Failure of PAF-acether to induce in vivo neutrophil migration

The ability of PAF-acether (platelet activating factor, 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine) to induce neutrophil migration was tested in the peritoneal cavities of rats and guinea-pigs and in rat skin air pouches. PAF-acether, at doses of 2 and 5 micrograms per animal, did not promote significant neutrophil migration. The ability of PAF-acether antagonists to inhibit carrageenin induced neutrophil migration in rat abdominal cavities was also investigated. Carrageenin is a substance described to cause the release of endogenous PAF-acether. Neutrophil migration was not affected by PAF-antagonists. These observations challenge the possible role of PAF-acether as a neutrophil chemotactic factor in vivo.