Figure 4 Logarithm concentration‐response curves of (+)WIN 55212‐2 in the absence or presence of increasing concentrations of SR141716 on electrical field stimulation induced contractions of longitudinal colonic muscle strips from controls (A) and patients with diverticulitis (B). The small panel in (A) shows the Schild plot from the curves for control colons. Results are mean (SEM) of 5–8 preparations from different patients. The response is expressed as a percentage of the maximal effect induced by 1 μmol/l atropine.