Which of the Following is Not an Action of TSH

Question

Which of the following is not an action of TSH?
A) stimulates T3 and T4 secretion
B) stimulates iodide trapping by thyroid follicle cells
C) inhibits T3 and T4 secretion
D) stimulates pinocytosis of colloid by thyroid follicle cells
E) increases cyclic AMP concentration within thyroid follicle cells

Accepted Answer

TSH stimulates thyroid hormone secretion and iodide trapping by thyroid follicle cells (options A and B) and increases intracellular cyclic AMP levels (option E). TSH does not inhibit thyroid hormone secretion (option C), but rather stimulates it. TSH also stimulates pinocytosis of colloid by thyroid follicle cells (option D).