title: Expression of endothelin receptors in the gastric mucosa of portal hypertensive rats.
abstract: BACKGROUND
  Portal hypertensive gastropathy is an abnormal circulatory state in gastric mucosa with vascular dilatation due to portal hypertension. The aim of the present study was to evaluate expression of endothelin receptors and their roles in the portal hypertensive gastric mucosa.
  
  
  METHODS
  Portal hypertensive rats were generated by staged portal vein occlusion. Expression of endothelin-A receptor and endothelin-B receptor mRNA was examined by reverse transcriptase-polymerase chain reaction, and protein were examined by immunohistochemistry. The changes of mucosal microcirculation by endothelin receptor antagonists were measured with in vivo microscope.
  
  
  RESULTS
  Expression of endothelin-A receptor mRNA was increased significantly in portal hypertensive rats in comparison with sham-operated control rats (P < 0.05). There was no significant difference between the two groups in endothelin-B receptor mRNA expression. Vessels of the gastric mucosa were dilated, and intravessel blood flow was increased significantly in the portal hypertensive group (P < 0.05). Diameters of mucosal vessels and blood flow were increased significantly by endothelin-A receptor antagonist (BQ-485) in the portal hypertensive rats. Endothelin-B receptor antagonist (IRL-1038) had no significant effect on mucosal microcirculation.
  
  
  CONCLUSIONS
  These data suggest that increased expression of endothelin-A receptor in the portal hypertensive gastric mucosa may be related to the regulation of gastric microcirculation.
authors.affiliation: Department of Surgery I, Oita University Faculty of Medicine, Oita, Japan. kaisei@med.oita-u.ac.jp
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Kai
authors.forename: Toshio
authors.initials: T
authors.lastname: Bandoh
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ohta
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tominaga
authors.forename: Seigo
authors.initials: S
authors.lastname: Kitano
mesh_terms: D000818:Animals; D001381:Azepines / Q000494:pharmacology; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000187:drug effects; D065130:Endothelin A Receptor Antagonists; D065131:Endothelin B Receptor Antagonists; D016232:Endothelins / Q000494:pharmacology; D005753:Gastric Mucosa / Q000098:blood supply / Q000378:metabolism*; D006975:Hypertension, Portal / Q000150:complications / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D009842:Oligopeptides / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D017082:Portal Pressure / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D044022:Receptor, Endothelin A / Q000378:metabolism*; D044023:Receptor, Endothelin B / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013272:Stomach Diseases / Q000209:etiology / Q000503:physiopathology
chemical_list: D001381:Azepines; D065130:Endothelin A Receptor Antagonists; D065131:Endothelin B Receptor Antagonists; D016232:Endothelins; D009842:Oligopeptides; D010446:Peptide Fragments; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; C083116:BQ 485; C077420:Cys(11)-Cys(15)-endothelin-1 (11-21)