Morphofunctional State and Microstructure of Regional Lymph Nodes in Experimental Hypothyroidism and Under Correction

Abstract

Lymph nodes play an important role in the life of humans and animals. In the modern concept, the lymph nodes are the main homeostatic organs of the internal environment of the body, the lymph nodes are part of the lymphatic bed, on the other hand, they are the organs of the lymphoid (immune) system. Purpose: The work presents data on the morphofunctional state and microstructure of regional lymph nodes in experimental hypothyroidism and under correction. Materials and Methods: Experimental hypothyroidism in animals was induced by per os administration of mercazolil at a dose of 20 mg per 100 g of body weight with drinking water for 21 days. To correct thyroid disorders, starting from the 22nd day of the experiment, the animals received for 30 days an iodine-containing dietary supplement "Renaissance Plus" balm in powder at the rate of 2 μg/100 g of body weight and a decoction of the roots of the white cinquefoil (Potentilla alba L.) 50 ml per 100 g per day with drinking water. Results: The results of the study showed that in conditions of hypothyroidism, the lymph node becomes compacted with a decrease in the main structural and functional zones against the background of reduced lymphopoietic function. In the lymphoid nodule, there is a decrease of 1.43 times in the number of lymphoblasts, 1.56 times in the number of medium lymphocytes, 1.50 times in the number of small lymphocytes due to an increase of 1.29 times in the number of macrophages per unit area of the lymphoid nodule in the lymph node. There was a static decrease in the number of small lymphocytes in all structural and functional areas; the number of blasts decreases in the lymphoid nodule and increases in the paracortex and Billroth's strand; the number of macrophages increases in the lymphoid nodule, cerebral sinus, the number of mature plasma cells decreases in the paracortex and Billroth's strand, and there is also inhibition of cellular reactions in the lymph node, which reflects a decrease in the lymphopoietic function of immune activity and as a result of the immunosuppressive action of mercazolil. Conclusions: After an administration of corrigents, the area of the medulla and paracortex was restored to the control level and the ratio of cortical and medulla in the overall structure of the lymph node was leveled.