Fig. 4. Isoflurane induces a contractile response in guinea pig bronchus. (A ) Typical traces and (B ) pooled data of the motor responses of guinea pig isolated bronchus to halothane (Hal; 150 μm; open triangle ) and isoflurane (Iso; 150 μm; filled circles ) or their vehicle (Veh) either alone or after pretreatment with capsaicin (CAP, 10 μM for 20 min), the combination of neurokinin receptor antagonists SR140333, SR48968, and SR142801 (NK, all 1 μM), the TRPA1 antagonist HC-030031 (HC, 50 μM), or the TRPV1 antagonist capsazepine (CPZ, 10 μM). Each column in (B ) represents the mean ± SEm, and the number of observations for each group is listed in parentheses. *P < 0.05 vs. Veh (one-way analysis of variance, followed by Student–Newman–Keuls post hoc test).