Analysis of the radiation effect on the activity of thyroid blood transport systems: connection with the features of thyroid status

Thyroid-binding proteins play an important role in regulating thyroid status. However, the question of the radiation effect on the functional state of thyroid blood transport systems remains insufficiently studied. The aim of the work was to assess the indicators of thyroid status and thyroid blood transport in persons exposed to radiation as a result of the Chernobyl accident. The task of the work was also to analyze the results of an oral test for thyroxine pharmacokinetics in patients with thyroid carcinoma who received radioiodine therapy. Screening studies conducted 5−6 years after the Chernobyl accident indicate the radiation effect on the free thyroxine content in the blood and the functional activity of thyroid protein transport in children and adolescents living in the territories of the Khoiniki district of the Gomel region. The dose-dependent effect of an absorbed dose of 131I was also detected in children and adolescents displaced from the 30 km zone of the Chernobyl accident. The results of an oral test for thyroxine pharmacokinetics demonstrate an increase in the free T4 content against the background of a stable total T4 fraction in patients with thyroid carcinoma who received high dose loads as a result of radioiodine therapy. The conducted studies confirm the possibility of the influence of a high dose of 131I on thyroid blood transport systems and on the ratio of free and bound fractions of thyroid hormones in the blood.