Effects of inhaled or intracerebroventricularly administered SR141716A on the antitussive effect of VDM11. SR141716A aerosol was inhaled for 4 min at 60 min after the administration of VDM11 (just prior to the second application of capsaicin). SR141716A was injected intracerebroventricularly, 50 min after VDM11 administration (10 min before the second application of capsaicin). The antitussive effect of VDM11 (10 mg/kg) was assessed 60 min after subcutaneous administration. Each column represents the mean with S.E. of 10 mice in each group. *P < 0.05 vs. vehicle-treated group.