Thyrotropin-releasing hormone structure

Werner, U., T. Kissel, and W. Stuber. Effects of peptide structure on transport properties of seven thyrotropin releasing hormone (TRH) analogues in a human intestinal cell line (Caco-2), Pharm. Res. 1997, 14, 246-250... 

Neuropeptides are often grouped by their structural similarity or tissue source. Among these are the hypothalamic releasing factors (e.g., corticotrophin-releasing factor [CRF], thyrotropin-releasing hormone), anteior pituitary hormones (e.g., adrenocorticotrophic hormone [ACTFI], follicle-stimulating hormone [FSFI]), and posterior pituitary hormones... 

The pituitary gland is involved in feedback regulation of thyroid activity High levels of T4 in the bloodstream result in inhibition of TSH secretion. Low levels of T4 result in an increase in TSH secretion. These effects are dependent on the conversion of T4 to T3 within the pituitary, fhe activity of the pituitary is controlled by thyrotropin-releasing hormone (TRH), a hormone synthesized in the hypothalamus. TRH is a tripeptide with the structure pyroglutamate-histidine-proline-NH . Note the C-terminal amide group, which is required for the activity of many peptide hormones. TRH stimulates the synthesis and secretion of TSH. Apparently TRH is involved in regulating the sensitivity of the pituitary to the inhibitory feedback control mechanism mentioned earlier. 

Thyrotropin-releasing hormone (TRH) is a tripeptide amide with the following structure ... 

Gesundheit, N., et al. (1987). Effect of Thyrotropin-releasing Hormone on the Carbohydrate Structure of Secreted Mouse Thyrotropin, J Biol. Chem. 262 5197-5203. 

Thyrotropin releasing hormone (TRH). Dr. Ouillemin has presented today an excellent account of his studies on sheep TRH. We would simply like to add that the properties of bovine and porcine TRH are similar to those described by Dr. Ouillemin for ovine TRH. We have prepared diat we think is homogenous pig TRH (3, 10). Porcine TRH is not a polypeptide, but studies by nuclear magnetic resonance and mass spectra have not yet revealed its full structure. 

Thyrotropin-releasing hormone (TRH) causes the release of thyrotropin from the pituitary gland, which then stimulates the thyroid gland. Examine its structure and comment on one unusual structural feature. 

Prolactin releasing factor (PRF), prolactin releasing hormone, prolactoliberin a hormone thought to be identical with thyrotropin releasing factor, llie structure of Prolactin release inhibiting hormone (PIH) (prolactostatin) is unknown. PRF promotes, whereas PIH inhibits the synthesis and secretion of prolaction by the anterior pituitary. 

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