INTRALIPID RAPIDLY ATTENUATES THE AGONIST-INDUCED ACTIVATION OF RAT PLATELETS IN-VITRO

This study examines the uptake of Intralipid by rat platelets and the effect of Intralipid on platelet activation and platelet lipid composi tion in vitro. H-3-cholesteryl hexadecyl ether labeled Intralipid (H-3 -Intralipid) was incubated with rat platelets for up to 4 hours. A sig nificant uptake of H-3-Intralipid occurred as indicated by the increas e of H-3 in platelets with time. Addition of unlabelled Intralipid or chyle chylomicrons decreased the uptake of labeled Intralipid by the p latelets, whereas Intralipid had less effect on the uptake of C-14 lin oleic acid labeled chylomicrons. Incubation of rat platelets with Intr alipid caused a dose dependent inhibition of ADP, collagen and thrombi n induced platelet aggregation and serotonin release. Both an attenuat ed response and a reduction of platelet cholesterol contents was seen within 10 minutes. Intralipid thus causes a rapid, dose-dependent inhi bition of agonist-induced activation of rat platelets in vitro. This i nhibition is linked to a loss of cholesterol and to an uptake of Intra lipid particles by the platelets. Copyright (C) 1997 Elsevier Science Ltd.