The effect of chemically induced colitis, psychological stress and their combination on visceral pain in female Wistar rats

AbstractVisceral sensitivity is of pathophysiological importance in abdominal pain disorders and can be modulated by inflammation and stress. However, it is unclear whether inflammation and stress alter visceral perception independently of each other or in conjunction through neuroendocrine interactions. Therefore, we compared the short- and long-term effects of experimental colitis and water avoidance stress (WAS), alone or in combination, on visceral sensitivity in female Wistar rats. Colitis was induced by trinitrobenzene sulfonic acid (TNBS) and colonoscopically confirmed. During WAS, rats were placed on a platform surrounded by water for 1 h. Visceral sensitivity was assessed by quantifying the visceromotor responses (VMRs) to colorectal distension. Activation of the hypothalamic–pituitary–adrenal axis was determined by measuring serum corticosterone in a separate protocol. TNBS instillation resulted in overt colitis, associated with significant visceral hypersensitivity during the acute inflammatory...