the main goal of this study was to evaluate the possible effect of whole-body magnetic field(mf) exposure on the variations of corticosterone, free-t3, free-t4 and malonyl dialdehyde inplasma in 48 adult white new zealand male rabbits. animals were divided into six groups namely,c1 (normal diet, not exposed), c2 (normal diet, sham exposed), t1 (normal diet, exposed toelectromagnetic field), c3 ...

The contribution of L-thyroxine (T4) to nuclear thyroid receptor occupancy was studied in GC cells incubated with concentrations of 3,5,3'-triiodo-L-thyronine (T3) and T4 that resulted in free iodothyronine levels similar to those in serum of euthyroid rats. T4 accounted for 5.4-10% of the occupied receptors: T3 derived from T4 [T3(T4)] and T3 added to medium accounted for the remainder of rece...

UNLABELLED The standard treatment of hypothyroidism (central and primary) consists of thyroxine (T4) administration alone. However, the normal thyroid gland produces a small proportion of triiodothyronine (T3) directly into the circulation. AIM We aimed to study the free T3 to free T4 ratio in treated central hypothyroidism compared with euthyroidism and treated primary hypothyroidism. METH...

We have investigated the transport of L- and D-triiodothyronine (T3) from plasma to cellular cytoplasm and from cytoplasm to nucleus by estimating the concentration of free hormone in these compartments in rat liver, kidney, brain, and heart. We assessed the distribution of T3 in various tissues and its metabolism by standard isotopic techniques and measured plasma and cytosolic tissue T3 by ra...

Serum thyrotropin (TSH), free thyroxine (T4), and free triiodothyronine (T3) levels illustrate the thyroid function set point, but the interrelations between these have never been characterized in detail. The aim of this study was to examine the associations between TSH and thyroid hormone levels in healthy euthyroid twins and to determine the extent to which the same genes influence more than ...

Neonatal changes in plasma total and free iodothyronine levels were monitored in 18 Limousin X Romanov suckling lambs (experiment 1) and 24 Limousin X Romanov animals bottle-fed in standardized conditions (experiment 2). In the two experiments, plasma free T3 levels were closely related to total T3 levels, whereas some differences could be observed between total and free plasma T4 levels. The n...

Concentrations of free thyroxin (T4) and free triiodothyronine (T3) were measured in sera from pregnant women, in subjects with congenitally increased or decreased thyroxin-binding globulin (TBG), and in euthyroid controls. Measured free hormone concentrations were compared with calculated values for free hormone derived from concentrations of total T4, total T3, and binding proteins. Measured ...

To the Editor: Ultrafiltration is a standard method for separating free T3 and free T4 from serum proteins and proteinbound hormone (1, 2 ). It is expected that free T3 and free T4 in aqueous solutions will accompany water as water moves across semipermeable membranes, a process that results in equal concentrations of free T3 and free T4 in the aqueous solutions on opposite sides of semipermeab...

A 60-year-old woman, free of other disease, with severe clinical hyperthyroidism had normal total serum T4 with elevated free T4 concentration and T3 resin uptake characteristic of hyperthyroidism, with thyroid binding globulin (TBG) deficiency. However, serum TBG concentration as determined by immunoassay was normal, suggesting that the biochemical defect affecting the T4 binding sites did not...

The main goal of this study was to evaluate the possible effect of whole-body magnetic field (MF) exposure on the variations of corticosterone, Free-T3, Free-T4 and malonyl dialdehyde in plasma in 48 adult white New Zealand male rabbits. Animals were divided into six groups namely, C1 (normal diet, not exposed), C2 (normal diet, sham exposed), T1 (normal diet, exposed to electromagnetic field),...