Alterations in mucosal neuropeptides in patients with irritable bowel syndrome and ulcerative colitis in remission: A role in pain symptom generation?

Abstract

Increased transcription of TRPV1 may provide a possible explanation for pain generation in IBS. While the neuropeptides SP and somatostatin were both found to be increased in IBS, these changes are not sufficient to explain pain generation. Pain generation in IBS is probably explained by a complex redundancy in the regulation of local nociceptive mechanisms, which remains a subject of intensive investigation.

Transient Receptor Potential Channels as Drug Targets: From the Science of Basic Research to the Art of Medicine

“…In a rat model TRP Channels as Drug Targets of irritable bowel syndrome, TRPV1 antagonists prevent the development of visceral hypersensitivity initiated by acetic acid treatment during the neonatal period (Winston et al, 2007). These findings imply a pathogenic role for the dysfunction of TRPV1-positive colonic fibers in irritable bowel syndrome (Keszthelyi et al, 2013). In accord, one study reported a positive correlation between the number of TRPV1-immunoreactive fibers in the rectosigmoid colon and the abdominal pain score in patients with irritable bowel syndrome (Akbar et al, 2008).…”

“…These observations imply that after a simultaneous loss of SP and CGRP, the SP-null phenotype will predominate. TRPV1 is also elevated in the colonic mucosa of patients with IBD and a positive correlation between TRPV1 and pain was noted (Keszthelyi et al, 2013). Furthermore, there is good evidence that deletion of TRPV1 by genetic manipulation (Szitter et al, 2010) or neonatal capsaicin treatment (Kihara et al, 2003) is protective in colitis models.…”

Expression and distribution of SP and its NK1 receptor in the brain-gut axis in neonatal maternally separated rat model with visceral hypersensitivity

“…Laird et al declared that the pain response was not altered in tachykinin NK1R knockout mice (Laird et al, 2000). In women with IBS, the transcription of transient receptor potential vanilloid 1 (TRPV1) and mucosal concentrations of SP were significantly higher, but the latter did not correlate with the severity of pain (Keszthelyi et al, 2013). The mechanisms of SP-mediated gastrointestinal function are complicated and contradictory.…”

Diagnosis and management of functional symptoms in inflammatory bowel disease in remission

“…A study in pediatric IBD patients in remission with residual abdominal pain observed that they presented rectal pain thresholds lower than those of healthy volunteers and similar to those of patients with functional digestive diseases [73] . Further on, two studies measured in rectosigmoid junction biopsies the density of nerve fibers that presented the transient potential vanilloid receptor type 1 (TRPV1), implicated in nociception and in IBS visceral hypersensitivity [74,75] . They observed that in symptomatic IBD patients in remission the density was significantly higher than in healthy controls and in asymptomatic IBD patients.…”