Effect of Iodide-Deficiency on Thyrocalcitonin Secretion.

Abstract
Summary Calcium chloride was infused intravenously in iodide-deficient, in I131-ir-radiated, and in thiouracil-treated rats. Serum calcium values were determined prior to and 30 minutes and 60 minutes after the infusion. Greater responses to calcium loading and retardations of return to the preinfusion levels were observed in iodide-deficient and iodide-deficient I131-irradiated animals. Thiouracil-treated animals showed normal response. It was concluded that normal content of iodide in diet may be necessary for activation of thyrocalcitonin, the thyroid hypocal-cemic principle.