Differential regulation of the release of tumor necrosis factor-alpha and of eicosanoids by mast cells in rat airways after antigen challenge

• Autor(a) principal: Trezena, A. G.
• Data de Publicação: 2003
• Outros Autores: Silva, Z. L. da, Oliveira, R. M., Damazo, Amilcar Sabino [UNIFESP], Straus, Anita Hilda [UNIFESP], Takahashi, Helio Kiyoshi [UNIFESP], Oliani, Sonia Maria [UNIFESP], Lima, W. T. de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.1080/09629350310001599684; http://repositorio.unifesp.br/handle/11600/27335
• topic: TNF; eicosanoids; mast cells; airways; asthma; rat

Background: Rat trachea display a differential topographical distribution of connective tissue mast cells (CTMC) and mucosal mast cells (MMC) that may imply regional differences in the release of allergic mediators such as tumor necrosis factor-alpha (TNF-alpha) and eicosanoids.Aim: To evaluate the role of CTMC and MMC for release of TNF-alpha and eicosanoids after allergenic challenge in distinct segments of rat trachea.Materials and methods: Proximal trachea ( PT) and distal trachea (DT) from ovalbumin (OVA)-sensitized rats, treated or not with compound 48/80 ( 48/80) or dexamethasone, were incubated in culture medium. After OVA challenge, aliquots were collected to study release of TNF-alpha and eicosanoids.Results: Release of TNF-alpha by PT upon OVA challenge peaked at 90 min and decayed at 6 and 24 h. Release from DT peaked at 30-90 min and decayed 6 and 24 h later. When CTMC were depleted with 48/80, OVA challenge exacerbated the TNF-alpha release by PT at all time intervals, while DT exacerbated TNF-alpha levels 6 and 24 h later only. Dexamethasone reduced TNF-alpha production after 90 min of OVA challenge in PT and at 3 and 6h in DT. OVA challenge increased prostaglandin D-2 in DT and leukotriene B-4 in both segments but did not modify prostaglandin E-2 and leukotriene C-4 release.Conclusion: OVA challenge induces TNF-alpha release from MMC, which is negatively regulated by CTMC. the profile of TNF-alpha and eicosanoids depends on the time after OVA challenge and of the tracheal segment considered.