A RADIOIMMUNOASSAY FOR MEASUREMENT OF 3,3'-L-DIIODOTHYRONINE (T₂)

Abstract

A sensitive, specific and reproducible radioimmunoassay (RIA) for measurement of 3,3'-L-diiodothyoride (T2) in concentrated ethanol extracts of serum and amniotic fluid is described. The T2 binding antiserum was prepared aby immunization of rabbits with T2-human serum albumin conjugate. Of various thyroid hormone derivatives tested, only 3-L-monoiodothyonine cross-reacted significantly with T2 binding sites on the antiserum...

Serum concentrations of 3,3'-diiodothyronine, 3',5'-diiodothyronine, and 3,5-diiodothyronine in altered thyroid states.

“…Previous studies (Wu et al, 1976;Burman et al, 1977;Burger et al, 1977;Gavin et al, 1978;Burman et al, 1978;Chopra et al, 1978;Faber et al, 1979) have demonstrated that serum T4, T3, rT3, 3,3' -T2 and 3' ,5'-T2 in hyperthyroidism, while they are diminished in hypothyroidism. The present study confirmed these previous observations and further demonstrated that serum 3,3'-T2 and 3',5'-T2 concentrations changed parallel with T4, T3 and rT3 concentrations to the norml ranges in hyperthyroid patients during the methimazole treatment and in hypothyroid patients during the T4 replacement therapy.…”

Hepatic extraction and renal production of 3,3'-diiodothyronine and 3',5'-diiodothyronine in man.

“…Receivedfor publication 21 April 1980 and in revisedform 8 July 1980. 1Abbreviations used in this paper: 3,3'-T2, 3,3'-diiodothyronine; 3',5'-T2, 3',5'-diiodothyronine; 3'-T1, 3'-monoiodothynormal components of human serum (1)(2)(3)(4)(5)(6). They are produced predominantly by extrathyroidal degradation of thyroxine (T4) (5), which proceeds by serial monodeiodination until all the iodine atoms have been removed (7).…”

Sequential deiodination of thyroxine in rat liver homogenate

“…174 metabolite, reverse tri-iodothyronine (by elimination of an iodine atom from the tyrosine ring). Both products are probably subject to further degradation into lower substituted iodothyronines (Wu et al, 1976;Rudolph et al, 1977). It has been shown that plasma tri-iodothyronine and reverse tri-iodothyronine vary in a reciprocal fashion in several clinical situations: in starvation (Vagenakis et al, 1975), systemic illness (Burger et al, 1976), after surgical operation (Burr et al, 1975) or on administration of the glucocorticosteroid analogue dexamethasone (Chopra et al, 1975), of the 16-adrenergic blocking agent propranolol (Verhoeven et al, 1977) or of the goitrogenic compound 6-propyl-2-thiouracil (Westgren et al, 1977).…”