BACKGROUND & AIMS: Chronic visceral hyperalgesia is considered an important pathophysiologic symptom in irritable bowel syndrome (IBS); previous gastrointestinal inflammation is a potent etiologic factor for developing IBS. Although there are several animal models of adult visceral hypersensitivity after neonatal perturbation or acute colonic irritation/inflammation, current models of postinflammatory chronic visceral hyperalgesia are unsatisfactory. The aim of this study was to establish a model of chronic visceral hyperalgesia after colonic inflammation in the rat. METHODS: Deoxycholic acid (DCA) was instilled into the rat colon daily for 3 days and animals were tested for up to 4 weeks. RESULTS: DCA induced mild, transient colonic inflammation within 3 days that resolved within 3 weeks. An exaggerated visceromotor response, referred pain to mechanical stimulation, increased spinal Fos expression, and colonic afferent and dorsal horn neuron activity were apparent by 1 week and persisted for at least 4 weeks, indicating chronic dorsal horn hyperexcitability and visceral hyperalgesia. There was no spontaneous pain, based on open field behavior. There was a significant increase in opioid-receptor activity. CONCLUSIONS: DCA induces mild, transient colitis, resulting in persistent visceral hyperalgesia and referred pain in rats, modeling some aspects of postinflammatory IBS.
BACKGROUND & AIMS:Chronic visceral hyperalgesia is considered an important pathophysiologic symptom in irritable bowel syndrome (IBS); previous gastrointestinal inflammation is a potent etiologic factor for developing IBS. Although there are several animal models of adult visceral hypersensitivity after neonatal perturbation or acute colonic irritation/inflammation, current models of postinflammatory chronic visceral hyperalgesia are unsatisfactory. The aim of this study was to establish a model of chronic visceral hyperalgesia after colonic inflammation in the rat. METHODS:Deoxycholic acid (DCA) was instilled into the rat colon daily for 3 days and animals were tested for up to 4 weeks. RESULTS:DCA induced mild, transient colonic inflammation within 3 days that resolved within 3 weeks. An exaggerated visceromotor response, referred pain to mechanical stimulation, increased spinal Fos expression, and colonic afferent and dorsal horn neuron activity were apparent by 1 week and persisted for at least 4 weeks, indicating chronic dorsal horn hyperexcitability and visceral hyperalgesia. There was no spontaneous pain, based on open field behavior. There was a significant increase in opioid-receptor activity. CONCLUSIONS:DCA induces mild, transient colitis, resulting in persistent visceral hyperalgesia and referred pain in rats, modeling some aspects of postinflammatory IBS.
Authors: Richard J Traub; Dong-Yuan Cao; Jane Karpowicz; Sangeeta Pandya; Yaping Ji; Susan G Dorsey; Dean Dessem Journal: J Pain Date: 2014-06-26 Impact factor: 5.820
Authors: Justin Cy Wu; Eric Tc Ziea; Lixing Lao; Emma Fc Lam; Catherine Sm Chan; Angela Yq Liang; Sunny Lh Chu; David Tw Yew; Brian M Berman; Joseph Jy Sung Journal: J Neurogastroenterol Motil Date: 2010-07-26 Impact factor: 4.924
Authors: Farzad Alemi; Daniel P Poole; Jonathan Chiu; Kristina Schoonjans; Fiore Cattaruzza; John R Grider; Nigel W Bunnett; Carlos U Corvera Journal: Gastroenterology Date: 2012-10-03 Impact factor: 22.682