Alkaline mucus

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Alkaline mucus is a thick fluid produced by animals which confers tissue protection in an acidic environment, such as in the stomach. [1]

Contents

Properties

Mucus that serves a protective function against acidic environments generally has a high viscosity, though the thickness and viscosity of the mucus layer can vary due to several factors. For example, alkaline mucus in the stomach increases in thickness when the stomach is distended. [2] The pH level of the mucus also plays a role in its viscosity, as higher pH levels tend to alter the thickness of the mucus, making it less viscous. [1] Because of this, invading agents such as Helicobacter pylori , a bacterium that causes stomach ulcers, can alter the pH of the mucus to make the mucus pliable enough to move through. [3] Exposure to atmospheric air also tends to increase the pH level of alkaline mucus. [4]

In humans

In humans, alkaline mucus is present in several organs and provides protection by way of its alkalinity and high viscosity. Alkaline mucus exists in the human eye, stomach, saliva, and cervix. [5]

In the stomach, alkaline mucus is secreted by gastric glands in the gastric mucosa of the stomach wall. [6] Secretion of alkaline mucus is necessary to protect the mucous membrane of the stomach from acids released during digestion. [6] Ulcers can develop as a result of damage caused to the gastric mucosal barrier. [7] Duodenal ulcers have been shown to develop in sites that are in direct contact with pepsin and acids. [8] To prevent damage and protect the mucus epithelium, alkaline mucus secretions increase in the digestive system when food is being eaten. [6]

In the cervix, alkaline mucus has been shown to possess bactericidal properties to protect the cervix, uterus, peritoneal cavity, and vagina from microbes. [9]

Related Research Articles

<span class="mw-page-title-main">Stomach</span> Digestive organ

The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach is involved in the gastric phase of digestion, following chewing. It performs a chemical breakdown by means of enzymes and hydrochloric acid.

<span class="mw-page-title-main">Peptic ulcer disease</span> Ulcer of an area of the gastrointestinal tract

Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines is a duodenal ulcer. The most common symptoms of a duodenal ulcer are waking at night with upper abdominal pain and upper abdominal pain that improves with eating. With a gastric ulcer, the pain may worsen with eating. The pain is often described as a burning or dull ache. Other symptoms include belching, vomiting, weight loss, or poor appetite. About a third of older people have no symptoms. Complications may include bleeding, perforation, and blockage of the stomach. Bleeding occurs in as many as 15% of cases.

<span class="mw-page-title-main">Duodenum</span> First section of the small intestine

The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In mammals it may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest part of the small intestine.

<i>Helicobacter pylori</i> Species of bacteria

Helicobacter pylori, previously known as Campylobacter pylori, is a gram-negative, microaerophilic, spiral (helical) bacterium usually found in the stomach. Its helical shape is thought to have evolved in order to penetrate the mucoid lining of the stomach and thereby establish infection. The bacterium was first identified in 1982 by the Australian doctors Barry Marshall and Robin Warren. H. pylori has been associated with cancer of the mucosa-associated lymphoid tissue in the stomach, esophagus, colon, rectum, or tissues around the eye, and of lymphoid tissue in the stomach.

<i>Helicobacter</i> Genus of bacteria

Helicobacter is a genus of Gram-negative bacteria possessing a characteristic helical shape. They were initially considered to be members of the genus Campylobacter, but in 1989, Goodwin et al. published sufficient reasons to justify the new genus name Helicobacter. The genus Helicobacter contains about 35 species.

<span class="mw-page-title-main">Delta cell</span>

Delta cells are somatostatin-producing cells. They can be found in the stomach, intestine and the pancreatic islets. Delta cells comprise ca 5% of the cells in the islets but may interact with many more islet cells than suggested by their low numbers. In rodents, delta-cells are located in the periphery of the islets; in humans the islet architecture is generally less organized and delta-cells are frequently observed inside the islets as well. In both species, the peptide hormone Urocortin III (Ucn3) is a major local signal that is released from beta cells to induce the local secretion of somatostatin. It has also been suggested that somatostatin may be implicated in insulin-induced hypoglycaemia through a mechanism involving SGLT-2 receptors. Ghrelin can also strongly stimulate somatostatin secretion, thus indirectly inhibiting insulin release. Viewed under an electron microscope, delta-cells can be identified as cells with smaller and slightly more compact granules than beta cells.

