C-reactive protein inhibits binding of platelet-activating factor to human platelets.
Serum concentration of C-reactive protein (CRP), a prototypical acute-phase protein rises dramatically in response to tissue injury or inflammation. We report here that CRP (1-20 micrograms/ml) inhibited platelet-activating factor (PAF)-induced aggregation of human platelets in time-, and dose-dependent manner. This inhibitory action of CRP was nearly completely removed by treatment with anti CRP antiserum. At higher concentrations (20-100 micrograms/ml), CRP stabilized platelet membrane against the detergent-like effect of beta-deoxy-lysolecithin. Furthermore, CRP (10 micrograms/ml) diminished specific [3H]PAF binding to platelets and displaced previously bound labeled PAF from platelets. These results suggest that by depressing the bioavailability of PAF, CRP may be an important modulator of platelet activation during acute inflammatory reactions.
Filep
J G
JG
Department of Pathophysiology, Semmelweis University Medical School, Budapest, Hungary.
Hermán
F
F
Kelemen
E
E
Földes-Filep
E
E
D000917:Antibody Formation; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002097:C-Reactive Protein / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis / Q000096:biosynthesis; D008244:Lysophosphatidylcholines / Q000494:pharmacology; D008297:Male; D010972:Platelet Activating Factor / Q000378:metabolism* / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011485:Protein Binding / Q000502:physiology
D008244:Lysophosphatidylcholines; D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D002097:C-Reactive Protein; D007770:L-Lactate Dehydrogenase