Lipopolysaccharide induces exposure of fibrinogen receptors on human platelets.
The effect of lipopolysaccharide (LPS) on the exposure of platelet fibrinogen receptors was investigated. The results showed that: 1) LPS increased the binding of fibrinogen-gold complexes to platelets and the labels were primarily limited to shape-changed platelets; 2) LPS caused a dose-dependent rise in intracellular Ca2+ concentration in platelets; 3) LPS induced the activation of platelet protein kinase C (PKC) and the phosphorylation of glycoprotein llla (GPllla) which was inhibited by H-7. All these results suggest that stimulation of platelets with LPS causes a conformational change in glycoprotein llb/llla (GPllb/llla) through platelet shape change and/or phosphorylation of GPllla via PKC, which serves to expose the fibrinogen binding sites of GPllb/llla on human platelets.
Yu
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X
Institute of Basic Medical Sciences, CAMS, Beijing.
Wu
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Q
D001693:Biological Transport, Active; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism
D008070:Lipopolysaccharides; D010980:Platelet Membrane Glycoproteins; D011493:Protein Kinase C; D002118:Calcium