Effect of platelet-activating factor (PAF) on cytosolic free calcium in human peripheral blood mononuclear leukocytes.
Cytosolic free calcium concentration, [Ca2+]i, in human peripheral blood mononuclear leukocytes was increased by platelet-activating factor (PAF) dose-dependently. The response was transient and was attenuated by EGTA (2 mM) in the medium. Furthermore, pretreatment of the cells with pertussis toxin did not alter significantly the rise in [Ca2+]i after stimulation by PAF. The data suggest that elevation of [Ca2+]i in human mononuclear leukocytes induced by PAF depends on: (1) calcium influx through calcium channels in the plasma membranes and (2) calcium mobilization from internal stores mediated via pathway(s) that is insensitive to the action of pertussis toxin.
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Department of Medicine, University of Alberta, Edmonton, Canada.
Wong
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D001572:Benzofurans / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D016257:Fura-2 / Q000031:analogs & derivatives*; D006801:Humans; D066298:In Vitro Techniques; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D037342:Pertussis Toxin; D010835:Phytohemagglutinins / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D001572:Benzofurans; D010835:Phytohemagglutinins; D010972:Platelet Activating Factor; D010566:Virulence Factors, Bordetella; C049925:fura-2-am; D037342:Pertussis Toxin; D002118:Calcium; D016257:Fura-2