title: Expression of cyclooxygenase-1 and -2 in the left dorsal colon after different durations of ischemia and reperfusion in horses.
abstract: OBJECTIVE-To identify expression and localization of cyclooxygenase (COX)-1 and COX-2 in healthy and ischemic-injured left dorsal colon of horses. SAMPLE POPULATION-Left dorsal colon tissue samples from 40 horses. PROCEDURES-Tissue samples that were used in several related studies on ischemia and reperfusion were evaluated. Samples were collected during anesthesia, before induction of ischemia, and following 1 hour of ischemia, 1 hour of ischemia and 30 minutes of reperfusion, 2 hours of ischemia, 2 hours of ischemia and 30 minutes of reperfusion, and 2 hours of ischemia and 18 hours of reperfusion. Histomorphometric analyses were performed to characterize morphological injury. Immunohistochemical analyses were performed to characterize expression and localization of COX-1 and COX-2. RESULTS-COX-1 and COX-2 were expressed in control tissues before ischemia was induced, predominantly in cells in the lamina propria. Ischemic injury significantly increased expression of COX-2 in epithelial cells on the colonic surface and in crypts. A similar significant increase of COX-1 expression was seen in the epithelial cells. CONCLUSIONS AND CLINICAL RELEVANCE-On the basis of information on the role of COX-2, upregulation of COX-2 in surface epithelium and crypt cells following ischemic injury in equine colon may represent an early step in the repair process.
authors: Island Whirl Equine Colic Research Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA. mortona@mail.vetmed.ufl.edu
authors: Alison J
authors: AJ
authors: Morton
authors: Astrid
authors: A
authors: Grosche
authors: Anna K
authors: AK
authors: Rötting
authors: Sarah A
authors: SA
authors: Matyjaszek
authors: Anthony T
authors: AT
authors: Blikslager
authors: David E
authors: DE
authors: Freeman
mesh_terms: D000818:Animals; D017091:Colitis, Ischemic / Q000662:veterinary*; D003106:Colon / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D051545:Cyclooxygenase 1 / Q000235:genetics / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D006734:Horse Diseases / Q000378:metabolism / Q000473:pathology*; D006736:Horses; D015427:Reperfusion Injury / Q000378:metabolism / Q000662:veterinary*; D013997:Time Factors
chemical_list: D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2