RT Journal Article SR Electronic T1 Alveolar antioxidant status in patients with acute respiratory distress syndrome JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 994 OP 999 DO 10.1183/09031936.04.00120703 VO 24 IS 6 A1 R. Schmidt A1 T. Luboeinski A1 P. Markart A1 C. Ruppert A1 C. Daum A1 F. Grimminger A1 W. Seeger A1 A. Günther YR 2004 UL http://erj.ersjournals.com/content/24/6/994.abstract AB In the acutely inflamed lung, oxidant stress occurs within the alveolar compartment. Under these conditions, the regulation of low molecular weight antioxidants in the epithelial lining fluid is poorly understood. Therefore, antioxidant levels were measured in the bronchoalveolar lavage fluid (BALF) of patients with acute respiratory distress syndrome (ARDS; n=40) and in healthy volunteers (n=20). Reduced glutathione (GSH), oxidised glutathione (GSSG; enzymatic assay), retinol (vitamin A), α-tocopherol (vitamin E), ascorbic acid (vitamin C), uric acid (all by HPLC), plasmalogens (1-alkenyl-2-acyl phospholipids), polyunsaturated fatty acids (PUFA; both by gas–liquid chromatography), and F2-isoprostanes (ELISA) were quantified. All values are expressed as concentrations in cell-depleted BALF. GSSG (ARDS: 0.13±0.02 µM; control: 0.03±0.01 µM; mean±sem) and F2-isoprostanes (ARDS: 78±10 pM; control: 26±5 pM) were increased in ARDS, thus indicating oxidant stress. GSH levels in patients did not change significantly, whereas concentrations of vitamins A and C, vitamin E (ARDS: 77±15 nM; control: 26±3 nM) and uric acid (ARDS: 11.8±2.2 µM; control: 0.7±0.0 µM) were significantly elevated in ARDS. PUFA of total lipids, which may act as sacrificial antioxidants, increased by a factor of ∼3 in patients, but plasmalogens showed a significant decrease. In conclusion, low molecular weight antioxidants are elevated in the alveolar compartment of patients with acute respiratory distress syndrome. Further research is warranted to elucidate the molecular mechanisms underlying this finding. This study was supported by the Deutsche Forschungsgemeinschaft (SCHM 1524/2-1), Bonn, Germany.