FIGURE 1.
Representative mechanical recordings from the circular muscle showing the effect of drotaverine (10–9 to 10–5 M) and HBB (10–7 to 10–5 M) on spontaneous phasic contractions (A), cch (10–5 M)-induced contractions (D), and the excitatory neural pathway under non-nitrergic non-purinergic conditions (G). Graphs (left) show the effect of accumulative concentrations of drotaverine (10–9 to 10–5 M). Two-way ANOVA (concentration x treatment) was performed without differences between drotaverine and vehicle (treatment p > 0.05). Histograms (right) show the effect of drotaverine 10–5 M plus HBB (10–7 to 10–5 M) on spontaneous phasic contractions, (B,C) cch-induced contractions (E,F), and electrical field stimulation-induced contractions (H,I) in the circular (B,E,H) and longitudinal (C,F,I) muscles. Dunnett’s post hoc test was done after ANOVA. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 compared with drotaverine 10–5 M. Data were normalized (i.e., 100%) to the basal AUC or the electrical field stimulation amplitude before drug addition. Data were expressed as mean ± SEM.
