Effects of several anti-inflammatory drugs on the various parameters involved in the inflammatory response in rat carrageenin-induced pleurisy.

In rat carrageenin pleurisy, both steroidal and non-steroidal anti-inflammatory drugs (SAID and NSAID respectively) produced a dose-related reduction of exudate volume and of prostaglandin (PG)E2 contents in the exudate at 3 h after carrageenin. However, with the exception of ketoprofen, administration of all the NSAID in low doses resulted in a significant reduction of PGE2 contents with no significant reduction in exudate volume. NSAID reduced leucocyte number and total activities of lysosomal enzymes in the exudate at 3 h after carrageenin only at the higher doses, while SAID did so in a dose-related manner. Both SAID and NSAID reduced the arylsulfatase activity released into the exudate (free activity) dose-relatedly but not the free activity of beta-glucuronidase at 3 h after carrageenin. However, some drug treatments resulted in a lower reduction in free arylsulfatase activity than in exudate volume. These results suggest that the reduction of PGE2 contents may be the main contribution to the anti-exudative activities of anti-inflammatory drugs in rat carrageenin pleurisy and that this effect may be complemented by the reduction of free activity of lysosomal enzymes such as arylsulfatase.