Pharmacological modulation of allergic inflammation in the rat airways and association with mast cell heterogeneity.
Administration of ovalbumin by aerosol to sensitised rats produced a rapid (15 min) protein exudation in different airway tissues, as determined by Evans blue staining. This was associated with marked mast cell degranulation determined by histological examination, with there being no difference between mucosal and connective tissue mast cells. A 5-day administration regimen with compound 48/80 selectively depleted connective tissue mast cell (positive to berberine staining) without modifying ovalbumin-induced plasma protein extravasation. Treatment of rats with dexamethasone (1 mg/kg, -12 h) or nor-dihydroguaiaretic acid (30 mg/kg i.p., -30 min) significantly reduced ovalbumin-induced protein extravasation and preserved mucosal mast cell morphology. Indomethacin (4 mg/kg i.v., -30 min) exerted no effect on either parameter. In conclusion, we propose the mucosal mast cell as a target cell responsible at least partly for the inhibitory actions of known anti-inflammatory drugs. We suggest an involvement of endogenous leukotriene(s), but not prostanoid(s), in mucosal mast cell activation/degranulation.
Damazo
A S
AS
Department of Biology, IBILCE-UNESP, São Paulo, São José do Rio Prêto, Brazil.
Tavares de Lima
W
W
Perretti
M
M
Oliani
S M
SM
D000280:Administration, Inhalation; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D000941:Antigens / Q000008:administration & dosage; D002199:Capillary Permeability / Q000187:drug effects; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D008297:Male; D009637:Masoprocol / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects* / Q000473:pathology; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar; D012130:Respiratory Hypersensitivity / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D014132:Trachea / Q000187:drug effects / Q000473:pathology; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D000941:Antigens; D016861:Cyclooxygenase Inhibitors; D016859:Lipoxygenase Inhibitors; D003189:p-Methoxy-N-methylphenethylamine; D009637:Masoprocol; D003907:Dexamethasone; D010047:Ovalbumin; D007213:Indomethacin