Abstract
The biosynthesis of iodoamino acids in the nodule and paranodular thyroid tissue in nontoxic nodular goiter was studied in thirty patients by paperchromatography using Na-I131.
The following 4 characteristic findings of the nodule were obtained from this study: 1) The activity of iodination of MIT was reduced. 2) The storage of iodide resulting from deiodination was disturbed. 3) Biosynthesis of iodoamino acids in the nodule was influenced by pituitary-thyroid feed back mechanism in different way from that in the paranodular thyroid tissue. 4) Probably, there was a defect of deiodination.
It is an obscure problem whether these defects contribute in any way to the development of nontoxic nodular goiter or not, but our understanding of enzyme which activates iodination of MIT in the thyroid may provide a clue to the development of nontoxic nodular goiter.
