Oxyntic mucosa

When the gastritis induced by H. pylori is confined to the antrum, the increase of gastrin and the reduction of somatostatin released by the G and D cells in the antrum, respectively, will increase the drive for acid secretion from the preserved oxyntic mucosa [45]. This increased... 

In another subpopulation, the Helicobacter gastritis extends into the corpus resulting in atrophy of the oxyntic mucosa and reduced acid secretion. It is not yet clear to which extent these manifestations reflect different stages or different courses of Helicobacter-induced gastritis [41, 45], H. pylori thus emerges as the main cause of acquired gastric hypochlorhydria [46-48],... 

Pernicious anemia is the classical autoimmune disease associated with immunologically mediated injury of the oxyntic mucosa resulting in achlorhydria [52], Parietal cell antibodies are also present in other autoimmune diseases [52, 53] and immunopathies [54] that can be associated with hypo- or achlorhydria. 

Figure 22.2 NIS mRNA in rat gastric mucosa. Section of rat stomach oxyntic mucosa autoradiographically labeled for NIS mRNA by a 33-mer oligonucleotide probe complementary to rat thyroid NIS mRNA 570-602 and 3 -endtailed with S-dATR Intense labeling (black silver grains) is seen in the gastric surface epithelium. Magnification X200.

Figure 22.3 Gastric NIS in rat fetus. Section of oxyntic mucosa from a rat fetus at E19 stained by immunohistochemistry with a polyclonal antiserum raised against the eight C-terminal amino acids of rat-NIS. The site of the antigen-antibody reaction was revealed by FITC-labeled pig anti-rabbit IgG. Staining is intense in the basolateral cell membranes of the epithelial surface cells. Magnification x200.

Figure 1-16. Ordinates, carbonic anhydrase concentration in arbitrary units in slices of oxyntic mucosa of the cat. Abscissae, 1,000 oxyntic cells in adjacent slices of the oxyntic mucosa of the cat. (From Davenport H W. Gastric carbonic anhydrase. I Physiol Lond 97 32-43, 1939.)... 

The amphibian oxyntic mucosa is composed, aside from the connective tissue. 

Figure 5-8. The distribution of histamine in the oxyntic mucosa of human subjects. (From Smith AN. The distribution of histamine in the human gastric tissue. Clin Sci 18 533-541, 1959.)...

Table 5-2. Percentage Distribution of Radioactive Methyl Histamines in Oxyntic Mucosa of the Stomach and of Heidenhain Pouches and in Gastric juice After Intravenous Infusion of C-Histamine for 140 Minutes...

In their analysis of the chemical phase of gastric secretion, Pavlov s students found that meat extracts applied to the oxyntic mucosa do not stimulate acid secretion. Instead, Pavlov s students Savich and Zeljony showed before the First World War... 

Jane Bowie and her colleagues at Bedford College in London thought they had inhibited acid secretion when they irrigated an anesthetized cat s oxyntic mucosa with 5 mN NaF. When J. N. Hunt at Guy s Hospital repeated Bowie s experiments, he too found that the procedure reduced the concentration of acid secreted following histamine stimulation, but he also found that 5 mN NaF increased the rate of disappearance of HCl instilled into the stomach and caused a 40-fold increase in the rate of disappearance of " Na from a solution bathing the mucosa. Hunt offered as one of three explanations that treatment with NaF increased the permeability of the mucosa. ... 

Physiological evidence of increased permeability was provided by the early experiments with eugenol, fatty acids, and aspirin in which both insorption and exsorption of Na were measured. In the undamaged oxyntic mucosa of the dog there is a small active insorption of and that probably accounted for part of... 

I could not use radioiodinated plasma albumin to measure the plasma component of shed fluid, for iodide liberated by degradation of the protein is secreted by the oxyntic mucosa in a very high juice-to-plasma ratio. I turned to albumin labeled with Cr. 

In this instance I estimated plasma proteins only by the radioactivity of Cr. Later I found several circumstances that made the oxyntic mucosa shed enormous amounts of plasma proteins without any bleeding whatever, and in those I positively identified the proteins by their ability to clot and by their electrophoretic pattern.Consequently, I had no doubt that mucosal permeability could be increased. 

Komarov, in addition, identified a small amount of gastrin in the duodenal mucosa but none in the jejunal mucosa. These facts were long used to explain the intestinal phase of gastric secretion. He also noted that there was no gastrin evident in the oxyntic mucosa but a small amount present in the mucosa of the cardia. Once his manuscript had been published in 1938, it was evident that all parties, except Ivy, accepted the reality of gastrin as a chemical and physiologic entity. 

In humans, EC cells are found in the antrum and oxyntic mucosa. Their main secretory product is 5-hydroxytryptamine (5-HT). It is this monoamine that reduces silver and chromium, constituting the argentaffin and chromaffin reactions, respectively. D cells secrete somatostatin and are distributed throughout the antral and oxyntic mucosa but are more numerous in the antrum. They display argyrophilic staining (i.e., they accumulate silver predpitates from a silver nitrate solution when treated with an exogenous... 

The ECL cells are subepithelial and are not in direct contact with the lumen of the stomach. They are therefore not affected directly by gastric contents. The other cell type of the oxyntic mucosa that contains histamine is the mast cell that, in different forms, is found throughout the gastrointestinal tract. It was initially thought that a spedalized type of mast cell was... 

The exact source of somatostatin acting on the oxyntic mucosa has been a matter of some debate, because cells containing somatostatin-D cells-are present both in the antrum and in the oxyntic mucosa. Additionally, postganglionic nerve fibers in the submucosa contain somatostatin, which may act as a neural transmitter. Because mucosal D cells, both in the antrum and in the fundus, possess elongated basal processes, somatostatin released locally may function as a paracrine regulator. 

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