Effect of BCTC on cough responses elicited by antigen challenge in sensitized guinea pigs. BCTC (1 and 3 mg/kg, i.p.) blocked the increase in cough produced by antigen ovalbumin (0.3%) challenge. Also shown are the activities of a second TRPV1 antagonist (given by aerosol 4 min before antigen provocation*), capsazepine (300 μM) on allergic cough. Each bar represents the Mean ± SEM of the number of coughs produced by a 4 min exposure to capsaicin. (*p < 0.05 compared to controls (sensitized and administered vehicle) animals using a Kruskal-Wallis in conjunction with a Mann-Whitney-U; n = 9–16).