Costa LRR, Eades SC, Venugopal CS, Moore RM. Plasma and pulmonary fluid endothelin in horses with seasonal recurrent airway obstruction.
J Vet Intern Med 2009;
23:1239-46. [PMID:
19761476 DOI:
10.1111/j.1939-1676.2009.0385.x]
[Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND
Summer pasture-associated recurrent airway obstruction (SPA-RAO), a seasonal airway obstructive disease of horses, is characterized by clinical exacerbation after exposure to pasture during warm months of the year. Endothelin (ET)-1, potent bronchoconstrictor, mitogen, secretagogue, and proinflammatory mediator, has been implicated in the pathogenesis of asthma and equine heaves.
HYPOTHESIS
Immunoreactive ET-1 concentrations increase during clinical exacerbation and return to basal values during periods of disease remission.
ANIMALS
Twelve horses, 6 affected with SPA-RAO and 6 nonaffected.
METHODS
Prospective, observational study. Bronchoalveolar lavage fluid (BALF), arterial and venous plasma samples, and clinical variables were obtained from affected horses during clinical exacerbation and remission. Samples and data of nonaffected horses were collected during the summer and winter on dates similar to affected horses. Immunoreactive ET-1 was determined using a commercial ELISA.
RESULTS
The median and range ET-1 concentrations (pg/ml) in arterial (1.3, 0.7-1.8) and venous (1.3, 1.2-1.7) plasma and in BALF (0.3, 0.2-0.4), and pulmonary epithelial lining fluid (PELF) (25.5, 21-50) were greater in affected horses during clinical exacerbation compared with remission (P < .01). The concentrations of immunoreactive ET-1 were greater in affected horses during clinical exacerbation compared with nonaffected horses (P < .05).
CONCLUSIONS AND CLINICAL IMPORTANCE
During clinical exacerbation of SPA-RAO, ET-1 is increased in circulation and pulmonary secretions. Intervention with ET receptor antagonists should provide further information on the role of ET-1 in SPA-RAO.
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