Blockade of the inflammatory effects of platelet-activating factor by cyclo-oxygenase inhibitors.

1. The edematogenic and hyperalgesic effects of synthetic Platelet-Activating Factor (PAF-acether) on the rat paw were investigated. 2. PAF-acether induced a dose-dependent oedema and hyperalgesia. 3. These effects were partially reduced by non-steroidal anti-inflammatory agents. 4. It is suggested that the oedema and hyperalgesia in response to PAF-acether are due at least in part to the release of a cyclo-oxygenase metabolite, probably prostacyclin.