RT Journal Article SR Electronic T1 S-carboxymethylcysteine normalises airway responsiveness in sensitised and challenged mice JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 577 OP 585 DO 10.1183/09031936.05.00090304 VO 26 IS 4 A1 K. Takeda A1 N. Miyahara A1 T. Kodama A1 C. Taube A1 A. Balhorn A1 A. Dakhama A1 K. Kitamura A1 A. Hirano A1 M. Tanimoto A1 E. W. Gelfand YR 2005 UL http://erj.ersjournals.com/content/26/4/577.abstract AB S-carboxymethylcysteine (S-CMC) has been used as a mucoregulator in respiratory diseases. However, the mechanism of action of S-CMC on allergic airway inflammation has not yet been defined. In the present study, BALB/c mice were initially sensitised and challenged to ovalbumin (OVA) and, weeks later, re-challenged with OVA (secondary challenge). S-CMC (5–100 mg·kg−1) was administered from 2 days before the secondary challenge through to the day of assay. Mice developed airway hyperresponsiveness (AHR) 6 h after the secondary challenge and increased numbers of neutrophils were present in the bronchoalveolar lavage (BAL) fluid. At 72 h after secondary challenge, mice again developed AHR, but the BAL fluid contained large numbers of eosinophils. S-CMC treatment was found to reduce AHR and neutrophilia at 6 h, as well as eosinophilia and AHR at 72 h. These effects appeared to be dose dependent. Goblet cell hyperplasia, observed at 72 h, was reduced by S-CMC. In BAL fluid, increased levels of interferon-γ, interleukin (IL)-12 and IL-10 and decreased levels of IL-5 and IL-13 were detected. In conclusion, the data indicate that S-carboxymethylcysteine is effective in reducing airway hyperresponsiveness and airway inflammation at two distinct phases of the response to the secondary allergen challenge in sensitised mice.