[Serum concentration of triiodothyronine in autonomous thyroid gland adenoma]

Serum Concentration of T3 was measured in 14 patients with autonomous thyroid adenoma using a chromatographic method. 9 patients had increased levels of T4, 5 were normal. In both groups serum-T3-concentration was significantly elevated. In patients with normal T4-values hypertriijodothyroninemia seems to be the biochemical base for clinical signs of hyperthyroidism. The pathogenetical importance of elevated T3-levels is discussed for T3-secretion and T4/T3 conversion.