FIGURE 4.
The effect of paracetamol on neural-mediated inhibitory responses under non-adrenergic non-cholinergic conditions in the circular muscle. Representative mechanical recordings show the relaxation (during the electrical field stimulation) and the off-contraction (rebound after the electrical field stimulation) in control (CTRL) conditions (top) and in the presence of paracetamol 10–5 M (bottom) (A). Graphs show the effect of paracetamol 10–5 M on electrical field stimulation trains of increasing voltage (5, 6, 7, 8, 10, and 20 V) on the relaxation (left) and the off-contraction (right) (B). Two-way ANOVA (voltage x treatment) was performed without differences with or without paracetamol 10−5 M (treatment p > 0.05). The relaxation was normalized (i.e., 100%) to the basal AUC before electrical field stimulation. The off-contraction was normalized (i.e., 100%) to the maximum response obtained with a stimulus of 20 V in CTRL conditions. Data were expressed as mean ± SEM.