title: Rapid activation of human platelets by low concentrations of low-density lipoprotein via phosphatidylinositol cycle.
abstract: The interaction of low-density lipoprotein (LDL) with the human platelet was investigated with regard to saturable high-affinity binding, shape change, cytosolic free Ca2+ concentration, phosphatidylinositol (PtdIns) turnover, and thromboxane B2 biosynthesis. The experiments show that LDL, at a concentration approximately 100 times lower than in plasma, causes platelet activation concomitantly with stimulation of the PtdIns cycle and thromboxane B2 formation, similarly to other activators of platelets. The effects of LDL were inhibited by high-density lipoprotein. The results suggest that activation of platelets by low concentrations of LDL may play a role in pathophysiological conditions and that platelet can serve as a model for studying the influence of LDL on various target cells.
authors.affiliation: Department of Medicine, University of Zürich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Knorr
authors.forename: R
authors.initials: R
authors.lastname: Locher
authors.forename: E
authors.initials: E
authors.lastname: Vogt
authors.forename: W
authors.initials: W
authors.lastname: Vetter
authors.forename: L H
authors.initials: LH
authors.lastname: Block
authors.forename: F
authors.initials: F
authors.lastname: Ferracin
authors.forename: H
authors.initials: H
authors.lastname: Lefkovits
authors.forename: A
authors.initials: A
authors.lastname: Pletscher
mesh_terms: D001665:Binding Sites; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000097:blood; D003600:Cytosol / Q000378:metabolism; D004075:Diglycerides / Q000096:biosynthesis; D006801:Humans; D066298:In Vitro Techniques; D008075:Lipoproteins, HDL / Q000494:pharmacology; D008077:Lipoproteins, LDL / Q000378:metabolism / Q000494:pharmacology*; D010712:Phosphatidic Acids / Q000096:biosynthesis; D010716:Phosphatidylinositols / Q000097:blood*; D013917:Thrombin / Q000494:pharmacology; D013929:Thromboxane B2 / Q000096:biosynthesis
chemical_list: D004075:Diglycerides; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D010712:Phosphatidic Acids; D010716:Phosphatidylinositols; D013929:Thromboxane B2; D013917:Thrombin; D002118:Calcium