Concentrations of cysteinyl leukotrienes in urine and bronchoalveolar lavage fluid of cats with experimentally induced asthma.
OBJECTIVE
To evaluate changes in cysteinyl leukotriene (LT) concentrations in urine and bronchoalveolar lavage fluid (BALF) in cats with experimentally induced asthma.


METHODS
19 cats with experimentally induced asthma and 5 control cats.


METHODS
Cats were sensitized to Bermuda grass or house dust mite allergen, and phenotypic features of asthma were confirmed with intradermal skin testing, evaluation of BALF eosinophil percentages, and pulmonary function testing. A competitive ELISA kit for LTC4, LTD4, and LTE4 was used for quantitative analysis of LTs. Urinary creatinine concentrations and BALF total protein (TP) concentrations were measured, and urinary LT-to-creatinine ratios and BALF LT-to-TP ratios were calculated.


RESULTS
Mean urinary LT-to-creatinine ratios did not differ significantly between control cats and allergen-sensitized cats before or after sensitization and challenge exposure with saline (0.9% NaCl) solution or allergen, respectively. In BALF the mean LT-to-TP ratio of control cats did not differ significantly before or after sensitization and challenge exposure with saline. Asthmatic cats had BALF LT-to-TP ratios that were significantly lower than control cats at all time points, whereas ratios for asthmatic cats did not differ significantly among the various time points.


CONCLUSIONS
Although LTs were readily detectable in urine, no significant increases in urinary LT concentrations were detected after challenge in allergen-sensitized cats. Spot testing of urinary LT concentrations appears to have no clinical benefit for use in monitoring the inflammatory asthmatic state in cats. The possibility that cysteinyl LTs bind effectively to their target receptors in BALF and, thus, decrease free LT concentrations deserves further study.
Norris
Carol R
CR
Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616-8734, USA.
Decile
Kendra C
KC
Berghaus
Londa J
LJ
Berghaus
Roy D
RD
Walby
William F
WF
Schelegle
Edward S
ES
Hyde
Dallas M
DM
Gershwin
Laurel J
LJ
D000818:Animals; D001250:Asthma, Exercise-Induced / Q000503:physiopathology / Q000652:urine / Q000662:veterinary*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D002371:Cat Diseases / Q000503:physiopathology* / Q000652:urine; D002415:Cats; D003545:Cysteine; D004797:Enzyme-Linked Immunosorbent Assay; D017997:Leukotriene C4 / Q000032:analysis; D017998:Leukotriene D4 / Q000032:analysis; D017999:Leukotriene E4 / Q000032:analysis; D015289:Leukotrienes / Q000032:analysis* / Q000652:urine
D015289:Leukotrienes; D017997:Leukotriene C4; D017998:Leukotriene D4; D017999:Leukotriene E4; D003545:Cysteine