Stomach secretion

A compound 148 which shows stomach secretion inhibition (80EUP48555) and the aminotriazolopyridine 149 (90JHC1649) are reduced catalytically to the 5,6,7,8-tetrahydro derivatives. The polarographic behaviour of Trazodone has been studied (87M12). The quaternary salts 150 are reduced by borohydride to the 4,5,6,7-tetrahydro derivatives (94ZOK440). 

The dinitro derivative of compound 2 reacts with anhydro bases of pyridine and quinoline to give zwitterions such as 215 (99RCB1391). Compound 216 has been made from the 3-bromo derivative of compound 3 by reaction with an amine, as an intermediate in the production of stomach secretion inhibitors (80EUP48555),... 

Some of the cells of the stomach secrete hydrochloric acid, a substance that aids in the initial digestive process. 

Gastric secretion. The human stomach secretes 1 to 2 1 of gastric juice per day. The gastric mucosa, which produces these secretions, is divided into two functional regions ... 

The pyloric gland area is located in the remaining distal 20% of the stomach. Secretions of the stomach include ... 

Moreover, some German patents claiming A-unsubstituted 6-arvi-3(2//)-pyridazinones and 4,5-dihydro congeners as stomach secretion inhibitors and ulcer inhibitors have to be cited [ 110-113], Several cardiotonic 6-aryl-pyridazi-nones, recently prepared in Japan, also have been reported to inhibit secretion... 

The problem to be solved with respect to the chemical reactions that constitute metabolism and sustain life is that, without the action of catalysts, they are far too slow. Let s consider the digestion of the proteins themselves, an important constituent of our diet. In an enviromnent similar to that of our digestive system, several tens of thousand years would be required to digest half of the protein content of a typical meal in the absence of a catalyst. Clearly, this will not do. In reality, the stomach secretes one protein catalyst, the enzyme pepsin, and the pancreas secretes several enzymes that catalyze the digestion of proteins. In the presence of these enzymes, dietary proteins are fully digested and reduced to their basic constituents, the amino acids, in a matter of hours. Obviously, these enzymes are enormously potent catalysts." ... 

The stomach secretes pepsinogens, which are inactive proteolytic enzymes, and protons - the high concentration of which initiates hydrolysis of the pepsinogens to form active pepsins, which then continue their own activation, via an autocatalytic, hydrolysis (Appendix 4.1). 

The stomach secretes a peptide known as ghrefin that increases appetite, stimulating energy intake. 

Glycopyrrolate inhibits secretion of digestive juices and restores normal stomach function. It is used for treating stomach ulcers, inflamed intestine, and also as a pre-operational drug for inhibiting excess stomach secretion. A synonym of this drug is robinul. 

Hj-receptor antagonists almost completely block secretion of hydrochloric acid in the stomach in response to most stimuli. These drugs play a major role in treating stomach ulcers associated with hypersecretion, because they have the ability to reduce both the volume of stomach secretion and overall acidity as well as pepsin activity. 

Pharmacokinetics The parietal cells of the stomach secrete intrinsic factor, which regulates the amount of vitamin B-12 absorbed in the terminal ileum. Bioavailability of oral preparations is approximately 25%. Vitamin B12 is primarily stored in the liver. Enterohepatic circulation plays a key role in recycling vitamin B-12 from mainly bile. If plasma-binding proteins are saturated, excess free vitamin B- 2 will be excreted in the kidney. 

The stomach secretes acid and peptic enzymes in response to a number of neural and humoral influences ... 

N.A. Marsdenia condurango R. Br. Condurangogenins, volatile oil, phytosterols.99 Stimulate stomach secretions. A digestive tonic. 

Parietal (oxyntic) cells located predominantly in the body and fundus of the stomach secrete hydrochloric acid. The gastric pH is not constant owing to variation in acid secretion and gastric content. The pH in the stomach at different states of feeding and various parts of the small intestine is shown in Table 2.1. The mucus layer restricts the diffusion of hydrogen ions secreted by the intestinal epithelial cells. As a result, the pH of this 700- m-thick microclimate region is on the order 5.8 to... 

Brainstem Opioid receptors mediate respiration, cough, nausea and vomiting, maintenance of blood pressure, pupillary diameter, and control of stomach secretions. 

Q9 The stomach secretes a very acid gastric juice with a pH of 1.5-2. The mucosa is normally protected from acid by a number of mechanisms. Mucus is produced by the large number of mucous cells in the body and fundus. It contains glycoproteins called mucins, and the mucus produced forms a kind of gel which coats the mucosal surface. In addition these cells secrete HCO3-, which is trapped in the mucus and increases the local pH to form a less acidic environment at the surface of the epithelial cells. 

Nerve endings in the stomach secrete two stimulatory neurotransmitters acetylcholine and gastrin-releasing peptide. Their action is both direct on parietal cells and mediated through the secretion of gastrin from G cells and histamine from ECL cells. Gastrin acts on parietal cells directly and indirectly too, by stimulating the release of histamine. 

The GI tract is the site of absorption for most nutrients. Thus, the GI tract has evolved to facilitate absorption of substances. The peristaltic action of the stomach, secretion of enzymes and hydrochloric acid, the villi and microvilli of the intestine, as well as the rich blood supply and lymphatics in this region, all facilitate absorption. Enteral absorption is generally by far the most effective drug delivery route and, whenever possible, drugs are administered in this way. 

Most dietary proteins are known not to be absorbed in humans as intact forms. Instead, they are usually broken down into amino acids or di- and tripeptides first in the GI tract. The stomach secretes pepsinogen, which is converted to the active protease pepsin by the action of acid. Pepsins, which are most active at pH 2-3, hydrolyze partially digested dietary proteins. The partially digested dietary proteins are further broken down by proteolytic enzymes (peptidases) produced by the pancreas and secreted in the duodenum of the small intestine. The peptidases that break the internal peptide linkages are known as endopeptidases, whereas those that attack the terminal, or end, groups of amino acids are called exopeptidases. 

The stomach secretes hydrochloric acid under the influences of vagus nerve stimulation, gastrin and histamine. Histamine is the most potent stimulus of gastric acid secretion in some animal species studied, such as the horse (Kitchen et al 1998a). Histamine is released by mast cells and enterochromaffin-like cells that are immediately adjacent to the parietal cells. Histamine interacts with two distinct subsets of histamine H2 receptors on the parietal cell membrane, initiating a series of reactions that result in the phosphorylation of protein kinases and increased intracellular calcium within the parietal cell. This, in turn, results in transformation and translocation of the... 

In response to a meal, the stomach secretes hydrochloric acid, causing a reduction in the plasma chloride concentration. The venous blood from the stomach contains an increased amount of bicarbonate. This condition reflects a... 

Gastrointestinal Tract Gastrin Peptide Stomach Secretion of gastric acid, gastric... 

The concept that the stomach secreted acid and digestive enzymes was not fully appreciated until the nineteenth century, although various hypotheses had been mooted since the time of the ancient Greeks. The discovery of gastric acid (7) was the first step to under-... 

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