title: Inhibition of human platelet activation by polymorphonuclear leukocytes.
abstract: 1. The effect of unstimulated human polymorphonuclear leukocytes (PMNs) on platelet activation was examined. 2. Human platelet aggregation and adenosine 5'-triphosphate (ATP) release induced by collagen (1-2 micrograms ml-1); thrombin (0.01-0.02 u ml-1) or arachidonic acid (AA) (0.1-0.2 mM) were markedly inhibited when conducted in the presence of unstimulated PMNs. 3. Platelet inhibition induced by PMNs was dependent on the number of PMNs and on the incubation time of the mixed cell suspension. 4. Platelet inhibition was not reversed in time when PMNs were depleted from the mixed-cell suspension. 5. PMN-mediated platelet-inhibition was not mediated by AA metabolites, oxygen reactive intermediates, nitric oxide or proteases. 6. The factor(s) accounting for the platelet inhibition mediated by PMNs are not yet characterized.
authors: Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires, Argentina.
authors: M A
authors: MA
authors: Schattner
authors: J R
authors: JR
authors: Geffner
authors: M A
authors: MA
authors: Isturiz
authors: M A
authors: MA
authors: Lazzari
mesh_terms: D000255:Adenosine Triphosphate / Q000097:blood; D006801:Humans; D066298:In Vitro Techniques; D009504:Neutrophils / Q000502:physiology*; D015539:Platelet Activation / Q000502:physiology*; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology
chemical_list: D000255:Adenosine Triphosphate