What question did this study set out to answer?

To determine how clinically prepared reconstituted high-density lipoprotein (rHDL) influences stimulus-induced platelet activity in vitro and ex vivo.

January 1, 1998Thrombosis and Haemostasis72 citations

Reconstituted High Density Lipoprotein (rHDL) Modulates Platelet Activity In Vitro and Ex Vivo

MSM. Spycher DJDoran Je PLP. Lerch

Key Points

To determine how clinically prepared reconstituted high-density lipoprotein (rHDL) influences stimulus-induced platelet activity in vitro and ex vivo.
Assessed in vitro aggregation and CD62P (P-selectin) expression in human platelet-rich plasma and purified platelets exposed to rHDL and stimulated with arachidonic acid, collagen, epinephrine, ADP, or thrombin.
Evaluated ex vivo platelet aggregation in platelet-rich plasma from human volunteers before and up to 30 hours after intravenous infusion of 25 mg/kg or 40 mg/kg rHDL.
In vitro rHDL mediated dose-dependent inhibition of platelet aggregation and suppressed collagen-induced, but not thrombin-induced, CD62P expression.
Ex vivo rHDL infusion caused a transient, stimulus-dependent inhibition of platelet aggregation triggered by arachidonic acid and collagen, with greater suppression observed at the 40 mg/kg dose.

Abstract

A reconstituted high density lipoprotein (rHDL) prepared for clinical use was tested for its influence on platelet activity modulated by various stimuli. In a first series of in vitro experiments, rHDL was added to blood in a concentration series, and platelet rich plasma (PRP) was isolated. Platelets were stimulated with arachidonic acid, collagen, epinephrine or ADP, and platelet aggregation was assessed. rHDL mediated a dose dependent inhibition of the platelet activity. With purified platelets rHDL inhibited the release reaction induced by collagen, but not by thrombin, as measured by CD62P (P-Selectin) expression on the plasma membrane. Ex vivo experiments were performed with PRP from volunteers, previously infused with 25 mg rHDL/kg body weight and 40 mg rHDL/kg body weight, respectively. Platelet activity in PRP was assessed before, and up to 30 h after the end of the rHDL infusion. A transient inhibition of the platelet aggregation induced by arachidonic acid and collagen was observed which was more pronounced in the group receiving 40 mg rHDL/kg body weight. In both groups of experiments, in vitro and ex vivo, the inhibition of the platelet activity was also dependent on the stimulus used.

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