Triiodothyronine uptake

3,5,3, -triiodothyronine is also called anti-rT3, which is converted from T4 inner ring deiodination (T4 outer ring deiodination is converted to T3), almost all rT3 in serum (97 %) Is derived from T4 in peripheral tissues. About 50% of T4 secreted by the thyroid gland is deiodinated to produce rT3; about 3% comes from thyroid secretion. Normal people produce about 32 g per day, and their serum half-life is 30-60 minutes. rT3 is not biologically active, but it is an important control of thyroid hormone metabolism.