Early and Late Allergic Phase
Related Cough Response in Sensitized Guinea Pigs with
Experimental Allergic Rhinitis
M. BROZMANOVÁ, V. ČALKOVSKÝ1, J.
PLEVKOVÁ, V. BARTOŠ2,
L. PLANK2, M. TATÁR
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
Summary
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
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