<span class="mw-page-title-main">Gastric acid</span> Digestive fluid formed in the stomach

Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the long chains of amino acids of proteins. Gastric acid is regulated in feedback systems to increase production when needed, such as after a meal. Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring a regulated pH. These cells also produce mucus – a viscous barrier to prevent gastric acid from damaging the stomach. The pancreas further produces large amounts of bicarbonate and secretes bicarbonate through the pancreatic duct to the duodenum to neutralize gastric acid passing into the digestive tract.

<span class="mw-page-title-main">Famotidine</span> Medication that reduces stomach acid

Famotidine, sold under the brand name Pepcid among others, is a histamine H2 receptor antagonist medication that decreases stomach acid production. It is used to treat peptic ulcer disease, gastroesophageal reflux disease, and Zollinger-Ellison syndrome. It is taken by mouth or by injection into a vein. It begins working within an hour.

<span class="mw-page-title-main">Gastritis</span> Stomach disease that is an inflammation of the lining of the stomach

Gastritis is inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain. Other possible symptoms include nausea and vomiting, bloating, loss of appetite and heartburn. Complications may include stomach bleeding, stomach ulcers, and stomach tumors. When due to autoimmune problems, low red blood cells due to not enough vitamin B12 may occur, a condition known as pernicious anemia.

<span class="mw-page-title-main">Achlorhydria</span> Medical condition

Achlorhydria and hypochlorhydria refer to states where the production of hydrochloric acid in gastric secretions of the stomach and other digestive organs is absent or low, respectively. It is associated with various other medical problems.

<span class="mw-page-title-main">Brunner's glands</span> Duodenal submucosal cells secreting bicarbonate-rich mucus

Brunner's glands are compound tubular submucosal glands found in that portion of the duodenum which is above the hepatopancreatic sphincter. It also contains submucosa which creates special glands. The main function of these glands is to produce a mucus-rich alkaline secretion i.e. mucous in order to:

<span class="mw-page-title-main">Atrophic gastritis</span> Medical condition

Atrophic gastritis is a process of chronic inflammation of the gastric mucosa of the stomach, leading to a loss of gastric glandular cells and their eventual replacement by intestinal and fibrous tissues. As a result, the stomach's secretion of essential substances such as hydrochloric acid, pepsin, and intrinsic factor is impaired, leading to digestive problems. The most common are vitamin B12 deficiency possibly leading to pernicious anemia; and malabsorption of iron, leading to iron deficiency anaemia. It can be caused by persistent infection with Helicobacter pylori, or can be autoimmune in origin. Those with autoimmune atrophic gastritis (Type A gastritis) are statistically more likely to develop gastric carcinoma, Hashimoto's thyroiditis, and achlorhydria.

<span class="mw-page-title-main">G cell</span>

In anatomy, the G cell or gastrin cell, is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasionally in the pancreas and duodenum. The vagus nerve innervates the G cells. Gastrin-releasing peptide is released by the post-ganglionic fibers of the vagus nerve onto G cells during parasympathetic stimulation. The peptide hormone bombesin also stimulates gastrin from G cells. Gastrin-releasing peptide, as well as the presence of amino acids in the stomach, stimulates the release of gastrin from the G cells. Gastrin stimulates enterochromaffin-like cells to secrete histamine. Gastrin also targets parietal cells by increasing the amount of histamine and the direct stimulation by gastrin, causing the parietal cells to increase HCl secretion in the stomach. G-cells frequently express PD-L1 during homeostasis which protects them from Helicobacter pylori-induced immune destruction

<span class="mw-page-title-main">Vagotomy</span> Surgical procedure

A vagotomy is a surgical procedure that involves removing part of the vagus nerve.

