Equinins in equine neutrophils: quantification in tracheobronchial secretions as an aid in the diagnosis of chronic pulmonary disease.
Equinins are a closely related group of proteins found in equine neutrophil granules. They demonstrate proteinase inhibiting activity restricted to microbial proteinase K and subtilisin, and they also possess antibacterial and antiviral properties. Antiproteinase K activity was measured in tracheobronchial secretions (TBS) of horses with mild (n = 15), moderate (n = 30) and severe (n = 16) chronic pulmonary disease, to determine its usefulness as an indicator of severity of disease and to measure neutrophil content. Determination of proteinase K inhibiting activity was based on a colorimetric assay measuring the suppression of 4-nitroaniline liberation from the synthetic substrate succinyl-L-alanyl-alanyl-alanin-4-nitroanilid, a process mediated by proteinase K. Proteinase K inhibiting activity proved to be a valid and simple indicator for assessing neutrophil content in TBS and a useful parameter to determine the severity of chronic pulmonary disease in the horse.
Pellegrini
A
A
Department of Veterinary Physiology, University of Zurich, Switzerland.
Kalkinc
M
M
Hermann
M
M
Grünig
B
B
Winder
C
C
Von Fellenberg
R
R
D000818:Animals; D015415:Biomarkers; D001980:Bronchi / Q000378:metabolism; D019286:Endopeptidase K / Q000378:metabolism; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis* / Q000503:physiopathology; D006736:Horses; D008171:Lung Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary*; D008297:Male; D009504:Neutrophils / Q000737:chemistry*; D011480:Protease Inhibitors / Q000032:analysis*; D012720:Severity of Illness Index; D014132:Trachea / Q000378:metabolism
D015415:Biomarkers; D011480:Protease Inhibitors; D019286:Endopeptidase K