[Congenital disorders of the thyroid gland in experimental litters obtained from mothers subjected to immunization and the action of I-131].

I131 injected to rabbits immunized with homologous thyroid gland on the 19th-20th day of pregnancy led to congenital disturbances of the thyroid gland in the experimental litters in the I and II generations. The functional activity and the activity of proteolytic enzymes of the thyroid gland decreased by the 30th day of the postnatal development. There was revealed a distinct correlation between the content in the thyroid gland of the experimental litters of DIT + MIT and of organic forms--T3 + T4. During the first days after birth DIT + MIT content showed a sharp fall and increased by the 30th day; on the contrary, iodine binding into organic forms decreased with the progress of age. Histological examination of the thyroid glands in the experimental litters demonstrated lymphoid-plasmocytic infiltration, along with connective tissue proliferation, which led to a marked sclerosis and fibrosis of tissues, hypofunction. Beginning from the age of one month there was seen an extensive nodular proliferation, which possibly served as the beginning of parenchymatous goiter formation. The appearance of lymphoid-plasmocytic infiltration in the thyroid gland of the II generation is considered to be the result of congenital predisposition to the autoimmune thyroiditis inlaid in the memory cells and intensified during birth.