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Comparison of non‐invasive measures of cholinergic and allergic airway responsiveness in rats
Author(s) -
Glaab T.,
Hecker H.,
Stephan M.,
Baelder R.,
Braun A.,
Korolewitz R.,
Krug N.,
Hoymann H. G.
Publication year - 2006
Publication title -
acta physiologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.591
H-Index - 116
eISSN - 1748-1716
pISSN - 1748-1708
DOI - 10.1111/j.1748-1716.2006.01567.x
Subject(s) - medicine , bronchoconstriction , ovalbumin , airway , cholinergic , pulmonary function testing , acetylcholine , spirometry , lung , asthma , immunology , anesthesia , immune system
Aim: Non‐invasive analysis of tidal expiratory flow parameters such as Tme/TE (time needed to reach peak expiratory flow divided by total expiratory time) or midexpiratory tidal flow (EF 50 ) has been shown useful for phenotypic characterization of lung function in humans and animal models. In this study, we aimed to compare the utility of two non‐invasive measures, EF 50 and Tme/TE, to monitor bronchoconstriction to inhaled cholinergic and allergic challenges in Brown‐Norway rats. Methods: Non‐invasive measurements of Tme/TE and EF 50 were paralleled by invasive recordings of Tme/TE, EF 50 and pulmonary conductance (GL). Results: First, dose–response studies with acetylcholine were performed in naive rats, showing that EF 50 better than Tme/TE reflected the dose‐related changes as observed with the classical invasive outcome parameter GL. The subsequent determination of allergen‐specific early airway responsiveness (EAR) showed that ovalbumin‐sensitized and ‐challenged rats exhibited airway inflammation and allergen‐specific EAR. Again, EF 50 was more sensitive than Tme/TE in detecting the allergen‐specific EAR recorded with invasive and non‐invasive lung function methods and agreed well with classical GL measurements. Conclusion: We conclude that non‐invasive assessment of EF 50 is significantly superior to Tme/TE and serves as a suitable and valid tool for phenotypic screening of cholinergic and allergic airway responsiveness in rats.