Specific binding of platelet-activating factor (PAF) by human peripheral blood mononuclear leukocytes.
Binding of platelet-activating factor (PAF) to human peripheral blood mononuclear leukocytes was time-dependent, reversible, and saturable. [3H]PAF binding to the cells was inhibited dose-dependently by unlabeled PAF and PAF receptor antagonists: L-659,989, triazolam, and alprazolam. Scatchard analysis of saturation binding data indicated one class of receptors for PAF with KD = 5.7 nM and Bmax = 18 fmol/10(6) cells (11,100 receptors/cell). PAF (10 nM) increased intracellular free calcium concentration in human lymphocytes and this effect was inhibited by L-659,989 dose-dependently. Our data suggest that human peripheral blood mononuclear leukocytes have specific receptors for PAF.
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Department of Medicine, University of Alberta, Edmonton, Canada.
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D000527:Alprostadil / Q000494:pharmacology; D001667:Binding, Competitive; D005663:Furans / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000378:metabolism* / Q000494:pharmacology; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface / Q000032:analysis* / Q000187:drug effects / Q000502:physiology; D043562:Receptors, G-Protein-Coupled
D005663:Furans; D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; C054893:L 659989; D009240:N-Formylmethionine Leucyl-Phenylalanine; D000527:Alprostadil