Differential regulation of the release of tumor necrosis factor-alpha and of eicosanoids by mast cells in rat airways after antigen challenge
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Data
2003-08-01
Autores
Trezena, A. G.
da Silva, Z. L.
Oliveira, R. M.
Damazo, A. S.
Straus, A. H.
Takahashi, H. K.
Oliani, S. M.
de Lima, W. T.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Carfax Publishing
Resumo
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.
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Palavras-chave
TNF, eicosanoids, Mast cells, airways, asthma, rat
Como citar
Mediators of Inflammation. Basingstoke: Carfax Publishing, v. 12, n. 4, p. 237-246, 2003.