Studies of iodine metabolism in endemic nodular goiter.

Abstract

Parenchymatous nodular, colloid nodular goiter, and mixed forms are found in the endemic goiter area of Cali, Colombia. Normal values for thyroid 131I uptake, PB131I and PB127I with a high stable urinary iodide excretion indicate sufficient iodine supply at the present (1). Intrathyroidal iodine metabolism was studied in pieces of nodular and paranodular tissue obtained from 19 goitrous, euthyroid, or hyperthyroid patients undergoing thyroid surgery after 131I administration. Iodide, MIT, DIT and T4 were found in all tissues examined. The amounts varied depending on the length of time after 131I administration and on the type of the tissue. All tissues from colloid goiters and nodular tissue from parenchymatous nontoxic goiters showed decreased stable iodide and 131I concentrations, a higher MIT:DIT ratio and lower amounts of thyroxine when compared with tissue from normal glands. Tissue of toxic nodules contained more stable iodide and 131I and had a lower MIT:DIT ratio and higher thyroxine content than ...