Reconstituted high density lipoprotein (rHDL) modulates platelet activity in vitro and ex vivo.
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.
Lerch
P G
PG
ZLB Central Laboratory, Blood Transfusion Service SRC, Bern, Switzerland.
Spycher
M O
MO
Doran
J E
JE
D006801:Humans; D007262:Infusions, Intravenous; D008055:Lipids / Q000097:blood; D008075:Lipoproteins, HDL / Q000494:pharmacology*; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D012016:Reference Values
D008055:Lipids; D008075:Lipoproteins, HDL; D010975:Platelet Aggregation Inhibitors