THE HORMONE SYNTHESIS OF HYPERFUNCTIONING THYROID NODULES IN EUTHYROID PATIENTS

Abstract

ABSTRACT Among fifty consecutive patients operated on for non-toxic goitre, ten were shown to have solitary, hyperfunctioning thyroid nodules. Seven days before operation the patients were given a tracerdose of Na125I orally; all had an increased iodine discharge from the thyroid gland and elevated [125I]PBI. Chromatography of the sera revealed 125I peaks corresponding only to the T4 and T3 bands. Total 1251 concentration ratio nodular/paranodular tissue varied between 11.1 and 0.4 indicating a great variation in metabolic activity in "hot" nodules in the different goitres. The thyroid tissue was chromatographically investigated; the [125I]MIT/DIT ratio of the "hot" nodules was not negatively correlated to the 127I concentration of the tissue as is the case for "cold" adenomata. Significantly more [125I]T4 and [125I]T3 were found in the nodules compared to paranodular tissue. In contrast to simple non-toxic goitre the [125I]T3/T4 ratio in the "hot" nodules was lower than in paranodular tissue in spite of a lower 127I concentration in the former. Thus the hormone synthesis of "hot" nodules was unrelated to tissue iodine concentration.