RESUMO
Immunoglobulin E (IgE) has been shown to play a critical role in the allergic late-phase reaction, which is marked by intense leukocyte infiltration and edema. In this study we assessed the allergic pleural inflammation triggered by intrapleural (i.pl.) challenge in sensitized rats. We examined pleural effluent from actively sensitized rats following anti-IgE monoclonal antibody (mAb) (MARE-1) provocation for protein exudation, neutrophil as well as eosinophil accumulation. Inflammatory changes triggered by antigen after passive sensitization with IgE mAb was also assessed for comparison. Total serum level of IgE was found to be about threefold increased 7-8 days post-active sensitization, remaining augmented for at least 30 days. Increased levels of peritoneal leukocyte-bound IgE and serum IgE with specificity to ovalbumin were also detected. Nevertheless, the anti-IgE challenge in 14-day actively sensitized was shown to be a weak stimulus of neutrophil and eosinophil accumulation, despite being able to cause intense protein extravasation. Similarly, antigen challenge of IgE-passively sensitized rats caused protein leakage that was comparable to that induced by anti-IgE mAb in actively sensitized rats but led to a much lower neutrophil/eosinophil infiltration. Also, blockade of complement with recombinant human soluble C receptor-1 (sCR1) treatment prevented actively sensitized rats from reacting to antigen with neutrophil and eosinophil recruitment without modifying protein extravasation. These data suggest that IgE and complement-mediated mechanisms probably account for the exudation and leukocyte infiltration that is characteristic of the pleural inflammatory response observed in actively sensitized rats.
Assuntos
Imunoglobulina E/imunologia , Pleurisia/imunologia , Proteínas/imunologia , Cloreto de Alumínio , Compostos de Alumínio , Animais , Anticorpos Monoclonais/imunologia , Cloretos , Eosinófilos/efeitos dos fármacos , Feminino , Imunoglobulina E/sangue , Contagem de Leucócitos/efeitos dos fármacos , Masculino , Neutrófilos/efeitos dos fármacos , Ovalbumina/imunologia , Proteínas/metabolismo , Ratos , Ratos Wistar , Receptores de Complemento/imunologiaRESUMO
The identity of the histamine-potentiating activity detected in the rat anaphylactic pleural washing was investigated. Wistar rats of both sexes, weighing 150-200 g, were sensitized by injecting subcutaneously (sc) a mixture of ovalbumin and Al(OH)3 14 days before allergen challenge. In sensitized rats, intrapleural (ipl) injection of ovalbumin (12 micrograms/cavity) caused an intense protein exudation. A single ipl administration of compound 48/80 (12 micrograms/cavity) exhausted the resident mast cell population and turned the pleural cavity hyporeactive to the allergen challenge performed 5 days later. Allergen-induced exudation occurred in parallel to a dramatic decrease in the amount of cell-stored histamine (from 9.6 +/- 1.4 (N = 8) to 1.3 +/- 0.1 (N = 6) micrograms/cavity, P < 0.001) in the pleural fluid within 10 min. The anaphylactic cell-free pleural washing obtained at this time, as well as histamine at a concentration equivalent to that stored in pleural mast cells (10 micrograms/cavity), did not induce pleural exudation when injected into normal rats. In contrast, the combined administration of histamine and anaphylactic pleural washing led to remarkable pleural exudation, comparable to that obtained with a high dose of histamine (200 micrograms/cavity) alone. It is noteworthy that the anaphylactic washing from compound 48/80-pretreated rats failed to synergize with histamine. Also, synergism was not reproduced when recipient rats were pretreated with methysergide (50 micrograms/cavity). Consistently, serotonin (5 micrograms/cavity) acted synergistically with histamine (10 micrograms/cavity), producing a greater exudative response than observed with the sum of the effects of each vasoactive amine alone. The results indicate that serotonin accounts for the histamine-potentiating activity noted in the anaphylactic pleural washing, confirming that the synergistic interaction between these vasoactive amines plays a critical role in the rat allergic pleurisy.
