Release of platelet-activating factor (PAF-acether) and 2-lyso PAF-acether from three cell types.

The release and formation of PAF-acether and of its deacetylated precursor (2-lyso PAF-acether) have been determined on mouse macrophages (M phi), human polymorphonuclear neutrophils (PMN) and rabbit platelets using specific secretagogue stimuli in the same experimental conditions. It was found that as opposed to M phi, PMN and platelets were good releasers of PAF-acether. However, the total amount of PAF-acether formed by M phi and PMN was larger than that formed by platelets. The total amount of 2-lyso PAF-acether varied also for the three cell types, with platelets being by far the best producer. Calculation of the amount of PAF-acether formed from 2-lyso PAF-acether indicated that M phi and PMN possess a higher acetylating ability than platelets.