Aim: to study the effects of light desynchronosis on the morphofunctional state of the spleen of white male rats. Material and Methods. The study of light desynchronosis was carried out on 48 male rats using the Light Light model with an illumination power of 300 Ix in the daylight and 500 Ix in the dark. The laboratory animals in the experiment were divided into four groups: the control and three experimental ones, in which they were exposed to light for 1 day, 10 days, 21 days respectively. In the course of morphometry of histological sections of the spleen, the following parameters were assessed: the area of white pulp lymphoid follicles, B- and T-clependent zones of white pulp, the number of germinative centers and immunoblasts in B- and T-zones. Results. On day 1 of the experiment, an increase in the area of the lymphoid follicle, periarterial and B-dependent zones, an increase in the number of immunoblasts and reproduction centers was registered. By the 10th day there was a partial restoration of these indicators relative to the control values. On the 21st day of the experiment, a decrease in the growth dynamics of all the morphometric parameters of the spleen was observed. Conclusion. Light desynchronosis induces by the Light Light model leads to the development of the pathology of the immune system with an extensive shift of all measurable indicators. Key words: morphofunctional state of the spleen, morphometric criteria, light desynchronosis, immunity.</p
