Consecutive allergen challenges resulted in decreased bronchial responsiveness.
- Author:
Jianxin HE
1
;
Zaifang JIANG
Author Information
- Publication Type:Journal Article
- MeSH: Acetylcholine; pharmacology; Airway Resistance; Allergens; immunology; Animals; Bronchi; drug effects; physiology; Bronchial Hyperreactivity; etiology; Bronchoconstriction; Lung; pathology; Male; Ovalbumin; immunology; Rats; Rats, Sprague-Dawley
- From: Chinese Medical Journal 2002;115(11):1727-1729
- CountryChina
- Language:English
-
Abstract:
OBJECTIVETo investigate bronchial responsiveness to acetylcholine in allergic airway inflammation of SD rats.
METHODSSD rats were immunized and challenged by chicken ovalbumin (OVA). Airway responsiveness, acetylcholine (Ach) provocation concentration needed to increase baseline airway resistance by 200% (PC(200)) were measured.
RESULTSThe value of baseline airway resistance in asthma group was significantly higher than that in control group (2.282 +/- 0.128 vs 3.193 +/- 0.239; P < 0.01). After multiple ovalbumin exposures, airway responsiveness to intravenous injection of acetylcholine decreased significantly (-LogPC(200): 4.006 +/- 0.554 vs 2.059 +/- 0.262; P < 0.01). Bronchial alveolar lavage fluid (BALF) and lung tissue specimen analysis indicated that airway allergic inflammation was present.
CONCLUSIONSThe study demonstrates a dissociation between the bronchoconstrictor response and bronchial hyper-responsiveness and indicates that multiple ovalbumin exposures induces persistent bronchoconstriction with airway hypo-responsiveness despite airway allergic inflammation.
