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Possible involvement of tetrodotoxin-resistant sodium channels in cough reflex

Authors :
Kamei, Junzo
Nakanishi, Yuki
Ishikawa, Yoko
Hayashi, Shun-suke
Asato, Megumi
Ohsawa, Masahiro
Source :
European Journal of Pharmacology. Feb2011, Vol. 652 Issue 1-3, p117-120. 4p.
Publication Year :
2011

Abstract

Abstract: We examined the involvement of tetrodotoxin (TTX)-resistant sodium channels in the peripheral mechanisms of the cough reflex in mice. We also examined the possibility of using ambroxol as an effective antitussive agent, and found that it produced antitussive effects through the inhibition of TTX-resistant sodium channels. The inhalation of fenvalerate, at concentrations of 0.3, 1 and 3μg/ml, for 5min produced coughs in a concentration-dependent manner. Pretreatment with tetrodotoxin, at a dose of 1μg/kg, s.c., slightly but significantly reduced the number of fenvalerate (3μg/ml)-induced coughs. However, the number of fenvalerate-induced coughs in tetorodotoxin-treated mice was still significantly greater than those in vehicle (0.4% DMSO) alone inhaled mice. On the other hand, pretreatment with tetrodotoxin, at a dose of 1μg/kg, s.c., almost completely reduced the number of citric acid (0.25M)-induced coughs to the level in vehicle (saline) alone inhaled mice. Pretreatment with ambroxol, at doses of 10, 30, 100 and 300mg/kg, p.o., dose-dependently and significantly reduced the number of fenvalerate (3μg/ml)-induced coughs. The present findings indicate that TTX-resistant sodium channels may play an important role in the enhancement of C-fiber-mediated cough pathways. Furthermore, ambroxol may prove to be a useful cough suppressant. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00142999
Volume :
652
Issue :
1-3
Database :
Academic Search Index
Journal :
European Journal of Pharmacology
Publication Type :
Academic Journal
Accession number :
57164745
Full Text :
https://doi.org/10.1016/j.ejphar.2010.11.019