JOSIAH BROWN, M.D.; INDER J. CHOPRA, M.D.; JAMES S. CORNELL, Ph.D.; JEROME M. HERSHMAN, M.D.; DAVID H. SOLOMON, M.D.; ROBERT P. ULLER, M.D.; ANDRE J. VAN HERLE, M.D.
The pituitary thyrotrophin reserve in 55 patients was tested with thyrotrophin-releasing hormone, and only 28% with deficient responses were hypothyroid; in three patients with hypothalamic disorders the response was delayed but otherwise normal. Three pituitary hormones, thyrotrophin, luteinizing hormone, and follicle-stimulating hormone, contain the same alpha polypeptide chain but different beta chains that confer specificity. Although the serum triiodothyronine (T3) concentration is 1/75th that of thyroxine (T4), its greater volume of distribution (threefold) and disappearance rate (sixfold) results in a T3 turnover one third to one fourth that of T4. Approximately 20% to 33% of T3 comes from the thyroid gland, the remainder from T4. But T4, a prohormone for T3, also contributes hormonal effects. The features of Graves' disease suggest it is an autoimmune disorder, but long-acting thyroid stimulator does not correlate with level or control of thyroid function. The serum thyroglobulin level is higher in women (6.0 ng/ml) than men (3.4 ng/ml); the levels are stable, higher in the newborn than in their mothers; and they rise after thyroid stimulation and fall after suppression. Thyroglobulin levels are elevated during active subacute thyroiditis and are persistently high in hyperthyroidism.
BROWN J, CHOPRA IJ, CORNELL JS, HERSHMAN JM, SOLOMON DH, ULLER RP, et al. Thyroid Physiology in Health and Disease. Ann Intern Med. ;81:68–81. doi: 10.7326/0003-4819-81-1-68
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Published: Ann Intern Med. 1974;81(1):68-81.
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