nodules in the transverse section of the mesenteric lymph node, the length and width of the lymphoid nodule with the center of reproduction, the area of the lymphoid nodule with and without the center of reproduction, the relative content of lymphoid nodules with the center of reproduction, the length and width of the center of reproduction. In stress-resistant rats, after the indicated effects, the total number of lymphoid cells forming the lymphoid tissue of mesenteric lymph nodes almost does not change. Conclusions. Structural and functional changes of the mesenteric lymph nodes in rats under stress depends on the individual resistance of the experimental animals stress factors. They are minimal in stress-resistant rats and are most significant in rats predisposed to stress.