[Structure of the thymus gland of the rat in the prenatal and early postnatal periods of development after exposure to tetracycline during the period of fetogenesis].

Structure of the thymus in Wistar rats has been studied during antenatal and early postnatal periods of ontogenesis by means of histological, morphometric and electron microscopic methods. Theraputic doses of tetracycline hydrochloride have been administered during fetogenesis (15-20 days of pregnancy). An accelerated formation of the thymic structures, cellular blasttransformation in the thymic cortex and movement of lymphocytes from the cortex into medulla and increased secretory activity of epithelioreticulocytes have been revealed. The data obtained are considered as a display of the organ's immune response to tetracycline administration.