Detailed Product Description
Triiodothyronine, the principal thyroid hormone, circulates in blood almost completely bound to carrier proteins. The main carrier is thyroxine-binding globulin (TBG). However, only the free (unbound) portion of triiodothyronine is responsible for the biological action. Futher, the concentrations of the carrier proteins are altered in many clinical conditions, such as pregnancy. In normal thyroid function as the concentrations of the carrier proteins alters, the total triiodothyronine level changes so that the free triiodothyronine concentration remains constant. Thus, measurements of free triiodothyronine concentrations correlate better with clinical status than total triiodothyronine level.
The free triiodothyronine concentration can help in the assessment of thyroid status.