Visceral and somatic hypersensitivity in a subset of rats following TNBS-induced colitis

Zhou, QiQi; Price, Donald D.; Caudle, Robert M.; Verne, G. Nicholas

doi:10.1016/j.pain.2007.03.029

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Volume 134, Issue 1 , Pages 9-15, January 2008

Visceral and somatic hypersensitivity in a subset of rats following TNBS-induced colitis

QiQi Zhou
- Department of Medicine, Division of Gasteroenterology, Hepatology, and Nutrition, University of Florida Colleges of Medicine and Dentistry, 1600 SW Archer Road, HD 602, PO Box 100214, Gainesville, FL 32610-0214, USA
Donald D. Price
- Department of Oral and Maxillofacial Surgery, University of Florida Colleges of Medicine and Dentistry, Gainesville, FL, USA
- Department of Neuroscience, University of Florida Colleges of Medicine and Dentistry, Gainesville, FL, USA
Robert M. Caudle
- Department of Oral and Maxillofacial Surgery, University of Florida Colleges of Medicine and Dentistry, Gainesville, FL, USA
- Department of Neuroscience, University of Florida Colleges of Medicine and Dentistry, Gainesville, FL, USA
G. Nicholas Verne
- Department of Medicine, Division of Gasteroenterology, Hepatology, and Nutrition, University of Florida Colleges of Medicine and Dentistry, 1600 SW Archer Road, HD 602, PO Box 100214, Gainesville, FL 32610-0214, USA
- North Florida/South Georgia VA Medical System, USA
- Corresponding author. Address: Department of Medicine, Division of Gasteroenterology, Hepatology, and Nutrition, University of Florida Colleges of Medicine and Dentistry, 1600 SW Archer Road, HD 602, PO Box 100214, Gainesville, FL 32610-0214, USA. Tel.: +1 352 392 2877; fax: +1 352 392 3618.

Received 16 January 2007; received in revised form 19 February 2007; accepted 19 March 2007.

Abstract

Background. Chronic abdominal pain is one of the most common gastrointestinal symptoms experienced by patients. Visceral hypersensitivity has been shown to be a biological marker in many patients with chronic visceral pain. We have previously shown that IBS patients with visceral hypersensitivity also have evidence of thermal hyperalgesia of the hand/foot. Objective. The objective of the current study was to develop an animal model of chronic visceral and somatic hypersensitivity in rats treated with intracolonic trinitrobenzene sulfonic acid. Design. Male Sprague–Dawley rats (200–250g) were treated with either 20mg/rat trinitrobenzene sulfonic acid (TNBS, Sigma Chemical Co.) in 50% ethanol (n=75), an equivalent volume of 50% ethanol (n=20) or an equivalent volume of saline (n=20). The agents were delivered with a 24-gauge catheter inserted into the lumen of the colon. Mechanical and thermal behavioral tests were performed using an automated von Frey and Hargreaves device to evaluate somatic hyperalgesia. Colonic distension was performed using an automated distension device to evaluate visceral pain thresholds. All animals were tested 16weeks after TNBS treatment following complete resolution of the colitis. Results. At 16weeks, 24% of the treated rats (18/75 rats) still exhibited evidence of visceral as well as somatic hypersensitivity compared to saline- and ethanol-treated rats. Conclusion. Transient colonic inflammation leads to chronic visceral and somatic hypersensitivity in a subset of rats. These findings are similar to the subset of patients who develop chronic gastrointestinal symptoms following enteric infection.