Alterations in Serum Iodine Fractions Induced by the Administration of Inorganic Iodidel in Massive Dosage*†

IT HAS been shown that in euthyroid adults on an intake of inorganic iodide limited to that ordinarily present in the diet the serum precipitable or protein-bound iodine remains relatively constant within the range of 4.0 to 8.0 gamma per cent (1, 2). Under these circumstances the inorganic iodide in serum also remains constant at approximately one gamma per cent (3, 4). If, however, the intake of inorganic iodide is greatly increased, the concentration of this inorganic fraction rises several hundred fold, or more (4, 5). The present study defines alterations in serum proteinbound or precipitable iodine which accompany such rises during the administration of inorganic iodide in massive doses. Materials and Methods The pertinent clinical data on 8 patients who received up to 3 grams of potassium iodide or up to 7 ml. of a saturated solution of the same salt daily during periods as long as six months are presented in the legends to Figures 2 through 9. The sera of these subjects were analyzed at intervals ...