Effects of suplatast tosilate, a new type of anti-allergic agent, on airway cough hypersensitivity induced by airway allergy in guinea-pigs.
BACKGROUND
Cough receptor hypersensitivity is a fundamental feature of some conditions presenting with chronic non-productive cough. Suplatast tosilate, an anti-allergic agent, is a T helper (Th)2 cytokine inhibitor that inhibits the synthesis of interleukin (IL)-4, IL-5, immunoglobulin (Ig)E production, and local eosinophil accumulation.


OBJECTIVE
The purpose of this study was to investigate the effect of suplatast on antigen-induced airway cough hypersensitivity and eosinophil infiltration into the airway.


METHODS
Number of coughs elicited by inhalation of increasing concentrations of capsaicin (10-8, 10-6 and 10-4 M) was counted 24 h after an antigen challenge in conscious guinea-pigs and then bronchoalveolar lavage was performed. We investigated the effect of single (before antigen challenge or capsaicin provocation) or repetitive treatment with intraperitoneal suplatast at a dose of 10 or 30 mg/kg on antigen-induced cough hypersensitivity.


RESULTS
Twenty-four hours after antigen challenge, guinea-pigs developed an increase in cough receptor sensitivity to inhaled capsaicin and eosinophil infiltration in the airways. After a 2-week treatment with suplatast, but not after only a single treatment before antigen challenge or capsaicin provocation, the antigen-induced early phase bronchoconstriction, cough hypersensitivity, and airway eosinophilia were inhibited in a dose-dependent manner.


CONCLUSIONS
These results indicate that suplatast inhibits airway cough hypersensitivity underlying allergic eosinophilic inflammation.
Myou
S
S
Third Department of Internal Medicine, Kanazawa University School of Medicine, Kanazawa, Japan. myous@nifyt.com
Fujimura
M
M
Kurashima
K
K
Kita
T
T
Tachibana
H
H
Ishiura
Y
Y
Abo
M
M
Nakao
S
S
D000403:Airway Resistance / Q000187:drug effects*; D000818:Animals; D018926:Anti-Allergic Agents / Q000627:therapeutic use*; D001190:Arylsulfonates / Q000627:therapeutic use*; D001985:Bronchial Provocation Tests / Q000009:adverse effects; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016084:Bronchoconstriction / Q000187:drug effects; D003371:Cough / Q000188:drug therapy*; D004195:Disease Models, Animal; D004804:Eosinophils / Q000187:drug effects; D006168:Guinea Pigs; D007564:Japan; D008297:Male; D010047:Ovalbumin / Q000009:adverse effects; D012130:Respiratory Hypersensitivity / Q000188:drug therapy*; D012680:Sensitivity and Specificity; D013452:Sulfonium Compounds / Q000627:therapeutic use*; D013997:Time Factors
D018926:Anti-Allergic Agents; D001190:Arylsulfonates; D013452:Sulfonium Compounds; D010047:Ovalbumin; C073028:suplatast tosilate