Effects of ozone and airway inflammation on glutathione status and iron homeostasis in the lungs of horses.
OBJECTIVE
To investigate the effects of ozone and airway inflammation on indices of oxidant injury in horses.


METHODS
5 clinically normal horses and 25 horses referred for poor performance.


METHODS
Blood, tracheal wash, and bronchoalveolar lavage fluid samples were collected before and after ozone exposure (n = 5) or from clinical cases (n = 25), and were analyzed for reduced glutathione (GSH), glutathione disulfide (GSSG), and free and total iron (Fe) values. A scoring system (0 to 5) was used to assess airway inflammation on the basis of clinical signs and cytologic analysis of the tracheal wash and bronchoalveolar lavage fluid samples.


RESULTS
Ozone induced significant (P < 0.05) increases in GSH (195.4 +/- 68.5 microM), GSSG (19.4 +/- 6.4 microM), and free (25.5 +/- 16.1 microM) and total (93.1 +/- 13.4 microM) Fe values in the pulmonary epithelial lining fluid, compared with preozone samples (49.2 +/- 18.6, 2.4 +/- 1.2, 0.0, and 33.1 +/- 5.9 microM, respectively). The presence of airway inflammation (19/25) was associated with high GSSG and free and total Fe, but not GSH, values in epithelial lining fluid, compared with values for clinically normal horses (6/25). There were no differences in the systemic values of GSH, GSSG, and free and total Fe between any of the groups. A strong correlation (r = 0.84; P < 0.001) existed between inflammation score and the glutathione redox ratio (GSSG/[GSH + GSSG]) in the 25 horses admitted for clinical examination.


CONCLUSIONS
Oxidant injury in the lung will induce changes in the glutathione status and Fe homeostasis that could affect pathogenesis of the disease.


CONCLUSIONS
Measurement of indices of oxidant injury may be useful in the diagnosis of airway inflammation and the response to inhaled oxidants.
Mills
P C
PC
Equine Centre, Animal Health Trust, New-Market, Suffolk, England.
Roberts
C A
CA
Smith
N C
NC
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D004848:Epithelium / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism*; D019803:Glutathione Disulfide; D006706:Homeostasis; D006734:Horse Diseases; D006736:Horses; D007249:Inflammation / Q000503:physiopathology / Q000662:veterinary*; D007501:Iron / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D010126:Ozone / Q000494:pharmacology*; D012016:Reference Values; D012044:Regression Analysis; D014133:Tracheal Diseases / Q000503:physiopathology / Q000662:veterinary*
D010126:Ozone; D007501:Iron; D005978:Glutathione; D019803:Glutathione Disulfide