Asthmatic airway hyperresponsiveness: the ants in the tree.
Airways from asthmatics have a propensity to narrow excessively in response to spasmogens (i.e., contractile agonists), a feature called airway hyperresponsiveness (AHR). AHR is an important contributor to asthma symptoms because the degree of responsiveness dictates the amount of airway narrowing that occurs in response to inflammation-derived spasmogens produced endogenously following exposure to environmental triggers, such as allergens, viruses, or pollutants. The smooth muscle encircling the airways is responsible for responsiveness because it constricts the airway lumen when commanded to contract by spasmogens. However, whether AHR seen in asthmatics is due to stronger muscle is equivocal. In this opinion article, I propose that environmental triggers and other inflammatory molecules released during asthma attacks contribute to AHR by increasing muscle force.
Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, G1V 4G5, Canada. ynuk.bosse@criucpq.ulaval.ca
Ynuk
Y
Bossé
D000393:Air Pollutants / Q000276:immunology; D000485:Allergens / Q000276:immunology*; D000818:Animals; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology*; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D009130:Muscle, Smooth / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D012137:Respiratory System / Q000276:immunology / Q000378:metabolism / Q000473:pathology
D000393:Air Pollutants; D000485:Allergens; D018927:Anti-Asthmatic Agents; D005938:Glucocorticoids; D018836:Inflammation Mediators