Preferential secretion of triiodothyronine in man.
The directly measured secretion rates of thyroxine (T4), 3,5,3'-triiodothyronine (T3), and 3,3',5'-triiodothyronine (rT3) were compared to the tissue concentrations of these hormones and to the distribution of follicular iodoproteins in 15 patients submitted to thyroid or parathyroid surgery. The T4/T3 and rT3/T3 ratios were higher for thyroid tissue than for the secretion rates, indicating a preferential secretion of T3. The concentrations of T4 and T3 were higher in the 27S iodoprotein fraction than in the 19S thyroglobulin fraction.
D000328:Adult; D000368:Aged; D006801:Humans; D007467:Iodoproteins / Q000032:analysis; D008875:Middle Aged; D013954:Thyroglobulin / Q000032:analysis; D013961:Thyroid Gland / Q000032:analysis; D013963:Thyroid Hormones / Q000032:analysis; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism*
D007467:Iodoproteins; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013954:Thyroglobulin; D013974:Thyroxine