Platelet Cyclooxygenase Expression in Normal Dogs
| Autor: | C. Langston, Andrew J. Mackin, Lesya M. Pinchuk, K. Mullins, Stephen B. Pruett, Robert W. Wills, John V. Stokes, Kari V. Lunsford, Ron McLaughlin, John M. Thomason |
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| Rok vydání: | 2011 |
| Předmět: |
Blood Platelets
medicine.medical_specialty Urinary system Population Urine chemistry.chemical_compound Dogs Internal medicine medicine Animals Cyclooxygenase Inhibitors Platelet education Aspirin Creatinine education.field_of_study General Veterinary biology business.industry Flow Cytometry Thromboxane B2 Endocrinology Epinephrine chemistry Cyclooxygenase 2 Prostaglandin-Endoperoxide Synthases Anesthesia Cyclooxygenase 1 biology.protein Female Cyclooxygenase business medicine.drug |
| Zdroj: | Journal of Veterinary Internal Medicine. 25:1106-1112 |
| ISSN: | 0891-6640 |
| DOI: | 10.1111/j.1939-1676.2011.00781.x |
| Popis: | Background: Human platelets express both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Variation in COX-2 expression could be a mechanism for variable response to aspirin. Hypothesis/Objectives: The hypotheses were that circulating canine platelets express COX-1 and COX-2, and that aspirin alters COX expression. The objective was to identify changes in platelet COX expression and in platelet function caused by aspirin administration to dogs. Animals: Eight female, intact hounds. Methods: A single population, repeated measures design was used to evaluate platelet COX-1 and COX-2 expression by flow cytometry before and after aspirin (10 mg/kg Q12h for 10 days). Platelet function was analyzed via PFA-100® (collagen/epinephrine), and urine 11-dehydro-thromboxane B2 (11-dTXB2) was measured and normalized to urinary creatinine. Differences in COX expression, PFA-100® closure times, and urine 11-dTXB2 : creatinine ratio were analyzed before and after aspirin administration. Results: Both COX-1 and COX-2 were expressed in canine platelets. COX-1 mean fluorescent intensity (MFI) increased in all dogs, by 250% (range 63–476%), while COX-2 expression did not change significantly (P = 0.124) after aspirin exposure, with large interindividual variation. PFA-100® closure times were prolonged and urine 11-dTXB2 concentration decreased in all dogs after aspirin administration. Conclusions and Clinical Importance: Canine platelets express both COX isoforms. After aspirin exposure, COX-1 expression increased despite impairment of platelet function, while COX-2 expression varied markedly among dogs. Variability in platelet COX-2 expression should be explored as a potential mechanism for, or marker of, variable aspirin responsiveness. |
| Databáze: | OpenAIRE |
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