Gastric mucosal barrier

Mucus is produced by the mucus neck cells and by the surface epithelial cells of the stomach wall. A thick layer of mucus adheres to the wall of the stomach, forming the gastric mucosal barrier. The function of this barrier is to protect the gastric mucosa from injury — specifically, from the corrosive actions of HCl and pepsin. Together with bicarbonate ion released into the lumen of the stomach, mucus neutralizes the acid and maintains the mucosal surface at a nearly neutral pH. 

Desai, H.G., Venugopalan, K., Philipose, M. (1977). Effect of red chili powder on gastric mucosal barrier and acid secretion. Indian J. Med. Res. 66 440-8. 

Gastric ulcer A peptic ulcer located in the stomach is called a gastric ulcer, caused by the breakdown of the gastric mucosal barrier, typically by Helicobacter pylori bacteria. Gastric ulcer results in burning pain 30 minutes to an hour and a half after eating. 

Figure 7-3. Relation between [Na ] and [H ] in the secretion of five Heidenhain pouch dogs stimulated with histamine injections before ( ) and after (x) irrigation of the pouches with eugenol. The thick line is the regression calculated by least squares, and the two finer lines define the limits of one standard deviation about the mean. The dotted line is regression calculated by the method of Bartlett Biometrics 5 207, 1949. (From Davenport HW, Warner HA, Code CF. Functional significance of gastric mucosal barrier to sodium. Gastroenterology 47 A42- 52, 1964.)...

After I returned to Ann Arbor, Code wrote up the results, and after I had offered some minor suggestions he sent the manuscript to Gastroenterology for publication. He called the paper Functional Significance of Gastric Mucosal Barrier to Sodium. " ... 

Teorell had done years before. The results showed that after the mucosa had been treated with eugenol, acid that was secreted in response to histamine stimulation disappeared by back-diffusion into the mucosa in exchange for sodium. The gastric mucosal barrier had been broken. 

I was looking for a new research problem, and with Code s permission I undertook to investigate (1) the nature of the gastric mucosal barrier and (2) what happens to the stomach when acid diffuses back into the mucosa through a broken barrier. The program of research continued after 1975, but only the results obtained before 1975 are summarized here. 

Does ischemia cause a breakdown of the gastric mucosal barrier ... 

Ischaemia and the presence of acid are the prerequisite pathogenic features. The gastric mucosal barrier in such patients is often highly permeable to acid and this phenomenon may also contribute significantly to the production of these lesions. ... 

Finally, I decided to combine ischemia with an attack on the barrier by including bile salts in the irrigation fluid. A few experiments gave equivocal results. I should have done more and better experiments, but by that time Barr had left, and I was tired of the project. I wrote up the results and submitted them for publication under the title Failure of Ischemia to Break the Dog s Gastric Mucosal Barrier. 

Figure 8-10. Aminopyrine clearances, net fluxes of and Na" in a dog s Heiden-hein pouch irrigated with 100 mN HCI, and simultaneous volume secretion by the pouch. At the left, the lines represent the mean results in three experiments done on different days when the pouch was stimulated by continuous intravenous infusion of a mixture of pentagastrin and bethanechol. The lines in the middle represent the results obtained in an experiment in which norepinephrine was infused without pentagastrin and bethanechol. The lines on the right represent the results of an experiment in which pentagastrin, bethanechol, and norepinephrine were infused together. (From Davenport HW, Barr LL. Failure of ischemia to break the dog s gastric mucosal barrier. Gastroenterology 65 6 9-624, 1973.)...

Davenport HW, Warner HA, Code CF. Functional significance of gastric mucosal barrier to sodium. Gastroenterology 41 142-152, 1964. 

Davenport HW, Barr LL. Failure of ischemia to break the dog s gastric mucosal barrier. Gastroenterology 65 619-624,1973. This paper may hold the record for delay in publication received December 17, 1971 accepted April 3, 1973. The delay was caused by my withdrawing the MS in what Morton Grossman called childish resentment of a referee s comments. 

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