Fig. 3

Relaxant effect of dexmedetomidine and lidocaine on exogenous acetylcholine (Ach)-induced contraction of guinea pig tracheal rings. a Representative trace of Ach-induced contraction and subsequent relaxation or sustained contraction. b, c, d Following stable Ach-induced contractions, 0.1–100 μM of dexmedetomidine, 2 nM–10 μM of remifentanil, 10–1000 μM of lidocaine or vehicle control (DMSO or water) was added to the buffer solutions and muscle force change was measured. Mean ± SEM (n = 5). **p < 0.01