Role of cyclopentenone prostaglandins in rat carrageenin pleurisy

In this study, using rat carrageenin-induced pleurisy, we found that treatment of rats with either indomethacin or NS398 suppressed the pleurisy at 2 h but significantly exacerbated this reaction at 48 h. Exacerbated inflammation was associated with reduced prostaglandin D-2 levels, decreased heat shock factor 1 (HSF1) activation, reduced hsp72 expression and increased activation of nuclear factor KB (NF-KB). Replacement of cyclopentenone prostaglandins by treating rats with either prostaglandin J(2) or prostaglandin D-2 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-kappaB inhibition, two crucial events for the remission of inflammation. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.