Assuntos
Histamina/imunologia , Derrame Pleural/imunologia , Serotonina/imunologia , Anafilaxia/imunologia , Animais , Feminino , Masculino , Pleura/imunologia , Derrame Pleural/patologia , Ratos , Ratos WistarRESUMO
OBJECTIVE: We investigated the antiinflammatory properties of a derived fraction of tetranortriterpenoids (TNTP) obtained from the seeds of Carapa guianensis Aublet. MATERIAL AND METHODS: Zymosan-induced arthritis and pleurisy in Swiss and C57/Bl6 mice (n = 10 per group). Western blot analysis was performed to analyze nuclear factor-kappaB (NFkappaB) translocation in mice peritoneal macrophages stimulated in vitro with zymosan (500 microg/ml). ELISA was performed to evaluate cytokine levels in knee joints. Values of p = 0.05 were regarded as significant. RESULTS: Zymosan intra-articular (i. a.) injection (500microg/ cavity) induced a significant increase in knee joint diameter within 6 h, peaked within 24 h and remained above control values for 20 days. Orally-given (p. o.) TNTP (100-200 mg/ kg) inhibited zymosan-induced increase in knee joint diameter and protein extravazation into synovial cavity within 6 h. TNTP (100-200 mg/kg, p. o.) also inhibited total leukocyte influx into the synovial space and tissue, as well as into the mice pleural cavity, due to neutrophil impairment 6 h after zymosan stimulation. The increase in TNF-alpha, IL-1beta and CXCL8/IL-8 levels that were detected in knee synovial extracts obtained from zymosan-stimulated mice was also inhibited by TNTP (100 mg/kg, p. o.). Moreover, the incubation of mice peritoneal macrophages with TNTP (100 mug/ml) inhibited zymosan (500 microg/ml)-induced NFkappaB translocation into the nucleus 6 h after stimulation. CONCLUSION: Taken together, these results indicate that TNTP present an important antiinflammatory effect, inhibiting zymosan-induced arthritis in mice via the impairment of TNF-alpha, IL-1beta and CXCL8/IL-8 generation, as well as NFkappaB signaling pathway.
Assuntos
Anti-Inflamatórios/farmacologia , Artrite Experimental/tratamento farmacológico , Limoninas/farmacologia , Meliaceae , Preparações de Plantas/farmacologia , Animais , Artrite Experimental/induzido quimicamente , Artrite Experimental/metabolismo , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Articulação do Joelho/metabolismo , Articulação do Joelho/patologia , Macrófagos Peritoneais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Fitoterapia/métodos , Sementes , Sinaptotagmina I/metabolismo , Membrana Sinovial/metabolismo , Membrana Sinovial/patologia , ZimosanRESUMO
The identity of the histamine-potentiating activity detected in the rat anaphylactic pleural washing was investigated. Wistar rats of both sexes, weighing 150-200 g, were sensitized by injecting subcutaneously (sc) a mixture of ovalbumin and Al(OH)3 14 days before allergen challenge. In sensitized rats, intrapleural (ipl) injection of ovalbumin (l2 mug/cavity) caused an intense protein exudation. A single ipl administration of compound 48/80 (l2 mug/cavity) exhausted the resident mast cell population and turned the pleural cavity hyporeactive to the allergen challenge performed 5 days later. Allergen-induced exudation occurred in parallel to a dramatic decrease in the amount of cell-stored histamine (from 9.6 ñ 1.4 (N = 8) to 1.3 ñ 0.1 (N = 6) mug/cavity, P<0.001) in the pleural fluid within 10 min. The anaphylactic cell-free pleural washing obtained at this time, as well as histamine at a concentration equivalent to that stored in pleural mast cells (10 mug/cavity), did not induce pleural exudation when injected into normal rats. In contrast the combined administration of histamine and anaphylactic pleural washing led to remarkable pleural exudation, comparable to that obtained with a high dose of histamine (200 mug/cavity) alone. It is noteworthy that the anaphylactic washing from compound 48/80 pretreated rats failed to synergize with histamine. Also, synergism was not reproduced when recipient rats were pretreated with methysergide (50 mug/cavity). Consistently, serotonin (5 mug/cavity) acted synergistically with histamine (1O mug/cavity), producing a greater exudative response than observed with the sum of the effects of each vasoactive amine alone. The results indicate that serotonin accounts for the histamine-potentiating activity noted in the anaphylactic pleural washing, confirming that the synergistic interaction between these vasoactive amines plays a critical role in the rat allergic pleurisy.