Serotonin receptor 2B induces visceral hyperalgesia in rat model and patients with diarrhea-predominant irritable bowel syndrome

Figure 9 The visceral pain conduction pathway involves transient receptor potential vanilloid type 1. The expression of the serotonin receptor 2B (5-HT_2B) receptor and transient receptor potential vanilloid type 1 (TRPV1) increased in colon tissues from irritable bowel syndrome with diarrhea patients and rats. The administration of a 5-HT_2B receptor agonist increased visceral pain, which was alleviated by successive administration of a TRPV1 antagonist. Treatment with a 5-HT_2B receptor antagonist suppressed TRPV1. The sensation of pain is thus attenuated, and the pain threshold is increased. 5-HT_2B receptor: Serotonin receptor 2B; TRPV1: Transient receptor potential vanilloid type 1.