Effects of airway inflammation on cough response in the guinea pig

• Published in: Journal of applied physiology (1985) 1998-11, Vol.85 (5), p.1847-1854
• Main Authors: Xiang, Anbo, Uchida, Yoshiyuki, Nomura, Akihiro, Iijima, Hiroaki, Dong, Fang, Zhang, Min-Jie, Hasegawa, Shizuo
• Format: Article
• Language: English
• Subjects: Allergies; Anatomy & physiology; Animals; Antitussive Agents - pharmacology; Asthma; Benzamides - pharmacology; Biological and medical sciences; Bronchoalveolar Lavage Fluid - cytology; Capsaicin; Chronic obstructive pulmonary disease, asthma; Codeine - pharmacology; Cough - chemically induced; Cough - pathology; Cough - physiopathology; Dipeptides - pharmacology; Female; Guinea Pigs; Indoles - pharmacology; Inflammation - pathology; Inflammation - physiopathology; Medical sciences; Peptides, Cyclic - pharmacology; Piperidines - pharmacology; Pneumology; Quinuclidines - pharmacology; Receptors, Neurokinin-2 - antagonists & inhibitors; Receptors, Tachykinin - antagonists & inhibitors; Respiratory Hypersensitivity - physiopathology; Respiratory Tract Diseases - pathology; Respiratory Tract Diseases - physiopathology; Rodents
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1998.85.5.1847

1  Department of Pulmonary Medicine, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki, 305-8575; and 2  Doctor Program in Engineering, Graduate School of Engineering, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan We have developed a guinea pig model for cough related to allergic airway inflammation. Unanesthetized animals were exposed to capsaicin aerosols for 10 min, and cough frequency was counted during this period. The cough evaluation was performed by the following three methods: visual observation, acoustic analysis, and monitoring of pressure changes in the body chamber. These analyses clearly differentiated a cough from a sneeze. To elucidate the relationship between cough response and airway inflammation, animals were immunosensitized and multiple challenged. Sensitized guinea pigs presented no specific changes microscopically, but multiple-challenged animals showed an increased infiltration of inflammatory cells into the airway. Cough number in response to capsaicin increased significantly from 4.7 ± 1.4 coughs/10 min in normal animals to 10.6 ± 2.0 coughs/10 min in sensitized animals and further to 22.8 ± 1.3 coughs/10 min in multiple-challenged animals. This augmented cough frequency was significantly inhibited by the inhalation of tachykinin-receptor antagonists and by oral ingestion, but not inhalation, of codeine phosphate. The results suggest that airway inflammation potentiates an elevation of cough sensitivity in this model. tachykinin; asthma; allergic inflammation; C fibers; capsaicin