[Dynamics of the changes in thyroid gland parenchyma on thyrocalcitonin administration]

Experiments were conducted on rats; a study was made of the effect of thyrocalcitonin (TCT) administration--5 Units a day--on thyroid gland. TCT administration during the first 5 days led to structural-functional reconstruction of the gland and activation of the synthesis and elimination of the iodine-containing hormones. Prolonged action of the iodine-containing hormones. Prolonged action of TCT (for 20 days) caused hypofunction of the gland, suppression of endogenous TCT production; it also intensified connective tissue proliferation, and destructive focal changes of the thyroid parenchyma.