Inhibitory effect of NS1619 on the cholinergic EFS-induced contractions. In the presence of 10 μM suramin and 10 μM α,β-methylene-ATP, activation of BK channel with NS1619 decreased the amplitude of the EFS-induced contractions in isolated DSM strips. Original recordings of nerve-evoked contractions induced by EFS (frequency of 0.5–50 Hz) in the absence (control, A) and following application of 30 μM NS1619 (B). C) EFS frequency-response curves showing a significant decrease in the amplitude of cholinergic EFS-induced contractions after application of 30 μM NS1619. The maximal contraction amplitude at EFS frequency of 50 Hz under control conditions in the presence of suramin and α,β-methylene-ATP was taken to be 100%. n=7, N=5, **P<0.005; *P<0.01. Data are means ± S.E.M.