Comparison of the antioxidant status in tracheal and bronchoalveolar epithelial lining fluids in recurrent airway obstruction

• Published in: Equine veterinary journal 2006-09, Vol.38 (5), p.417-422
• Main Authors: Deaton, C.M, Marlin, D.J, Deaton, L, Smith, N.C, Harris, P.A, Schroter, R.C, Kelly, F.J
• Format: Article
• Language: English
• Subjects: Animals; antioxidant activity; Antioxidants - analysis; Antioxidants - metabolism; ascorbic acid; Ascorbic Acid - analysis; body fluids; bronchi; bronchoalveolar lavage fluid; Bronchoalveolar Lavage Fluid - chemistry; Bronchoalveolar Lavage Fluid - cytology; Dust; epithelium; Epithelium - metabolism; Epithelium - physiopathology; Female; horse; horse diseases; Horse Diseases - metabolism; Horse Diseases - physiopathology; Horses; hypersensitivity; inflammation; Lung Diseases, Obstructive - metabolism; Lung Diseases, Obstructive - physiopathology; Lung Diseases, Obstructive - veterinary; Male; Oxidation-Reduction; Oxidative Stress; Recurrence; recurrent airway obstruction; respiratory tract diseases; straw dust; trachea (vertebrates); Trachea - cytology; Trachea - metabolism; Trachea - pathology; tracheal wash; tracheal wash fluid
• ISSN: 0425-1644; 2042-3306
• DOI: 10.2746/042516406778400556

Summary Reasons for performing study: Following a period of airway inflammation the clearance of inflammatory cells along the mucociliary escalator may impose a considerable oxidant load on the trachea. Objectives: To determine the degree of oxidative stress in tracheal epithelial lining fluid (ELF) in comparison to that present in peripheral airways after an acute exposure to organic dust. Methods: Tracheal wash fluid and bronchoalveolar lavage fluid (BALF) were collected for cytology and antioxidant analyses from 6 recurrent airway obstruction (RAO)‐affected horses and 6 healthy control horses before and after stabling on straw bedding for 24 h. Results: In RAO‐affected horses, organic dust exposure resulted in a significant decrease in ascorbic acid concentration in tracheal ELF (P < 0.0001), which was greater than the decrease in bronchoalveolar ELF (P = 0.0003). The percentage decrease in tracheal ELF ascorbic acid correlated with the percentage decrease in bronchoalveolar ELF ascorbic acid (r = 0.76; P = 0.004) following exposure. Conclusions: Acute organic dust exposure results in significant antioxidant depletion in the trachea, which may reflect inflammation and oxidative processes in peripheral airways. Potential relevance: Further work is required to evaluate the role of ascorbic acid depletion in the pathogenesis of RAO.