Timeline of peptic ulcer disease and <i>Helicobacter pylori</i>

This is a timeline of the events relating to the discovery that peptic ulcer disease and some cancers are caused by H. pylori. In 2005, Barry Marshall and Robin Warren were awarded the Nobel Prize in Physiology or Medicine for their discovery that peptic ulcer disease (PUD) was primarily caused by Helicobacter pylori, a bacterium with affinity for acidic environments, such as the stomach. As a result, PUD that is associated with H. pylori is currently treated with antibiotics used to eradicate the infection. For decades prior to their discovery, it was widely believed that PUD was caused by excess acid in the stomach. During this time, acid control was the primary method of treatment for PUD, to only partial success. Among other effects, it is now known that acid suppression alters the stomach milieu to make it less amenable to H. pylori infection.

<span class="mw-page-title-main">Stomach disease</span> Medical condition

Stomach diseases include gastritis, gastroparesis, Crohn's disease and various cancers.

Lafutidine (INN) is a second generation histamine H2 receptor antagonist having multimodal mechanism of action and used to treat gastrointestinal disorders. It is marketed in South Korea, Japan and India.

<span class="mw-page-title-main">Human digestive system</span> Digestive system in humans

The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase.

Equine gastric ulcer syndrome (EGUS) is a common cause of colic and decreased performance in horses. Horses form ulcers in the mucosa of the stomach, leading to pain, decreased appetite, weight loss, and behavioral changes. Treatment generally involves reducing acid production of the stomach and dietary management. Unlike some animals, however, stomach rupture is rare, and the main goal of treating is to reduce pain and improve performance of animals used for showing or racing.

Ranitidine bismuth citrate - drug, which has antisecretory and bactericidal action.

References

  1. 1 2 Hwang, S. H.; Litt, M.; Forsman, W. C. (1969). "Rheological Properties of Mucus". Rheologica Acta. 8 (4): 439. doi:10.1007/BF01976227. S2CID   97367831.
  2. ↑ Bickel, Martin; Kauffman, Gordon L. (April 1981). "Gastric gel mucus thickness: Effect of distention, 16,16-dimethyl prostaglandin E2, and carbenoxolone". Gastroenterology. 80 (4): 770–775. doi: 10.1016/0016-5085(81)90139-6 . PMID   6162705.
  3. ↑ Celli, Jonathan P.; Turner, Bradley S.; Afdhal, Nezam H.; Keates, Sarah; Ghiran, Ionita; Kelly, Ciaran P.; Ewoldt, Randy H.; McKinley, Gareth H.; So, Peter; Erramilli, Shyamsunder; Bansil, Rama (25 August 2009). "Helicobacter pylori moves through mucus by reducing mucin viscoelasticity". Proceedings of the National Academy of Sciences. 106 (34): 14321–14326. Bibcode:2009PNAS..10614321C. doi: 10.1073/pnas.0903438106 . PMC   2732822 . PMID   19706518. S2CID   1092202.
  4. ↑ Correa, C.H.M.; Mattos, A.L.G.; Ferrari, A.N. (June 2001). "In situ variation of cervical mucus pH during exposure to atmospheric air". Brazilian Journal of Medical and Biological Research. 34 (6): 767–770. doi: 10.1590/S0100-879X2001000600011 . PMID   11378666.
  5. ↑ Wang, Ying-Ying; Lai, Samuel K.; Ensign, Laura M.; Zhong, Weixi; Cone, Richard; Hanes, Justin (2013). "The Microstructure and Bulk Rheology of Human Cervicovaginal Mucus Are Remarkably Resistant to Changes in PH". Biomacromolecules. 14 (12): 4429–435. doi:10.1021/bm401356q. PMC   3918948 . PMID   24266646.
  6. 1 2 3 "Stomach Histophysiology." World of Anatomy and Physiology, Gale, 2007. Science In Context[ verification needed ]
  7. ↑ Smith, Margaret E.; Morton, Dion G. (2010). The Digestive System. Churchill Livingstone. pp.  39–50. ISBN   9780702033674.
  8. ↑ "Duodenal Ulcer". The British Medical Journal. 2 (5456): 291–292. 1965. doi:10.1136/bmj.2.5456.291-a. JSTOR   25403227. PMC   1845815 . PMID   20790630.
  9. ↑ "An Epitome of Current Medical Literature". The British Medical Journal. 2 (2070): 33–36. 1900. JSTOR   20265592.
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