Early timing of low-dose dexamethasone decreases inflammation in a murine model of eosinophilic airway disease.
CONCLUSIONS
A very low dose of dexamethasone (DEX) was as equally as sufficient as a pharmacological dose to decrease eosinophil inflammation in airways and bone marrow. The timing of DEX treatment in relation to allergen challenge was strongly decisive for the outcome of the inflammatory response.


OBJECTIVE
We aimed to study compartmental allergic airway inflammatory responses to classic pharmacological and also extremely low physiological DEX dosage, given at different time points close to allergen challenge in a murine model.


METHODS
Ovalbumin-sensitized BALB/c-mice were exposed to intra-nasal ovalbumin. DEX was given i.p. as 1 microg/kg low-dose or 500 microg/kg pharmacological single-dose 2 h before, immediately before or 7 h after each of three challenges. Inflammatory cells were evaluated in bronchoalveolar lavage (BAL), lungs, nasal mucosa, and bone marrow.


RESULTS
Groups treated with low-dose DEX decreased eosinophilia in BAL to the same extent as the pharmacological dose, but only when administered before challenge. The most prominent decrease of eosinophils in BAL was seen in mice treated with the low dose 2 h before challenge. A similar response pattern as in BAL eosinophilia was detected in lung histopathology. DEX treatments had no obvious effects on inflammation in nasal mucosa.
Georén
Susanna Kumlien
SK
Department of Clinical Science, Division of ENT Diseases, Karolinska Institutet, Huddinge, Sweden. susanna.georen@ki.se
Tcacencu
Ion
I
Wikström
Ann-Charlotte
AC
Stierna
Pontus
P
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001853:Bone Marrow / Q000187:drug effects / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004802:Eosinophilia / Q000473:pathology*; D004804:Eosinophils / Q000187:drug effects / Q000473:pathology; D007274:Injections, Intraperitoneal; D007958:Leukocyte Count; D007975:Leukotriene B4 / Q000032:analysis; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009297:Nasal Mucosa / Q000187:drug effects / Q000473:pathology; D010047:Ovalbumin; D011292:Premedication; D011657:Pulmonary Eosinophilia / Q000473:pathology*; D012130:Respiratory Hypersensitivity / Q000473:pathology*
D000893:Anti-Inflammatory Agents; D007975:Leukotriene B4; D003907:Dexamethasone; D010047:Ovalbumin