G protein activation and mediator release from human neutrophils and platelets after stimulation with sodium fluoride and receptor-mediated stimuli.
Immunology
; 73(3): 287-92, 1991 Jul.
Article
en En
| MEDLINE
| ID: mdl-1652553
ABSTRACT
Human polymorphonuclear granulocytes (PMN) and platelets were pre-activated with a receptor-mediated stimulus [formyl-methionyl-leucyl-phenylalanine (FMLP) or thrombin, respectively] and subsequently incubated with sodium fluoride (NaF). We investigated various cell responses, such as chemiluminescence by PMN, platelet aggregation and the release of lipid mediators [i.e. leukotriene B4 (LTB4) and its omega-oxidation products from neutrophils and 12-hydroxy-eicosatetraenoic acid (12-HETE) from platelets]. As a marker of G protein involvement, the binding of [3H]guanylylimidodiphosphate (Gpp (NH) p) to the membrane fractions of stimulated cells was determined. PMN pre-stimulated with FMLP showed a synergistically enhanced generation of leukotrienes returning to control values with the time of preincubation. Platelets preliminary treated with thrombin followed by incubation with NaF resulted in a sub-additive and time-independent mediator generation. Neither chemiluminescence by PMN nor platelet aggregation showed a similar pattern compared to the mediator release PMN preincubated with FMLP followed by NaF resulted in a second chemiluminescence response; the aggregation of platelets which were preincubated with thrombin was partially inhibited by the addition of NaF. Membrane fractions isolated from FMLP-pre-stimulated neutrophils showed a pattern in [3H]Gpp (NH) p-binding capacity that was comparable to the respective leukotriene release. With thrombin-prestimulated platelets, no similarities between Gpp (NH) p binding, aggregation or 12-HETE generation were observed. The sequential activation of different cell populations using the same kind of stimulation lead to different cell responses, indicating the diversity of G proteins and their control mechanisms.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fluoruro de Sodio
/
Plaquetas
/
Proteínas de Unión al GTP
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Neutrófilos
Límite:
Humans
Idioma:
En
Revista:
Immunology
Año:
1991
Tipo del documento:
Article
País de afiliación:
Alemania