Role of cyclopentenone prostaglandins in rat carrageenin pleurisy

In this study, using rat carrageenin-induced pleurisy, we found that treatm ent of rats with either indomethacin or NS398 suppressed the pleurisy at 2 h but significantly exacerbated this reaction at 48 h. Exacerbated inflamma tion was associated with reduced prostaglandin D-2 levels, decreased heat s hock factor 1 (HSF1) activation, reduced hsp72 expression and increased act ivation of nuclear factor KB (NF-KB). Replacement of cyclopentenone prostag landins 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 cyclope ntenone prostaglandins may act as anti-inflammatory mediators by inducing i n inflammatory cells HSF1-dependent hsp72 expression and NF-kappaB inhibiti on, two crucial events for the remission of inflammation. (C) 2001 Federati on of European Biochemical Societies. Published by Elsevier Science B.V. Al l rights reserved.