Acetyl glyceryl ether phosphorylcholine. Intravascular alterations following intravenous infusion into the baboon

The intravenous infusion of 1-O-hexadecyl/octadecyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (AGEPC) in baboons (28 micrograms per kg.) induced acute, but reversible, thrombocytopenia and neutropenia and the intravascular release of platelet factor 4 and thromboxane B2. Maximal depression of circulating platelets and neutrophils occurred within 30 seconds after AGEPC infusion and was accompanied by significant elevations in plasma platelet factor 4 and thromboxane B2 levels (p less than 0.02). Hematocrit values increased after AGEPC infusion, but this increase was delayed relative to the other intravascular alterations, i.e., maximal hematocrit values occurred at 10 to 20 minutes after AGEPC infusion.. The thrombocytopenia induced by AGEPC was reversed within 2 to 3 minutes; in contrast, circulating neutrophils did not return to preinfusion levels until 30 minutes after AGEPC infusion. Plasma platelet factor 4 and thromboxane B2 elevations gradually decreased and returned to preinfusion levels within 30 to 60 minutes. The deacetylated derivative of AGEPC, lyso-glyceryl ether phosphorylcholine, had no effect when similarly infused into baboons. These studies demonstrate that the intravenous administration of AGEPC into baboons initiated significant but reversible intravascular alterations; thus, this unusual acetylated alkyl phosphoglyceride may be an important mediator of inflammation in primates, including man.