Metabolic behavior of acetyl glyceryl ether phosphorylcholine on interaction with rabbit platelets

The metabolic fate of 1-O-³H]alkyl-2-acetyl-sn-glycero-3-phosphorylcholine (³H]-AGEPC) upon interaction with rabbit platelets was investigated. ³H]AGEPC was converted to a product identified as the long-chain fatty acyl analog. The reaction was unaffected by extracellular calcium. After a lag time of 30 to 60 s the kinetics of the conversion was linear. The rate of the reaction was found to be a function of platelet and AGEPC concentrations. Of the ³H]AGEPC (10^?9m) 85 ± 5% was processed into the-long chain fatty acyl analog within 1 h when incubated at 37 2C with a 1.25 × 10⁹ platelets per milliliter suspension. A maximal number of 1200 to 3600 ³H]AGEPC molecules were converted to the long-chain fatty acyl derivative per minute per platelet in the presence of 2 mm EDTA. Under similar conditions the 1-O-³H]alkyl-2-(lyso)-sn-glycero-3-phosphorylcholine (³H]lysoGEPC) also was transformed to a comparable long-chain fatty acyl derivative at a much slower rate and to a lower extent. No significant increase in lysoGEPC was noted in incubation mixtures containing ³H]AGEPC. The possible direct transacylation of AGEPC upon interaction with platelets is discussed as well as the possible involvement of this reaction in directly triggering the platelet response to AGEPC stimuli.