Thyroxine-binding globulin serum

Gershengorn MC, Larsen PR, Robbins J. Radioimmunoassay for serum thyroxine-binding globulin Results in normal subjects and in patients with hepatoceUular carcinoma. J Clin Endocrinol Metab 1976 42 907-11. 

C3. Cavalieri, R. R., and Searle, G. L., Kinetics of distribution between plasma and liver of I-labeled 1,-thyroxine in man Observations of subjects with normal and decreased serum thyroxine-binding globulin. J. Clin. Invest. 45, 939-949... 

Use with tricyclic antidepressants or sympathomimet-ics may increase the effects of these medications or of thyroid USP, possibly leading to coronary insufficiency or cardiac arrhythmias. Use with oral antidiabetic agents or insulin may affect dosage requirements of these agents. Estrogens, which increase serum thyroxine-binding globulin levels, raise thyroid USP requirements. 

Vranckx, R., L. Savu, M. Maya, and E. A. Nunez. 1990. Characterization of a major development regulated serum thyroxine-binding globulin in the euthyroid mouse. Biochemical Journal 21 -3Ti- iJ9. 

Estrogen, oral contraceptives—Estrogens tend to inorease serum thyroxine-binding globulin (TBG), thus inoreasing thyroid requirements. 

Estrogen may increase hepatic production of thyroxine-binding globulin (TBG) and decrease TBG clearance, thus increasing serum total thyroxine (tT4) and, to a lesser extent, total triiodothyronine (tT3). As a result, increased tT4 and tT3 are seen in states of excessive estrogen and/or progestin, such as... 

Thyroid function tests - Decreased levels of thyroxine-binding globulin, resulting in decreased total T4 serum levels and increased resin uptake of T3 and T4. Free thyroid hormone levels remain unchanged, and there is no... 

Thyroid hormones and most steroid hormones are associated with carrier proteins in the serum. The carrier proteins are called, appropriately, thyroxine-binding globulin, transcortin (for cortisol), and sex-steroid-binding protein. These proteins have a high affinity (Kd 10—9— 10 8 m) for their respective hormones. They buffer the concentration of free hormone and retard hormone degradation and excretion. The carrier proteins are distinguishable from the intracellular receptors for these hormones. 

Chopra IJ, Solomon DH, Ho RS (1972) Competitive ligandbinding assay for measurement of thyroxine-binding globulin (TBG). J Clin Endocrinol 35 565-573 DSL Diagnostic Systems (2005) Multispecies endocrine assay cross-reactivity information New Resource from DSL - AnimalDx.com. [Internet resource] http //www.dslabs.com/temp/animaldx.htm Larsen PR (1972) Direct immunoassay of triidothyronine in human serum. J Clin Invest 51 1939-1949 Larsen PR (1972) Direct immunoassay of triidothyronine in human serum. J Clin Invest 51 1939-1949 Levy RP, Marshall JS, Velayo NL (1971) Radioimmunoassay of human thyroxine-binding globuline (TBG). J Clin Endocrinol Metab 32 372-381... 

This patient has a high serum T j because the oestrogen component of hormone replacement therapy stimulates the synthesis of thyroxine-binding globulin. Thus, to maintain a normal level of the physiologically active Free T the total serum T, needs to be increased. 

The competitive principle of immunoassays can be applied to nonimmuno-logic systems. Any substance that can bind specifically to a macromolecule can be measured using the principle of competitive protein binding. The specific binding macromolecule can be a serum protein such as thyroxine binding globulin, a specific receptor, or an antibody. 

Larsson, M., T. Pettersson, and A. Carlstrom. 1985. Thyroid hormone binding in serum of 15 vertebrate species Isolation of thyroxine-binding globulin and prealbumin analogs. General Comparative Endocrinology 58 360-375. 

L3. Larsen, P. R., Salicylate-induced increases in free triiodothyronine in human serum Evidence of inhibition of triiodothyronine binding to thyroxine-binding globulin and thyroxine-binding prealbumin. /. Clin. Invest. 51, 1125-1134... 

Sterling, K., and Milch, P. O., Thermal inactivation of thyroxine-binding globulin for direct radioimmunoassay of triiodothyronine in serum, J. Clin. Endocrinol. Metab. 38, 866-875 (1974). 

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