Wolff-chaikoff effect is ?: (A) Reduced thyroxine synthesis by radiotherapy, (B) Reduced thyroxine synthesis by propylthiouracil, (C) Reduced thyroxine synthesis by iodides, (D) None of the above
Answer is C. Ans. is 'c' i.e., Reduced thyroxine synthesis by iodides Iodine and Iodides Iodine is the fastest acting thyroid inhibitor. Most impoant action is inhibition of hormone release (thyroid constipation); but all facets of thyroid synthesis may be affected. Excess iodide inhibits its own transpo in thyroid cells and may alter the redox potential of cells, thus interfering iodination -reduced TIT3 synthesis ( Wolffichaikoff effect).