In vitro effects of platelet factor 4 on normal human neutrophil functions (original) (raw)

Platelet factor (PF4) prepared from human outdated platelets by heparinagarose affinity chromatography was confirmed to be chemotactic for human neutrophils and in a concentration-dependent fashion caused significant release of lysosomal enzymes (myeloperoxidase, lysozyme, beta-glucuronidase) from human neutrophils treated with cytochalasin B. Lysosomal enzyme release from PF4-stimulated neutrophils was rapid and reached a plateau by 1-3 min. PF4 did not cause release of the cytoplasmic enzyme lactate dehydrogenase which indicates that exocytosis of granule-containing lysosomal enzymes did not result from cytolysis. In contrast, superoxide anion generation from human neutrophils stimulated with PF4 was undetectable even at the highest PF4 concentration tested (2 X 10(-5) M). Pretreatment of neutrophils with PF4 caused significant increased adherence of neutrophils to plastic surfaces and cultured pulmonary artery endothelial cells. The concentration of PF4 that elicited neutrophil c...