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Mediators of Inflammation
Volume 12 (2003), Issue 4, Pages 237-246
http://dx.doi.org/10.1080/09629350310001599684

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

1Laboratory of Immunogenetics and Laboratory of Anaerobic Vaccines, Butantan Institute, São Paulo, Brazil
2Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
3Department of Biology IBILCE, São José Rio Preto, São Paulo, Brazil
4Department of Biochemistry, UNIFESP, Sao Paulo, Brazil

Copyright © 2003 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

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-α (TNF-α) and eicosanoids.

Aim: To evaluate the role of CTMC and MMC for release of TNF-α 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-α and eicosanoids.

Results: Release of TNF-α 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-α release by PT at all time intervals, while DT exacerbated TNF-α levels 6 and 24 h later only. Dexamethasone reduced TNF-α production after 90 min of OVA challenge in PT and at 3 and 6h in DT. OVA challenge increased prostaglandin D2 in DT and leukotriene B4 in both segments but did not modify prostaglandin E2 and leukotriene C4 release.

Conclusion: OVA challenge induces TNF-α release from MMC, which is negatively regulated by CTMC. The profile of TNF-α and eicosanoids depends on the time after OVA challenge and of the tracheal segment considered.