Effects of SAB-378 on repetitive noxious CRD-evoked pain related responses in rats. A, Effects of SAB-378 (0.27 or 2.7 μmol/kg) or vehicle (1 ml/kg), administered intravenously between distensions 3 and 4, on CRD-evoked pain-related responses. Graphs with open symbols and broken lines correspond to the basal activity of the abdominal musculature between distensions. The arrow indicates the point of SAB-378 or vehicle administration. Data are mean ± SEM of 4–8 animals per group. B, Overall effects of SAB-378 (% inhibition vs the response in the vehicle group, set up at 100%; broken line) on pain-related responses during distensions 4–12 of the noxious CRD protocol. Data are mean ± SEM of 4–8 animals per group. *p < 0.05 versus vehicle.