Dexamethasone inhibits platelet activating factor-induced inflammation in the paw but not the pleural cavity of rats.

The effect of drugs upon the inflammatory responses occurring after injection of 1 microgram platelet activating factor into the foot-pad and pleural cavity of the rat were investigated. Dexamethasone, but not indomethacin, BW755C, mepyramine or methysergide inhibited development of paw oedema; none of these drugs were effective in the pleurisy model. The triazolobenzodiazepine derivative WEB 2086 inhibited responses in both models. We conclude that the development of oedema in response to platelet activating factor in the rat is not dependent upon eicosanoid synthesis; and possible reasons for the difference in steroid sensitivity between the two sites are discussed.