Beta-glucuronidase and trypsin inhibitor capacity of tracheal lavage fluid as indicators of seasonal airway irritation in the horse.

Abstract

The health of the respiratory tracts of 19 horses was studied for 11 months. The horses were placed into 3 groups (healthy, periodically diseased and continuously diseased) based on the measurements of blood gases, intrapleural pressure and on neutrophil content of tracheal mucus. Lysosomal enzymes (N-acetyl-beta-D-glucosaminidase and beta-glucuronidase) and reflectors of the proteolytic system (plasmin, plasminogen, trypsin inhibitor capacity) were determined. beta-glucuronidase appeared to be a good indicator of the presence of disease of the respiratory system. High beta-glucuronidase values were seen in horses with elevated numbers of neutrophils, elevated arterial alveolar and intrapleural differences as well as in diseased horses during the stabling period. Trypsin inhibitor capacity seemed to be lower in the diseased respiratory system, probably due to the increased consumption of trypsin inhibitors.