title: Esophageal mucosal blood flow: a central role for calcitonin gene-related peptide.
abstract: BACKGROUND
  Esophageal mucosal blood flow is a dynamic phenomenon dependent on luminal content. Reactive hyperemia, likely a factor in mucosal protection, follows luminal exposure to noxious substances, including bile. The mediators of this response are unknown, although the likelihood is that visceral afferent nerves play a major role. The purpose of this study was to determine whether substance P, calcitonin gene-related peptide (CGRP), or adenosine could mediate this reactive blood flow response.
  
  
  METHODS
  Esophageal mucosal blood flow was studied in a rabbit model with the radiolabeled microsphere technique. The effect of intraarterial infusion of CGRP and substance P and intravenous adenosine was studied. Subsequently, the hyperemic response to luminal deoxycholate was measured in the presence of antagonists to CGRP, substance P, and adenosine. Immunohistochemical studies were performed to determine the distribution of CGRP and substance P in the esophagus.
  
  
  RESULTS
  CGRP proved to be a potent stimulus to mucosal blood flow. The presence of a CGRP antagonist reduced mucosal blood flow at baseline and after exposure to deoxycholate. Antagonists to substance P and adenosine had no effect on baseline and deoxycholate-stimulated blood flow.
  
  
  CONCLUSIONS
  CGRP is likely a major mediator involved in the regulation of esophageal mucosal blood flow.
authors.affiliation: Department of Surgery, Veterans Affairs Medical Center, Washington, D.C.
authors.forename: L D
authors.initials: LD
authors.lastname: McKie
authors.forename: B J
authors.initials: BJ
authors.lastname: Dunkin
authors.forename: M F
authors.initials: MF
authors.lastname: Pennanen
authors.forename: K W
authors.initials: KW
authors.lastname: Dunlap
authors.forename: J W
authors.initials: JW
authors.lastname: Harmon
authors.forename: B L
authors.initials: BL
authors.lastname: Bass
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D004947:Esophagus / Q000098:blood supply*; D007150:Immunohistochemistry; D008297:Male; D009092:Mucous Membrane / Q000098:blood supply; D010446:Peptide Fragments / Q000494:pharmacology; D011817:Rabbits; D012039:Regional Blood Flow / Q000187:drug effects; D013373:Substance P / Q000032:analysis / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology
chemical_list: D010446:Peptide Fragments; C058636:calcitonin gene-related peptide (8-37); D013373:Substance P; D013806:Theophylline; D015740:Calcitonin Gene-Related Peptide