title: Gastroduodenal mucosal defense.
abstract: OBJECTIVE
  The gastrointestinal tract has developed multiple mechanisms of protection from intrinsic and extrinsic sources of injury, including but not limited to drugs, ischemic/reperfusion injuries, and infections such as Helicobacter pylori. We review recent developments in host defense against Helicobacter pylori, duodenal bicarbonate secretion, protection from nonsteroidal anti-inflammatory drug induced gastrointestinal injury, and apoptosis, as well as newer therapies.
  
  
  RESULTS
  Leptin and survivin confer protection against ethanol and indomethacin induced injury. Mucin-1, a cell surface mucin, is an important barrier to gastrointestinal infection. Prostaglandin E(2), Escherichia coli heat-stable enterotoxin, orexins, and carbonated beverages stimulate duodenal bicarbonate secretion.
  
  
  CONCLUSIONS
  Gastroduodenal mucosal defense is a dynamic process, and further insights into these defense mechanisms have and will lead to safer and more effective treatments.
authors.affiliation: Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA, USA.
authors.forename: Maggie
authors.initials: M
authors.lastname: Ham
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Kaunitz
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D001639:Bicarbonates / Q000378:metabolism*; D004378:Duodenal Diseases / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D004386:Duodenum / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D005744:Gastric Acid / Q000378:metabolism*; D005752:Gastric Mucins / Q000378:metabolism; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D013272:Stomach Diseases / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D000077022:Survivin
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D051017:Apoptosis Regulatory Proteins; C107489:BIRC5 protein, human; D001639:Bicarbonates; D005752:Gastric Mucins; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D000077022:Survivin; D020782:Matrix Metalloproteinases