[Characteristics of the action of excess thyroid hormones in guinea pigs].

A study was made of the action of various doses of thyroidin in its prolonged administration to guinea pigs on the functional and morphological changes of the thyroid gland and the adenohypophysis. A high sensitivity of guinea pigs to the excess of thyroid hormone in comparison with such in dogs was shown. Already with the less thyroidin doses guinea pigs displayed an increased oxygen consumption under conditions of the basic metabolism, a marked increase of the content of protein-bound iodine in the blood serum and of the corticosteroid urinary excretion. There were revealed no significant differences in the thyroidin action depending on the method of its administration, i.e. in case of a gradual increase of the doses or in the administration of high doses from the very beginning. The presence of significant individual differences in guinea pigs in the resistance to the excess of the thyroid hormones was demonstrated.