ОБМЕН РНК В СЕКРЕТОРНЫХ СТРОМАЛЬНЫХ ЭПИТЕЛИОЦИТАХ МОЗГОВОГО ВЕЩЕСТВА ТИМУСA В ДИНАМИКЕ ЭМБРИОГЕНЕЗА БЕЛОЙ КРЫСЫ

Abstract

Currently, the thymus is considered as a polyfunctional organ that performs immunological, lympho- cytopoietic and endocrine functions, the performance of which is closely related to the differentiation of T-lymphocytes under the influence of hormones secreted by reticuloepithelial cells of the stroma. In this regard, the article describes the processes of syhthetic activity of RNA in the nuclei of stroticuloepithelial cells of the thymic medulla in the dynamics of embryogenesis of the white rat. According to the results of a quantative cytophotometric study, indicators of the RNA level in the nucleoli of the medulla epithelial stromal cells have been obtained. It was revealed that the synthesis of thymopoetines, which provide the processes of differentiation of immune competent T-lymphocytes of the thymus gland, begins on the 15th day of embryogenesis Subseguently, the secretory activity of RNA in the nucleoli of reticuloepithelial cells increases in waves in the form of two peaks on the 17 and 19 days of embryogenesis. By the time the fetus is born, on day 21. there is consistently high and uniform level of thymopoetines, which determine the thymus as a finally differentiated immunocompetential organ that provides the mechanismes of cellular immunity.