title: Localization of cholecystokinin A and cholecystokinin B-gastrin receptors in the human stomach.
abstract: OBJECTIVE
  Gastrin and cholecystokinin (CCK) are gut-brain peptides, with multiple functions in the gastrointestinal tract mediated through CCK-B-gastrin and CCK-A receptors. The receptor localization is, however, not well established in humans. The aim of this study was to investigate the distribution and pharmacological characteristics of CCK-A and CCK-B receptors in the human upper gastrointestinal tract and compare them with those in the rat and dog.
  
  
  METHODS
  CCK receptors were localized by in vitro receptor autoradiography with 125I-[Leu15]gastrin-I and 125I-[D-Tyr-Gly, Nle(28,31)]-CCK 26-33 in stomach and gallbladder.
  
  
  RESULTS
  High concentrations of CCK-B-gastrin receptors were detected in the midglandular region of the human fundic mucosa. CCK-A receptors were found in the basal region of the antral and fundic mucosa. CCK-A receptors were also located in the muscularis propria of antrum, fundus, and gallbladder, whereas CCK-B-gastrin receptors were only detected in gastric fundic circular muscle. Two nonpeptide CCK receptor antagonists distinguish both receptor subtypes. Comparisons among humans, dogs, and rats suggest that localization and density of CCK receptor subtypes in the upper gastrointestinal tract are species-dependent.
  
  
  CONCLUSIONS
  Localization of CCK receptor subtypes in human upper gastrointestinal tract provides a biochemical and morphological basis for the separate regulatory roles of gastrin and CCK.
authors.affiliation: Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Switzerland.
authors.forename: J C
authors.initials: JC
authors.lastname: Reubi
authors.forename: B
authors.initials: B
authors.lastname: Waser
authors.forename: U
authors.initials: U
authors.lastname: Läderach
authors.forename: C
authors.initials: C
authors.lastname: Stettler
authors.forename: H
authors.initials: H
authors.lastname: Friess
authors.forename: F
authors.initials: F
authors.lastname: Halter
authors.forename: A
authors.initials: A
authors.lastname: Schmassmann
mesh_terms: D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D004285:Dogs; D005704:Gallbladder / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D009115:Muridae; D051381:Rats; D011949:Receptors, Cholecystokinin / Q000378:metabolism*; D013045:Species Specificity; D014018:Tissue Distribution
chemical_list: D011949:Receptors, Cholecystokinin