Changes in the Structure of the Mucous Gel on the Mucosal Surface of the Stomach in Association with Peptic Ulcer Disease

Younan, Fekry; Pearson, Jeffrey P.; Allen, Adrian; Venables, C W

doi:10.1016/s0016-5085(82)80241-2

Cited by 136 publications

(28 citation statements)

References 17 publications

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“…Pepsin 1 increases from 4% of the total pepsin activity in gastric juice from non-symptomatics to 17 and 23% in juice from duodenal Agents in 4 mL H,O were instilled into oesophageal, pylorus ligated rat stomachs for 2 h followed by equilibration with instillate for 30 min of 0.1 mol/L HC1/0.05 mol/L NaCl pH 1 and then 4 x 30 min instillates of pepsin 5 mg/mL in 0.1 mol/L HC1/0.05 NaCl pH 1. and gastric ulcer patients, respectively, while total pepsin activity is not significantly changed.2' Further, chis is associated with an impaired structure of the adherent gastric mucus barrier in gastric ulcer patients. 22 The proportion of the gel forming polymeric much in adherent mucus from gastric ulcer patients is significantly reduced to a mean of 35% from a mean of 67% in non-symptomatics. This decreased polymeric rnucin content can be directly correlated to a rheologically weaker mucus gel structure.…”

Section: Discussionmentioning

confidence: 98%

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E₂, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate

Copeman

Matuz

Leonard

et al. 1994

J of Gastro and Hepatol

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Mucus and bicarbonate secretions have been widely implicated as an important pre-epithelial protective barrier against autodigestion of the gastric mucosa by acid and pepsin. Evidence from several independent studies shows there is a continuous layer of resilient viscoelastic mucus gel adherent to the surface of the gastroduodenal mucosa. The median thickness of the adherent gastric mucus layer in humans is 180 microns, range 50-450 microns. The epithelial bicarbonate secretion permeates the unstirred matrix of mucus gel neutralizing luminal acid and establishing a pH gradient within the gel. In the duodenum, evidence supports the mucus bicarbonate barrier as a major protective mechanism against acid aggression. The adherent mucus gel, by acting as an effective 'permeability' barrier to pepsin, protects the underlying sensitive mucosa from digestion. However, pepsin slowly digests mucus gel at its luminal surface to produce soluble degraded mucin. In a rat gastric damage model in vivo, pepsin in excess digests the gastric mucus barrier sufficiently rapidly to outweigh new mucus secretion and lead to breaching of the mucus barrier with the formation of small punctate ulcers in the epithelium accompanied by mucosal haemorrhage. The mucus secretagogue 16,16 dimethyl prostaglandin E2 and the muco-adhesive carbopol-polyacrylate both fully protected the mucosa against pepsin damage by enhancing the protective properties of the mucus barrier. Sucralfate and bismuth subsalicylate were partially effective in protection against pepsin damage but this protection was mainly mediated at the level of the mucosa. In peptic ulcer disease, there is increased mucolytic (mucus degrading) activity in gastric juice and this is associated with an impaired mucin polymeric structure and a weaker mucus barrier.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionmentioning

confidence: 98%

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E₂, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate

Copeman

Matuz

Leonard

et al. 1994

J of Gastro and Hepatol

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“…In duodenal and gastric ulcer patients the mucus glycoprotein in the surface gel layer has been reported to partially change into a lower molecular weight or less polymerized mucin. 35 Colonization of H. pylori signi®cantly decreased the gel-forming polymeric mucin content in adherent mucus, and altered the threedimensional network ultrastructure of the gastric mucus gel layer, giving it a fragile, lumpy, globular appearance. 9,36 Further, some experimental studies using rat 7,37 and pig 8 also demonstrated that the proportion of degraded and lower molecular weight glycoprotein in the mucus gel layer increased in injured stomachs caused by aspirin or bile duct ligation.…”

