Role of type II phospholipase A2 in the inflammatory process of carrageenan-induced pleurisy in rats.

In order to investigate the role of type II phospholipase A2 (PLA2) in the inflammatory process, the effect of a monoclonal antibody specific to type II PLA2 on carrageenan-induced pleurisy was studied in rats. Intravenous injection of the antibody (MB5.2), which inhibits the catalytic activity of type II PLA2, significantly reduced both the pleural exudate volume and the intrapleural leukocyte count, while a control antibody did not have any appreciable effect. MB5.2 caused no change in the level of type II PLA2 in the pleural fluid. These results suggest that type II PLA2 generated at inflamed sites, at least in part, have a crucial role in the pathogenesis of acute inflammation.