Platelet release products modulate some aspects of polymorphonuclear leukocyte activation.
The aim of this research was to evaluate in vitro interactions between platelets and polymorphonuclear leukocytes. The effects of supernatant from thrombin-activated platelets and two platelet release products (adenosine triphosphate and beta-thromboglobulin) were tested on the following features of polymorphonuclear leukocytes activation: opsonized zymosan and phorbol myristate acetate stimulated chemiluminescence, release of membrane bound calcium, NADPH-oxidase activity, and membrane fluidity (fluorescent polarization). The results showed that the addition of platelet supernatant to polymorphonuclear leukocytes induces a significant activation of cells. On the other hand, after three hours of preincubation of polymorphonuclear leukocytes with platelet supernatant, a decreased response of polymorphonuclear leukocytes to stimulation with phorbol myristate acetate, a significant decrease in NADPH-oxidase activity, and a lowered membrane fluidity were observed. Adenosine triphosphate modulated only opsonized zymosan stimulated chemiluminescence, with and without preincubation with polymorphonuclear leukocytes. Beta-thromboglobulin caused a decrease of the chemiluminescent response of polymorphonuclear leukocytes, using both agonists, with and without preincubation with polymorphonuclear leukocytes. Moreover beta-thromboglobulin only caused a decrease of the polymorphonuclear leukocytes membrane fluidity without preincubation with the cells. These results support the thesis that platelets have a "time-related" modulating activity on polymorphonuclear leukocytes.
Allegrezza-Giulietti
A
A
Institute of Rheumatology, Faculty of Medicine, University of Ancona, Italy.
Serretti
R
R
Beccerica
E
E
Muti
S
S
Ferretti
G
G
Cervini
C
C
D000255:Adenosine Triphosphate / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D005454:Fluorescence Polarization; D006801:Humans; D008163:Luminescent Measurements; D008560:Membrane Fluidity / Q000187:drug effects / Q000502:physiology; D008566:Membranes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000032:analysis; D019255:NADPH Oxidases; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D015539:Platelet Activation / Q000187:drug effects / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology; D001620:beta-Thromboglobulin / Q000494:pharmacology
D001620:beta-Thromboglobulin; D000255:Adenosine Triphosphate; D015054:Zymosan; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D013917:Thrombin; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium