title: Expression of cyclooxygenase isoforms in ulcerated tissues of the nonglandular portion of the stomach in horses.
abstract: OBJECTIVE
  To characterize the expression of the cyclooxygenase (COX)-1 and COX-2 isoforms in naturally occurring ulcers of the nonglandular portion of the stomach in horses. SPECIMEN POPULATION: 38 specimens from ulcerated stomachs and 10 specimens from healthy stomachs.
  
  
  METHODS
  Specimens were collected at an abbatoir; for each specimen of squamous gastric mucosa, 1 portion was fixed in neutral-buffered 10% formalin for immunohistochemical analysis and another was frozen at -70 degrees C for immunoblotting analysis. Immunoreactivity to 2 antibodies, MF241 (selective for COX-1) and MF243 (selective for COX-2), was evaluated by a veterinary pathologist using a scoring system. Expression of COX-1 and COX-2 was confirmed by use of immunoblotting analyses.
  
  
  RESULTS
  All specimens from healthy stomachs strongly expressed COX-1, whereas only 2 of 10 expressed COX-2. The expression of both isoforms varied greatly in the ulcerated mucosal specimens. Expression of COX-1 was significantly lower and expression of COX-2 was significantly higher in ulcerated versus healthy specimens.
  
  
  CONCLUSIONS
  Increased expression of COX-2 in gastric ulcers of the squamous portion of the stomach in horses suggested a role for this enzyme in gastric ulcer healing.
authors.affiliation: Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 7C6, Canada.
authors.forename: Natália L F
authors.initials: NL
authors.lastname: Rodrigues
authors.forename: Monique
authors.initials: M
authors.lastname: Doré
authors.forename: Michèle Y
authors.initials: MY
authors.lastname: Doucet
mesh_terms: D000818:Animals; D051545:Cyclooxygenase 1 / Q000235:genetics* / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics* / Q000378:metabolism; D005753:Gastric Mucosa / Q000201:enzymology* / Q000473:pathology; D006734:Horse Diseases / Q000201:enzymology* / Q000473:pathology; D006736:Horses; D015151:Immunoblotting; D007150:Immunohistochemistry; D012016:Reference Values; D013270:Stomach / Q000201:enzymology*; D013276:Stomach Ulcer / Q000201:enzymology / Q000473:pathology / Q000662:veterinary*
chemical_list: D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2