A SENSITIVE METHOD FOR THE DETECTION OF IODINATED COMPOUNDS IN HUMAN PLASMA, AND ITS APPLICATIONS IN THE STUDY OF THYROTOXICOSIS*

Abstract

Iodinated tyrosines were identified in human plasma in certain familial disorders, after the large doses of radiation given in some cases of carcinoma of the thyroid and, as previously reported by this department, in some, but not all cases of thyrotoxicosis. The evidence for this statement is further strengthened by the results obtained with a modification of a chemical method for the detection of small amounts of iodinated compounds which were separated by paper chromatography. This method depends essentially on the treatment of paper chromatograms with ceric sulphate-arsenious acid reagent and is a development of that described by Bowden et al. (Biochem. J. 59 93, 1955). Using this technique alone, and in conjuntion with scintillation counting, it was possible to study the plasma of patients before and after the administration of radioiodine. In this way a radiation effect on the thyroid may be excluded as the cause for the appearance of abnormal iodinated compounds in the plasma of certain patients with thyrotoxicosis. Iodinated compounds in the plasma of normal people were examined.