DYNAMIC ANALYSIS OF IODINE METABOLISM IN 4 NORMAL SUBJECTS*†

Abstract

Observations of I131 in the urine, serum, and thyroid and I analysis of urine and serum were made over a 3-week period on 4 normal subjects. Data were analyzed by means of an analogue computer, and values of thyroid I content and serum PBI content were obtained as well as the rate of release of I from the thyroid. The shape of the specific activity curves agrees well with those calculated on the basis of a 3-compartment model of I metabolism, with the exception of the early phase of the iodide curve, which indicates the presence of a 2nd iodide compartment within the body. The serum PBI curve shows that one labeled constituent predominates.