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Platelet‐leukocyte interaction: activation of rabbit platelets by FMLP‐stimulated neutrophils
Author(s) -
Coëffier Eliane,
Joseph Danielle,
Prévost MarieChristine,
Vargaftig B. Boris
Publication year - 1987
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1987.tb11336.x
Subject(s) - platelet , n formylmethionine leucyl phenylalanine , chemistry , lysozyme , neutrophile , platelet activation , endocrinology , chemotaxis , lactate dehydrogenase , medicine , biochemistry , biology , enzyme , receptor , in vitro
1 The effect of the chemotactic peptide, N‐fonnyl‐ l ‐methionyl‐ l ‐leucyl‐ l ‐phenylalanine (FMLP) was studied on cells in whole rabbit blood or on a mixture of purified rabbit platelets and neutrophils. 2 In blood, FMLP triggered cell aggregation (measured by electrical impedance) which was dependent upon the concentration of FMLP (9.9 ± 0.7 and 5.2 ± 1.2 ohms at 1 and 0.01 μ m FMLP respectively). This aggregation was accompanied by a strong decrease in platelet counts (54.6 ± 6.0 and 45.6 ± 3.8% for 1 and 0.01 μ m FMLP respectively) and by a smaller decrease in neutrophil counts (25.0 ± 1.9 and 12.9 ± 1.7% at 1 and 0.01 μ m FMLP respectively). 3 When purified platelets and neutrophils were co‐incubated, the addition of 0.1 μ m induced a marked aggregation (50.0 ±1.6 vs. 19.5 ±1.6% of light transmission, n = 8, P < 0.001), ATP secretion (8.4 ± 1.0 vs. 0.1 ± 0.1 nmol ml −1 , n = 6, P < 0.001) and a decrease in platelet counts. FMLP induced aggregation of purified neutrophils and release of lysozyme but lacked direct platelet‐stimulating effects. The release of lactate dehydrogenase, a cytoplasmic marker and lysozyme were unchanged under the interaction conditions. 4 Platelet activation was reduced by about 30% with 100 μ m aspirin or indomethacin and by about 70% with 100 μ m BW 755C. Two Paf‐acether antagonists, BN 52021 (100 μ m ) and WEB 2086 (1 μ m ) suppressed platelet activation by 70–80%. 5 The supernatant of FMLP‐stimulated neutrophils induced platelet activation only when bovine serum albumin was present. Rabbit neutrophils stimulated in the presence of serum albumin by 1 μ m FMLP formed 2 n m Paf‐acether of which half was released to the extracellular medium. 6 Our results indicate that the stimulation of neutrophils by FMLP induces platelet activation in whole blood and on isolated cells and that both arachidonic acid‐metabolites and Paf‐acether participate in platelet activation.