Alveolar clearance in horses with chronic obstructive pulmonary disease.
OBJECTIVE
To assess sensitivity of scintigraphic alveolar clearance rate as an indicator of alveolar epithelium damage in horses.


METHODS
5 healthy horses (group A) and 5 with chronic obstructive pulmonary disease (COPD; group B).


METHODS
Horses underwent clearance rate (k [%/min]) determination. Clearance rate of group-B horses was determined after remission of the disease following 2 months at pasture (remission 1), stabling in a controlled environment (remission 2), and during crisis induced by exposure to moldy hay and straw. Methacholine challenge test was performed at each investigation period to determine nonspecific pulmonary airway hyperresponsiveness. Pulmonary function tests (PFT) also were performed, and cell populations in bronchoalveolar lavage (BAL) fluid were determined on another occasion.


RESULTS
Group-B horses had significantly faster mean clearance rate during crisis (k = 4.30+/-0.95%/min), compared with that for remission 1(k = 1.98+/-0.55%/min), which did not differ from the rate in group-A horses (k = 1.95+/-0.33%/min). Despite lack of clinical signs of COPD during remission when stabled in a controlled environment, an intermediate value was found (k = 3.20+/-0.72%/min).


CONCLUSIONS
This technique allowed grading of lung damage induced by COPD, whereas use of PFT and determination of BAL fluid cell populations failed to differentiate between remission 1 and remission 2.


CONCLUSIONS
Determination of alveolar clearance rate by use of scintigraphy is a sensitive indicator of lung damage. A modified clearance rate was found despite the lack of clinical and functional changes.
Votion
D M
DM
Department of Physiology, Faculty of Veterinary Medicine, University of Liege, Belgium.
Vandenput
S N
SN
Duvivier
D H
DH
Lambert
P
P
van Erck
E
E
Art
T
T
Lekeux
P M
PM
D000818:Animals; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses; D008173:Lung Diseases, Obstructive / Q000662:veterinary*; D008657:Metabolic Clearance Rate; D011650:Pulmonary Alveoli / Q000503:physiopathology*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012129:Respiratory Function Tests / Q000662:veterinary; D015656:Respiratory Mechanics; D016284:Technetium Tc 99m Pentetate / Q000493:pharmacokinetics
D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate