title: Significance of cyclooxygenase-2 induced via p38 mitogen-activated protein kinase in mechanical stimulus-induced peritoneal adhesion in mice.
abstract: Postoperative peritoneal adhesion represents a major complication of surgery, but the molecular mechanism underlying pathogenesis of adhesion is not fully understood. The present study investigated the roles of cyclooxygenase (COX)-1 and COX-2 in peritoneal adhesion induced by scraping the surface of the cecum and abdominal wall in mice. Slight, but macroscopically observable, peritoneal adhesion was induced even on day 1, and the extent of adhesion reached a maximum on day 7 and beyond. COX-1 mRNA was constitutively expressed in the intact cecum, and its expression level was not altered after the mechanical stimulus. In contrast, expression of the COX-2 gene was markedly increased after the stimulus, and maximum expression was observed on days 3 to 7. Mofezolac, a specific COX-1 inhibitor, had no effect on peritoneal adhesion at 30 mg/kg and had only marginal effects on prostaglandin (PG)E2 levels in the cecum or peritoneal fluid. On the other hand, two highly selective inhibitors for COX-2, NS-398 (N-[2-(cyclohexyloxy)-4-nitrophenyl]-methanesulfonamide) and CAY10404 [3-(4-methylsulphonylphenyl)-4-phenyl-5-trifluoromethylisoxazole], dose-dependently inhibited both adhesion formation and the increase in PGE2 levels (3-30 mg/kg). The effects of NS-398 were eliminated when PGE2 or (R)-butaprost was administered exogenously. A COX-2 antisense oligonucleotide also attenuated adhesion formation. Activation of p38 mitogen-activated protein (MAP) kinase was observed in the traumatized cecum, and an MAP kinase inhibitor, SB202190 [4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole], inhibited adhesion formation (54% inhibition at 15 microM) and also reduced the COX-2 mRNA level and PGE2 levels. In conclusion, COX-2, but not COX-1, plays a significant role in mechanical stimulus-induced peritoneal formation in the mouse cecum.
authors.affiliation: KEIO Research Park 2N4, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan. katada@kt.rim.or.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Katada
authors.forename: Hitomi
authors.initials: H
authors.lastname: Saito
authors.forename: Akira
authors.initials: A
authors.lastname: Ohashi
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002432:Cecum / Q000293:injuries / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D047468:Immunoprecipitation; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010529:Peritoneal Cavity / Q000166:cytology; D010812:Physical Stimulation; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D011982:Receptors, Prostaglandin / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D007093:Imidazoles; D008565:Membrane Proteins; D016376:Oligonucleotides, Antisense; D011725:Pyridines; D011982:Receptors, Prostaglandin; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496512:Ptgs1 protein, mouse; D048051:p38 Mitogen-Activated Protein Kinases; D015232:Dinoprostone; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole