Role of cyclopentenone prostaglandins in rat carrageenin pleurisy

AbstractIn this study, using rat carrageenin-induced pleurisy, we found that treatment of rats with either indomethacin or NS-398 suppressed the pleurisy at 2 h but significantly exacerbated this reaction at 48 h. Exacerbated inflammation was associated with reduced prostaglandin D2 levels, decreased heat shock factor 1 (HSF1) activation, reduced hsp72 expression and increased activation of nuclear factor κB (NF-κB). Replacement of cyclopentenone prostaglandins by treating rats with either prostaglandin J2 or prostaglandin D2 reversed the exacerbating effects of cyclooxygenase inhibitors leading to the resolution of the reaction. In conclusion, we demonstrate that cyclopentenone prostaglandins may act as anti-inflammatory mediators by inducing in inflammatory cells HSF1-dependent hsp72 expression and NF-κB inhibition, two crucial events for the remission of inflammation