Fate of iodide derived from intrathyroidal hyrolysis of thyroglobulin.

Abstract

We have studied the effect of certain pharmacologic agents (all at a concentration of 103M) on the secretion of labeled iodide from the prelabeled rat thyroid perfused in situ with single-pass, nonradioactive blood. Each preparation served as its own control during the pre-drug period. Under control conditions 10- 20% of the secreted radioactivity was I–, the remainder T3 +T4. Perchlorate or ouabain induced a prompt 4-fold increase in secretion of labeled I– to 50-60% of the total secreted radioactivity. In contrast, PTU or methimazole induced only a slight ( 90% of the secreted radioactivity. We interpret the data as follows: ...