Comparison of the antioxidant status in tracheal and bronchoalveolar epithelial lining fluids in recurrent airway obstruction.
BACKGROUND
Following a period of airway inflammation the clearance of inflammatory cells along the mucociliary escalator may impose a considerable oxidant load on the trachea.


OBJECTIVE
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.


CONCLUSIONS
Further work is required to evaluate the role of ascorbic acid depletion in the pathogenesis of RAO.
Deaton
C M
CM
Centre for Equine Studies, Animal Health Trust, Kentford, Suffolk, UK.
Marlin
D J
DJ
Deaton
L
L
Smith
N C
NC
Harris
P A
PA
Schroter
R C
RC
Kelly
F J
FJ
D000818:Animals; D000975:Antioxidants / Q000032:analysis* / Q000378:metabolism; D001205:Ascorbic Acid / Q000032:analysis*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology; D004391:Dust; D004848:Epithelium / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D006734:Horse Diseases / Q000378:metabolism* / Q000503:physiopathology; D006736:Horses; D008173:Lung Diseases, Obstructive / Q000378:metabolism / Q000503:physiopathology / Q000662:veterinary*; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D012008:Recurrence; D014132:Trachea / Q000166:cytology / Q000378:metabolism / Q000473:pathology
D000975:Antioxidants; D004391:Dust; D001205:Ascorbic Acid