Differences in the Control of Secondary Peristalsis in the Human Esophagus: Influence of the 5-HT(4) Receptor versus the TRPV1 Receptor

OBJECTIVE: Acute administration of 5-hydroxytryptamine4 (5-HT(4)) receptor agonist, mosapride or esophageal infusion of the transient receptor potential vanilloid receptor-1 (TRPV(1)) agonist capsaicin promotes secondary peristalsis. We aimed to investigate whether acute esophageal instillation of capsaicin-containing red pepper sauce or administration of mosapride has different effects on the physiological characteristics of secondary peristalsis. METHODS: Secondary peristalsis was induced with mid-esophageal air injections in 14 healthy subjects. We compared the effects on secondary peristalsis subsequent to capsaicin-containing red pepper sauce (pure capsaicin, 0.84 mg) or 40 mg oral mosapride. RESULTS: The threshold volume for generating secondary peristalsis during slow air distensions was significantly decreased with capsaicin infusion compared to mosapride (11.6 ± 1.0 vs. 14.1 ± 0.8 mL, P = 0.02). The threshold volume required to produce secondary peristalsis during rapid air distension was also significantly decreased with capsaicin infusion (4.6 ± 0.5 vs. 5.2 ± 0.6 mL, P = 0.02). Secondary peristalsis was noted more frequently in response to rapid air distension after capsaicin infusion than mosapride (80% [60–100%] vs. 65% [5–100%], P = 0.04). Infusion of capsaicin or mosapride administration didn’t change any parameters of primary or secondary peristalsis. CONCLUSIONS: Esophageal infusion with capsaicin-containing red pepper sauce suspension does create greater mechanosensitivity as measured by secondary peristalsis than 5-HT(4) receptor agonist mosapride. Capsaicin-sensitive afferents appear to be more involved in the sensory modulation of distension-induced secondary peristalsis.