Increased capsaicin receptor TRPV1 expressing sensory fibres in irritable bowel syndrome and their correlation with abdominal pain

Ayesha Akbar ¹, Yiangos Yiangou ¹, Paul Facer ¹, Julian R F Walters ¹, Praveen Anand ¹ and Subrata Ghosh ^1*

¹ Imperial College London, United Kingdom

^* To whom correspondence should be addressed. E-mail: s.ghosh{at}imperial.ac.uk.

Accepted 22 January 2008

Abstract

Objective: The capsaicin receptor TRPV1 may play an important role in visceral pain and hypersensitivity states. In irritable bowel syndrome (IBS), abdominal pain is a common and distressing symptom where the pathophysiology is still not clearly defined. We investigated TRPV1-immunoreactive nerve fibers in colonic biopsies from patients with IBS, and related this to abdominal pain.

Design, setting and patients: Recto-sigmoid biopsies were collected from 23 IBS patients fulfilling Rome II criteria, and from 22 controls. Abdominal pain scores were recorded using a validated questionnaire.

Main outcome measures: TRPV1-, substance P-, and neuronal marker PGP 9.5-expressing nerve fibres, mast cells (c-kit), and lymphocytes (CD3 and CD4) were quantified, following immunohistochemistry with specific antibodies. The biopsy findings were related to the abdominal pain scores.

Results: A significant 3.5-fold increase in median numbers of TRPV1-immunoreactive fibres was found in biopsies from IBS patients compared with controls (p< 0.0001). Substance P-immunoreactive fibres (p=0.01), total nerve fibres (PGP 9.5) (p=0.002), mast cells (c-kit) (p=0.02) and lymphocytes (CD3) (p=0.03) were also significantly increased in the IBS group. In multivariate regression analysis, only TRPV1-immunoreactive fibres (p=0.005) and mast cells (p=0.008) were significantly related to the abdominal pain score.

Conclusions: Increased TRPV1 nerve fibres are observed in IBS, together with a low-grade inflammatory response. The increased TRPV1 nerve fibres may contribute to visceral hypersensitivity and pain in IBS, and provide a novel therapeutic target.

Keywords: Irritable bowel syndrome, Mast cells, Pain, Transient receptor potential vanilloid-1 (TRPV1)

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

Relevant Article

TRPV1: a new target for treatment of visceral pain in IBS?

Peter Holzer
Gut 2008 57: 882-884. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

• Farmer, A. D., Aziz, Q. (2009). Visceral pain hypersensitivity in functional gastrointestinal disorders. Br Med Bull 91: 123-136 [Abstract] [Full Text]  
• Matsumoto, K., Kurosawa, E., Terui, H., Hosoya, T., Tashima, K., Murayama, T., Priestley, J. V., Horie, S. (2009). Localization of TRPV1 and contractile effect of capsaicin in mouse large intestine: high abundance and sensitivity in rectum and distal colon. Am. J. Physiol. Gastrointest. Liver Physiol. 297: G348-G360 [Abstract] [Full Text]  
• Hong, S, Fan, J, Kemmerer, E S, Evans, S, Li, Y, Wiley, J W (2009). Reciprocal changes in vanilloid (TRPV1) and endocannabinoid (CB1) receptors contribute to visceral hyperalgesia in the water avoidance stressed rat. Gut 58: 202-210 [Abstract] [Full Text]  
• Holzer, P. (2008). TRPV1: a new target for treatment of visceral pain in IBS?. Gut 57: 882-884 [Full Text]