Effects of CP-96,345, a novel non-peptide antagonist of NK1 receptor, on the peristalsis in isolated guinea pig ileum.

CP-96,345, a novel non-peptide antagonist of the NK1 receptor, at 10(-8)-10(-6) M decreased the frequency of peristalsis and reduced peristalsis-associated longitudinal muscle contractions in isolated guinea pig ileum. In the presence of 10(-6) M CP-96,345, further addition of 10(-6) M atropine blocked the peristalsis. When 10(-6) M atropine was first applied, more than half of the preparations developed atropine-resistant peristalsis. CP-96,345 at 10(-6) M blocked the atropine-resistant peristalsis. These results are consistent with the view that substance P is involved in the peristalsis in guinea pig ileum.