Section: Discussionmentioning

confidence: 99%

Ecabet sodium, a novel locally‐acting anti‐ulcer agent, protects the integrity of the gastric mucosal gel layer from pepsin‐induced disruption in the rat

Kinoshita¹,

Endo²,

Yasoshima³

et al. 1999

Aliment Pharmacol Ther

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Background : Ecabet sodium, a novel non‐systemic anti‐ulcer agent, possesses high affinity to gastric adherent mucus, which plays an important role in the protection of the gastric epithelium against acid and pepsin. Aim : To assess the effect of ecabet on pepsin‐induced degradation of the structure of the mucus gel layer. Methods : Everted sacs of rat stomach were incubated in HCl solution containing pepsin with or without ecabet. Pepsin‐induced release of the cleaved peptides and hexosamine from the sacs was determined. Changes in the molecular size of glycoproteins in the adherent mucus (using gel filtration methods) and in the morphology of the epithelium (using both light and scanning electron microscopy) were also examined. Results : Ecabet reduced the pepsin‐induced release of peptides and hexosamine, depending on its content in the adherent mucus. Pepsin treatment partially lowered the molecular weight of native glycoproteins in the adherent mucus, caused exfoliation of the epithelial cells, and degraded the network‐like ultrastructure of the mucus layer, giving it a lumpy, globular appearance. Ecabet prevented both the pepsin‐induced molecular size shift in mucus glycoproteins, and morphological alteration of the epithelium, including ultrastructural derangement of the mucus gel layer. Conclusion : Ecabet protects the polymeric structure of mucus glycoproteins from proteolytic degradation by pepsin, and thus maintains integrity of the gastric mucus gel layer.

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“…The mucus barrier is made of mucus, lipids and proteins. These form a continuous gel and along with bicarbonate secretion protect the stomach from acidic insult [20]. Cytoprotective agents like prostaglandins have shown to increase the mucus gel thickness but does not protect the surface epithelium in contrast to protection of the deeper layers [21].…”

Section: Stimulation Of Mucus and Bicarbonate Secretionmentioning

confidence: 99%

Pharmacotherapy of Peptic Ulcer Disease and Latest Research

Ommurugan¹,

Rao²

2019

Gastritis - New Approaches and Treatments

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Peptic ulcers have unquestionably been a disease of the twentieth century. Epidemiological data for this disease and its complications have shown striking variation in incidence and prevalence. Various drugs have been used to treat peptic ulcer disease like proton-pump inhibitors, histamine (H2) receptor antagonists, prostaglandin analogues and sucralfate. Because these drugs are complex, expensive and toxic, efforts have been constantly made to find a suitable, palliative and curative agent for the treatment of peptic ulcer disease from natural products of plant and animal origin. Recently, antioxidants are being used to treat peptic ulcer disease. Antioxidants help in scavenging the free radicals and controlling the oxidative stress responsible for the progression of peptic ulcer.

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Changes in the Structure of the Mucous Gel on the Mucosal Surface of the Stomach in Association with Peptic Ulcer Disease

Cited by 136 publications

References 17 publications

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E₂, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E₂, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate

Ecabet sodium, a novel locally‐acting anti‐ulcer agent, protects the integrity of the gastric mucosal gel layer from pepsin‐induced disruption in the rat

Pharmacotherapy of Peptic Ulcer Disease and Latest Research

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Changes in the Structure of the Mucous Gel on the Mucosal Surface of the Stomach in Association with Peptic Ulcer Disease

Cited by 136 publications

References 17 publications

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E2, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E2, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate

Ecabet sodium, a novel locally‐acting anti‐ulcer agent, protects the integrity of the gastric mucosal gel layer from pepsin‐induced disruption in the rat

Pharmacotherapy of Peptic Ulcer Disease and Latest Research

Contact Info

Product

Resources

About

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E₂, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate

The gastroduodenal mucus barrier and its role in protection against luminal pepsins: The effect of 16,16 dimethyl prostaglandin E₂, carbopol‐polyacrylate, sucralfate and bismuth subsalicylate