Previously presented in the form of a poster at the 25th Symposium of the Veterinary Comparative Respiratory Society, Lafayette, IN.
Influence of Age on Surfactant Isolated from Healthy Horses Maintained on Pasture
Article first published online: 13 APR 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 23, Issue 3, pages 612–618, May/June 2009
How to Cite
Christmann, U., Hite, R.D., Witonsky, S.G., Elvinger, F., Werre, S.R., Thatcher, C.D., Tan, R.H.H. and Buechner-Maxwell, V.A. (2009), Influence of Age on Surfactant Isolated from Healthy Horses Maintained on Pasture. Journal of Veterinary Internal Medicine, 23: 612–618. doi: 10.1111/j.1939-1676.2009.0298.x
- Issue published online: 19 MAY 2009
- Article first published online: 13 APR 2009
- Submitted August 18, 2008; Revised January 21, 2009; Accepted January 21, 2009.
- Bronchoalveolar lavage;
- Respiratory tract
Background: Surfactant alterations are described in horses after exercise, anesthesia, and prolonged transport, in horses with recurrent airway obstruction, and in neonatal foals. The effect of horse age or bronchoalveolar lavage fluid (BALF) sample characteristics on surfactant is unknown.
Objectives: To evaluate surfactant phospholipid composition and function in healthy horses, and to investigate the influence of age and BALF sample characteristics on surfactant.
Animals: Seventeen healthy horses 6–25 years of age maintained on pasture year-round.
Methods: BALF was collected by standard procedures and was assessed for recovery volume, nucleated cell count (NCC), and cytology. Cell-free BALF was separated into crude surfactant pellet (CSP) and surfactant supernatant (Supe) by ultracentrifugation. Phospholipid and protein content were determined from both fractions. CSP phospholipid composition was analyzed by high-performance liquid chromatography with an evaporative light scatter detector. Surface tension of CSP was evaluated with a pulsating bubble surfactometer. Regression analysis was used to evaluate associations between age, BALF sample characteristics, and surfactant variables.
Results: Results and conclusions were derived from 15 horses. Increasing age was associated with decreased phospholipid content in CSP but not Supe. Age did not affect protein content of CSP or Supe, or surfactant phospholipid composition or function. Age-related surfactant changes were unaffected by BALF recovery percentage, NCC, and cytological profile.
Conclusions and Clinical Importance: Older horses have decreased surfactant phospholipid content, which might be because of age-related pulmonary changes. Surfactant composition is unaffected by BALF sample characteristics at a BALF recovery percentage of at least 50%.