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This Article Full Text Full Text (PDF) All Versions of this Article: 296/5/R1631    most recent 90527.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kanashiro, A. Articles by de Souza, G. E. P. Search for Related Content PubMed PubMed Citation Articles by Kanashiro, A. Articles by de Souza, G. E. P.

TEMPERATURE AND FEVER

Characterization and pharmacological evaluation of febrile response on zymosan-induced arthritis in rats

¹Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil; and ²Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil

Submitted 23 June 2008 ; accepted in final form 18 February 2009

The present study investigated the febrile response in zymosan-induced arthritis, as well as the increase in PGE₂ concentration in the cerebrospinal fluid (CSF), along with the effects of antipyretic drugs on these responses in rats. Zymosan intra-articularly injected at the dose of 0.5 mg did not affect the body core temperature (Tc) compared with saline (control), whereas at doses of 1 and 2 mg, zymosan promoted a flattened increase in Tc and declined thereafter. The dose of 4 mg of zymosan was selected for further experiments because it elicited a marked and long-lasting Tc elevation starting at 3 1/2 h, peaking at 5 1/2 h, and remaining until 10 h. This temperature increase was preceded by a decrease in the tail skin temperature, as well as hyperalgesia and edema in the knee joint. No febrile response was observed in the following days. In addition, zymosan-induced fever was not modified by the sciatic nerve excision. Zymosan increased PGE₂ concentration in the CSF but not in the plasma. Oral pretreatment with ibuprofen (5–20 mg/kg), celecoxib (1–10 mg/kg), dipyrone (60–240 mg/kg), and paracetamol (100–200 mg/kg) or subcutaneous injection of dexamethasone (0.25–1.0 mg/kg) dose-dependently reduced or prevented the fever during the zymosan-induced arthritis. Celecoxib (5 mg/kg), paracetamol (150 mg/kg), and dipyrone (120 mg/kg) decreased CSF PGE₂ concentration and fever during zymosan-induced arthritis, suggesting the involvement of PGE₂ in this response.

fever; anti-inflammatory drugs; paracetamol; dipyrone; celacoxib; prostaglandin E₂