Peristalsis evoked by 5‐HT and renzapride: evidence for putative 5‐HT4 receptor activation

Abstract
The effect of 5‐hydroxytryptamine and renzapride was studied on the peristaltic reflex elicited in vitro in the guinea‐pig ileum. Both agents evoked the reflex at subthreshold intraluminal pressures (50% of threshold) and were blocked by ICS 205–930 (3 μm), but not ondansetron (5 μm). This novel finding suggests strongly that the prokinetic action of renzapride and gut motility stimulating action of 5‐hydroxytryptamine are mediated via agonism at the putative 5‐HT4 receptor.