title: Induction of cyclo-oxygenase-2 expression in naturally occurring gastric ulcers.
abstract: Cyclo-oxygenase-2 (COX-2) is believed to participate in the repair of gastric ulcer. Like humans, pigs frequently develop gastric ulcers and thus represent an attractive animal model in which to study the repair process of naturally occurring gastric ulcers. However, expression of COX in the pig stomach has not been reported. The objectives of this study were to determine whether COX isoenzymes are expressed in porcine gastric ulcers and to characterize the porcine COX-2 cDNA. Normal stomachs (n=5) and those with gastric ulcers (n=35) were studied by immunohistochemistry and immunoblotting analysis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to isolate the complete porcine COX-2 cDNA. COX-1 staining was present in normal stomach and in ulcerated areas. No COX-2 was detected in normal stomach, but COX-2 was strongly expressed in the ulcerated area in 28/35 (80%) gastric ulcers (p<0.01). Immunoblotting analysis confirmed the restricted expression of COX-2 in the ulcerated areas. The porcine COX-2 cDNA was shown to code for a 604 amino acid protein that is 89% identical to human COX-2. These results provide the complete primary structure of porcine COX-2 and demonstrate for the first time that the enzyme is induced in naturally occurring porcine gastric ulcers.
authors.affiliation: Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Québec, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lajoie
authors.forename: Jean
authors.initials: J
authors.lastname: Sirois
authors.forename: Monique
authors.initials: M
authors.lastname: Doré
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015151:Immunoblotting; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000201:enzymology / Q000648:ultrastructure; D013276:Stomach Ulcer / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D013552:Swine
chemical_list: D007527:Isoenzymes; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases