MORPHOFUNCTIONAL CHANGES OF THYROID GLAND THYROCYTES AND C-CELLS IN HYPOTHYROIDISM INDUCED BY ACTINOMYCIN D ADMINISTRATION

Thyroidin status and thyrocyte ultrastructure of thyroid gland in case of hypofunction induced by introduction of aktinomicin D were studied in the corse of experiments on laboratory animals using radioimmunologic and electronomicroscopic techniques. Confirmation of hypothyroidism was obtained at the tissue level. Morphometric studies of the nuclear apparatus and organelles of thyrocytes and C-cells cytoplasm were held. The proportion of inert heterochromatin in the nucleus is reduced, and the nucleoli decrease in size and lose their cellular structure. Changes occur in vacuolar-lysosomal system. The presence of synergism in the action of actinomycin D and triiodothyronine on thyrocytes. The ultrastructural changes violating biosynthesis and triiodothyronine transportation in thyrocytes and biosynthesis of somatostatin and calcitonin in C-cells were discovered.