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.