EIAgen Total T3

brief description

Thyroxine (T4) and 3, 5, 3'-triiodothyronine (T3) are the two principal thyroid hormones. In contrast to T4, which is exclusively a product of the thyroid gland, T3 is mainly produced in the peripheral tissues by 5'-monodeiodination of circulating T4. In normal adults about 80% of T3 is produced by peripheral conversion and about 20% is secreted directly by the thyroid. A small amount of T4 is 5-monodeiodinated to form 3,3',5'-triiodothyronine (reverse T3): this is probably biologically inactive (2). The proportion of T4 converted to reverse T3 may be increased under certain circumstances, such as severe illness or medication with Amiodarone or radiographic contrast agents. This reduces the production and hence the circulating level of T3. Considerable evidence exists to show that T3 is the more active thyroid hormone and some authors have suggested that T4 has no intrinsic activity. Both T3 and T4 circulate in association with serum proteins, the most important of which is thyroxine binding globulin (TBG).

intended use

EIAgen Total T3 is a direct solid phase enzyme immunoassay for the quantitative measurement of total 3,5,3'-triiodothyronine (T3) in human serum or plasma.