High‐density lipoprotein fails to inhibit serotonin‐induced activation of blood platelets

Abstract

High-density lipoprotein (HDL) of 100-400 micrograms/ml did not prevent morphological alterations of human blood platelets treated with serotonin (1-5 microM). Highly concentrated HDL (1,200 micrograms/ml) appeared to activate platelets in vitro. These findings indicate that whole HDL may not inhibit agonist-induced platelet activation.

Serotonin Levels in Platelet-Poor Plasma and Whole Blood from Healthy Subjects: Relationship with Lipid Markers and Coronary Heart Disease Risk Score

“…During the rolling process, platelets become bind to scavenger receptors, but oxidized LDL can bind to the receptors and promote foam cell formation 8) . A number of studies have shown a close relationship between platelet activation and lipoproteins such as LDL, oxidized LDL and HDL [9][10][11][12][13][14][15] . Oxidized LDL can be transported by platelets to macrophages, leading to foam cell formation 9) .…”

“…Platelets are activated by LDL or oxidized LDL, and the activation inhibited by HDL [9][10][11][12] ; however, several reports have indicated that HDL activates platelets in vitro [13][14][15] ; highly concentrated HDL appears to activate platelets in vitro 13) . ApoE-rich HDL2 inhibits aggregation of platelets stimulated with ADP in vitro, but HDL3 accelerates aggregation 14) .…”