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Cyclooxygenase expression and prostanoid production in pyloric and duodenal mucosae in dogs after administration of nonsteroidal anti-inflammatory drugs

2008; American Veterinary Medical Association; Volume: 69; Issue: 4 Linguagem: Inglês

10.2460/ajvr.69.4.457

1943-5681

Jenna G. Wooten, Anthony T. Blikslager, Kathleen A. Ryan, Steve L. Marks, J. Mac Law, B. Duncan X. Lascelles,

Estrogen and related hormone effects

Abstract Objective —To assess cyclooxygenase (COX) expression and prostanoid concentrations in pyloric and duodenal mucosae of dogs after administration of nonsteroidal anti-inflammatory drugs (NSAIDs). Animals —8 healthy dogs. Procedures —Each dog received carprofen (4.4 mg/kg, q 24 h), deracoxib (2 mg/kg, q 24 h), aspirin (10 mg/kg, q 12 h), and placebo (1 dog treat, q 24 h) orally for 3 days (4-week interval between treatments). Before study commencement (baseline) and on day 3 of each treatment, pyloric and duodenal mucosal appearance was assessed endoscopically and biopsy specimens were obtained for histologic examination. Cyclooxygenase-1 and COX-2 protein expressions were assessed via western blotting, and prostanoid concentrations were measured via ELISAs. An ANOVA was used to analyze data. Results —Treatments had no effect on mucosal appearance and ulceration was not evident histologically. In pyloric and duodenal mucosae, COX-1 expression was unaffected by treatments. Cyclooxygenase-2 expression remained unchanged in pyloric mucosa; in duodenal mucosa, aspirin significantly increased COX-2 expression, compared with effects of deracoxib and carprofen. At baseline, total prostaglandin and thromboxane B 2 concentrations in pyloric mucosa were significantly greater than those in duodenal mucosa. Aspirin significantly decreased both prostanoid concentrations in both mucosal tissues, compared with other treatments. In pyloric mucosa, carprofen administration significantly decreased total prostaglandin and thromboxane B 2 concentrations, compared with deracoxib administration. Conclusions and Clinical Relevance —In dogs, prostanoid synthesis was greater in pyloric mucosa than it was in duodenal mucosa. Nonselective NSAIDs significantly decreased prostanoid concentrations in these mucosae, compared with the effects of a selective COX-2 NSAID.