title: Corticosteroid treatment inhibits airway hyperresponsiveness and lung injury in a murine model of chemical-induced airway inflammation.
abstract: BACKGROUND
  Exposure to toxic alkylating mustard agents causes both acute and long-term effects to the lungs as indicated by increased number of inflammatory cells in airways, lung edema and lung tissue fibrosis. We have previously demonstrated that treatment with the corticosteroid dexamethasone 1 h after lung exposure to the nitrogen mustard analog melphalan protects mice from acute and sub-acute inflammatory responses, as well as from lung tissue fibrosis.
  
  
  OBJECTIVE
  In order to address the importance of early anti-inflammatory treatment, we investigated the therapeutic effect of dexamethasone administered 1, 2 or 6 h following exposure to melphalan.
  
  
  METHODS
  C57BL/6 mice were exposed to melphalan and treated with dexamethasone 1, 2 or 6 h after exposure. Twenty hours or 14 days post exposure mice were subjected to analysis of respiratory mechanics where the effects of incremental doses of methacholine on central and peripheral lung components were measured. We also determined the amount of inflammatory cells in the bronchoalveolar lavage fluid and measured the amount of collagen content in the lungs.
  
  
  RESULTS
  Melphalan exposure increased airway hyperresponsiveness in both central and peripheral airways and induced an airway inflammation dominated by infiltration of macrophages and neutrophils. Dexamethasone given 1 h after exposure to melphalan provided better protection against airway inflammation than administration 2 or 6 h after exposure. Collagen deposition 14 days after exposure was decreased due to dexamethasone treatment.
  
  
  CONCLUSIONS
  Early treatment with dexamethasone is important in order to reduce the airway hyperresponsiveness and inflammation caused by toxic alkylating mustards such as melphalan.
authors: Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå, Sweden. elisabeth.wigenstam@foi.se
authors: Elisabeth
authors: E
authors: Wigenstam
authors: Sofia
authors: S
authors: Jonasson
authors: Bo
authors: B
authors: Koch
authors: Anders
authors: A
authors: Bucht
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology; D016535:Bronchial Hyperreactivity / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid; D003094:Collagen / Q000378:metabolism; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004195:Disease Models, Animal; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D055370:Lung Injury / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008558:Melphalan / Q000633:toxicity*; D016210:Methacholine Chloride / Q000008:administration & dosage / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D016210:Methacholine Chloride; D003907:Dexamethasone; D003094:Collagen; D008558:Melphalan