Hormones, gastrointestinal

The gastrointestinal hormone secretin is prepared by fragment condensation. The tetrapeptide L-Thr-L-Phe-L-Thr-L Ser is coupled to the C-terminal nonadecapeptide of the hormone, and the tetrapeptide L-His-L-Ser- 3-benzyl-L-Asp-Gly is coupled to the tricosa-peptide resulting from the first coupling. 

Explain how the following mechanisms regulate activity of the digestive system intrinsic nerve plexuses, extrinsic autonomic nerves, and gastrointestinal hormones... 

Many neuropeptides were originally identified as pituitary or gastrointestinal hormones 317 Peptides can be grouped by structural and functional similarity 317 The function of peptides as first messengers is evolutionarily very old 318 Various techniques are used to identify additional neuropeptides 319 The neuropeptides exhibit a few key differences from the classical neurotransmitters 319... 

Improved stability with simultaneous preservation of activity has been demonstrated with analogues of glucagon-like peptide-1 and gastric inhibitory polypeptide, two hormones that stimulate the release of insulin. Glucagon-like peptide-1 (GLP-1) is a 30-residue gastrointestinal hormone, ami-dated at the C-terminus that has potential as a treatment for type-2 diabetes. However, GLP-1 is rapidly degraded by dipeptidyl-peptidase IV (EC... 

In the body, insulin is synthesized by j3-cells of Langerhans islets in the pancreas. The rate of formation changes depending on the type of food consnmed, gastrointestinal hormones, and nenronal control. Insnlin circnlating in the body has a biological half-life of about 5 min. It is qnickly broken down by enzymes and is removed from the blood by the liver or kidneys. 

Rehfeld JF 1998 The new biology of gastrointestinal hormones. Physiol Rev 78 1087-1108 Reppert SM, Weaver DR 2002 Coordination of circadian timing in mammals. Nature 418 935-941... 

C. Carcinoid tumors arise from neuroendocrine cells of the gut and secrete serotonin and gastrointestinal hormones, which activate the gastrointestinal tract and result in diarrhea. Most of these tumors have receptors for somatostatin, which inhibit secretion when activated, resulting in reduced activity of the gut. Octreotide is a stable analogue of... 

Johnston, K.L., Clifford, M.N., and Morgan, L.M., Coffee acutely modifies gastrointestinal hormone secretion and glucose tolerance in humans glycemic effects of chlorogenic acid and caffeine. Am. J. Clin. Nutr., 78, 728, 2003. 

Some Pancreatic and Gastrointestinal Hormones and Neurohormones and Their Sequences... 

Snap, W.J.J., S.A. Matarazzo, and S. Cohen. 1978. Effect of eating and gastrointestinal hormones on human colonic myoelectrical and motor activity. Gastroenterology 75 373. 

Vergnano AM, Ferrini F, Salio C, Lossi L, Baratta M, Merighi A (2008) The gastrointestinal hormone ghreUn modulates inhibitory neurotransmission in deep Itiminae of mouse spinal cord dorsal horn. Endocrinology 149 2306-2312... 

Townsend, C. M and Thompson, j, C. (1985). Surgical management of tumors that produce gastrointestinal hormones, Anna. Rev. Med. 36,111-124,... 

Elahi, D., Meneilly, G. S., Hinaker, K. L., Rowe, J. W. and Andersen, D. K. (1986). In Proc. 6th Int. Conf. Gastrointestinal Hormones , Vancouver, BC, p. 18. National Research Council of Canadian Research Journals, Ottawa. 

Sturm, K., C. G. Macintosh, B. A. Parker, J. Wishart, M. Horowitz and I. M. Chapman (2003). Appetite, food intake, and plasma concentrations of cholecystokinin, ghrelin, and other gastrointestinal hormones in undernourished older women and well-nourished young and older women. J Clin Endocrinol Metab 88(8) 3747-55. 

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