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Plasma cortisol concentration increases within 6 hours of stabling in RAO ‐affected horses
Author(s) -
Shaba J. J.,
Behan Braman A.,
Robinson N. E.
Publication year - 2014
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/evj.12201
Subject(s) - plasma concentration , horse , endocrinology , medicine , chemistry , biology , paleontology
Summary Reasons for performing study In many inflammatory diseases plasma cortisol concentration ( CORT ) increases at the onset of acute inflammation, but the situation in recurrent airway obstruction ( RAO ) of horses is unknown. Study design Split‐plot repeated measures design with one grouping factor (disease) and two repeated factors (day and 3‐hour intervals). Objective To test the hypothesis that CORT increases as acute exacerbations of RAO develop. Methods Four RAO ‐susceptible and 4 control horses were placed in a low dust environment ( LDE nv) for 2 days followed by 2 days in a high dust environment ( HDE nv). Exacerbations of RAO were indicated by increases in maximal change in pleural pressure (Δ P plmax) and decreases in breathing frequency variability ( BFV ), which was continuously measured by respiratory inductance plethysmography. Plasma samples for determination of CORT were collected every 6 h. Results In control horses, Δ P plmax and BFV were unaffected by the HDE nv, whereas in RAO ‐affected horses Δ P plmax increased and BFV decreased significantly. In the LDE nv, there was a circadian variation in CORT in both control and RAO ‐affected horses. In HDE nv, CORT was unaffected in control horses, but increased significantly in RAO ‐affected horses between 6 and 12 h after entering the HDE nv. Conclusions Plasma cortisol concentration increases concurrently with the development of acute exacerbations of RAO .