Faculty Opinions recommendation of Hepcidin is localised in gastric parietal cells, regulates acid secretion and is induced by Helicobacter pylori infection.

Actin cytoskeleton plays an important role in the establishment of epithelial cell polarity. Cdc42, a member of Rho GTPase family, modulates actin dynamics via its regulators, such as IQGAP proteins. Gastric parietal cells are polarized epithelial cells in which regulated acid secretion occurs in the apical membrane upon stimulation. We have previously shown that actin isoforms are polarized to different membrane domains and that the integrity of the actin cytoskeleton is essential for acid secretion. Herein, we show that Cdc42 is preferentially distributed to the apical membrane of gastric parietal cells. In addition, we revealed that two Cdc42 regulators, IQGAP1 and IQGAP2, are present in gastric parietal cells. Interestingly, IQGAP2 is polarized to the apical membrane of the parietal cells, whereas IQGAP1 is mainly distributed to the basolateral membrane. An IQGAP peptide that competes with full-length IQGAP proteins for Cdc42-binding in vitro also inhibits acid secretion in streptolysin-O-permeabilized gastric glands. Furthermore, this peptide disrupts the association of IQGAP and Cdc42 with the apical actin cytoskeleton and prevents the apical membrane remodeling upon stimulation. We propose that IQGAP2 forms a link that associates Cdc42 with the apical cytoskeleton and thus allows for activation of polarized secretion in gastric parietal cells.

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Helicobacter pylori infection is associated with decreased gastric acid secretion in young bangladesm children

Gastroenterology ◽

10.1016/s0016-5085(00)85038-6 ◽

2000 ◽

Vol 118 (4) ◽

pp. A727

Author(s):

Shafiqul A. Sarker ◽

Pius Hildebrand ◽

George K. Fuchs

Keyword(s):

Helicobacter Pylori ◽

Acid Secretion ◽

Gastric Acid Secretion ◽

Gastric Acid ◽

Helicobacter Pylori Infection

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Effect of Histamine H2-Receptor Antagonists on Vitamin B12 Absorption

Annals of Pharmacotherapy ◽

10.1177/106002809202601018 ◽

1992 ◽

Vol 26 (10) ◽

pp. 1283-1286 ◽

Cited By ~ 29

Author(s):

Rex W. Force ◽

Milap C. Nahata

Keyword(s):

Acid Secretion ◽

Healthcare Providers ◽

Intrinsic Factor ◽

Parietal Cells ◽

Data Sources ◽

Vitamin B ◽

Receptor Antagonists ◽

Histamine H2 Receptor ◽

Medline Search ◽

Gastric Parietal Cells

OBJECTIVE: To discuss the potential of histamine H2-receptor antagonists (H2RAs) to cause malabsorption of vitamin B12 (cyanocobalamin). DATA SOURCES: Pertinent literature was identified via a MEDLINE search. Journals and references cited in published articles also were used as data sources. STUDY SELECTION: Studies evaluating the effect of H2RAs on vitamin B12 absorption were reviewed. DATA SYNTHESIS: H2RAs decrease acid secretion by the gastric parietal cells. Gastric acid and pepsin produced by these cells are required for the cleavage of vitamin B12 from dietary sources. Intrinsic factor (IF), also produced by gastric parietal cells, is required for vitamin B12 absorption from the gastrointestinal tract. Although H2RAs have not conclusively been shown to decrease IF secretion, studies have demonstrated a significant reduction in food-bound vitamin B12 absorption secondary to decreased acid secretion in patients taking these drugs. CONCLUSIONS: H2RAs have the potential to cause vitamin B12 deficiency. This may be important in patients with inadequate stores of vitamin B12 (e.g., poor diet), particularly those receiving H2RA therapy continuously for more than two years. Healthcare providers should be aware of this potential adverse effect.

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Inhibition of Acid Secretion in Gastric Parietal Cells by the Ca2+/ Calmodulin-Dependent Protein Kinase II Inhibitor KN-93.

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)50001-4 ◽

1994 ◽

Vol 64 ◽

pp. 90

Author(s):

NAOTO MAMIYA ◽

JAMES R. GOLDENRING ◽

YASUHIRO TSUNODA ◽

IRVIN M. MODLIN ◽

KIYOSHI YASUI ◽

...

Keyword(s):

Protein Kinase ◽

Acid Secretion ◽

Parietal Cells ◽

Dependent Protein Kinase ◽

Protein Kinase Ii ◽

Dependent Protein ◽

Gastric Parietal Cells

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Immunological localization of an 80-kDa phosphoprotein to the apical membrane of gastric parietal cells

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1989.256.6.g1082 ◽

1989 ◽

Vol 256 (6) ◽

pp. G1082-G1089 ◽

Cited By ~ 17

Author(s):

D. K. Hanzel ◽

T. Urushidani ◽

W. R. Usinger ◽

A. Smolka ◽

J. G. Forte

Keyword(s):

Monoclonal Antibodies ◽

Acid Secretion ◽

Parietal Cell ◽

Blood Cells ◽

Apical Membrane ◽

Staining Pattern ◽

Parietal Cells ◽

Entire Cell ◽

Gastric Parietal Cells ◽

Stimulation Of

Monoclonal antibodies were raised against an 80-kDa phosphoprotein (80K) that is phosphorylated upon stimulation of gastric acid secretion and that copurifies with the acid-forming H+-K+-ATPase isolated from stimulated tissue. These antibodies were used to demonstrate that in the gastric mucosa 80K is limited to parietal cells and not found in surface, mucous neck, or chief cells. 80K was also found in other transporting epithelia, including intestine and kidney, but was not found in brain, liver, red blood cells, or colon. Immunohistological localization of 80K in resting glands revealed a fine network, projecting from the gland lumen and anastomosing throughout the parietal cell. This network is quite similar to the staining pattern for F-actin contained in microvilli that line the apical membrane of parietal cells. Stimulation of acid secretion rearranges 80K to a more rugose pattern filling the entire cell. In stimulated cells the distribution pattern of 80K is indistinguishable from that stained with antibodies against the H+-K+-ATPase. These data strongly suggest that 80K is an apical membrane protein of the parietal cell.

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