Assuntos
Fluorescência , Neoplasias Pulmonares/diagnóstico , Escarro , Adolescente , Adulto , Idoso , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , TetraciclinaRESUMO
Inhaled frusemide has been shown to inhibit bronchoconstriction induced by immunological and nonimmunological stimuli in asthmatic patients. The mechanisms by which this compound exerts its effect in asthmatic airways are unknown, but an inhibitory action on the activation of inflammatory cells or on the responsiveness of sensory epithelial nerves may be involved. In this study, we give evidence that frusemide prevents in part the activation of bronchial epithelial cells and pulmonary macrophages, as it reduces the rate of superoxide anion generation induced by IgE receptor cross-linking and by phorbol myristate acetate by 40-60%. The effect was not specific since we used stimuli which activate different signal transduction pathways for NADPH oxidase stimulation and frusemide was equally effective.
Assuntos
Brônquios/metabolismo , Furosemida/farmacologia , Macrófagos Alveolares/metabolismo , Superóxidos/metabolismo , Antígenos de Diferenciação de Linfócitos B/efeitos dos fármacos , Antígenos de Diferenciação de Linfócitos B/metabolismo , Brônquios/citologia , Brônquios/efeitos dos fármacos , Células Cultivadas , Reagentes de Ligações Cruzadas/farmacologia , Ativação Enzimática , Células Epiteliais , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Humanos , Ativação de Macrófagos/efeitos dos fármacos , Ativação de Macrófagos/fisiologia , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/fisiologia , NADH NADPH Oxirredutases/efeitos dos fármacos , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidases , Receptores Fc/efeitos dos fármacos , Receptores Fc/metabolismo , Receptores de IgE , Espectrofotometria , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
The aim of the present study was to evaluate the release of some potential mediators of allergic reactions, such as histamine, peptide leukotrienes (LTs), LTB4 and prostaglandin D2 (PGD2), in bronchoalveolar lavage (BAL) fluids from 11 patients with respiratory allergy (eight with bronchial asthma and three with allergic rhinitis), who underwent specific endobronchial challenge. Histamine, peptide LT, and PGD2 levels in BAL fluids increased significantly after antigen stimulation both in patients with asthma and in patients with rhinitis. By contrast, LTB4 concentration was always below the limits of detection of the radioimmunoassay. In patients with asthma, histamine concentration increased from 5.3 +/- 0.6 ng/ml in lavages obtained before provocation to 20.2 +/- 5.8 ng/ml (mean +/- SEM; p less than 0.04) 5 minutes after bronchoprovocation. Peptide LTs increased from 0.32 +/- 0.08 to 0.82 +/- 0.21 ng/ml (p less than 0.02) and PGD2 from 0.06 +/- 0.01 ng/ml to 0.36 +/- 0.09 ng/ml (p less than 0.02). Elevated histamine, peptide LT, and PGD2 concentrations were also found in the 15-minute postchallenge BAL fluids. Similar results were obtained in patients with rhinitis. Histamine concentration was 3.4 +/- 0.6 ng/ml in prechallenge bronchial lavages and 11.3 +/- 1.7 ng/ml in postchallenge lavages; peptide LTs increased from 0.13 +/- 0.008 ng/ml to 0.73 +/- 0.21 ng/ml, and PGD2 from 0.05 +/- 0.01 ng/ml to 0.26 +/- 0.06 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Liberação de Histamina , Leucotrienos/metabolismo , Prostaglandina D2/metabolismo , Hipersensibilidade Respiratória/metabolismo , Adulto , Asma/metabolismo , Testes de Provocação Brônquica , Líquido da Lavagem Broncoalveolar/metabolismo , Feminino , Humanos , Masculino , Rinite Alérgica Perene/metabolismo , Fatores de TempoRESUMO
Local antigen challenge in patients with respiratory allergy is associated with histamine and arachidonic acid metabolites release, both in upper and in lower respiratory airways. Raised histamine levels can be detected in nasal secretions 5 min after allergen stimulation. Increased leukotriene C4 and prostaglandin D2 concentrations persist for a longer period (respectively 20 and 30 min). Endobronchial antigen stimulation is also followed by release of histamine, leukotriene C4 and prostaglandin D2, which can be detected in bronchial lavage fluid. Elevated concentrations of these mediators can be found 5 and 15 min after challenge. Moreover, endobronchial antigen stimulation is associated with an increase in the number of bronchial epithelial cells recovered in bronchial lavage fluids.