title: Inhibitory effect of unstimulated neutrophils on platelet aggregation by release of a factor similar to endothelium-derived relaxing factor (EDRF).
abstract: Previous studies have indicated a possible role for polymorphonuclear leukocytes (PMNLs) in the maintenance of hemostasis and vascular tone. We now demonstrate that unstimulated isolated PMNLs maintained at 37 degrees inhibited human platelet aggregation in a concentration- and time-dependent fashion. In addition, PMNLs increased platelet cyclic GMP concentrations. The platelet aggregation inhibitory effect of PMNLs was potentiated by superoxide dismutase and attenuated by hemoglobin and methylene blue. This inhibitory effect of PMNLs was not observed in 48-hr-old killed cells and was not modulated by aspirin treatment or by adenosine deaminase. These observations suggest that human PMNLs maintained at 37 degrees produce a substance with biological characteristics similar to those of the endothelium-derived relaxing factor.
authors: Division of Cardiology, University of Florida College of Medicine, Gainesville 32610.
authors: F A
authors: FA
authors: Nicolini
authors: J L
authors: JL
authors: Mehta
mesh_terms: D006454:Hemoglobins / Q000494:pharmacology; D006801:Humans; D008751:Methylene Blue / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology*; D010975:Platelet Aggregation Inhibitors; D010976:Platelet Count; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D006454:Hemoglobins; D010975:Platelet Aggregation Inhibitors; D009569:Nitric Oxide; D013482:Superoxide Dismutase; D008751:Methylene Blue