Physiol. Res. 55: 577-584, 2006

Early and Late Allergic Phase Related Cough Response in Sensitized Guinea Pigs with Experimental Allergic Rhinitis


Department of Pathophysiology, 1Department of Otorhinolaryngology and 2Department of Pathological Anatomy, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic

Received date July 28, 2005
Accepted date November 16, 2005
On-line available December 12, 2005

Cough is a common and important symptom of asthma and allergic rhinitis. Previous experimental evidence has shown enhanced cough sensitivity during early phase of experimental allergic rhinitis in guinea pigs. We hypothesized that airway inflammation during the late phase response after repeated nasal antigen challenge may affect the afferent sensory nerve endings in the larynx and tracheobronchial tree and may also modulate cough response. In the present study we evaluated the cough sensitivity during a period of early and late allergic response in sensitized guinea pigs after repeated nasal antigen challenges. Forty-five guinea pigs were sensitized with ovalbumin (OVA). Four weeks later 0.015 ml of 0.5 % OVA was intranasally instilled to develop a model of allergic rhinitis that was evaluated from the occurrence of typical clinical symptoms. Animals were repeatedly intranasally challenged either by OVA (experimental group) or by saline (controls) in 7-day intervals for nine weeks. Cough was elicited by inhalation of citric acid aerosols. Cough was evaluated at 1 or 3 h after the 6th nasal challenge and 17 or 24 h after the 9th nasal challenge. The cough reflex was significantly increased at 1 and 3 h after repeated nasal challenge in contrast to cough responses evoked at 17 and 24 h after repeated nasal challenge. In conclusion, enhanced cough sensitivity only corresponds to an early allergic response after repeated nasal challenges.

Key words
Allergic inflammation • Experimental allergic rhinitis • Ovalbumin • Citric acid - induced cough • Guinea pig

© 2006 by the Institute of Physiology, Czech Academy of Sciences