Antral gastrin

Harper et al. (HI) found no significant difference between the concentration of gastrin in antral extracts from cases of gastric ulcer and normal individuals. In duodenal ulcer, however, antral gastrin concentration was about twice that in gastric ulcer, and its concentration correlated with both the basal secretion and the response intensity to a maximal histamine stimulation. 

However, although calcium salts can produce short-term rehef from dyspepsia, calcium ions stimulate antral gastrin release, and hence gastric acid secretion, making them unsuitable for long-term treatment of peptic disorders (1). 

H6. Hilsted, L., and Hansen, C. P., Co-release of amidated and glycine-extended antral gastrins after a meal. Am. J. Physiol. 255, G665-G669 (1988). 

The technique of the gastrin radioimmunoassay was further modified by Yalow and Berson, and it became apparent that plasma levels could differentiate between patients with various disease states. In addition, it was evident that hypergastrinemia associated with achlorhydria could be inhibited by oral administration of 300 mL of 0.1 N HCl by straw or by stomach tube. This confirmed the role of luminal pH in the regulation of antral gastrin secretion and of a class of HCl to antral glands. 

The major gastric factor that affects motility and the rate of emptying is the volume of chyme in the stomach. As the volume of chyme increases, the wall of the stomach becomes distended and mechanoreceptors are stimulated. This elicits reflexes that enhance gastric motility by way of the intrinsic and vagus nerves. The release of the hormone gastrin from the antral region of the stomach further contributes to enhanced motility. 

Gastrin inhibition. Hydrogenated oil, administered to adult rats, produced a significant reduction in antral and plasma gastrin concentrations . Gastrointestinal effect. Oil, administered to rats, induced the secretion of surfactantlike particles in the small intestine ". Genotoxic activity. Coconut oil acid diethanolamine condensate with or without S9 activation enzyme, in cell culture, pro-... 

The parietal cell contains receptors for gastrin (CCK-B), histamine (H2), and acetylcholine (muscarinic, M3) (Figure 62-1). When acetylcholine (from vagal postganglionic nerves) or gastrin (released from antral G cells into the blood) bind to the parietal cell receptors, they cause an increase in cytosolic calcium, which in turn stimulates... 

It is likely that the hormone gastrin, which is secreted by the stomach antral mucosa in response to distension, also plays some role in this effect because gastrin has an excitatory effect on the colon and an inhibitory effect on the ileocecal valve, thus allowing rapid emptying of ileal contents into the cecum. This in turn elicits increased colonic activity. 

GW, MacLeod JK, Preston J, Sheppard RC, Morley JS. Antral hormone gastrin. Synthesis of gastrin. Nature 1964 204 933-934. 30. 

McDonald TJ, Jornvall H, Nilsson G, Vague M, Ghatei M, Bloom SR, Mutt V. Characterization of a gastrin releasing peptide from porcine non-antral gastric tissue. Biochem. Biophys. Res. Commun. 1979 90 227-233. 

It is not as yet known whether gastrin enters the human gastric juice from the antral mucosa under normal or pathological conditions. 

C69a. Gregory, R. A., and Tracy, H. J., The constitution and properties of two gastrins extracted from hog antral mucosa. Part I. The isolation of two gastrins from hog antral mucosa. Part II. The properties of two gastrins isolated from hog antral mucosa. Gut 5, 103-114 (1964). 

Gastric acid is secreted by the parietal cells in gastric mucosa. The basolateral membranes of these cells contain receptors for the three main stimulants of acid secretion, namely gastrin (from antral G cells), histamine (from enterochromaffin-Uke cells) and acetylcholine (from vagal efferents). The action... 

The fasting stomach pH is about 2 to 6. In the fed state, the stomach pH is about 1.5 to 2, due to hydrochloric acid secreted by parietal cells. Stomach acid secretion is stimulated by gastrin and histamine. Mixing is intense and pressurized in the antral part of the stomach, a process of breaking down large food particles described as antral milling. Food and liquid are emptied by opening the pyloric sphincter into the duodenum... 

Gastric acid secretion can be inhibited by several mechanisms including acid in the stomach (pH 3 inhibits gastrin release), acid in the duodenum, the presence of fat in the pancreas, and hypertonic fluids or hyperglycemia. Somatostatin, a hormone produced by antral mucosal endocrine cells (D cells), inhibits the release of gastrin by directly inhibiting the parietal cells. Somatostatin is also present in other GI tissue and the pancreas. C cells, endocrine cells in the proximal small intestine, secrete secretin in response to mucosal acidification, which also decreases gastric secretion. 

Maximal secretion of gastrin occurs at an antral pH of 5 to 7. At pH 2,5, secretion is reduced by about 80% maximal... 

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