Pancreatic peptide hormone

Knip, M. Analysis of pancreatic peptide hormones by reversed-phase high-performance liquid chromatography. Horm.Metab.Res., 1984,16, 487-491... 

The reaction has been used to introduce a thiol group in the 2-position of a number of indole-containing compounds, in particular tryptamine, serotonin, skatole and tryptophan, the yields ranging from 65 to 95 per cent (727, 431). The single tryptophan residue of the pancreatic peptide hormone glucagon (29 amino acids) has also been modified by this method to the thioxindolylalanine derivative (727). 

Appetite-suppressing. Neuropqrtide modulators and gut hormones with anorexigenic effects are a-melanocortin-stimulating hormone (a-MSH), cocaine- and amphetamine-regulated transcript (CART), glucagon-like peptide-1 (GLP-1), leptin, insulin, oxyntomodulin, pancreatic peptide PP, peptide YY and PYY3 36, and others. 

The predominant cell type in the pancreatic islets of Langerhans. The main secretory product of the (3 -cell is the peptide hormone insulin which has vital actions for the control of nutrient homeostasis and cellular differentiation. 

CCK, a 33 amino acid regulatory peptide hormone, regulates motility, pancreatic enzyme secretion, gastric emptying, and gastric acid... 

Peptide Hormones Peptide hormones may have from 3 to 200 or more amino acid residues. They include the pancreatic hormones insulin, glucagon, and somatostatin, the parathyroid hormone, calcitonin, and all the hormones of the hypothalamus and pituitary (described below). These hormones are synthesized on ribosomes in the form of longer precursor proteins (prohormones),... 

Many secreted proteins, as well as smaller peptide hormones, are acted upon in the endoplasmic reticulum by tryptases and other serine proteases. They often cut between pairs of basic residues such as KK, KR, or RR.214-216 A substilisin-like protease cleaves adjacent to methionine.217 Other classes of proteases (e.g., zinc-dependent carboxypeptidases) also participate in this processing. Serine carboxypeptidases are involved in processing human prohormones.218 Among the serine carboxypeptidases of known structure is one from wheat219 and carboxypeptidase Y, a vacuolar enzyme from yeast.220 Like the pancreatic metallocarboxypeptidases discussed in Section 4, these enzymes remove one amino acid at a time, a property that has made carboxypeptidases valuable reagents for determination of amino acid sequences. Carboxypeptidases may also be used for modification of proteins by removal of one or a few amino acids from the ends. 

Occasionally, tumors of organs that do not usually produce a given hormone (ectopic tumors) synthesize and secrete peptide hormones, as in ACTH synthesis by certain lung tumors and GRH production from a pancreatic islet... 

Peptide hormones (aglandular hormones), whose action makes possible the secretory processes necessary for the normal course of the digestive process, are formed in the gastric and intestinal mucosae and in the excretory pancreatic tissue (islets of Langer-hans). 

Neuropeptide Y (NPY) receptors are a class of G-protein-coupled receptors that are activated by the closely related peptide hormones NPY, peptide YY and pancreatic polypeptide. These receptors are involved in control of a diverse set of behavioural processes, including appetite, circadian rhythm and anxiety. AgRP is a receptor antagonist of CNS melanocortin receptors and appears to have an important role in the control of food intake. Hypothalamic POMC neurons are important mediators in the regulation of feeding behaviour, insulin levels and ultimately body weight. 

Amylin is a 37-residue peptide hormone first discovered independently by two research groups in 1987 (78, 79). Amylin is secreted by pancreatic 3-cells at the same time as insulin (in a roughly 100 1 ratio), and it is the major component of diabetes-associated islet amyloid deposits. It inhibits basal and insulin-stimulated glucose uptake as well as glycogen synthesis by soleus muscles (80). Thus, amylin is also known as a diabetes-associated peptide. 

Pancreatic polypeptide is a peptide hormone secreted by pancreatic polypeptide-producing cells in the islets of Langerhans... 

Secretin is a peptide hormone that stimulates pancreatic secretion. It has been used to treat autism, without success (1-3). 

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