Gastric exocrine and endocrine secretion.
OBJECTIVE
This review summarizes the last year's literature regarding the regulation and measurement of gastric exocrine and endocrine secretion.


RESULTS
Parietal cells, distributed along much of the length of the oxyntic glands, with highest density in the neck and base, secrete HCl as well as transforming growth factor-alpha, amphiregulin, heparin-binding epidermal growth factor-like growth factor, and sonic hedgehog. Acid facilitates the digestion of protein and absorption of iron, calcium, vitamin B(12) as well as prevents bacterial overgrowth, enteric infection, and possibly food allergy. The major stimulants of acid secretion are gastrin, histamine, and acetylcholine. Ghrelin and orexin also stimulate acid secretion. The main inhibitor of acid secretion is somatostatin. Nitric oxide and dopamine also inhibit acid secretion. Although Helicobacter pylori is associated with duodenal ulcer disease, most patients infected with the organism produce less than normal amount of acid. The cytoskeletal proteins ezrin and moesin participate in parietal cell acid and chief cell pepsinogen secretion, respectively.


CONCLUSIONS
Despite our vast knowledge, the understanding of the regulation of gastric acid secretion in health and disease is far from complete. A better understanding of the pathways and mechanisms regulating acid secretion should lead to improved management of patients with acid-induced disorders as well as those who secrete too little acid.
Schubert
Mitchell L
ML
Department of Medicine, Division of Gastroenterology, Virginia Commonwealth University Health System and McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA. Mitchell.Schubert@va.gov
D000109:Acetylcholine / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000502:physiology; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism*; D005755:Gastrins / Q000502:physiology; D054439:Ghrelin / Q000502:physiology; D016481:Helicobacter Infections / Q000378:metabolism; D016480:Helicobacter pylori; D006632:Histamine / Q000502:physiology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology; D008840:Microfilament Proteins / Q000502:physiology; D009479:Neuropeptides / Q000502:physiology; D000068797:Orexins; D010295:Parietal Cells, Gastric / Q000378:metabolism*; D020116:Pepsinogen A / Q000378:metabolism; D000099149:Ezrin
D000109:Acetylcholine; D003598:Cytoskeletal Proteins; D005755:Gastrins; D054439:Ghrelin; D006632:Histamine; D047908:Intracellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D009479:Neuropeptides; D000068797:Orexins; D020116:Pepsinogen A; D000099149:Ezrin; C071058:moesin