This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Wolff-chaikoff effect is ? \nSelect and explain. \nA. Reduced thyroxine synthesis by radiotherapy, B. Reduced thyroxine synthesis by propylthiouracil, C. Reduced thyroxine synthesis by iodides, D. None of the above', 'role': 'user'}, {'content': "Answer: C \nExplanation: 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).", 'role': 'assistant'}]