Triiodothyronine (T3) stimulates a robust increase (>40-fold) in transcription of the malic enzyme gene in chick embryo hepatocytes. Previous work has shown that optimal T3 regulation of malic enzyme transcription is dependent on the presence of an accessory element (designated as region E) that immediately flanks a cluster of five T3 response elements in the malic enzyme gene. Here, we have an...

We investigated the effects of phenolic and phenol compounds on 3,3',5-L-125I-triiodothyronine (125I-T3) binding to purified Xenopus laevis transthyretin (xTTR) and to the ligand-binding domain of X. laevis thyroid hormone receptor beta (xTR LBD), on T3-induced metamorphosis in X. laevis tadpoles and on the induction of T3-dependent reporter gene in a X. laevis cell line. Of the halogenated phe...

BACKGROUND The concentration of triiodothyronine (T3) in human serum is extremely low and can be determined only by very sensitive methods. We developed a homogeneous enzyme immunoassay for T3 analysis in unextracted serum. METHODS A T(3) derivative was conjugated to the -SH groups of glycogen phosphorylase b (GPb) from rabbit muscle. Conjugation caused inhibition of enzyme activity, and the ...

We describe a one-step, labeled-antibody radioassay for measuring free thyroxin (FT4) in serum or plasma, based on a novel principle. FT4 in the sample competes with a gross molar excess (over antibody) of a cross-reactant (L-triiodothyronine, T3), chemically coupled to magnetizable polymer particles, for binding to avid 125l-labeled monoclonal anti-thyroxin antibodies. As in conventional immun...

Two hundred and forty male Cobb broilers were used to study the reasons of causing ascites. The results showed that cold ambient temperature could induce ascites (33.89% vs. 2.50%) and significantly increase triiodothyronine (T3), but reduce thyroxine (T4) concentrations in plasma (p<0.05). The ascitic broilers had high concentrations of aldosterone and K , but low concentrations of T3 and T4 i...

Reverse triiodothyronine (rT3), triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) values were measured by radioimmunoassay in 40 children with congenital hypothyroidism who were being given levothyroxine (0.05-0.35 mg/day) and in 14 normal controls. In 15 of the children with hypothyroidism the treatment, judged by serum T4 and TSH values and thyrotrophin releasing ho...

Study objective: To determine if temperature during cardiopulmonary bypass (CPB) has an effect on peri¬ operative and postoperative thyroid function. Design: Prospective study comparing thyroid function duringand afterhypothermicandnormothermic CPB. Setting: Cardiac surgical unit at a university-affiliated hospital. Patients: Twelve patients scheduled to undergo car¬ diac operations with normot...

Chadd, M. A., Gray, 0. P., and Davies, D. F. (1970). Archives of Disease in Childhood, 45, 374. Thyroid function tests in the newborn. The 131I triiodothyronine (T3) resin uptake test reflects thyroid function more closely than other acceptable tests currently available. The T3 uptake and protein-bound iodine (PBI) level were estimated in 20 premature and 20 full-term infants at birth and at th...

THYROID PHYSIOLOGY The thyroid gland lies inferior to the thyroid cartilage and is composed of 2 lobes that lie on either side of the trachea (Figure 1). The lobes are joined by a small band of tissue called the isthmus. Normally not visible on inspection, the thyroid gland can be palpated during swallowing when it is upwardly displaced. Thyroid tissue is highly vascular and is composed of foll...

The metabolism of 3, 5-[3'-125I]triiodothyronin (T3) and 3-[3', 5'-125I]triiodothyronine (rT3) was studied in cultured monkey hepatocarcinoma cells (NCLP-6E), and the deiodinations of these iodothyronines were also investigated in cultured cell homogenates and in rat liver homogenates. The metabolites were analyzed by ion exchange column chromatography. For nonphenolic ring deiodination of 3, 5...