AGE-RELATED-CHANGES OF TSH RECEPTORS IN THYROID TISSUES OBTAINED FROMEUTHYROID PATIENTS

The results obtained in the comparative study of age-related changes i n TSH binding by thyroid tissues of euthyroid patients indicated that the content of high affinity binding sites of TSH receptors is not sig nificantly decreased during aging, while the level of low affinity bin ding sites is increased in thyroid tissues of aged people. However, th e dissociation constant of low affinity binding sites for TSH is signi ficantly increased in thyroid tissues of old patients, compared with m iddle-aged people. Further investigation of functional characteristics of observed changes in TSH receptors and their binding parameters wil l provide a better understanding of the mechanisms involved in the reg ulation of thyroid gland function during the aging.