Direct effect of protirelin (TRH) on PB[123I] in autonomous thyroid adenoma.
In a retrospective study of 27 cases of iodine deficiency and/or latent primary hypothyroidism and in 16 cases of thyroid adenoma with hyperthyreosis the routine radioiodine uptake test was combined with a protirelin (TRH) test. After TRH infusion, [PB*I] and TSH increased significantly in all of these 27 patients who served as controls for the hyperthyroid patients. At the same time, the conversion rate Q rose in 14 of the control patients, but it dropped in 13 cases, thus indicating a TSH-induced discharge from the thyroid of radioiodine containing substances that were not bound to serum proteins. In nine of the 16 patients with autonomous adenoma, PB[*I] rose slightly, but Q did not increase significantly. In seven of the 16 adenoma patients, both PB[*I] and Q even dropped slightly in the absence of measurable serum TSH, thus indicating a negative direct effect of TRH on thyroid hormone metabolism.
Kallee
E
E
Medizinische Klinik and Poliklinik, Abteilung IV, Isotopenlabor, Eberhard-Karls-Universität, Tübingen, Germany.
Müh
U
U
Wahl
R
R
D000236:Adenoma / Q000097:blood*; D000368:Aged; D001798:Blood Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood; D007455:Iodine / Q000097:blood* / Q000378:metabolism; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D001798:Blood Proteins; D007457:Iodine Radioisotopes; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D007455:Iodine