Thyrotropin

Molecular formula C1039H1602N274O307S27 Molecular weight 23709.28 CAS Registry No 9002-71-5 Merck index 13,9870 

Mobile phase Gradient. A was 50 mM pH 7.0 phosphate buffer. B was MeCN 50 mM pH 7.0 phosphate buffer 50 50. A B from 75 25 to 0 100 over 40 min. (Place a silica column packed with 7.9-12.4 p.m LiChrosorb Si-60 silica between pump and injector.) Flow rate 0.5 Injection volume 5-200 Detector UV 280 

Ezequiel de Oliveira, J. de Mendonpa, F. Peroni, C.N. Bartolini, P. Ribela, M.T.C.P. Determination of Chinese hamster ovary cell-derived recombinant thyrotropin by reversed-phase liquid chromatography, J.Chromatogr.B, 2003, 787, 345-355. 

Mobile phase 20 mM pH 7.0 phosphate buffer containing 150 mM NaCl Flow rate 1 Injection volume 5-50 Detector UV 280 ( ) 

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ITiYROID AND ANTITTiYROID PREPARATIONS] (Vol 24) Thyrotropin-releasing hormone... 

Thyrotropin-releasing factor (TRF) = thyrotropin-releasing hormone (TRH) = thyroliberin. 

The BZ stmcture also has provided a molecular scaffold for a number of peptide receptor ligands (26). Antagonists for the cholecystokinin (CCK-A) receptor, eg, devazepide (65), the thyrotropin-releasing hormone (TRH) receptor, eg, midazolam (66), and the /i -opiate receptor, eg, tifluadom (67), as well as a series of ras famyl transferase inhibitors, eg, BZA-2B (68) (30) have been identified (Table 4). 

DUP996 [105431-72-9] nicotine [54-11-5] antigalanin agents somatostatin [51110-01-0] thyrotropin-releasing hormone [24305-27-9]... 

Leucine residues 2, 5, 7, 12, 20, and 24 of the motif are invariant in both type A and type B repeats of the ribonuclease inhibitor. An examination of more than 500 tandem repeats from 68 different proteins has shown that residues 20 and 24 can be other hydrophobic residues, whereas the remaining four leucine residues are present in all repeats. On the basis of the crystal structure of the ribonuclease inhibitor and the important structural role of these leucine residues, it has been possible to construct plausible structural models of several other proteins with leucine-rich motifs, such as the extracellular domains of the thyrotropin and gonadotropin receptors. 

Regulatory proteins Insulin Somatotropin Thyrotropin lac repressor NEl (nuclear factor 1) Catabolite activator protein (CAP) API... 

Paschke R, Ludgate M (1997) The thyrotropin receptor in thyroid diseases. N Engl J Med 337 1675-1681... 

Most GPCRs interact with and activate more than one G-protein subfamily, e.g., with Gs plus Gq/n (histamine H2, parathyroid hormone and calcitonin recqrtors), Gs plus G (luteinising hormone receptor, 32-adrenoceptor) or Gq/11 plus G12/13 (thromboxane A2, angiotensin ATb endothelin ETA receptors). Some receptors show even broader G-protein coupling, e.g., to Gi, Gq/n plus Gi n ( protease-activated receptors, lysophosphatidate and sphingosine-1-phosphate receptors) or even to all four G-protein subfamilies (thyrotropin receptor). This multiple coupling results in multiple signaling via different pathways and in a concerted reaction of the cell to the stimulus. 

Thyrotropin (TSH) regulates the production and secretion of thyroid hormones as well as thyroid epithelial cell growth via the TSH receptor. The TSH receptor belongs to the family of G protein-coupled receptors. It is composed of 764 amino acids. The receptor contains a long hydrophilic region orientated towards the exterior of the cell (ectodomain), 7 hydrophobic transmembrane domains and a short cytoplasmic region. 

In mammals, peptide hormones typically contain only the a-amino acids of proteins finked by standard peptide bonds. Other peptides may, however, contain nonprotein amino acids, derivatives of the protein amino acids, or amino acids finked by an atypical peptide bond. For example, the amino terminal glutamate of glutathione, which participates in protein folding and in the metabolism of xenobiotics (Chapter 53), is finked to cysteine by a non-a peptide bond (Figure 3—3). The amino terminal glutamate of thyrotropin-... 

FSH Follicle-stimulating hormone TSH Thyrotropin-stimulating hormone... 

FIGURE 41-1. Hypothalamic-pituitary-thyroid axis. Thyrotropinreleasing hormone (TRH) is synthesized in the neurons within the paraventricular nucleus of the hypothalamus. TRH is released into the hypothalamic-pituitary portal circulation and carried to the pituitary, where it activates the pituitary to synthesize and release thyrotropin (TSH). TSH activates the thyroid to stimulate the synthesis and secretion of thyroxine (T4) and triiodothyronine (T3). T4 and T3 inhibit TRH and TSH secretion, closing the feedback loop. 

Prolactin is an essential hormone for normal production of breast milk following childbirth. It also plays a pivotal role in a variety of reproductive functions. Prolactin is regulated primarily by the hypothalamus-pituitary axis and secreted solely by the lactotroph cells of the anterior pituitary gland. Under normal conditions, secretion of prolactin is predominantly under inhibitory control by dopamine and acts on the D2 receptors located on the lactotroph cells. Increase of hypothalamic thyrotropin-releasing hormone (TRH) in primary hypothyroidism can stimulate the release of prolactin. 

B41. Bonte, H. A., Vermes, I., and van der Sluijs Veer, G., Analytical and clinical evaluation of three sensitive thyrotropin assays. Ann. Clin. Biochem. 26,508-512 (1989). 

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